generated from ztimson/template
3111 lines
97 KiB
JavaScript
3111 lines
97 KiB
JavaScript
var pi = Math.PI;
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||
var twoPi = pi * 2;
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||
var deg2rad = pi / 180.0;
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var rad2deg = 180 / pi;
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var minutesPerDay = 1440.0;
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var mu = 398600.8; // in km3 / s2
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||
var earthRadius = 6378.135; // in km
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||
var xke = 60.0 / Math.sqrt(earthRadius * earthRadius * earthRadius / mu);
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var vkmpersec = earthRadius * xke / 60.0;
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var tumin = 1.0 / xke;
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var j2 = 0.001082616;
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var j3 = -0.00000253881;
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var j4 = -0.00000165597;
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var j3oj2 = j3 / j2;
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var x2o3 = 2.0 / 3.0;
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var xpdotp = 1440.0 / (2.0 * pi); // 229.1831180523293;
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var constants = /*#__PURE__*/Object.freeze({
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__proto__: null,
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deg2rad: deg2rad,
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earthRadius: earthRadius,
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j2: j2,
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j3: j3,
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j3oj2: j3oj2,
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j4: j4,
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minutesPerDay: minutesPerDay,
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mu: mu,
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pi: pi,
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rad2deg: rad2deg,
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tumin: tumin,
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twoPi: twoPi,
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vkmpersec: vkmpersec,
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x2o3: x2o3,
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xke: xke,
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xpdotp: xpdotp
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});
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/* -----------------------------------------------------------------------------
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*
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* procedure days2mdhms
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*
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* this procedure converts the day of the year, days, to the equivalent month
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* day, hour, minute and second.
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*
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* algorithm : set up array for the number of days per month
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* find leap year - use 1900 because 2000 is a leap year
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* loop through a temp value while the value is < the days
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* perform int conversions to the correct day and month
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* convert remainder into h m s using type conversions
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*
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* author : david vallado 719-573-2600 1 mar 2001
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*
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* inputs description range / units
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* year - year 1900 .. 2100
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* days - julian day of the year 0.0 .. 366.0
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*
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* outputs :
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* mon - month 1 .. 12
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* day - day 1 .. 28,29,30,31
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* hr - hour 0 .. 23
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* min - minute 0 .. 59
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* sec - second 0.0 .. 59.999
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*
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* locals :
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* dayofyr - day of year
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* temp - temporary extended values
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* inttemp - temporary int value
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* i - index
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* lmonth[12] - int array containing the number of days per month
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*
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* coupling :
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* none.
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* --------------------------------------------------------------------------- */
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function days2mdhms(year, days) {
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var lmonth = [31, year % 4 === 0 ? 29 : 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
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var dayofyr = Math.floor(days);
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// ----------------- find month and day of month ----------------
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var i = 1;
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var inttemp = 0;
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// i starts from 1 so no null check is needed
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while (dayofyr > inttemp + lmonth[i - 1] && i < 12) {
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inttemp += lmonth[i - 1];
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i += 1;
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}
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var mon = i;
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var day = dayofyr - inttemp;
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// ----------------- find hours minutes and seconds -------------
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var temp = (days - dayofyr) * 24.0;
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var hr = Math.floor(temp);
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temp = (temp - hr) * 60.0;
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var minute = Math.floor(temp);
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var sec = (temp - minute) * 60.0;
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return {
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mon: mon,
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day: day,
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hr: hr,
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minute: minute,
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sec: sec
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};
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}
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/* -----------------------------------------------------------------------------
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*
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* procedure jday
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*
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* this procedure finds the julian date given the year, month, day, and time.
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* the julian date is defined by each elapsed day since noon, jan 1, 4713 bc.
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*
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* algorithm : calculate the answer in one step for efficiency
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*
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* author : david vallado 719-573-2600 1 mar 2001
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*
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* inputs description range / units
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* year - year 1900 .. 2100
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* mon - month 1 .. 12
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* day - day 1 .. 28,29,30,31
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* hr - universal time hour 0 .. 23
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* min - universal time min 0 .. 59
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* sec - universal time sec 0.0 .. 59.999
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*
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* outputs :
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* jd - julian date days from 4713 bc
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*
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* locals :
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* none.
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*
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* coupling :
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* none.
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*
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* references :
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* vallado 2007, 189, alg 14, ex 3-14
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*
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* --------------------------------------------------------------------------- */
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function jdayInternal(year, mon, day, hr, minute, sec) {
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var msec = arguments.length > 6 && arguments[6] !== undefined ? arguments[6] : 0;
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return 367.0 * year - Math.floor(7 * (year + Math.floor((mon + 9) / 12.0)) * 0.25) + Math.floor(275 * mon / 9.0) + day + 1721013.5 + ((msec / 60000 + sec / 60.0 + minute) / 60.0 + hr) / 24.0 // ut in days
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// # - 0.5*sgn(100.0*year + mon - 190002.5) + 0.5;
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;
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}
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function jday(yearOrDate, mon, day, hr, minute, sec) {
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var msec = arguments.length > 6 && arguments[6] !== undefined ? arguments[6] : 0;
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if (yearOrDate instanceof Date) {
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var date = yearOrDate;
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return jdayInternal(date.getUTCFullYear(), date.getUTCMonth() + 1,
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// Note, this function requires months in range 1-12.
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date.getUTCDate(), date.getUTCHours(), date.getUTCMinutes(), date.getUTCSeconds(), date.getUTCMilliseconds());
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}
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return jdayInternal(yearOrDate, mon, day, hr, minute, sec, msec);
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}
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function invjday(jd, asArray) {
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// --------------- find year and days of the year -
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var temp = jd - 2415019.5;
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var tu = temp / 365.25;
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var year = 1900 + Math.floor(tu);
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var leapyrs = Math.floor((year - 1901) * 0.25);
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// optional nudge by 8.64x10-7 sec to get even outputs
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var days = temp - ((year - 1900) * 365.0 + leapyrs) + 0.00000000001;
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// ------------ check for case of beginning of a year -----------
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if (days < 1.0) {
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year -= 1;
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leapyrs = Math.floor((year - 1901) * 0.25);
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days = temp - ((year - 1900) * 365.0 + leapyrs);
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}
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// ----------------- find remaing data -------------------------
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var mdhms = days2mdhms(year, days);
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var mon = mdhms.mon,
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day = mdhms.day,
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hr = mdhms.hr,
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minute = mdhms.minute;
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var sec = mdhms.sec - 0.00000086400;
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if (asArray) {
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return [year, mon, day, hr, minute, Math.floor(sec)];
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}
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return new Date(Date.UTC(year, mon - 1, day, hr, minute, Math.floor(sec)));
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}
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/* -----------------------------------------------------------------------------
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*
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* procedure dpper
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*
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* this procedure provides deep space long period periodic contributions
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* to the mean elements. by design, these periodics are zero at epoch.
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* this used to be dscom which included initialization, but it's really a
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* recurring function.
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*
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* author : david vallado 719-573-2600 28 jun 2005
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*
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* inputs :
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* e3 -
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* ee2 -
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* peo -
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* pgho -
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* pho -
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* pinco -
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* plo -
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* se2 , se3 , sgh2, sgh3, sgh4, sh2, sh3, si2, si3, sl2, sl3, sl4 -
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* t -
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* xh2, xh3, xi2, xi3, xl2, xl3, xl4 -
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* zmol -
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* zmos -
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* ep - eccentricity 0.0 - 1.0
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* inclo - inclination - needed for lyddane modification
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* nodep - right ascension of ascending node
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* argpp - argument of perigee
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* mp - mean anomaly
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*
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* outputs :
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* ep - eccentricity 0.0 - 1.0
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* inclp - inclination
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* nodep - right ascension of ascending node
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* argpp - argument of perigee
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* mp - mean anomaly
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*
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* locals :
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* alfdp -
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* betdp -
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* cosip , sinip , cosop , sinop ,
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* dalf -
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* dbet -
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* dls -
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* f2, f3 -
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* pe -
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* pgh -
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* ph -
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* pinc -
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* pl -
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* sel , ses , sghl , sghs , shl , shs , sil , sinzf , sis ,
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* sll , sls
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* xls -
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* xnoh -
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* zf -
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* zm -
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*
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* coupling :
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* none.
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*
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* references :
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* hoots, roehrich, norad spacetrack report #3 1980
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* hoots, norad spacetrack report #6 1986
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* hoots, schumacher and glover 2004
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* vallado, crawford, hujsak, kelso 2006
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||
----------------------------------------------------------------------------*/
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function dpper(satrec, options) {
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var e3 = satrec.e3,
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ee2 = satrec.ee2,
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peo = satrec.peo,
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pgho = satrec.pgho,
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pho = satrec.pho,
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pinco = satrec.pinco,
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plo = satrec.plo,
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se2 = satrec.se2,
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se3 = satrec.se3,
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sgh2 = satrec.sgh2,
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sgh3 = satrec.sgh3,
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sgh4 = satrec.sgh4,
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sh2 = satrec.sh2,
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sh3 = satrec.sh3,
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si2 = satrec.si2,
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si3 = satrec.si3,
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sl2 = satrec.sl2,
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sl3 = satrec.sl3,
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sl4 = satrec.sl4,
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t = satrec.t,
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xgh2 = satrec.xgh2,
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xgh3 = satrec.xgh3,
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xgh4 = satrec.xgh4,
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xh2 = satrec.xh2,
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xh3 = satrec.xh3,
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xi2 = satrec.xi2,
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xi3 = satrec.xi3,
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xl2 = satrec.xl2,
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xl3 = satrec.xl3,
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xl4 = satrec.xl4,
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zmol = satrec.zmol,
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zmos = satrec.zmos;
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var init = options.init,
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opsmode = options.opsmode;
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var ep = options.ep,
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inclp = options.inclp,
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nodep = options.nodep,
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argpp = options.argpp,
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mp = options.mp;
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// Copy satellite attributes into local variables for convenience
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// and symmetry in writing formulae.
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var alfdp;
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var betdp;
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var cosip;
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var sinip;
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var cosop;
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var sinop;
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var dalf;
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var dbet;
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var dls;
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var f2;
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var f3;
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var pe;
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var pgh;
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var ph;
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var pinc;
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var pl;
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var sinzf;
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var xls;
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var xnoh;
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var zf;
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var zm;
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// ---------------------- constants -----------------------------
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var zns = 1.19459e-5;
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var zes = 0.01675;
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var znl = 1.5835218e-4;
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var zel = 0.05490;
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// --------------- calculate time varying periodics -----------
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zm = zmos + zns * t;
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// be sure that the initial call has time set to zero
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if (init === 'y') {
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zm = zmos;
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}
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zf = zm + 2.0 * zes * Math.sin(zm);
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sinzf = Math.sin(zf);
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f2 = 0.5 * sinzf * sinzf - 0.25;
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f3 = -0.5 * sinzf * Math.cos(zf);
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var ses = se2 * f2 + se3 * f3;
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var sis = si2 * f2 + si3 * f3;
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var sls = sl2 * f2 + sl3 * f3 + sl4 * sinzf;
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var sghs = sgh2 * f2 + sgh3 * f3 + sgh4 * sinzf;
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var shs = sh2 * f2 + sh3 * f3;
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zm = zmol + znl * t;
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if (init === 'y') {
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zm = zmol;
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}
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zf = zm + 2.0 * zel * Math.sin(zm);
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sinzf = Math.sin(zf);
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f2 = 0.5 * sinzf * sinzf - 0.25;
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f3 = -0.5 * sinzf * Math.cos(zf);
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var sel = ee2 * f2 + e3 * f3;
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var sil = xi2 * f2 + xi3 * f3;
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var sll = xl2 * f2 + xl3 * f3 + xl4 * sinzf;
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||
var sghl = xgh2 * f2 + xgh3 * f3 + xgh4 * sinzf;
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var shll = xh2 * f2 + xh3 * f3;
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||
pe = ses + sel;
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pinc = sis + sil;
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pl = sls + sll;
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pgh = sghs + sghl;
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ph = shs + shll;
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||
if (init === 'n') {
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pe -= peo;
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pinc -= pinco;
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||
pl -= plo;
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pgh -= pgho;
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ph -= pho;
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||
inclp += pinc;
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||
ep += pe;
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||
sinip = Math.sin(inclp);
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||
cosip = Math.cos(inclp);
|
||
/* ----------------- apply periodics directly ------------ */
|
||
// sgp4fix for lyddane choice
|
||
// strn3 used original inclination - this is technically feasible
|
||
// gsfc used perturbed inclination - also technically feasible
|
||
// probably best to readjust the 0.2 limit value and limit discontinuity
|
||
// 0.2 rad = 11.45916 deg
|
||
// use next line for original strn3 approach and original inclination
|
||
// if (inclo >= 0.2)
|
||
// use next line for gsfc version and perturbed inclination
|
||
if (inclp >= 0.2) {
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||
ph /= sinip;
|
||
pgh -= cosip * ph;
|
||
argpp += pgh;
|
||
nodep += ph;
|
||
mp += pl;
|
||
} else {
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||
// ---- apply periodics with lyddane modification ----
|
||
sinop = Math.sin(nodep);
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||
cosop = Math.cos(nodep);
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||
alfdp = sinip * sinop;
|
||
betdp = sinip * cosop;
|
||
dalf = ph * cosop + pinc * cosip * sinop;
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||
dbet = -ph * sinop + pinc * cosip * cosop;
|
||
alfdp += dalf;
|
||
betdp += dbet;
|
||
nodep %= twoPi;
|
||
// sgp4fix for afspc written intrinsic functions
|
||
// nodep used without a trigonometric function ahead
|
||
if (nodep < 0.0 && opsmode === 'a') {
|
||
nodep += twoPi;
|
||
}
|
||
xls = mp + argpp + cosip * nodep;
|
||
dls = pl + pgh - pinc * nodep * sinip;
|
||
xls += dls;
|
||
xnoh = nodep;
|
||
nodep = Math.atan2(alfdp, betdp);
|
||
// sgp4fix for afspc written intrinsic functions
|
||
// nodep used without a trigonometric function ahead
|
||
if (nodep < 0.0 && opsmode === 'a') {
|
||
nodep += twoPi;
|
||
}
|
||
if (Math.abs(xnoh - nodep) > pi) {
|
||
if (nodep < xnoh) {
|
||
nodep += twoPi;
|
||
} else {
|
||
nodep -= twoPi;
|
||
}
|
||
}
|
||
mp += pl;
|
||
argpp = xls - mp - cosip * nodep;
|
||
}
|
||
}
|
||
return {
|
||
ep: ep,
|
||
inclp: inclp,
|
||
nodep: nodep,
|
||
argpp: argpp,
|
||
mp: mp
|
||
};
|
||
}
|
||
|
||
/*-----------------------------------------------------------------------------
|
||
*
|
||
* procedure dscom
|
||
*
|
||
* this procedure provides deep space common items used by both the secular
|
||
* and periodics subroutines. input is provided as shown. this routine
|
||
* used to be called dpper, but the functions inside weren't well organized.
|
||
*
|
||
* author : david vallado 719-573-2600 28 jun 2005
|
||
*
|
||
* inputs :
|
||
* epoch -
|
||
* ep - eccentricity
|
||
* argpp - argument of perigee
|
||
* tc -
|
||
* inclp - inclination
|
||
* nodep - right ascension of ascending node
|
||
* np - mean motion
|
||
*
|
||
* outputs :
|
||
* sinim , cosim , sinomm , cosomm , snodm , cnodm
|
||
* day -
|
||
* e3 -
|
||
* ee2 -
|
||
* em - eccentricity
|
||
* emsq - eccentricity squared
|
||
* gam -
|
||
* peo -
|
||
* pgho -
|
||
* pho -
|
||
* pinco -
|
||
* plo -
|
||
* rtemsq -
|
||
* se2, se3 -
|
||
* sgh2, sgh3, sgh4 -
|
||
* sh2, sh3, si2, si3, sl2, sl3, sl4 -
|
||
* s1, s2, s3, s4, s5, s6, s7 -
|
||
* ss1, ss2, ss3, ss4, ss5, ss6, ss7, sz1, sz2, sz3 -
|
||
* sz11, sz12, sz13, sz21, sz22, sz23, sz31, sz32, sz33 -
|
||
* xgh2, xgh3, xgh4, xh2, xh3, xi2, xi3, xl2, xl3, xl4 -
|
||
* nm - mean motion
|
||
* z1, z2, z3, z11, z12, z13, z21, z22, z23, z31, z32, z33 -
|
||
* zmol -
|
||
* zmos -
|
||
*
|
||
* locals :
|
||
* a1, a2, a3, a4, a5, a6, a7, a8, a9, a10 -
|
||
* betasq -
|
||
* cc -
|
||
* ctem, stem -
|
||
* x1, x2, x3, x4, x5, x6, x7, x8 -
|
||
* xnodce -
|
||
* xnoi -
|
||
* zcosg , zsing , zcosgl , zsingl , zcosh , zsinh , zcoshl , zsinhl ,
|
||
* zcosi , zsini , zcosil , zsinil ,
|
||
* zx -
|
||
* zy -
|
||
*
|
||
* coupling :
|
||
* none.
|
||
*
|
||
* references :
|
||
* hoots, roehrich, norad spacetrack report #3 1980
|
||
* hoots, norad spacetrack report #6 1986
|
||
* hoots, schumacher and glover 2004
|
||
* vallado, crawford, hujsak, kelso 2006
|
||
----------------------------------------------------------------------------*/
|
||
function dscom(options) {
|
||
var epoch = options.epoch,
|
||
ep = options.ep,
|
||
argpp = options.argpp,
|
||
tc = options.tc,
|
||
inclp = options.inclp,
|
||
nodep = options.nodep,
|
||
np = options.np;
|
||
var a1;
|
||
var a2;
|
||
var a3;
|
||
var a4;
|
||
var a5;
|
||
var a6;
|
||
var a7;
|
||
var a8;
|
||
var a9;
|
||
var a10;
|
||
var cc;
|
||
var x1;
|
||
var x2;
|
||
var x3;
|
||
var x4;
|
||
var x5;
|
||
var x6;
|
||
var x7;
|
||
var x8;
|
||
var zcosg;
|
||
var zsing;
|
||
var zcosh;
|
||
var zsinh;
|
||
var zcosi;
|
||
var zsini;
|
||
var ss1;
|
||
var ss2;
|
||
var ss3;
|
||
var ss4;
|
||
var ss5;
|
||
var ss6;
|
||
var ss7;
|
||
var sz1;
|
||
var sz2;
|
||
var sz3;
|
||
var sz11;
|
||
var sz12;
|
||
var sz13;
|
||
var sz21;
|
||
var sz22;
|
||
var sz23;
|
||
var sz31;
|
||
var sz32;
|
||
var sz33;
|
||
var s1;
|
||
var s2;
|
||
var s3;
|
||
var s4;
|
||
var s5;
|
||
var s6;
|
||
var s7;
|
||
var z1;
|
||
var z2;
|
||
var z3;
|
||
var z11;
|
||
var z12;
|
||
var z13;
|
||
var z21;
|
||
var z22;
|
||
var z23;
|
||
var z31;
|
||
var z32;
|
||
var z33;
|
||
// -------------------------- constants -------------------------
|
||
var zes = 0.01675;
|
||
var zel = 0.05490;
|
||
var c1ss = 2.9864797e-6;
|
||
var c1l = 4.7968065e-7;
|
||
var zsinis = 0.39785416;
|
||
var zcosis = 0.91744867;
|
||
var zcosgs = 0.1945905;
|
||
var zsings = -0.98088458;
|
||
// --------------------- local variables ------------------------
|
||
var nm = np;
|
||
var em = ep;
|
||
var snodm = Math.sin(nodep);
|
||
var cnodm = Math.cos(nodep);
|
||
var sinomm = Math.sin(argpp);
|
||
var cosomm = Math.cos(argpp);
|
||
var sinim = Math.sin(inclp);
|
||
var cosim = Math.cos(inclp);
|
||
var emsq = em * em;
|
||
var betasq = 1.0 - emsq;
|
||
var rtemsq = Math.sqrt(betasq);
|
||
// ----------------- initialize lunar solar terms ---------------
|
||
var peo = 0.0;
|
||
var pinco = 0.0;
|
||
var plo = 0.0;
|
||
var pgho = 0.0;
|
||
var pho = 0.0;
|
||
var day = epoch + 18261.5 + tc / 1440.0;
|
||
var xnodce = (4.5236020 - 9.2422029e-4 * day) % twoPi;
|
||
var stem = Math.sin(xnodce);
|
||
var ctem = Math.cos(xnodce);
|
||
var zcosil = 0.91375164 - 0.03568096 * ctem;
|
||
var zsinil = Math.sqrt(1.0 - zcosil * zcosil);
|
||
var zsinhl = 0.089683511 * stem / zsinil;
|
||
var zcoshl = Math.sqrt(1.0 - zsinhl * zsinhl);
|
||
var gam = 5.8351514 + 0.0019443680 * day;
|
||
var zx = 0.39785416 * stem / zsinil;
|
||
var zy = zcoshl * ctem + 0.91744867 * zsinhl * stem;
|
||
zx = Math.atan2(zx, zy);
|
||
zx += gam - xnodce;
|
||
var zcosgl = Math.cos(zx);
|
||
var zsingl = Math.sin(zx);
|
||
// ------------------------- do solar terms ---------------------
|
||
zcosg = zcosgs;
|
||
zsing = zsings;
|
||
zcosi = zcosis;
|
||
zsini = zsinis;
|
||
zcosh = cnodm;
|
||
zsinh = snodm;
|
||
cc = c1ss;
|
||
var xnoi = 1.0 / nm;
|
||
var lsflg = 0;
|
||
while (lsflg < 2) {
|
||
lsflg += 1;
|
||
a1 = zcosg * zcosh + zsing * zcosi * zsinh;
|
||
a3 = -zsing * zcosh + zcosg * zcosi * zsinh;
|
||
a7 = -zcosg * zsinh + zsing * zcosi * zcosh;
|
||
a8 = zsing * zsini;
|
||
a9 = zsing * zsinh + zcosg * zcosi * zcosh;
|
||
a10 = zcosg * zsini;
|
||
a2 = cosim * a7 + sinim * a8;
|
||
a4 = cosim * a9 + sinim * a10;
|
||
a5 = -sinim * a7 + cosim * a8;
|
||
a6 = -sinim * a9 + cosim * a10;
|
||
x1 = a1 * cosomm + a2 * sinomm;
|
||
x2 = a3 * cosomm + a4 * sinomm;
|
||
x3 = -a1 * sinomm + a2 * cosomm;
|
||
x4 = -a3 * sinomm + a4 * cosomm;
|
||
x5 = a5 * sinomm;
|
||
x6 = a6 * sinomm;
|
||
x7 = a5 * cosomm;
|
||
x8 = a6 * cosomm;
|
||
z31 = 12.0 * x1 * x1 - 3.0 * x3 * x3;
|
||
z32 = 24.0 * x1 * x2 - 6.0 * x3 * x4;
|
||
z33 = 12.0 * x2 * x2 - 3.0 * x4 * x4;
|
||
z1 = 3.0 * (a1 * a1 + a2 * a2) + z31 * emsq;
|
||
z2 = 6.0 * (a1 * a3 + a2 * a4) + z32 * emsq;
|
||
z3 = 3.0 * (a3 * a3 + a4 * a4) + z33 * emsq;
|
||
z11 = -6.0 * a1 * a5 + emsq * (-24.0 * x1 * x7 - 6.0 * x3 * x5);
|
||
z12 = -6.0 * (a1 * a6 + a3 * a5) + emsq * (-24.0 * (x2 * x7 + x1 * x8) + -6.0 * (x3 * x6 + x4 * x5));
|
||
z13 = -6.0 * a3 * a6 + emsq * (-24.0 * x2 * x8 - 6.0 * x4 * x6);
|
||
z21 = 6.0 * a2 * a5 + emsq * (24.0 * x1 * x5 - 6.0 * x3 * x7);
|
||
z22 = 6.0 * (a4 * a5 + a2 * a6) + emsq * (24.0 * (x2 * x5 + x1 * x6) - 6.0 * (x4 * x7 + x3 * x8));
|
||
z23 = 6.0 * a4 * a6 + emsq * (24.0 * x2 * x6 - 6.0 * x4 * x8);
|
||
z1 = z1 + z1 + betasq * z31;
|
||
z2 = z2 + z2 + betasq * z32;
|
||
z3 = z3 + z3 + betasq * z33;
|
||
s3 = cc * xnoi;
|
||
s2 = -0.5 * s3 / rtemsq;
|
||
s4 = s3 * rtemsq;
|
||
s1 = -15.0 * em * s4;
|
||
s5 = x1 * x3 + x2 * x4;
|
||
s6 = x2 * x3 + x1 * x4;
|
||
s7 = x2 * x4 - x1 * x3;
|
||
// ----------------------- do lunar terms -------------------
|
||
if (lsflg === 1) {
|
||
ss1 = s1;
|
||
ss2 = s2;
|
||
ss3 = s3;
|
||
ss4 = s4;
|
||
ss5 = s5;
|
||
ss6 = s6;
|
||
ss7 = s7;
|
||
sz1 = z1;
|
||
sz2 = z2;
|
||
sz3 = z3;
|
||
sz11 = z11;
|
||
sz12 = z12;
|
||
sz13 = z13;
|
||
sz21 = z21;
|
||
sz22 = z22;
|
||
sz23 = z23;
|
||
sz31 = z31;
|
||
sz32 = z32;
|
||
sz33 = z33;
|
||
zcosg = zcosgl;
|
||
zsing = zsingl;
|
||
zcosi = zcosil;
|
||
zsini = zsinil;
|
||
zcosh = zcoshl * cnodm + zsinhl * snodm;
|
||
zsinh = snodm * zcoshl - cnodm * zsinhl;
|
||
cc = c1l;
|
||
}
|
||
}
|
||
var zmol = (4.7199672 + (0.22997150 * day - gam)) % twoPi;
|
||
var zmos = (6.2565837 + 0.017201977 * day) % twoPi;
|
||
// ------------------------ do solar terms ----------------------
|
||
var se2 = 2.0 * ss1 * ss6;
|
||
var se3 = 2.0 * ss1 * ss7;
|
||
var si2 = 2.0 * ss2 * sz12;
|
||
var si3 = 2.0 * ss2 * (sz13 - sz11);
|
||
var sl2 = -2.0 * ss3 * sz2;
|
||
var sl3 = -2.0 * ss3 * (sz3 - sz1);
|
||
var sl4 = -2.0 * ss3 * (-21.0 - 9.0 * emsq) * zes;
|
||
var sgh2 = 2.0 * ss4 * sz32;
|
||
var sgh3 = 2.0 * ss4 * (sz33 - sz31);
|
||
var sgh4 = -18.0 * ss4 * zes;
|
||
var sh2 = -2.0 * ss2 * sz22;
|
||
var sh3 = -2.0 * ss2 * (sz23 - sz21);
|
||
// ------------------------ do lunar terms ----------------------
|
||
var ee2 = 2.0 * s1 * s6;
|
||
var e3 = 2.0 * s1 * s7;
|
||
var xi2 = 2.0 * s2 * z12;
|
||
var xi3 = 2.0 * s2 * (z13 - z11);
|
||
var xl2 = -2.0 * s3 * z2;
|
||
var xl3 = -2.0 * s3 * (z3 - z1);
|
||
var xl4 = -2.0 * s3 * (-21.0 - 9.0 * emsq) * zel;
|
||
var xgh2 = 2.0 * s4 * z32;
|
||
var xgh3 = 2.0 * s4 * (z33 - z31);
|
||
var xgh4 = -18.0 * s4 * zel;
|
||
var xh2 = -2.0 * s2 * z22;
|
||
var xh3 = -2.0 * s2 * (z23 - z21);
|
||
return {
|
||
snodm: snodm,
|
||
cnodm: cnodm,
|
||
sinim: sinim,
|
||
cosim: cosim,
|
||
sinomm: sinomm,
|
||
cosomm: cosomm,
|
||
day: day,
|
||
e3: e3,
|
||
ee2: ee2,
|
||
em: em,
|
||
emsq: emsq,
|
||
gam: gam,
|
||
peo: peo,
|
||
pgho: pgho,
|
||
pho: pho,
|
||
pinco: pinco,
|
||
plo: plo,
|
||
rtemsq: rtemsq,
|
||
se2: se2,
|
||
se3: se3,
|
||
sgh2: sgh2,
|
||
sgh3: sgh3,
|
||
sgh4: sgh4,
|
||
sh2: sh2,
|
||
sh3: sh3,
|
||
si2: si2,
|
||
si3: si3,
|
||
sl2: sl2,
|
||
sl3: sl3,
|
||
sl4: sl4,
|
||
s1: s1,
|
||
s2: s2,
|
||
s3: s3,
|
||
s4: s4,
|
||
s5: s5,
|
||
s6: s6,
|
||
s7: s7,
|
||
ss1: ss1,
|
||
ss2: ss2,
|
||
ss3: ss3,
|
||
ss4: ss4,
|
||
ss5: ss5,
|
||
ss6: ss6,
|
||
ss7: ss7,
|
||
sz1: sz1,
|
||
sz2: sz2,
|
||
sz3: sz3,
|
||
sz11: sz11,
|
||
sz12: sz12,
|
||
sz13: sz13,
|
||
sz21: sz21,
|
||
sz22: sz22,
|
||
sz23: sz23,
|
||
sz31: sz31,
|
||
sz32: sz32,
|
||
sz33: sz33,
|
||
xgh2: xgh2,
|
||
xgh3: xgh3,
|
||
xgh4: xgh4,
|
||
xh2: xh2,
|
||
xh3: xh3,
|
||
xi2: xi2,
|
||
xi3: xi3,
|
||
xl2: xl2,
|
||
xl3: xl3,
|
||
xl4: xl4,
|
||
nm: nm,
|
||
z1: z1,
|
||
z2: z2,
|
||
z3: z3,
|
||
z11: z11,
|
||
z12: z12,
|
||
z13: z13,
|
||
z21: z21,
|
||
z22: z22,
|
||
z23: z23,
|
||
z31: z31,
|
||
z32: z32,
|
||
z33: z33,
|
||
zmol: zmol,
|
||
zmos: zmos
|
||
};
|
||
}
|
||
|
||
/*-----------------------------------------------------------------------------
|
||
*
|
||
* procedure dsinit
|
||
*
|
||
* this procedure provides deep space contributions to mean motion dot due
|
||
* to geopotential resonance with half day and one day orbits.
|
||
*
|
||
* author : david vallado 719-573-2600 28 jun 2005
|
||
*
|
||
* inputs :
|
||
* cosim, sinim-
|
||
* emsq - eccentricity squared
|
||
* argpo - argument of perigee
|
||
* s1, s2, s3, s4, s5 -
|
||
* ss1, ss2, ss3, ss4, ss5 -
|
||
* sz1, sz3, sz11, sz13, sz21, sz23, sz31, sz33 -
|
||
* t - time
|
||
* tc -
|
||
* gsto - greenwich sidereal time rad
|
||
* mo - mean anomaly
|
||
* mdot - mean anomaly dot (rate)
|
||
* no - mean motion
|
||
* nodeo - right ascension of ascending node
|
||
* nodedot - right ascension of ascending node dot (rate)
|
||
* xpidot -
|
||
* z1, z3, z11, z13, z21, z23, z31, z33 -
|
||
* eccm - eccentricity
|
||
* argpm - argument of perigee
|
||
* inclm - inclination
|
||
* mm - mean anomaly
|
||
* xn - mean motion
|
||
* nodem - right ascension of ascending node
|
||
*
|
||
* outputs :
|
||
* em - eccentricity
|
||
* argpm - argument of perigee
|
||
* inclm - inclination
|
||
* mm - mean anomaly
|
||
* nm - mean motion
|
||
* nodem - right ascension of ascending node
|
||
* irez - flag for resonance 0-none, 1-one day, 2-half day
|
||
* atime -
|
||
* d2201, d2211, d3210, d3222, d4410, d4422, d5220, d5232, d5421, d5433 -
|
||
* dedt -
|
||
* didt -
|
||
* dmdt -
|
||
* dndt -
|
||
* dnodt -
|
||
* domdt -
|
||
* del1, del2, del3 -
|
||
* ses , sghl , sghs , sgs , shl , shs , sis , sls
|
||
* theta -
|
||
* xfact -
|
||
* xlamo -
|
||
* xli -
|
||
* xni
|
||
*
|
||
* locals :
|
||
* ainv2 -
|
||
* aonv -
|
||
* cosisq -
|
||
* eoc -
|
||
* f220, f221, f311, f321, f322, f330, f441, f442, f522, f523, f542, f543 -
|
||
* g200, g201, g211, g300, g310, g322, g410, g422, g520, g521, g532, g533 -
|
||
* sini2 -
|
||
* temp -
|
||
* temp1 -
|
||
* theta -
|
||
* xno2 -
|
||
*
|
||
* coupling :
|
||
* getgravconst
|
||
*
|
||
* references :
|
||
* hoots, roehrich, norad spacetrack report #3 1980
|
||
* hoots, norad spacetrack report #6 1986
|
||
* hoots, schumacher and glover 2004
|
||
* vallado, crawford, hujsak, kelso 2006
|
||
----------------------------------------------------------------------------*/
|
||
function dsinit(options) {
|
||
var cosim = options.cosim,
|
||
argpo = options.argpo,
|
||
s1 = options.s1,
|
||
s2 = options.s2,
|
||
s3 = options.s3,
|
||
s4 = options.s4,
|
||
s5 = options.s5,
|
||
sinim = options.sinim,
|
||
ss1 = options.ss1,
|
||
ss2 = options.ss2,
|
||
ss3 = options.ss3,
|
||
ss4 = options.ss4,
|
||
ss5 = options.ss5,
|
||
sz1 = options.sz1,
|
||
sz3 = options.sz3,
|
||
sz11 = options.sz11,
|
||
sz13 = options.sz13,
|
||
sz21 = options.sz21,
|
||
sz23 = options.sz23,
|
||
sz31 = options.sz31,
|
||
sz33 = options.sz33,
|
||
t = options.t,
|
||
tc = options.tc,
|
||
gsto = options.gsto,
|
||
mo = options.mo,
|
||
mdot = options.mdot,
|
||
no = options.no,
|
||
nodeo = options.nodeo,
|
||
nodedot = options.nodedot,
|
||
xpidot = options.xpidot,
|
||
z1 = options.z1,
|
||
z3 = options.z3,
|
||
z11 = options.z11,
|
||
z13 = options.z13,
|
||
z21 = options.z21,
|
||
z23 = options.z23,
|
||
z31 = options.z31,
|
||
z33 = options.z33,
|
||
ecco = options.ecco,
|
||
eccsq = options.eccsq;
|
||
var emsq = options.emsq,
|
||
em = options.em,
|
||
argpm = options.argpm,
|
||
inclm = options.inclm,
|
||
mm = options.mm,
|
||
nm = options.nm,
|
||
nodem = options.nodem,
|
||
irez = options.irez,
|
||
atime = options.atime,
|
||
d2201 = options.d2201,
|
||
d2211 = options.d2211,
|
||
d3210 = options.d3210,
|
||
d3222 = options.d3222,
|
||
d4410 = options.d4410,
|
||
d4422 = options.d4422,
|
||
d5220 = options.d5220,
|
||
d5232 = options.d5232,
|
||
d5421 = options.d5421,
|
||
d5433 = options.d5433,
|
||
dedt = options.dedt,
|
||
didt = options.didt,
|
||
dmdt = options.dmdt,
|
||
dnodt = options.dnodt,
|
||
domdt = options.domdt,
|
||
del1 = options.del1,
|
||
del2 = options.del2,
|
||
del3 = options.del3,
|
||
xfact = options.xfact,
|
||
xlamo = options.xlamo,
|
||
xli = options.xli,
|
||
xni = options.xni;
|
||
var f220;
|
||
var f221;
|
||
var f311;
|
||
var f321;
|
||
var f322;
|
||
var f330;
|
||
var f441;
|
||
var f442;
|
||
var f522;
|
||
var f523;
|
||
var f542;
|
||
var f543;
|
||
var g200;
|
||
var g201;
|
||
var g211;
|
||
var g300;
|
||
var g310;
|
||
var g322;
|
||
var g410;
|
||
var g422;
|
||
var g520;
|
||
var g521;
|
||
var g532;
|
||
var g533;
|
||
var sini2;
|
||
var temp;
|
||
var temp1;
|
||
var xno2;
|
||
var ainv2;
|
||
var aonv;
|
||
var cosisq;
|
||
var eoc;
|
||
var q22 = 1.7891679e-6;
|
||
var q31 = 2.1460748e-6;
|
||
var q33 = 2.2123015e-7;
|
||
var root22 = 1.7891679e-6;
|
||
var root44 = 7.3636953e-9;
|
||
var root54 = 2.1765803e-9;
|
||
// eslint-disable-next-line no-loss-of-precision
|
||
var rptim = 4.37526908801129966e-3; // equates to 7.29211514668855e-5 rad/sec
|
||
var root32 = 3.7393792e-7;
|
||
var root52 = 1.1428639e-7;
|
||
var znl = 1.5835218e-4;
|
||
var zns = 1.19459e-5;
|
||
// -------------------- deep space initialization ------------
|
||
irez = 0;
|
||
if (nm < 0.0052359877 && nm > 0.0034906585) {
|
||
irez = 1;
|
||
}
|
||
if (nm >= 8.26e-3 && nm <= 9.24e-3 && em >= 0.5) {
|
||
irez = 2;
|
||
}
|
||
// ------------------------ do solar terms -------------------
|
||
var ses = ss1 * zns * ss5;
|
||
var sis = ss2 * zns * (sz11 + sz13);
|
||
var sls = -zns * ss3 * (sz1 + sz3 - 14.0 - 6.0 * emsq);
|
||
var sghs = ss4 * zns * (sz31 + sz33 - 6.0);
|
||
var shs = -zns * ss2 * (sz21 + sz23);
|
||
// sgp4fix for 180 deg incl
|
||
if (inclm < 5.2359877e-2 || inclm > pi - 5.2359877e-2) {
|
||
shs = 0.0;
|
||
}
|
||
if (sinim !== 0.0) {
|
||
shs /= sinim;
|
||
}
|
||
var sgs = sghs - cosim * shs;
|
||
// ------------------------- do lunar terms ------------------
|
||
dedt = ses + s1 * znl * s5;
|
||
didt = sis + s2 * znl * (z11 + z13);
|
||
dmdt = sls - znl * s3 * (z1 + z3 - 14.0 - 6.0 * emsq);
|
||
var sghl = s4 * znl * (z31 + z33 - 6.0);
|
||
var shll = -znl * s2 * (z21 + z23);
|
||
// sgp4fix for 180 deg incl
|
||
if (inclm < 5.2359877e-2 || inclm > pi - 5.2359877e-2) {
|
||
shll = 0.0;
|
||
}
|
||
domdt = sgs + sghl;
|
||
dnodt = shs;
|
||
if (sinim !== 0.0) {
|
||
domdt -= cosim / sinim * shll;
|
||
dnodt += shll / sinim;
|
||
}
|
||
// ----------- calculate deep space resonance effects --------
|
||
var dndt = 0.0;
|
||
var theta = (gsto + tc * rptim) % twoPi;
|
||
em += dedt * t;
|
||
inclm += didt * t;
|
||
argpm += domdt * t;
|
||
nodem += dnodt * t;
|
||
mm += dmdt * t;
|
||
// sgp4fix for negative inclinations
|
||
// the following if statement should be commented out
|
||
// if (inclm < 0.0)
|
||
// {
|
||
// inclm = -inclm;
|
||
// argpm = argpm - pi;
|
||
// nodem = nodem + pi;
|
||
// }
|
||
// -------------- initialize the resonance terms -------------
|
||
if (irez !== 0) {
|
||
aonv = Math.pow(nm / xke, x2o3);
|
||
// ---------- geopotential resonance for 12 hour orbits ------
|
||
if (irez === 2) {
|
||
cosisq = cosim * cosim;
|
||
var emo = em;
|
||
em = ecco;
|
||
var emsqo = emsq;
|
||
emsq = eccsq;
|
||
eoc = em * emsq;
|
||
g201 = -0.306 - (em - 0.64) * 0.440;
|
||
if (em <= 0.65) {
|
||
g211 = 3.616 - 13.2470 * em + 16.2900 * emsq;
|
||
g310 = -19.302 + 117.3900 * em - 228.4190 * emsq + 156.5910 * eoc;
|
||
g322 = -18.9068 + 109.7927 * em - 214.6334 * emsq + 146.5816 * eoc;
|
||
g410 = -41.122 + 242.6940 * em - 471.0940 * emsq + 313.9530 * eoc;
|
||
g422 = -146.407 + 841.8800 * em - 1629.014 * emsq + 1083.4350 * eoc;
|
||
g520 = -532.114 + 3017.977 * em - 5740.032 * emsq + 3708.2760 * eoc;
|
||
} else {
|
||
g211 = -72.099 + 331.819 * em - 508.738 * emsq + 266.724 * eoc;
|
||
g310 = -346.844 + 1582.851 * em - 2415.925 * emsq + 1246.113 * eoc;
|
||
g322 = -342.585 + 1554.908 * em - 2366.899 * emsq + 1215.972 * eoc;
|
||
g410 = -1052.797 + 4758.686 * em - 7193.992 * emsq + 3651.957 * eoc;
|
||
g422 = -3581.690 + 16178.110 * em - 24462.770 * emsq + 12422.520 * eoc;
|
||
if (em > 0.715) {
|
||
g520 = -5149.66 + 29936.92 * em - 54087.36 * emsq + 31324.56 * eoc;
|
||
} else {
|
||
g520 = 1464.74 - 4664.75 * em + 3763.64 * emsq;
|
||
}
|
||
}
|
||
if (em < 0.7) {
|
||
g533 = -919.22770 + 4988.6100 * em - 9064.7700 * emsq + 5542.21 * eoc;
|
||
g521 = -822.71072 + 4568.6173 * em - 8491.4146 * emsq + 5337.524 * eoc;
|
||
g532 = -853.66600 + 4690.2500 * em - 8624.7700 * emsq + 5341.4 * eoc;
|
||
} else {
|
||
g533 = -37995.780 + 161616.52 * em - 229838.20 * emsq + 109377.94 * eoc;
|
||
g521 = -51752.104 + 218913.95 * em - 309468.16 * emsq + 146349.42 * eoc;
|
||
g532 = -40023.880 + 170470.89 * em - 242699.48 * emsq + 115605.82 * eoc;
|
||
}
|
||
sini2 = sinim * sinim;
|
||
f220 = 0.75 * (1.0 + 2.0 * cosim + cosisq);
|
||
f221 = 1.5 * sini2;
|
||
f321 = 1.875 * sinim * (1.0 - 2.0 * cosim - 3.0 * cosisq);
|
||
f322 = -1.875 * sinim * (1.0 + 2.0 * cosim - 3.0 * cosisq);
|
||
f441 = 35.0 * sini2 * f220;
|
||
f442 = 39.3750 * sini2 * sini2;
|
||
f522 = 9.84375 * sinim * (sini2 * (1.0 - 2.0 * cosim - 5.0 * cosisq) + 0.33333333 * (-2.0 + 4.0 * cosim + 6.0 * cosisq));
|
||
f523 = sinim * (4.92187512 * sini2 * (-2.0 - 4.0 * cosim + 10.0 * cosisq) + 6.56250012 * (1.0 + 2.0 * cosim - 3.0 * cosisq));
|
||
f542 = 29.53125 * sinim * (2.0 - 8.0 * cosim + cosisq * (-12.0 + 8.0 * cosim + 10.0 * cosisq));
|
||
f543 = 29.53125 * sinim * (-2.0 - 8.0 * cosim + cosisq * (12.0 + 8.0 * cosim - 10.0 * cosisq));
|
||
xno2 = nm * nm;
|
||
ainv2 = aonv * aonv;
|
||
temp1 = 3.0 * xno2 * ainv2;
|
||
temp = temp1 * root22;
|
||
d2201 = temp * f220 * g201;
|
||
d2211 = temp * f221 * g211;
|
||
temp1 *= aonv;
|
||
temp = temp1 * root32;
|
||
d3210 = temp * f321 * g310;
|
||
d3222 = temp * f322 * g322;
|
||
temp1 *= aonv;
|
||
temp = 2.0 * temp1 * root44;
|
||
d4410 = temp * f441 * g410;
|
||
d4422 = temp * f442 * g422;
|
||
temp1 *= aonv;
|
||
temp = temp1 * root52;
|
||
d5220 = temp * f522 * g520;
|
||
d5232 = temp * f523 * g532;
|
||
temp = 2.0 * temp1 * root54;
|
||
d5421 = temp * f542 * g521;
|
||
d5433 = temp * f543 * g533;
|
||
xlamo = (mo + nodeo + nodeo - (theta + theta)) % twoPi;
|
||
xfact = mdot + dmdt + 2.0 * (nodedot + dnodt - rptim) - no;
|
||
em = emo;
|
||
emsq = emsqo;
|
||
}
|
||
// ---------------- synchronous resonance terms --------------
|
||
if (irez === 1) {
|
||
g200 = 1.0 + emsq * (-2.5 + 0.8125 * emsq);
|
||
g310 = 1.0 + 2.0 * emsq;
|
||
g300 = 1.0 + emsq * (-6.0 + 6.60937 * emsq);
|
||
f220 = 0.75 * (1.0 + cosim) * (1.0 + cosim);
|
||
f311 = 0.9375 * sinim * sinim * (1.0 + 3.0 * cosim) - 0.75 * (1.0 + cosim);
|
||
f330 = 1.0 + cosim;
|
||
f330 *= 1.875 * f330 * f330;
|
||
del1 = 3.0 * nm * nm * aonv * aonv;
|
||
del2 = 2.0 * del1 * f220 * g200 * q22;
|
||
del3 = 3.0 * del1 * f330 * g300 * q33 * aonv;
|
||
del1 = del1 * f311 * g310 * q31 * aonv;
|
||
xlamo = (mo + nodeo + argpo - theta) % twoPi;
|
||
xfact = mdot + xpidot + dmdt + domdt + dnodt - (no + rptim);
|
||
}
|
||
// ------------ for sgp4, initialize the integrator ----------
|
||
xli = xlamo;
|
||
xni = no;
|
||
atime = 0.0;
|
||
nm = no + dndt;
|
||
}
|
||
return {
|
||
em: em,
|
||
argpm: argpm,
|
||
inclm: inclm,
|
||
mm: mm,
|
||
nm: nm,
|
||
nodem: nodem,
|
||
irez: irez,
|
||
atime: atime,
|
||
d2201: d2201,
|
||
d2211: d2211,
|
||
d3210: d3210,
|
||
d3222: d3222,
|
||
d4410: d4410,
|
||
d4422: d4422,
|
||
d5220: d5220,
|
||
d5232: d5232,
|
||
d5421: d5421,
|
||
d5433: d5433,
|
||
dedt: dedt,
|
||
didt: didt,
|
||
dmdt: dmdt,
|
||
dndt: dndt,
|
||
dnodt: dnodt,
|
||
domdt: domdt,
|
||
del1: del1,
|
||
del2: del2,
|
||
del3: del3,
|
||
xfact: xfact,
|
||
xlamo: xlamo,
|
||
xli: xli,
|
||
xni: xni
|
||
};
|
||
}
|
||
|
||
/* -----------------------------------------------------------------------------
|
||
*
|
||
* function gstime
|
||
*
|
||
* this function finds the greenwich sidereal time.
|
||
*
|
||
* author : david vallado 719-573-2600 1 mar 2001
|
||
*
|
||
* inputs description range / units
|
||
* jdut1 - julian date in ut1 days from 4713 bc
|
||
*
|
||
* outputs :
|
||
* gstime - greenwich sidereal time 0 to 2pi rad
|
||
*
|
||
* locals :
|
||
* temp - temporary variable for doubles rad
|
||
* tut1 - julian centuries from the
|
||
* jan 1, 2000 12 h epoch (ut1)
|
||
*
|
||
* coupling :
|
||
* none
|
||
*
|
||
* references :
|
||
* vallado 2004, 191, eq 3-45
|
||
* --------------------------------------------------------------------------- */
|
||
function gstimeInternal(jdut1) {
|
||
var tut1 = (jdut1 - 2451545.0) / 36525.0;
|
||
var temp = -6.2e-6 * tut1 * tut1 * tut1 + 0.093104 * tut1 * tut1 + (876600.0 * 3600 + 8640184.812866) * tut1 + 67310.54841; // # sec
|
||
temp = temp * deg2rad / 240.0 % twoPi; // 360/86400 = 1/240, to deg, to rad
|
||
// ------------------------ check quadrants ---------------------
|
||
if (temp < 0.0) {
|
||
temp += twoPi;
|
||
}
|
||
return temp;
|
||
}
|
||
function gstime(first, month, day, hour, minute, second, millisecond) {
|
||
if (first instanceof Date) {
|
||
return gstimeInternal(jday(first));
|
||
} else if (month !== undefined) {
|
||
return gstimeInternal(jday(first, month, day, hour, minute, second, millisecond));
|
||
} else {
|
||
return gstimeInternal(first);
|
||
}
|
||
}
|
||
|
||
/*-----------------------------------------------------------------------------
|
||
*
|
||
* procedure initl
|
||
*
|
||
* this procedure initializes the sgp4 propagator. all the initialization is
|
||
* consolidated here instead of having multiple loops inside other routines.
|
||
*
|
||
* author : david vallado 719-573-2600 28 jun 2005
|
||
*
|
||
* inputs :
|
||
* ecco - eccentricity 0.0 - 1.0
|
||
* epoch - epoch time in days from jan 0, 1950. 0 hr
|
||
* inclo - inclination of satellite
|
||
* no - mean motion of satellite
|
||
* satn - satellite number
|
||
*
|
||
* outputs :
|
||
* ainv - 1.0 / a
|
||
* ao - semi major axis
|
||
* con41 -
|
||
* con42 - 1.0 - 5.0 cos(i)
|
||
* cosio - cosine of inclination
|
||
* cosio2 - cosio squared
|
||
* eccsq - eccentricity squared
|
||
* method - flag for deep space 'd', 'n'
|
||
* omeosq - 1.0 - ecco * ecco
|
||
* posq - semi-parameter squared
|
||
* rp - radius of perigee
|
||
* rteosq - square root of (1.0 - ecco*ecco)
|
||
* sinio - sine of inclination
|
||
* gsto - gst at time of observation rad
|
||
* no - mean motion of satellite
|
||
*
|
||
* locals :
|
||
* ak -
|
||
* d1 -
|
||
* del -
|
||
* adel -
|
||
* po -
|
||
*
|
||
* coupling :
|
||
* getgravconst
|
||
* gstime - find greenwich sidereal time from the julian date
|
||
*
|
||
* references :
|
||
* hoots, roehrich, norad spacetrack report #3 1980
|
||
* hoots, norad spacetrack report #6 1986
|
||
* hoots, schumacher and glover 2004
|
||
* vallado, crawford, hujsak, kelso 2006
|
||
----------------------------------------------------------------------------*/
|
||
function initl(options) {
|
||
var ecco = options.ecco,
|
||
epoch = options.epoch,
|
||
inclo = options.inclo,
|
||
opsmode = options.opsmode;
|
||
var no = options.no;
|
||
// sgp4fix use old way of finding gst
|
||
// ----------------------- earth constants ---------------------
|
||
// sgp4fix identify constants and allow alternate values
|
||
// ------------- calculate auxillary epoch quantities ----------
|
||
var eccsq = ecco * ecco;
|
||
var omeosq = 1.0 - eccsq;
|
||
var rteosq = Math.sqrt(omeosq);
|
||
var cosio = Math.cos(inclo);
|
||
var cosio2 = cosio * cosio;
|
||
// ------------------ un-kozai the mean motion -----------------
|
||
var ak = Math.pow(xke / no, x2o3);
|
||
var d1 = 0.75 * j2 * (3.0 * cosio2 - 1.0) / (rteosq * omeosq);
|
||
var delPrime = d1 / (ak * ak);
|
||
var adel = ak * (1.0 - delPrime * delPrime - delPrime * (1.0 / 3.0 + 134.0 * delPrime * delPrime / 81.0));
|
||
delPrime = d1 / (adel * adel);
|
||
no /= 1.0 + delPrime;
|
||
var ao = Math.pow(xke / no, x2o3);
|
||
var sinio = Math.sin(inclo);
|
||
var po = ao * omeosq;
|
||
var con42 = 1.0 - 5.0 * cosio2;
|
||
var con41 = -con42 - cosio2 - cosio2;
|
||
var ainv = 1.0 / ao;
|
||
var posq = po * po;
|
||
var rp = ao * (1.0 - ecco);
|
||
var method = 'n';
|
||
// sgp4fix modern approach to finding sidereal time
|
||
var gsto;
|
||
if (opsmode === 'a') {
|
||
// sgp4fix use old way of finding gst
|
||
// count integer number of days from 0 jan 1970
|
||
var ts70 = epoch - 7305.0;
|
||
var ds70 = Math.floor(ts70 + 1.0e-8);
|
||
var tfrac = ts70 - ds70;
|
||
// find greenwich location at epoch
|
||
var c1 = 1.72027916940703639e-2; // eslint-disable-line no-loss-of-precision
|
||
var thgr70 = 1.7321343856509374; // eslint-disable-line no-loss-of-precision
|
||
var fk5r = 5.07551419432269442e-15; // eslint-disable-line no-loss-of-precision
|
||
var c1p2p = c1 + twoPi;
|
||
gsto = (thgr70 + c1 * ds70 + c1p2p * tfrac + ts70 * ts70 * fk5r) % twoPi;
|
||
if (gsto < 0.0) {
|
||
gsto += twoPi;
|
||
}
|
||
} else {
|
||
gsto = gstime(epoch + 2433281.5);
|
||
}
|
||
return {
|
||
no: no,
|
||
method: method,
|
||
ainv: ainv,
|
||
ao: ao,
|
||
con41: con41,
|
||
con42: con42,
|
||
cosio: cosio,
|
||
cosio2: cosio2,
|
||
eccsq: eccsq,
|
||
omeosq: omeosq,
|
||
posq: posq,
|
||
rp: rp,
|
||
rteosq: rteosq,
|
||
sinio: sinio,
|
||
gsto: gsto
|
||
};
|
||
}
|
||
|
||
/*-----------------------------------------------------------------------------
|
||
*
|
||
* procedure dspace
|
||
*
|
||
* this procedure provides deep space contributions to mean elements for
|
||
* perturbing third body. these effects have been averaged over one
|
||
* revolution of the sun and moon. for earth resonance effects, the
|
||
* effects have been averaged over no revolutions of the satellite.
|
||
* (mean motion)
|
||
*
|
||
* author : david vallado 719-573-2600 28 jun 2005
|
||
*
|
||
* inputs :
|
||
* d2201, d2211, d3210, d3222, d4410, d4422, d5220, d5232, d5421, d5433 -
|
||
* dedt -
|
||
* del1, del2, del3 -
|
||
* didt -
|
||
* dmdt -
|
||
* dnodt -
|
||
* domdt -
|
||
* irez - flag for resonance 0-none, 1-one day, 2-half day
|
||
* argpo - argument of perigee
|
||
* argpdot - argument of perigee dot (rate)
|
||
* t - time
|
||
* tc -
|
||
* gsto - gst
|
||
* xfact -
|
||
* xlamo -
|
||
* no - mean motion
|
||
* atime -
|
||
* em - eccentricity
|
||
* ft -
|
||
* argpm - argument of perigee
|
||
* inclm - inclination
|
||
* xli -
|
||
* mm - mean anomaly
|
||
* xni - mean motion
|
||
* nodem - right ascension of ascending node
|
||
*
|
||
* outputs :
|
||
* atime -
|
||
* em - eccentricity
|
||
* argpm - argument of perigee
|
||
* inclm - inclination
|
||
* xli -
|
||
* mm - mean anomaly
|
||
* xni -
|
||
* nodem - right ascension of ascending node
|
||
* dndt -
|
||
* nm - mean motion
|
||
*
|
||
* locals :
|
||
* delt -
|
||
* ft -
|
||
* theta -
|
||
* x2li -
|
||
* x2omi -
|
||
* xl -
|
||
* xldot -
|
||
* xnddt -
|
||
* xndt -
|
||
* xomi -
|
||
*
|
||
* coupling :
|
||
* none -
|
||
*
|
||
* references :
|
||
* hoots, roehrich, norad spacetrack report #3 1980
|
||
* hoots, norad spacetrack report #6 1986
|
||
* hoots, schumacher and glover 2004
|
||
* vallado, crawford, hujsak, kelso 2006
|
||
----------------------------------------------------------------------------*/
|
||
function dspace(options) {
|
||
var irez = options.irez,
|
||
d2201 = options.d2201,
|
||
d2211 = options.d2211,
|
||
d3210 = options.d3210,
|
||
d3222 = options.d3222,
|
||
d4410 = options.d4410,
|
||
d4422 = options.d4422,
|
||
d5220 = options.d5220,
|
||
d5232 = options.d5232,
|
||
d5421 = options.d5421,
|
||
d5433 = options.d5433,
|
||
dedt = options.dedt,
|
||
del1 = options.del1,
|
||
del2 = options.del2,
|
||
del3 = options.del3,
|
||
didt = options.didt,
|
||
dmdt = options.dmdt,
|
||
dnodt = options.dnodt,
|
||
domdt = options.domdt,
|
||
argpo = options.argpo,
|
||
argpdot = options.argpdot,
|
||
t = options.t,
|
||
tc = options.tc,
|
||
gsto = options.gsto,
|
||
xfact = options.xfact,
|
||
xlamo = options.xlamo,
|
||
no = options.no;
|
||
var atime = options.atime,
|
||
em = options.em,
|
||
argpm = options.argpm,
|
||
inclm = options.inclm,
|
||
xli = options.xli,
|
||
mm = options.mm,
|
||
xni = options.xni,
|
||
nodem = options.nodem,
|
||
nm = options.nm;
|
||
var fasx2 = 0.13130908;
|
||
var fasx4 = 2.8843198;
|
||
var fasx6 = 0.37448087;
|
||
var g22 = 5.7686396;
|
||
var g32 = 0.95240898;
|
||
var g44 = 1.8014998;
|
||
var g52 = 1.0508330;
|
||
var g54 = 4.4108898;
|
||
// eslint-disable-next-line no-loss-of-precision
|
||
var rptim = 4.37526908801129966e-3; // equates to 7.29211514668855e-5 rad/sec
|
||
var stepp = 720.0;
|
||
var stepn = -720.0;
|
||
var step2 = 259200.0;
|
||
var delt;
|
||
var x2li;
|
||
var x2omi;
|
||
var xl;
|
||
var xldot;
|
||
var xnddt;
|
||
var xndt;
|
||
var xomi;
|
||
var dndt = 0.0;
|
||
var ft = 0.0;
|
||
// ----------- calculate deep space resonance effects -----------
|
||
var theta = (gsto + tc * rptim) % twoPi;
|
||
em += dedt * t;
|
||
inclm += didt * t;
|
||
argpm += domdt * t;
|
||
nodem += dnodt * t;
|
||
mm += dmdt * t;
|
||
// sgp4fix for negative inclinations
|
||
// the following if statement should be commented out
|
||
// if (inclm < 0.0)
|
||
// {
|
||
// inclm = -inclm;
|
||
// argpm = argpm - pi;
|
||
// nodem = nodem + pi;
|
||
// }
|
||
/* - update resonances : numerical (euler-maclaurin) integration - */
|
||
/* ------------------------- epoch restart ---------------------- */
|
||
// sgp4fix for propagator problems
|
||
// the following integration works for negative time steps and periods
|
||
// the specific changes are unknown because the original code was so convoluted
|
||
// sgp4fix take out atime = 0.0 and fix for faster operation
|
||
if (irez !== 0) {
|
||
// sgp4fix streamline check
|
||
if (atime === 0.0 || t * atime <= 0.0 || Math.abs(t) < Math.abs(atime)) {
|
||
atime = 0.0;
|
||
xni = no;
|
||
xli = xlamo;
|
||
}
|
||
// sgp4fix move check outside loop
|
||
if (t > 0.0) {
|
||
delt = stepp;
|
||
} else {
|
||
delt = stepn;
|
||
}
|
||
var iretn = 381; // added for do loop
|
||
while (iretn === 381) {
|
||
// ------------------- dot terms calculated -------------
|
||
// ----------- near - synchronous resonance terms -------
|
||
if (irez !== 2) {
|
||
xndt = del1 * Math.sin(xli - fasx2) + del2 * Math.sin(2.0 * (xli - fasx4)) + del3 * Math.sin(3.0 * (xli - fasx6));
|
||
xldot = xni + xfact;
|
||
xnddt = del1 * Math.cos(xli - fasx2) + 2.0 * del2 * Math.cos(2.0 * (xli - fasx4)) + 3.0 * del3 * Math.cos(3.0 * (xli - fasx6));
|
||
xnddt *= xldot;
|
||
} else {
|
||
// --------- near - half-day resonance terms --------
|
||
xomi = argpo + argpdot * atime;
|
||
x2omi = xomi + xomi;
|
||
x2li = xli + xli;
|
||
xndt = d2201 * Math.sin(x2omi + xli - g22) + d2211 * Math.sin(xli - g22) + d3210 * Math.sin(xomi + xli - g32) + d3222 * Math.sin(-xomi + xli - g32) + d4410 * Math.sin(x2omi + x2li - g44) + d4422 * Math.sin(x2li - g44) + d5220 * Math.sin(xomi + xli - g52) + d5232 * Math.sin(-xomi + xli - g52) + d5421 * Math.sin(xomi + x2li - g54) + d5433 * Math.sin(-xomi + x2li - g54);
|
||
xldot = xni + xfact;
|
||
xnddt = d2201 * Math.cos(x2omi + xli - g22) + d2211 * Math.cos(xli - g22) + d3210 * Math.cos(xomi + xli - g32) + d3222 * Math.cos(-xomi + xli - g32) + d5220 * Math.cos(xomi + xli - g52) + d5232 * Math.cos(-xomi + xli - g52) + 2.0 * (d4410 * Math.cos(x2omi + x2li - g44) + d4422 * Math.cos(x2li - g44) + d5421 * Math.cos(xomi + x2li - g54) + d5433 * Math.cos(-xomi + x2li - g54));
|
||
xnddt *= xldot;
|
||
}
|
||
// ----------------------- integrator -------------------
|
||
// sgp4fix move end checks to end of routine
|
||
if (Math.abs(t - atime) >= stepp) {
|
||
iretn = 381;
|
||
} else {
|
||
ft = t - atime;
|
||
iretn = 0;
|
||
}
|
||
if (iretn === 381) {
|
||
xli += xldot * delt + xndt * step2;
|
||
xni += xndt * delt + xnddt * step2;
|
||
atime += delt;
|
||
}
|
||
}
|
||
nm = xni + xndt * ft + xnddt * ft * ft * 0.5;
|
||
xl = xli + xldot * ft + xndt * ft * ft * 0.5;
|
||
if (irez !== 1) {
|
||
mm = xl - 2.0 * nodem + 2.0 * theta;
|
||
dndt = nm - no;
|
||
} else {
|
||
mm = xl - nodem - argpm + theta;
|
||
dndt = nm - no;
|
||
}
|
||
nm = no + dndt;
|
||
}
|
||
return {
|
||
atime: atime,
|
||
em: em,
|
||
argpm: argpm,
|
||
inclm: inclm,
|
||
xli: xli,
|
||
mm: mm,
|
||
xni: xni,
|
||
nodem: nodem,
|
||
dndt: dndt,
|
||
nm: nm
|
||
};
|
||
}
|
||
|
||
var SatRecError;
|
||
(function (SatRecError) {
|
||
/**
|
||
* No error, propagation for the last supplied date is successful
|
||
*/
|
||
SatRecError[SatRecError["None"] = 0] = "None";
|
||
/**
|
||
* Mean eccentricity is out of range 0 ≤ e < 1
|
||
*/
|
||
SatRecError[SatRecError["MeanEccentricityOutOfRange"] = 1] = "MeanEccentricityOutOfRange";
|
||
/**
|
||
* Mean motion has fallen below zero.
|
||
*/
|
||
SatRecError[SatRecError["MeanMotionBelowZero"] = 2] = "MeanMotionBelowZero";
|
||
/**
|
||
* Perturbed eccentricity is out of range 0 ≤ e < 1
|
||
*/
|
||
SatRecError[SatRecError["PerturbedEccentricityOutOfRange"] = 3] = "PerturbedEccentricityOutOfRange";
|
||
/**
|
||
* Length of the orbit’s semi-latus rectum has fallen below zero.
|
||
*/
|
||
SatRecError[SatRecError["SemiLatusRectumBelowZero"] = 4] = "SemiLatusRectumBelowZero";
|
||
// 5 is not used
|
||
/**
|
||
* Orbit has decayed: the computed position is underground.
|
||
*/
|
||
SatRecError[SatRecError["Decayed"] = 6] = "Decayed";
|
||
})(SatRecError || (SatRecError = {}));
|
||
|
||
/*----------------------------------------------------------------------------
|
||
*
|
||
* procedure sgp4
|
||
*
|
||
* this procedure is the sgp4 prediction model from space command. this is an
|
||
* updated and combined version of sgp4 and sdp4, which were originally
|
||
* published separately in spacetrack report //3. this version follows the
|
||
* methodology from the aiaa paper (2006) describing the history and
|
||
* development of the code.
|
||
*
|
||
* author : david vallado 719-573-2600 28 jun 2005
|
||
*
|
||
* inputs :
|
||
* satrec - initialised structure from sgp4init() call.
|
||
* tsince - time since epoch (minutes)
|
||
*
|
||
* outputs :
|
||
* r - position vector km
|
||
* v - velocity km/sec
|
||
* return code - non-zero on error.
|
||
* 1 - mean elements, ecc >= 1.0 or ecc < -0.001 or a < 0.95 er
|
||
* 2 - mean motion less than 0.0
|
||
* 3 - pert elements, ecc < 0.0 or ecc > 1.0
|
||
* 4 - semi-latus rectum < 0.0
|
||
* 5 - epoch elements are sub-orbital
|
||
* 6 - satellite has decayed
|
||
*
|
||
* locals :
|
||
* am -
|
||
* axnl, aynl -
|
||
* betal -
|
||
* cosim , sinim , cosomm , sinomm , cnod , snod , cos2u ,
|
||
* sin2u , coseo1 , sineo1 , cosi , sini , cosip , sinip ,
|
||
* cosisq , cossu , sinsu , cosu , sinu
|
||
* delm -
|
||
* delomg -
|
||
* dndt -
|
||
* eccm -
|
||
* emsq -
|
||
* ecose -
|
||
* el2 -
|
||
* eo1 -
|
||
* eccp -
|
||
* esine -
|
||
* argpm -
|
||
* argpp -
|
||
* omgadf -
|
||
* pl -
|
||
* r -
|
||
* rtemsq -
|
||
* rdotl -
|
||
* rl -
|
||
* rvdot -
|
||
* rvdotl -
|
||
* su -
|
||
* t2 , t3 , t4 , tc
|
||
* tem5, temp , temp1 , temp2 , tempa , tempe , templ
|
||
* u , ux , uy , uz , vx , vy , vz
|
||
* inclm - inclination
|
||
* mm - mean anomaly
|
||
* nm - mean motion
|
||
* nodem - right asc of ascending node
|
||
* xinc -
|
||
* xincp -
|
||
* xl -
|
||
* xlm -
|
||
* mp -
|
||
* xmdf -
|
||
* xmx -
|
||
* xmy -
|
||
* nodedf -
|
||
* xnode -
|
||
* nodep -
|
||
* np -
|
||
*
|
||
* coupling :
|
||
* getgravconst-
|
||
* dpper
|
||
* dspace
|
||
*
|
||
* references :
|
||
* hoots, roehrich, norad spacetrack report //3 1980
|
||
* hoots, norad spacetrack report //6 1986
|
||
* hoots, schumacher and glover 2004
|
||
* vallado, crawford, hujsak, kelso 2006
|
||
----------------------------------------------------------------------------*/
|
||
function sgp4(satrec, tsince) {
|
||
var coseo1;
|
||
var sineo1;
|
||
var cosip;
|
||
var sinip;
|
||
var cosisq;
|
||
var delm;
|
||
var delomg;
|
||
var eo1;
|
||
var argpm;
|
||
var argpp;
|
||
var su;
|
||
var t3;
|
||
var t4;
|
||
var tc;
|
||
var tem5;
|
||
var temp;
|
||
var tempa;
|
||
var tempe;
|
||
var templ;
|
||
var inclm;
|
||
var mm;
|
||
var nm;
|
||
var nodem;
|
||
var xincp;
|
||
var xlm;
|
||
var mp;
|
||
var nodep;
|
||
/* ------------------ set mathematical constants --------------- */
|
||
// sgp4fix divisor for divide by zero check on inclination
|
||
// the old check used 1.0 + cos(pi-1.0e-9), but then compared it to
|
||
// 1.5 e-12, so the threshold was changed to 1.5e-12 for consistency
|
||
var temp4 = 1.5e-12;
|
||
// --------------------- clear sgp4 error flag -----------------
|
||
satrec.t = tsince;
|
||
satrec.error = SatRecError.None;
|
||
// ------- update for secular gravity and atmospheric drag -----
|
||
var xmdf = satrec.mo + satrec.mdot * satrec.t;
|
||
var argpdf = satrec.argpo + satrec.argpdot * satrec.t;
|
||
var nodedf = satrec.nodeo + satrec.nodedot * satrec.t;
|
||
argpm = argpdf;
|
||
mm = xmdf;
|
||
var t2 = satrec.t * satrec.t;
|
||
nodem = nodedf + satrec.nodecf * t2;
|
||
tempa = 1.0 - satrec.cc1 * satrec.t;
|
||
tempe = satrec.bstar * satrec.cc4 * satrec.t;
|
||
templ = satrec.t2cof * t2;
|
||
if (satrec.isimp !== 1) {
|
||
delomg = satrec.omgcof * satrec.t;
|
||
// sgp4fix use mutliply for speed instead of pow
|
||
var delmtemp = 1.0 + satrec.eta * Math.cos(xmdf);
|
||
delm = satrec.xmcof * (delmtemp * delmtemp * delmtemp - satrec.delmo);
|
||
temp = delomg + delm;
|
||
mm = xmdf + temp;
|
||
argpm = argpdf - temp;
|
||
t3 = t2 * satrec.t;
|
||
t4 = t3 * satrec.t;
|
||
tempa = tempa - satrec.d2 * t2 - satrec.d3 * t3 - satrec.d4 * t4;
|
||
tempe += satrec.bstar * satrec.cc5 * (Math.sin(mm) - satrec.sinmao);
|
||
templ = templ + satrec.t3cof * t3 + t4 * (satrec.t4cof + satrec.t * satrec.t5cof);
|
||
}
|
||
nm = satrec.no;
|
||
var em = satrec.ecco;
|
||
inclm = satrec.inclo;
|
||
if (satrec.method === 'd') {
|
||
tc = satrec.t;
|
||
var dspaceOptions = {
|
||
irez: satrec.irez,
|
||
d2201: satrec.d2201,
|
||
d2211: satrec.d2211,
|
||
d3210: satrec.d3210,
|
||
d3222: satrec.d3222,
|
||
d4410: satrec.d4410,
|
||
d4422: satrec.d4422,
|
||
d5220: satrec.d5220,
|
||
d5232: satrec.d5232,
|
||
d5421: satrec.d5421,
|
||
d5433: satrec.d5433,
|
||
dedt: satrec.dedt,
|
||
del1: satrec.del1,
|
||
del2: satrec.del2,
|
||
del3: satrec.del3,
|
||
didt: satrec.didt,
|
||
dmdt: satrec.dmdt,
|
||
dnodt: satrec.dnodt,
|
||
domdt: satrec.domdt,
|
||
argpo: satrec.argpo,
|
||
argpdot: satrec.argpdot,
|
||
t: satrec.t,
|
||
tc: tc,
|
||
gsto: satrec.gsto,
|
||
xfact: satrec.xfact,
|
||
xlamo: satrec.xlamo,
|
||
no: satrec.no,
|
||
atime: satrec.atime,
|
||
em: em,
|
||
argpm: argpm,
|
||
inclm: inclm,
|
||
xli: satrec.xli,
|
||
mm: mm,
|
||
xni: satrec.xni,
|
||
nodem: nodem,
|
||
nm: nm
|
||
};
|
||
var dspaceResult = dspace(dspaceOptions);
|
||
em = dspaceResult.em;
|
||
argpm = dspaceResult.argpm;
|
||
inclm = dspaceResult.inclm;
|
||
mm = dspaceResult.mm;
|
||
nodem = dspaceResult.nodem;
|
||
nm = dspaceResult.nm;
|
||
}
|
||
if (nm <= 0.0) {
|
||
// printf("// error nm %f\n", nm);
|
||
satrec.error = SatRecError.MeanMotionBelowZero;
|
||
// sgp4fix add return
|
||
return null;
|
||
}
|
||
var am = Math.pow(xke / nm, x2o3) * tempa * tempa;
|
||
nm = xke / Math.pow(am, 1.5);
|
||
em -= tempe;
|
||
// fix tolerance for error recognition
|
||
// sgp4fix am is fixed from the previous nm check
|
||
if (em >= 1.0 || em < -0.001) {
|
||
// || (am < 0.95)
|
||
// printf("// error em %f\n", em);
|
||
satrec.error = SatRecError.MeanEccentricityOutOfRange;
|
||
// sgp4fix to return if there is an error in eccentricity
|
||
return null;
|
||
}
|
||
// sgp4fix fix tolerance to avoid a divide by zero
|
||
if (em < 1.0e-6) {
|
||
em = 1.0e-6;
|
||
}
|
||
mm += satrec.no * templ;
|
||
xlm = mm + argpm + nodem;
|
||
nodem %= twoPi;
|
||
argpm %= twoPi;
|
||
xlm %= twoPi;
|
||
mm = (xlm - argpm - nodem) % twoPi;
|
||
var meanElements = {
|
||
am: am,
|
||
em: em,
|
||
im: inclm,
|
||
Om: nodem,
|
||
om: argpm,
|
||
mm: mm,
|
||
nm: nm
|
||
};
|
||
// ----------------- compute extra mean quantities -------------
|
||
var sinim = Math.sin(inclm);
|
||
var cosim = Math.cos(inclm);
|
||
// -------------------- add lunar-solar periodics --------------
|
||
var ep = em;
|
||
xincp = inclm;
|
||
argpp = argpm;
|
||
nodep = nodem;
|
||
mp = mm;
|
||
sinip = sinim;
|
||
cosip = cosim;
|
||
if (satrec.method === 'd') {
|
||
var dpperParameters = {
|
||
inclo: satrec.inclo,
|
||
init: 'n',
|
||
ep: ep,
|
||
inclp: xincp,
|
||
nodep: nodep,
|
||
argpp: argpp,
|
||
mp: mp,
|
||
opsmode: satrec.operationmode
|
||
};
|
||
var dpperResult = dpper(satrec, dpperParameters);
|
||
ep = dpperResult.ep;
|
||
nodep = dpperResult.nodep;
|
||
argpp = dpperResult.argpp;
|
||
mp = dpperResult.mp;
|
||
xincp = dpperResult.inclp;
|
||
if (xincp < 0.0) {
|
||
xincp = -xincp;
|
||
nodep += pi;
|
||
argpp -= pi;
|
||
}
|
||
if (ep < 0.0 || ep > 1.0) {
|
||
// printf("// error ep %f\n", ep);
|
||
satrec.error = SatRecError.PerturbedEccentricityOutOfRange;
|
||
// sgp4fix add return
|
||
return null;
|
||
}
|
||
}
|
||
// -------------------- long period periodics ------------------
|
||
if (satrec.method === 'd') {
|
||
sinip = Math.sin(xincp);
|
||
cosip = Math.cos(xincp);
|
||
satrec.aycof = -0.5 * j3oj2 * sinip;
|
||
// sgp4fix for divide by zero for xincp = 180 deg
|
||
if (Math.abs(cosip + 1.0) > 1.5e-12) {
|
||
satrec.xlcof = -0.25 * j3oj2 * sinip * (3.0 + 5.0 * cosip) / (1.0 + cosip);
|
||
} else {
|
||
satrec.xlcof = -0.25 * j3oj2 * sinip * (3.0 + 5.0 * cosip) / temp4;
|
||
}
|
||
}
|
||
var axnl = ep * Math.cos(argpp);
|
||
temp = 1.0 / (am * (1.0 - ep * ep));
|
||
var aynl = ep * Math.sin(argpp) + temp * satrec.aycof;
|
||
var xl = mp + argpp + nodep + temp * satrec.xlcof * axnl;
|
||
// --------------------- solve kepler's equation ---------------
|
||
var u = (xl - nodep) % twoPi;
|
||
eo1 = u;
|
||
tem5 = 9999.9;
|
||
var ktr = 1;
|
||
// sgp4fix for kepler iteration
|
||
// the following iteration needs better limits on corrections
|
||
while (Math.abs(tem5) >= 1.0e-12 && ktr <= 10) {
|
||
sineo1 = Math.sin(eo1);
|
||
coseo1 = Math.cos(eo1);
|
||
tem5 = 1.0 - coseo1 * axnl - sineo1 * aynl;
|
||
tem5 = (u - aynl * coseo1 + axnl * sineo1 - eo1) / tem5;
|
||
if (Math.abs(tem5) >= 0.95) {
|
||
if (tem5 > 0.0) {
|
||
tem5 = 0.95;
|
||
} else {
|
||
tem5 = -0.95;
|
||
}
|
||
}
|
||
eo1 += tem5;
|
||
ktr += 1;
|
||
}
|
||
// ------------- short period preliminary quantities -----------
|
||
var ecose = axnl * coseo1 + aynl * sineo1;
|
||
var esine = axnl * sineo1 - aynl * coseo1;
|
||
var el2 = axnl * axnl + aynl * aynl;
|
||
var pl = am * (1.0 - el2);
|
||
if (pl < 0.0) {
|
||
// printf("// error pl %f\n", pl);
|
||
satrec.error = SatRecError.SemiLatusRectumBelowZero;
|
||
// sgp4fix add return
|
||
return null;
|
||
}
|
||
var rl = am * (1.0 - ecose);
|
||
var rdotl = Math.sqrt(am) * esine / rl;
|
||
var rvdotl = Math.sqrt(pl) / rl;
|
||
var betal = Math.sqrt(1.0 - el2);
|
||
temp = esine / (1.0 + betal);
|
||
var sinu = am / rl * (sineo1 - aynl - axnl * temp);
|
||
var cosu = am / rl * (coseo1 - axnl + aynl * temp);
|
||
su = Math.atan2(sinu, cosu);
|
||
var sin2u = (cosu + cosu) * sinu;
|
||
var cos2u = 1.0 - 2.0 * sinu * sinu;
|
||
temp = 1.0 / pl;
|
||
var temp1 = 0.5 * j2 * temp;
|
||
var temp2 = temp1 * temp;
|
||
// -------------- update for short period periodics ------------
|
||
if (satrec.method === 'd') {
|
||
cosisq = cosip * cosip;
|
||
satrec.con41 = 3.0 * cosisq - 1.0;
|
||
satrec.x1mth2 = 1.0 - cosisq;
|
||
satrec.x7thm1 = 7.0 * cosisq - 1.0;
|
||
}
|
||
var mrt = rl * (1.0 - 1.5 * temp2 * betal * satrec.con41) + 0.5 * temp1 * satrec.x1mth2 * cos2u;
|
||
// sgp4fix for decaying satellites
|
||
if (mrt < 1.0) {
|
||
// printf("// decay condition %11.6f \n",mrt);
|
||
satrec.error = SatRecError.Decayed;
|
||
return null;
|
||
}
|
||
su -= 0.25 * temp2 * satrec.x7thm1 * sin2u;
|
||
var xnode = nodep + 1.5 * temp2 * cosip * sin2u;
|
||
var xinc = xincp + 1.5 * temp2 * cosip * sinip * cos2u;
|
||
var mvt = rdotl - nm * temp1 * satrec.x1mth2 * sin2u / xke;
|
||
var rvdot = rvdotl + nm * temp1 * (satrec.x1mth2 * cos2u + 1.5 * satrec.con41) / xke;
|
||
// --------------------- orientation vectors -------------------
|
||
var sinsu = Math.sin(su);
|
||
var cossu = Math.cos(su);
|
||
var snod = Math.sin(xnode);
|
||
var cnod = Math.cos(xnode);
|
||
var sini = Math.sin(xinc);
|
||
var cosi = Math.cos(xinc);
|
||
var xmx = -snod * cosi;
|
||
var xmy = cnod * cosi;
|
||
var ux = xmx * sinsu + cnod * cossu;
|
||
var uy = xmy * sinsu + snod * cossu;
|
||
var uz = sini * sinsu;
|
||
var vx = xmx * cossu - cnod * sinsu;
|
||
var vy = xmy * cossu - snod * sinsu;
|
||
var vz = sini * cossu;
|
||
// --------- position and velocity (in km and km/sec) ----------
|
||
var r = {
|
||
x: mrt * ux * earthRadius,
|
||
y: mrt * uy * earthRadius,
|
||
z: mrt * uz * earthRadius
|
||
};
|
||
var v = {
|
||
x: (mvt * ux + rvdot * vx) * vkmpersec,
|
||
y: (mvt * uy + rvdot * vy) * vkmpersec,
|
||
z: (mvt * uz + rvdot * vz) * vkmpersec
|
||
};
|
||
return {
|
||
position: r,
|
||
velocity: v,
|
||
meanElements: meanElements
|
||
};
|
||
}
|
||
|
||
/*-----------------------------------------------------------------------------
|
||
*
|
||
* procedure sgp4init
|
||
*
|
||
* this procedure initializes variables for sgp4.
|
||
*
|
||
* author : david vallado 719-573-2600 28 jun 2005
|
||
* author : david vallado 719-573-2600 28 jun 2005
|
||
*
|
||
* inputs :
|
||
* opsmode - mode of operation afspc or improved 'a', 'i'
|
||
* satn - satellite number
|
||
* bstar - sgp4 type drag coefficient kg/m2er
|
||
* ecco - eccentricity
|
||
* epoch - epoch time in days from jan 0, 1950. 0 hr
|
||
* argpo - argument of perigee (output if ds)
|
||
* inclo - inclination
|
||
* mo - mean anomaly (output if ds)
|
||
* no - mean motion
|
||
* nodeo - right ascension of ascending node
|
||
*
|
||
* outputs :
|
||
* rec - common values for subsequent calls
|
||
* return code - non-zero on error.
|
||
* 1 - mean elements, ecc >= 1.0 or ecc < -0.001 or a < 0.95 er
|
||
* 2 - mean motion less than 0.0
|
||
* 3 - pert elements, ecc < 0.0 or ecc > 1.0
|
||
* 4 - semi-latus rectum < 0.0
|
||
* 5 - epoch elements are sub-orbital
|
||
* 6 - satellite has decayed
|
||
*
|
||
* locals :
|
||
* cnodm , snodm , cosim , sinim , cosomm , sinomm
|
||
* cc1sq , cc2 , cc3
|
||
* coef , coef1
|
||
* cosio4 -
|
||
* day -
|
||
* dndt -
|
||
* em - eccentricity
|
||
* emsq - eccentricity squared
|
||
* eeta -
|
||
* etasq -
|
||
* gam -
|
||
* argpm - argument of perigee
|
||
* nodem -
|
||
* inclm - inclination
|
||
* mm - mean anomaly
|
||
* nm - mean motion
|
||
* perige - perigee
|
||
* pinvsq -
|
||
* psisq -
|
||
* qzms24 -
|
||
* rtemsq -
|
||
* s1, s2, s3, s4, s5, s6, s7 -
|
||
* sfour -
|
||
* ss1, ss2, ss3, ss4, ss5, ss6, ss7 -
|
||
* sz1, sz2, sz3
|
||
* sz11, sz12, sz13, sz21, sz22, sz23, sz31, sz32, sz33 -
|
||
* tc -
|
||
* temp -
|
||
* temp1, temp2, temp3 -
|
||
* tsi -
|
||
* xpidot -
|
||
* xhdot1 -
|
||
* z1, z2, z3 -
|
||
* z11, z12, z13, z21, z22, z23, z31, z32, z33 -
|
||
*
|
||
* coupling :
|
||
* getgravconst-
|
||
* initl -
|
||
* dscom -
|
||
* dpper -
|
||
* dsinit -
|
||
* sgp4 -
|
||
*
|
||
* references :
|
||
* hoots, roehrich, norad spacetrack report #3 1980
|
||
* hoots, norad spacetrack report #6 1986
|
||
* hoots, schumacher and glover 2004
|
||
* vallado, crawford, hujsak, kelso 2006
|
||
----------------------------------------------------------------------------*/
|
||
function sgp4init(satrecInit, options) {
|
||
var opsmode = options.opsmode,
|
||
satn = options.satn,
|
||
epoch = options.epoch,
|
||
xbstar = options.xbstar,
|
||
xecco = options.xecco,
|
||
xargpo = options.xargpo,
|
||
xinclo = options.xinclo,
|
||
xmo = options.xmo,
|
||
xno = options.xno,
|
||
xnodeo = options.xnodeo;
|
||
var cosim;
|
||
var sinim;
|
||
var cc1sq;
|
||
var cc2;
|
||
var cc3;
|
||
var coef;
|
||
var coef1;
|
||
var cosio4;
|
||
var em;
|
||
var emsq;
|
||
var eeta;
|
||
var etasq;
|
||
var argpm;
|
||
var nodem;
|
||
var inclm;
|
||
var mm;
|
||
var nm;
|
||
var perige;
|
||
var pinvsq;
|
||
var psisq;
|
||
var qzms24;
|
||
var s1;
|
||
var s2;
|
||
var s3;
|
||
var s4;
|
||
var s5;
|
||
var sfour;
|
||
var ss1;
|
||
var ss2;
|
||
var ss3;
|
||
var ss4;
|
||
var ss5;
|
||
var sz1;
|
||
var sz3;
|
||
var sz11;
|
||
var sz13;
|
||
var sz21;
|
||
var sz23;
|
||
var sz31;
|
||
var sz33;
|
||
var tc;
|
||
var temp;
|
||
var temp1;
|
||
var temp2;
|
||
var temp3;
|
||
var tsi;
|
||
var xpidot;
|
||
var xhdot1;
|
||
var z1;
|
||
var z3;
|
||
var z11;
|
||
var z13;
|
||
var z21;
|
||
var z23;
|
||
var z31;
|
||
var z33;
|
||
/* ------------------------ initialization --------------------- */
|
||
// sgp4fix divisor for divide by zero check on inclination
|
||
// the old check used 1.0 + Math.cos(pi-1.0e-9), but then compared it to
|
||
// 1.5 e-12, so the threshold was changed to 1.5e-12 for consistency
|
||
var temp4 = 1.5e-12;
|
||
var satrec = satrecInit;
|
||
// ----------- set all near earth variables to zero ------------
|
||
satrec.isimp = 0;
|
||
satrec.method = 'n';
|
||
satrec.aycof = 0.0;
|
||
satrec.con41 = 0.0;
|
||
satrec.cc1 = 0.0;
|
||
satrec.cc4 = 0.0;
|
||
satrec.cc5 = 0.0;
|
||
satrec.d2 = 0.0;
|
||
satrec.d3 = 0.0;
|
||
satrec.d4 = 0.0;
|
||
satrec.delmo = 0.0;
|
||
satrec.eta = 0.0;
|
||
satrec.argpdot = 0.0;
|
||
satrec.omgcof = 0.0;
|
||
satrec.sinmao = 0.0;
|
||
satrec.t = 0.0;
|
||
satrec.t2cof = 0.0;
|
||
satrec.t3cof = 0.0;
|
||
satrec.t4cof = 0.0;
|
||
satrec.t5cof = 0.0;
|
||
satrec.x1mth2 = 0.0;
|
||
satrec.x7thm1 = 0.0;
|
||
satrec.mdot = 0.0;
|
||
satrec.nodedot = 0.0;
|
||
satrec.xlcof = 0.0;
|
||
satrec.xmcof = 0.0;
|
||
satrec.nodecf = 0.0;
|
||
// ----------- set all deep space variables to zero ------------
|
||
satrec.irez = 0;
|
||
satrec.d2201 = 0.0;
|
||
satrec.d2211 = 0.0;
|
||
satrec.d3210 = 0.0;
|
||
satrec.d3222 = 0.0;
|
||
satrec.d4410 = 0.0;
|
||
satrec.d4422 = 0.0;
|
||
satrec.d5220 = 0.0;
|
||
satrec.d5232 = 0.0;
|
||
satrec.d5421 = 0.0;
|
||
satrec.d5433 = 0.0;
|
||
satrec.dedt = 0.0;
|
||
satrec.del1 = 0.0;
|
||
satrec.del2 = 0.0;
|
||
satrec.del3 = 0.0;
|
||
satrec.didt = 0.0;
|
||
satrec.dmdt = 0.0;
|
||
satrec.dnodt = 0.0;
|
||
satrec.domdt = 0.0;
|
||
satrec.e3 = 0.0;
|
||
satrec.ee2 = 0.0;
|
||
satrec.peo = 0.0;
|
||
satrec.pgho = 0.0;
|
||
satrec.pho = 0.0;
|
||
satrec.pinco = 0.0;
|
||
satrec.plo = 0.0;
|
||
satrec.se2 = 0.0;
|
||
satrec.se3 = 0.0;
|
||
satrec.sgh2 = 0.0;
|
||
satrec.sgh3 = 0.0;
|
||
satrec.sgh4 = 0.0;
|
||
satrec.sh2 = 0.0;
|
||
satrec.sh3 = 0.0;
|
||
satrec.si2 = 0.0;
|
||
satrec.si3 = 0.0;
|
||
satrec.sl2 = 0.0;
|
||
satrec.sl3 = 0.0;
|
||
satrec.sl4 = 0.0;
|
||
satrec.gsto = 0.0;
|
||
satrec.xfact = 0.0;
|
||
satrec.xgh2 = 0.0;
|
||
satrec.xgh3 = 0.0;
|
||
satrec.xgh4 = 0.0;
|
||
satrec.xh2 = 0.0;
|
||
satrec.xh3 = 0.0;
|
||
satrec.xi2 = 0.0;
|
||
satrec.xi3 = 0.0;
|
||
satrec.xl2 = 0.0;
|
||
satrec.xl3 = 0.0;
|
||
satrec.xl4 = 0.0;
|
||
satrec.xlamo = 0.0;
|
||
satrec.zmol = 0.0;
|
||
satrec.zmos = 0.0;
|
||
satrec.atime = 0.0;
|
||
satrec.xli = 0.0;
|
||
satrec.xni = 0.0;
|
||
// sgp4fix - note the following variables are also passed directly via satrec.
|
||
// it is possible to streamline the sgp4init call by deleting the "x"
|
||
// variables, but the user would need to set the satrec.* values first. we
|
||
// include the additional assignments in case twoline2rv is not used.
|
||
satrec.bstar = xbstar;
|
||
satrec.ecco = xecco;
|
||
satrec.argpo = xargpo;
|
||
satrec.inclo = xinclo;
|
||
satrec.mo = xmo;
|
||
satrec.no = xno;
|
||
satrec.nodeo = xnodeo;
|
||
// sgp4fix add opsmode
|
||
satrec.operationmode = opsmode;
|
||
// ------------------------ earth constants -----------------------
|
||
// sgp4fix identify constants and allow alternate values
|
||
var ss = 78.0 / earthRadius + 1.0;
|
||
// sgp4fix use multiply for speed instead of pow
|
||
var qzms2ttemp = (120.0 - 78.0) / earthRadius;
|
||
var qzms2t = qzms2ttemp * qzms2ttemp * qzms2ttemp * qzms2ttemp;
|
||
satrec.init = 'y';
|
||
satrec.t = 0.0;
|
||
var initlOptions = {
|
||
satn: satn,
|
||
ecco: satrec.ecco,
|
||
epoch: epoch,
|
||
inclo: satrec.inclo,
|
||
no: satrec.no,
|
||
method: satrec.method,
|
||
opsmode: satrec.operationmode
|
||
};
|
||
var initlResult = initl(initlOptions);
|
||
var ao = initlResult.ao,
|
||
con42 = initlResult.con42,
|
||
cosio = initlResult.cosio,
|
||
cosio2 = initlResult.cosio2,
|
||
eccsq = initlResult.eccsq,
|
||
omeosq = initlResult.omeosq,
|
||
posq = initlResult.posq,
|
||
rp = initlResult.rp,
|
||
rteosq = initlResult.rteosq,
|
||
sinio = initlResult.sinio;
|
||
satrec.no = initlResult.no;
|
||
satrec.con41 = initlResult.con41;
|
||
satrec.gsto = initlResult.gsto;
|
||
satrec.a = Math.pow(satrec.no * tumin, -2.0 / 3.0);
|
||
satrec.alta = satrec.a * (1.0 + satrec.ecco) - 1.0;
|
||
satrec.altp = satrec.a * (1.0 - satrec.ecco) - 1.0;
|
||
satrec.error = 0;
|
||
// sgp4fix remove this check as it is unnecessary
|
||
// the mrt check in sgp4 handles decaying satellite cases even if the starting
|
||
// condition is below the surface of te earth
|
||
// if (rp < 1.0)
|
||
// {
|
||
// printf("// *** satn%d epoch elts sub-orbital ***\n", satn);
|
||
// satrec.error = 5;
|
||
// }
|
||
if (omeosq >= 0.0 || satrec.no >= 0.0) {
|
||
satrec.isimp = 0;
|
||
if (rp < 220.0 / earthRadius + 1.0) {
|
||
satrec.isimp = 1;
|
||
}
|
||
sfour = ss;
|
||
qzms24 = qzms2t;
|
||
perige = (rp - 1.0) * earthRadius;
|
||
// - for perigees below 156 km, s and qoms2t are altered -
|
||
if (perige < 156.0) {
|
||
sfour = perige - 78.0;
|
||
if (perige < 98.0) {
|
||
sfour = 20.0;
|
||
}
|
||
// sgp4fix use multiply for speed instead of pow
|
||
var qzms24temp = (120.0 - sfour) / earthRadius;
|
||
qzms24 = qzms24temp * qzms24temp * qzms24temp * qzms24temp;
|
||
sfour = sfour / earthRadius + 1.0;
|
||
}
|
||
pinvsq = 1.0 / posq;
|
||
tsi = 1.0 / (ao - sfour);
|
||
satrec.eta = ao * satrec.ecco * tsi;
|
||
etasq = satrec.eta * satrec.eta;
|
||
eeta = satrec.ecco * satrec.eta;
|
||
psisq = Math.abs(1.0 - etasq);
|
||
coef = qzms24 * Math.pow(tsi, 4.0);
|
||
coef1 = coef / Math.pow(psisq, 3.5);
|
||
cc2 = coef1 * satrec.no * (ao * (1.0 + 1.5 * etasq + eeta * (4.0 + etasq)) + 0.375 * j2 * tsi / psisq * satrec.con41 * (8.0 + 3.0 * etasq * (8.0 + etasq)));
|
||
satrec.cc1 = satrec.bstar * cc2;
|
||
cc3 = 0.0;
|
||
if (satrec.ecco > 1.0e-4) {
|
||
cc3 = -2.0 * coef * tsi * j3oj2 * satrec.no * sinio / satrec.ecco;
|
||
}
|
||
satrec.x1mth2 = 1.0 - cosio2;
|
||
satrec.cc4 = 2.0 * satrec.no * coef1 * ao * omeosq * (satrec.eta * (2.0 + 0.5 * etasq) + satrec.ecco * (0.5 + 2.0 * etasq) - j2 * tsi / (ao * psisq) * (-3.0 * satrec.con41 * (1.0 - 2.0 * eeta + etasq * (1.5 - 0.5 * eeta)) + 0.75 * satrec.x1mth2 * (2.0 * etasq - eeta * (1.0 + etasq)) * Math.cos(2.0 * satrec.argpo)));
|
||
satrec.cc5 = 2.0 * coef1 * ao * omeosq * (1.0 + 2.75 * (etasq + eeta) + eeta * etasq);
|
||
cosio4 = cosio2 * cosio2;
|
||
temp1 = 1.5 * j2 * pinvsq * satrec.no;
|
||
temp2 = 0.5 * temp1 * j2 * pinvsq;
|
||
temp3 = -0.46875 * j4 * pinvsq * pinvsq * satrec.no;
|
||
satrec.mdot = satrec.no + 0.5 * temp1 * rteosq * satrec.con41 + 0.0625 * temp2 * rteosq * (13.0 - 78.0 * cosio2 + 137.0 * cosio4);
|
||
satrec.argpdot = -0.5 * temp1 * con42 + 0.0625 * temp2 * (7.0 - 114.0 * cosio2 + 395.0 * cosio4) + temp3 * (3.0 - 36.0 * cosio2 + 49.0 * cosio4);
|
||
xhdot1 = -temp1 * cosio;
|
||
satrec.nodedot = xhdot1 + (0.5 * temp2 * (4.0 - 19.0 * cosio2) + 2.0 * temp3 * (3.0 - 7.0 * cosio2)) * cosio;
|
||
xpidot = satrec.argpdot + satrec.nodedot;
|
||
satrec.omgcof = satrec.bstar * cc3 * Math.cos(satrec.argpo);
|
||
satrec.xmcof = 0.0;
|
||
if (satrec.ecco > 1.0e-4) {
|
||
satrec.xmcof = -x2o3 * coef * satrec.bstar / eeta;
|
||
}
|
||
satrec.nodecf = 3.5 * omeosq * xhdot1 * satrec.cc1;
|
||
satrec.t2cof = 1.5 * satrec.cc1;
|
||
// sgp4fix for divide by zero with xinco = 180 deg
|
||
if (Math.abs(cosio + 1.0) > 1.5e-12) {
|
||
satrec.xlcof = -0.25 * j3oj2 * sinio * (3.0 + 5.0 * cosio) / (1.0 + cosio);
|
||
} else {
|
||
satrec.xlcof = -0.25 * j3oj2 * sinio * (3.0 + 5.0 * cosio) / temp4;
|
||
}
|
||
satrec.aycof = -0.5 * j3oj2 * sinio;
|
||
// sgp4fix use multiply for speed instead of pow
|
||
var delmotemp = 1.0 + satrec.eta * Math.cos(satrec.mo);
|
||
satrec.delmo = delmotemp * delmotemp * delmotemp;
|
||
satrec.sinmao = Math.sin(satrec.mo);
|
||
satrec.x7thm1 = 7.0 * cosio2 - 1.0;
|
||
// --------------- deep space initialization -------------
|
||
if (2 * pi / satrec.no >= 225.0) {
|
||
satrec.method = 'd';
|
||
satrec.isimp = 1;
|
||
tc = 0.0;
|
||
inclm = satrec.inclo;
|
||
var dscomOptions = {
|
||
epoch: epoch,
|
||
ep: satrec.ecco,
|
||
argpp: satrec.argpo,
|
||
tc: tc,
|
||
inclp: satrec.inclo,
|
||
nodep: satrec.nodeo,
|
||
np: satrec.no,
|
||
e3: satrec.e3,
|
||
ee2: satrec.ee2,
|
||
peo: satrec.peo,
|
||
pgho: satrec.pgho,
|
||
pho: satrec.pho,
|
||
pinco: satrec.pinco,
|
||
plo: satrec.plo,
|
||
se2: satrec.se2,
|
||
se3: satrec.se3,
|
||
sgh2: satrec.sgh2,
|
||
sgh3: satrec.sgh3,
|
||
sgh4: satrec.sgh4,
|
||
sh2: satrec.sh2,
|
||
sh3: satrec.sh3,
|
||
si2: satrec.si2,
|
||
si3: satrec.si3,
|
||
sl2: satrec.sl2,
|
||
sl3: satrec.sl3,
|
||
sl4: satrec.sl4,
|
||
xgh2: satrec.xgh2,
|
||
xgh3: satrec.xgh3,
|
||
xgh4: satrec.xgh4,
|
||
xh2: satrec.xh2,
|
||
xh3: satrec.xh3,
|
||
xi2: satrec.xi2,
|
||
xi3: satrec.xi3,
|
||
xl2: satrec.xl2,
|
||
xl3: satrec.xl3,
|
||
xl4: satrec.xl4,
|
||
zmol: satrec.zmol,
|
||
zmos: satrec.zmos
|
||
};
|
||
var dscomResult = dscom(dscomOptions);
|
||
satrec.e3 = dscomResult.e3;
|
||
satrec.ee2 = dscomResult.ee2;
|
||
satrec.peo = dscomResult.peo;
|
||
satrec.pgho = dscomResult.pgho;
|
||
satrec.pho = dscomResult.pho;
|
||
satrec.pinco = dscomResult.pinco;
|
||
satrec.plo = dscomResult.plo;
|
||
satrec.se2 = dscomResult.se2;
|
||
satrec.se3 = dscomResult.se3;
|
||
satrec.sgh2 = dscomResult.sgh2;
|
||
satrec.sgh3 = dscomResult.sgh3;
|
||
satrec.sgh4 = dscomResult.sgh4;
|
||
satrec.sh2 = dscomResult.sh2;
|
||
satrec.sh3 = dscomResult.sh3;
|
||
satrec.si2 = dscomResult.si2;
|
||
satrec.si3 = dscomResult.si3;
|
||
satrec.sl2 = dscomResult.sl2;
|
||
satrec.sl3 = dscomResult.sl3;
|
||
satrec.sl4 = dscomResult.sl4;
|
||
sinim = dscomResult.sinim;
|
||
cosim = dscomResult.cosim;
|
||
em = dscomResult.em;
|
||
emsq = dscomResult.emsq;
|
||
s1 = dscomResult.s1;
|
||
s2 = dscomResult.s2;
|
||
s3 = dscomResult.s3;
|
||
s4 = dscomResult.s4;
|
||
s5 = dscomResult.s5;
|
||
ss1 = dscomResult.ss1;
|
||
ss2 = dscomResult.ss2;
|
||
ss3 = dscomResult.ss3;
|
||
ss4 = dscomResult.ss4;
|
||
ss5 = dscomResult.ss5;
|
||
sz1 = dscomResult.sz1;
|
||
sz3 = dscomResult.sz3;
|
||
sz11 = dscomResult.sz11;
|
||
sz13 = dscomResult.sz13;
|
||
sz21 = dscomResult.sz21;
|
||
sz23 = dscomResult.sz23;
|
||
sz31 = dscomResult.sz31;
|
||
sz33 = dscomResult.sz33;
|
||
satrec.xgh2 = dscomResult.xgh2;
|
||
satrec.xgh3 = dscomResult.xgh3;
|
||
satrec.xgh4 = dscomResult.xgh4;
|
||
satrec.xh2 = dscomResult.xh2;
|
||
satrec.xh3 = dscomResult.xh3;
|
||
satrec.xi2 = dscomResult.xi2;
|
||
satrec.xi3 = dscomResult.xi3;
|
||
satrec.xl2 = dscomResult.xl2;
|
||
satrec.xl3 = dscomResult.xl3;
|
||
satrec.xl4 = dscomResult.xl4;
|
||
satrec.zmol = dscomResult.zmol;
|
||
satrec.zmos = dscomResult.zmos;
|
||
nm = dscomResult.nm;
|
||
z1 = dscomResult.z1;
|
||
z3 = dscomResult.z3;
|
||
z11 = dscomResult.z11;
|
||
z13 = dscomResult.z13;
|
||
z21 = dscomResult.z21;
|
||
z23 = dscomResult.z23;
|
||
z31 = dscomResult.z31;
|
||
z33 = dscomResult.z33;
|
||
var dpperOptions = {
|
||
inclo: inclm,
|
||
init: satrec.init,
|
||
ep: satrec.ecco,
|
||
inclp: satrec.inclo,
|
||
nodep: satrec.nodeo,
|
||
argpp: satrec.argpo,
|
||
mp: satrec.mo,
|
||
opsmode: satrec.operationmode
|
||
};
|
||
var dpperResult = dpper(satrec, dpperOptions);
|
||
satrec.ecco = dpperResult.ep;
|
||
satrec.inclo = dpperResult.inclp;
|
||
satrec.nodeo = dpperResult.nodep;
|
||
satrec.argpo = dpperResult.argpp;
|
||
satrec.mo = dpperResult.mp;
|
||
argpm = 0.0;
|
||
nodem = 0.0;
|
||
mm = 0.0;
|
||
var dsinitOptions = {
|
||
cosim: cosim,
|
||
emsq: emsq,
|
||
argpo: satrec.argpo,
|
||
s1: s1,
|
||
s2: s2,
|
||
s3: s3,
|
||
s4: s4,
|
||
s5: s5,
|
||
sinim: sinim,
|
||
ss1: ss1,
|
||
ss2: ss2,
|
||
ss3: ss3,
|
||
ss4: ss4,
|
||
ss5: ss5,
|
||
sz1: sz1,
|
||
sz3: sz3,
|
||
sz11: sz11,
|
||
sz13: sz13,
|
||
sz21: sz21,
|
||
sz23: sz23,
|
||
sz31: sz31,
|
||
sz33: sz33,
|
||
t: satrec.t,
|
||
tc: tc,
|
||
gsto: satrec.gsto,
|
||
mo: satrec.mo,
|
||
mdot: satrec.mdot,
|
||
no: satrec.no,
|
||
nodeo: satrec.nodeo,
|
||
nodedot: satrec.nodedot,
|
||
xpidot: xpidot,
|
||
z1: z1,
|
||
z3: z3,
|
||
z11: z11,
|
||
z13: z13,
|
||
z21: z21,
|
||
z23: z23,
|
||
z31: z31,
|
||
z33: z33,
|
||
ecco: satrec.ecco,
|
||
eccsq: eccsq,
|
||
em: em,
|
||
argpm: argpm,
|
||
inclm: inclm,
|
||
mm: mm,
|
||
nm: nm,
|
||
nodem: nodem,
|
||
irez: satrec.irez,
|
||
atime: satrec.atime,
|
||
d2201: satrec.d2201,
|
||
d2211: satrec.d2211,
|
||
d3210: satrec.d3210,
|
||
d3222: satrec.d3222,
|
||
d4410: satrec.d4410,
|
||
d4422: satrec.d4422,
|
||
d5220: satrec.d5220,
|
||
d5232: satrec.d5232,
|
||
d5421: satrec.d5421,
|
||
d5433: satrec.d5433,
|
||
dedt: satrec.dedt,
|
||
didt: satrec.didt,
|
||
dmdt: satrec.dmdt,
|
||
dnodt: satrec.dnodt,
|
||
domdt: satrec.domdt,
|
||
del1: satrec.del1,
|
||
del2: satrec.del2,
|
||
del3: satrec.del3,
|
||
xfact: satrec.xfact,
|
||
xlamo: satrec.xlamo,
|
||
xli: satrec.xli,
|
||
xni: satrec.xni
|
||
};
|
||
var dsinitResult = dsinit(dsinitOptions);
|
||
satrec.irez = dsinitResult.irez;
|
||
satrec.atime = dsinitResult.atime;
|
||
satrec.d2201 = dsinitResult.d2201;
|
||
satrec.d2211 = dsinitResult.d2211;
|
||
satrec.d3210 = dsinitResult.d3210;
|
||
satrec.d3222 = dsinitResult.d3222;
|
||
satrec.d4410 = dsinitResult.d4410;
|
||
satrec.d4422 = dsinitResult.d4422;
|
||
satrec.d5220 = dsinitResult.d5220;
|
||
satrec.d5232 = dsinitResult.d5232;
|
||
satrec.d5421 = dsinitResult.d5421;
|
||
satrec.d5433 = dsinitResult.d5433;
|
||
satrec.dedt = dsinitResult.dedt;
|
||
satrec.didt = dsinitResult.didt;
|
||
satrec.dmdt = dsinitResult.dmdt;
|
||
satrec.dnodt = dsinitResult.dnodt;
|
||
satrec.domdt = dsinitResult.domdt;
|
||
satrec.del1 = dsinitResult.del1;
|
||
satrec.del2 = dsinitResult.del2;
|
||
satrec.del3 = dsinitResult.del3;
|
||
satrec.xfact = dsinitResult.xfact;
|
||
satrec.xlamo = dsinitResult.xlamo;
|
||
satrec.xli = dsinitResult.xli;
|
||
satrec.xni = dsinitResult.xni;
|
||
}
|
||
// ----------- set variables if not deep space -----------
|
||
if (satrec.isimp !== 1) {
|
||
cc1sq = satrec.cc1 * satrec.cc1;
|
||
satrec.d2 = 4.0 * ao * tsi * cc1sq;
|
||
temp = satrec.d2 * tsi * satrec.cc1 / 3.0;
|
||
satrec.d3 = (17.0 * ao + sfour) * temp;
|
||
satrec.d4 = 0.5 * temp * ao * tsi * (221.0 * ao + 31.0 * sfour) * satrec.cc1;
|
||
satrec.t3cof = satrec.d2 + 2.0 * cc1sq;
|
||
satrec.t4cof = 0.25 * (3.0 * satrec.d3 + satrec.cc1 * (12.0 * satrec.d2 + 10.0 * cc1sq));
|
||
satrec.t5cof = 0.2 * (3.0 * satrec.d4 + 12.0 * satrec.cc1 * satrec.d3 + 6.0 * satrec.d2 * satrec.d2 + 15.0 * cc1sq * (2.0 * satrec.d2 + cc1sq));
|
||
}
|
||
/* finally propogate to zero epoch to initialize all others. */
|
||
// sgp4fix take out check to let satellites process until they are actually below earth surface
|
||
// if(satrec.error == 0)
|
||
}
|
||
sgp4(satrec, 0);
|
||
satrec.init = 'n';
|
||
}
|
||
|
||
/* -----------------------------------------------------------------------------
|
||
*
|
||
* function twoline2satrec
|
||
*
|
||
* this function converts the two line element set character string data to
|
||
* variables and initializes the sgp4 variables. several intermediate varaibles
|
||
* and quantities are determined. note that the result is a structure so multiple
|
||
* satellites can be processed simultaneously without having to reinitialize. the
|
||
* verification mode is an important option that permits quick checks of any
|
||
* changes to the underlying technical theory. this option works using a
|
||
* modified tle file in which the start, stop, and delta time values are
|
||
* included at the end of the second line of data. this only works with the
|
||
* verification mode. the catalog mode simply propagates from -1440 to 1440 min
|
||
* from epoch and is useful when performing entire catalog runs.
|
||
*
|
||
* author : david vallado 719-573-2600 1 mar 2001
|
||
*
|
||
* inputs :
|
||
* longstr1 - first line of the tle
|
||
* longstr2 - second line of the tle
|
||
* typerun - type of run verification 'v', catalog 'c',
|
||
* manual 'm'
|
||
* typeinput - type of manual input mfe 'm', epoch 'e', dayofyr 'd'
|
||
* opsmode - mode of operation afspc or improved 'a', 'i'
|
||
* whichconst - which set of constants to use 72, 84
|
||
*
|
||
* outputs :
|
||
* satrec - structure containing all the sgp4 satellite information
|
||
*
|
||
* coupling :
|
||
* getgravconst-
|
||
* days2mdhms - conversion of days to month, day, hour, minute, second
|
||
* jday - convert day month year hour minute second into julian date
|
||
* sgp4init - initialize the sgp4 variables
|
||
*
|
||
* references :
|
||
* norad spacetrack report #3
|
||
* vallado, crawford, hujsak, kelso 2006
|
||
--------------------------------------------------------------------------- */
|
||
/**
|
||
* Return a Satellite imported from two lines of TLE data.
|
||
*
|
||
* Provide the two TLE lines as strings `tleLine1` and `tleLine2`,
|
||
* and select which standard set of gravitational constants you want
|
||
* by providing `gravity_constants`:
|
||
*
|
||
* `sgp4.propagation.wgs72` - Standard WGS 72 model
|
||
* `sgp4.propagation.wgs84` - More recent WGS 84 model
|
||
* `sgp4.propagation.wgs72old` - Legacy support for old SGP4 behavior
|
||
*
|
||
* Normally, computations are made using letious recent improvements
|
||
* to the algorithm. If you want to turn some of these off and go
|
||
* back into "afspc" mode, then set `afspc_mode` to `True`.
|
||
*/
|
||
function twoline2satrec(longstr1, longstr2) {
|
||
var opsmode = 'i';
|
||
var error = 0;
|
||
var satnum = longstr1.substring(2, 7);
|
||
var epochyr = parseInt(longstr1.substring(18, 20), 10);
|
||
var epochdays = parseFloat(longstr1.substring(20, 32));
|
||
var ndot = parseFloat(longstr1.substring(33, 43));
|
||
var nddot = parseFloat("".concat(longstr1.substring(44, 45), ".").concat(longstr1.substring(45, 50), "E").concat(longstr1.substring(50, 52)));
|
||
var bstar = parseFloat("".concat(longstr1.substring(53, 54), ".").concat(longstr1.substring(54, 59), "E").concat(longstr1.substring(59, 61)));
|
||
// satrec.satnum = longstr2.substring(2, 7);
|
||
// ---- find standard orbital elements ----
|
||
var inclo = parseFloat(longstr2.substring(8, 16)) * deg2rad;
|
||
var nodeo = parseFloat(longstr2.substring(17, 25)) * deg2rad;
|
||
var ecco = parseFloat(".".concat(longstr2.substring(26, 33).replace(/\s/g, '0')));
|
||
var argpo = parseFloat(longstr2.substring(34, 42)) * deg2rad;
|
||
var mo = parseFloat(longstr2.substring(43, 51)) * deg2rad;
|
||
// ---- find no, ndot, nddot ----
|
||
var no = parseFloat(longstr2.substring(52, 63)) / xpdotp;
|
||
// satrec.nddot= satrec.nddot * Math.pow(10.0, nexp);
|
||
// satrec.bstar= satrec.bstar * Math.pow(10.0, ibexp);
|
||
// ---- convert to sgp4 units ----
|
||
// satrec.ndot /= (xpdotp * 1440.0); // ? * minperday
|
||
// satrec.nddot /= (xpdotp * 1440.0 * 1440);
|
||
// ----------------------------------------------------------------
|
||
// find sgp4epoch time of element set
|
||
// remember that sgp4 uses units of days from 0 jan 1950 (sgp4epoch)
|
||
// and minutes from the epoch (time)
|
||
// ----------------------------------------------------------------
|
||
// ---------------- temp fix for years from 1957-2056 -------------------
|
||
// --------- correct fix will occur when year is 4-digit in tle ---------
|
||
var year = epochyr < 57 ? epochyr + 2000 : epochyr + 1900;
|
||
var mdhmsResult = days2mdhms(year, epochdays);
|
||
var mon = mdhmsResult.mon,
|
||
day = mdhmsResult.day,
|
||
hr = mdhmsResult.hr,
|
||
minute = mdhmsResult.minute,
|
||
sec = mdhmsResult.sec;
|
||
var jdsatepoch = jday(year, mon, day, hr, minute, sec);
|
||
var satrec = {
|
||
error: error,
|
||
satnum: satnum,
|
||
epochyr: epochyr,
|
||
epochdays: epochdays,
|
||
ndot: ndot,
|
||
nddot: nddot,
|
||
bstar: bstar,
|
||
inclo: inclo,
|
||
nodeo: nodeo,
|
||
ecco: ecco,
|
||
argpo: argpo,
|
||
mo: mo,
|
||
no: no,
|
||
jdsatepoch: jdsatepoch
|
||
};
|
||
// ---------------- initialize the orbit at sgp4epoch -------------------
|
||
sgp4init(satrec, {
|
||
opsmode: opsmode,
|
||
satn: satrec.satnum,
|
||
epoch: satrec.jdsatepoch - 2433281.5,
|
||
xbstar: satrec.bstar,
|
||
xecco: satrec.ecco,
|
||
xargpo: satrec.argpo,
|
||
xinclo: satrec.inclo,
|
||
xmo: satrec.mo,
|
||
xno: satrec.no,
|
||
xnodeo: satrec.nodeo
|
||
});
|
||
return satrec;
|
||
}
|
||
/* -----------------------------------------------------------------------------
|
||
*
|
||
* function json2satrec
|
||
*
|
||
* this function converts the OMM json data to variables and initializes the sgp4
|
||
* variables. several intermediate varaibles and quantities are determined. note
|
||
* that the result is a structure so multiple satellites can be processed
|
||
* simultaneously without having to reinitialize. the verification mode is an
|
||
* important option that permits quick checks of any changes to the underlying
|
||
* technical theory. this option works using a modified tle file in which the
|
||
* start, stop, and delta time values are included at the end of the second line
|
||
* of data. this only works with the verification mode. the catalog mode simply
|
||
* propagates from -1440 to 1440 min from epoch and is useful when performing
|
||
* entire catalog runs.
|
||
*
|
||
* author : Hariharan Vitaladevuni 18 Aug 2023
|
||
* Theodore Kruczek 19 Aug 2023
|
||
*
|
||
* inputs :
|
||
* jsonobj - OMM json data
|
||
* opsmode - mode of operation afspc or improved 'a', 'i'. Default: 'i'.
|
||
*
|
||
* outputs :
|
||
* satrec - structure containing all the sgp4 satellite information
|
||
*
|
||
* coupling :
|
||
* days2mdhms - conversion of days to month, day, hour, minute, second
|
||
* jday - convert day month year hour minute second into julian date
|
||
* sgp4init - initialize the sgp4 variables
|
||
*
|
||
* warning : the epoch date in OMM format is more accurate than TLE format!
|
||
* this will result in extremely close, but different
|
||
* position/velocity values. Depending on your use case, it may
|
||
* be better to use twoline2satrec, but for the average user this
|
||
* will provide comparable results.
|
||
*
|
||
* references :
|
||
* https://celestrak.org/NORAD/documentation/gp-data-formats.php
|
||
--------------------------------------------------------------------------- */
|
||
function json2satrec(jsonobj) {
|
||
var opsmode = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 'i';
|
||
var error = 0;
|
||
var satnum = jsonobj.NORAD_CAT_ID.toString();
|
||
var epoch = new Date(jsonobj.EPOCH.endsWith('Z') ? jsonobj.EPOCH : jsonobj.EPOCH + 'Z');
|
||
var year = epoch.getUTCFullYear();
|
||
var epochyr = Number(year.toString().slice(-2));
|
||
var epochdays = (epoch.valueOf() - new Date(Date.UTC(year, 0, 1, 0, 0, 0)).valueOf()) / (86400 * 1000) + 1;
|
||
var ndot = Number(jsonobj.MEAN_MOTION_DOT);
|
||
var nddot = Number(jsonobj.MEAN_MOTION_DDOT);
|
||
var bstar = Number(jsonobj.BSTAR);
|
||
var inclo = Number(jsonobj.INCLINATION) * deg2rad;
|
||
var nodeo = Number(jsonobj.RA_OF_ASC_NODE) * deg2rad;
|
||
var ecco = Number(jsonobj.ECCENTRICITY);
|
||
var argpo = Number(jsonobj.ARG_OF_PERICENTER) * deg2rad;
|
||
var mo = Number(jsonobj.MEAN_ANOMALY) * deg2rad;
|
||
var no = Number(jsonobj.MEAN_MOTION) / xpdotp;
|
||
// ----------------------------------------------------------------
|
||
// find sgp4epoch time of element set
|
||
// remember that sgp4 uses units of days from 0 jan 1950 (sgp4epoch)
|
||
// and minutes from the epoch (time)
|
||
// ----------------------------------------------------------------
|
||
var mdhmsResult = days2mdhms(year, epochdays);
|
||
var mon = mdhmsResult.mon,
|
||
day = mdhmsResult.day,
|
||
hr = mdhmsResult.hr,
|
||
minute = mdhmsResult.minute,
|
||
sec = mdhmsResult.sec;
|
||
var jdsatepoch = jday(year, mon, day, hr, minute, sec);
|
||
var satrec = {
|
||
error: error,
|
||
satnum: satnum,
|
||
epochyr: epochyr,
|
||
epochdays: epochdays,
|
||
ndot: ndot,
|
||
nddot: nddot,
|
||
bstar: bstar,
|
||
inclo: inclo,
|
||
nodeo: nodeo,
|
||
ecco: ecco,
|
||
argpo: argpo,
|
||
mo: mo,
|
||
no: no,
|
||
jdsatepoch: jdsatepoch
|
||
};
|
||
// ---------------- initialize the orbit at sgp4epoch -------------------
|
||
sgp4init(satrec, {
|
||
opsmode: opsmode,
|
||
satn: satrec.satnum,
|
||
epoch: satrec.jdsatepoch - 2433281.5,
|
||
xbstar: satrec.bstar,
|
||
xecco: satrec.ecco,
|
||
xargpo: satrec.argpo,
|
||
xinclo: satrec.inclo,
|
||
xmo: satrec.mo,
|
||
xno: satrec.no,
|
||
xnodeo: satrec.nodeo
|
||
});
|
||
return satrec;
|
||
}
|
||
|
||
function propagate(satrec) {
|
||
for (var _len = arguments.length, jdayArgs = new Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
|
||
jdayArgs[_key - 1] = arguments[_key];
|
||
}
|
||
// Return a position and velocity vector for a given date and time.
|
||
var j = jday.apply(void 0, jdayArgs);
|
||
var m = (j - satrec.jdsatepoch) * minutesPerDay;
|
||
return sgp4(satrec, m);
|
||
}
|
||
|
||
var earthRotation = 7.292115E-5;
|
||
var c = 299792.458; // Speed of light in km/s
|
||
/**
|
||
* Negative range rate means the satellite is moving towards the observer and
|
||
* its frequency is shifted higher because 1 minus a negative range rate is
|
||
* positive. If the range rate is positive, the satellite is moving away from
|
||
* the observer and its frequency is shifted lower.
|
||
*/
|
||
function dopplerFactor(observerCoordsEcf, positionEcf, velocityEcf) {
|
||
var rangeX = positionEcf.x - observerCoordsEcf.x;
|
||
var rangeY = positionEcf.y - observerCoordsEcf.y;
|
||
var rangeZ = positionEcf.z - observerCoordsEcf.z;
|
||
var length = Math.sqrt(Math.pow(rangeX, 2) + Math.pow(rangeY, 2) + Math.pow(rangeZ, 2));
|
||
var rangeVel = {
|
||
x: velocityEcf.x + earthRotation * observerCoordsEcf.y,
|
||
y: velocityEcf.y - earthRotation * observerCoordsEcf.x,
|
||
z: velocityEcf.z
|
||
};
|
||
var rangeRate = (rangeX * rangeVel.x + rangeY * rangeVel.y + rangeZ * rangeVel.z) / length;
|
||
return 1 - rangeRate / c;
|
||
}
|
||
|
||
function radiansToDegrees(radians) {
|
||
return radians * rad2deg;
|
||
}
|
||
function degreesToRadians(degrees) {
|
||
return degrees * deg2rad;
|
||
}
|
||
function degreesLat(radians) {
|
||
if (radians < -pi / 2 || radians > pi / 2) {
|
||
throw new RangeError('Latitude radians must be in range [-pi/2; pi/2].');
|
||
}
|
||
return radiansToDegrees(radians);
|
||
}
|
||
function degreesLong(radians) {
|
||
if (radians < -pi || radians > pi) {
|
||
throw new RangeError('Longitude radians must be in range [-pi; pi].');
|
||
}
|
||
return radiansToDegrees(radians);
|
||
}
|
||
function radiansLat(degrees) {
|
||
if (degrees < -90 || degrees > 90) {
|
||
throw new RangeError('Latitude degrees must be in range [-90; 90].');
|
||
}
|
||
return degreesToRadians(degrees);
|
||
}
|
||
function radiansLong(degrees) {
|
||
if (degrees < -180 || degrees > 180) {
|
||
throw new RangeError('Longitude degrees must be in range [-180; 180].');
|
||
}
|
||
return degreesToRadians(degrees);
|
||
}
|
||
function geodeticToEcf(_ref) {
|
||
var longitude = _ref.longitude,
|
||
latitude = _ref.latitude,
|
||
height = _ref.height;
|
||
var a = 6378.137;
|
||
var b = 6356.7523142;
|
||
var f = (a - b) / a;
|
||
var e2 = 2 * f - f * f;
|
||
var normal = a / Math.sqrt(1 - e2 * (Math.sin(latitude) * Math.sin(latitude)));
|
||
var x = (normal + height) * Math.cos(latitude) * Math.cos(longitude);
|
||
var y = (normal + height) * Math.cos(latitude) * Math.sin(longitude);
|
||
var z = (normal * (1 - e2) + height) * Math.sin(latitude);
|
||
return {
|
||
x: x,
|
||
y: y,
|
||
z: z
|
||
};
|
||
}
|
||
function eciToGeodetic(eci, gmst) {
|
||
// http://www.celestrak.com/columns/v02n03/
|
||
var a = 6378.137;
|
||
var b = 6356.7523142;
|
||
var R = Math.sqrt(eci.x * eci.x + eci.y * eci.y);
|
||
var f = (a - b) / a;
|
||
var e2 = 2 * f - f * f;
|
||
var longitude = Math.atan2(eci.y, eci.x) - gmst;
|
||
while (longitude < -pi) {
|
||
longitude += twoPi;
|
||
}
|
||
while (longitude > pi) {
|
||
longitude -= twoPi;
|
||
}
|
||
var kmax = 20;
|
||
var k = 0;
|
||
var latitude = Math.atan2(eci.z, Math.sqrt(eci.x * eci.x + eci.y * eci.y));
|
||
var C;
|
||
while (k++ < kmax) {
|
||
C = 1 / Math.sqrt(1 - e2 * (Math.sin(latitude) * Math.sin(latitude)));
|
||
latitude = Math.atan2(eci.z + a * C * e2 * Math.sin(latitude), R);
|
||
}
|
||
var height = R / Math.cos(latitude) - a * C;
|
||
return {
|
||
longitude: longitude,
|
||
latitude: latitude,
|
||
height: height
|
||
};
|
||
}
|
||
function ecfToEci(ecf, gmst) {
|
||
// ccar.colorado.edu/ASEN5070/handouts/coordsys.doc
|
||
//
|
||
// [X] [C -S 0][X]
|
||
// [Y] = [S C 0][Y]
|
||
// [Z]eci [0 0 1][Z]ecf
|
||
//
|
||
var X = ecf.x * Math.cos(gmst) - ecf.y * Math.sin(gmst);
|
||
var Y = ecf.x * Math.sin(gmst) + ecf.y * Math.cos(gmst);
|
||
var Z = ecf.z;
|
||
return {
|
||
x: X,
|
||
y: Y,
|
||
z: Z
|
||
};
|
||
}
|
||
function eciToEcf(eci, gmst) {
|
||
// ccar.colorado.edu/ASEN5070/handouts/coordsys.doc
|
||
//
|
||
// [X] [C -S 0][X]
|
||
// [Y] = [S C 0][Y]
|
||
// [Z]eci [0 0 1][Z]ecf
|
||
//
|
||
//
|
||
// Inverse:
|
||
// [X] [C S 0][X]
|
||
// [Y] = [-S C 0][Y]
|
||
// [Z]ecf [0 0 1][Z]eci
|
||
var x = eci.x * Math.cos(gmst) + eci.y * Math.sin(gmst);
|
||
var y = eci.x * -Math.sin(gmst) + eci.y * Math.cos(gmst);
|
||
var z = eci.z;
|
||
return {
|
||
x: x,
|
||
y: y,
|
||
z: z
|
||
};
|
||
}
|
||
function topocentric(observerGeodetic, satelliteEcf) {
|
||
// http://www.celestrak.com/columns/v02n02/
|
||
// TS Kelso's method, except I'm using ECF frame
|
||
// and he uses ECI.
|
||
var longitude = observerGeodetic.longitude,
|
||
latitude = observerGeodetic.latitude;
|
||
var observerEcf = geodeticToEcf(observerGeodetic);
|
||
var rx = satelliteEcf.x - observerEcf.x;
|
||
var ry = satelliteEcf.y - observerEcf.y;
|
||
var rz = satelliteEcf.z - observerEcf.z;
|
||
var topS = Math.sin(latitude) * Math.cos(longitude) * rx + Math.sin(latitude) * Math.sin(longitude) * ry - Math.cos(latitude) * rz;
|
||
var topE = -Math.sin(longitude) * rx + Math.cos(longitude) * ry;
|
||
var topZ = Math.cos(latitude) * Math.cos(longitude) * rx + Math.cos(latitude) * Math.sin(longitude) * ry + Math.sin(latitude) * rz;
|
||
return {
|
||
topS: topS,
|
||
topE: topE,
|
||
topZ: topZ
|
||
};
|
||
}
|
||
function topocentricToLookAngles(tc) {
|
||
var topS = tc.topS,
|
||
topE = tc.topE,
|
||
topZ = tc.topZ;
|
||
var rangeSat = Math.sqrt(topS * topS + topE * topE + topZ * topZ);
|
||
var El = Math.asin(topZ / rangeSat);
|
||
var Az = Math.atan2(-topE, topS) + pi;
|
||
return {
|
||
azimuth: Az,
|
||
elevation: El,
|
||
rangeSat: rangeSat // Range in km
|
||
};
|
||
}
|
||
function ecfToLookAngles(observerGeodetic, satelliteEcf) {
|
||
var topocentricCoords = topocentric(observerGeodetic, satelliteEcf);
|
||
return topocentricToLookAngles(topocentricCoords);
|
||
}
|
||
|
||
////////////////////////////////////////////////////////////////////////////////////
|
||
/* Line by Line MATLAB-to-Javascript conversion of "sun.mat" from Vallado package */
|
||
////////////////////////////////////////////////////////////////////////////////////
|
||
/* -----------------------------------------------------------------------------
|
||
*
|
||
* function sunPos
|
||
*
|
||
* this function calculates the geocentric equatorial position vector
|
||
* the sun given the julian date. this is the low precision formula and
|
||
* is valid for years from 1950 to 2050. accuaracy of apparent coordinates
|
||
* is 0.01 degrees. notice many of the calculations are performed in
|
||
* degrees, and are not changed until later. this is due to the fact that
|
||
* the almanac uses degrees exclusively in their formulations.
|
||
*
|
||
* author : david vallado 719-573-2600 1 mar 2001
|
||
*
|
||
* inputs description range / units
|
||
* jd - julian date days from 4713 bc
|
||
*
|
||
* outputs :
|
||
* rsun - ijk position vector of the sun au
|
||
* rtasc - right ascension rad
|
||
* decl - declination rad
|
||
*
|
||
* coupling :
|
||
* -
|
||
*
|
||
* references :
|
||
* VALLADO, DAVID A. (2022) ‘Computer software in MATLAB’, in Fundamentals of astrodynamics and applications. 5th edn.
|
||
* Computer software in MATLAB: http://celestrak.org/software/vallado-sw.php
|
||
* --------------------------------------------------------------------------- */
|
||
function sunPos(jday) {
|
||
// ------------------------- implementation -----------------
|
||
// ------------------- initialize values --------------------
|
||
var tut1 = (jday - 2451545) / 36525;
|
||
var meanlong = (280.460 + 36000.77 * tut1) % 360; //deg
|
||
var ttdb = tut1; // is this declaration required instead of replacing `ttdb` with `tut1`
|
||
var meananomaly = (357.5277233 + 35999.05034 * ttdb * deg2rad) % twoPi; //rad
|
||
if (meananomaly < 0) {
|
||
meananomaly += twoPi;
|
||
}
|
||
var eclplong_raw = (meanlong + 1.914666471 * Math.sin(meananomaly) + 0.019994643 * Math.sin(2.0 * meananomaly)) % 360.0 * deg2rad; //rad
|
||
var obliquity = (23.439291 - 0.0130042 * ttdb) * deg2rad; //rad
|
||
// --------- find magnitude of sun vector, and it's components ------
|
||
var magr = 1.000140612 - 0.016708617 * Math.cos(meananomaly) - 0.000139589 * Math.cos(2.0 * meananomaly); // in au's
|
||
var rsun = [magr * Math.cos(eclplong_raw), magr * Math.cos(obliquity) * Math.sin(eclplong_raw), magr * Math.sin(obliquity) * Math.sin(eclplong_raw)];
|
||
var rtasc_raw = Math.atan(Math.cos(obliquity) * Math.tan(eclplong_raw));
|
||
var rtasc = rtasc_raw;
|
||
if (Math.abs(eclplong_raw - rtasc) > pi * 0.5) {
|
||
rtasc += 0.5 * pi * Math.round((eclplong_raw - rtasc_raw) / (0.5 * pi));
|
||
}
|
||
var decl = Math.asin(Math.sin(obliquity) * Math.sin(eclplong_raw));
|
||
return {
|
||
rsun: rsun,
|
||
rtasc: rtasc,
|
||
decl: decl
|
||
};
|
||
}
|
||
/* Original MATLAB code for Sun position from Vallado package (sun.mat) */
|
||
/*
|
||
function [rsun,rtasc,decl] = sun ( jd );
|
||
|
||
twopi = 2.0*pi;
|
||
deg2rad = pi/180.0;
|
||
show = 'n';
|
||
|
||
% ------------------------- implementation -----------------
|
||
% ------------------- initialize values --------------------
|
||
tut1= ( jd - 2451545.0 )/ 36525.0;
|
||
|
||
if show == 'y'
|
||
fprintf(1,'tut1 %14.9f \n',tut1);
|
||
end
|
||
|
||
meanlong= 280.460 + 36000.77*tut1;
|
||
meanlong= rem( meanlong,360.0 ); %deg
|
||
|
||
ttdb= tut1;
|
||
meananomaly= 357.5277233 + 35999.05034 *ttdb;
|
||
meananomaly= rem( meananomaly*deg2rad,twopi ); %rad
|
||
if ( meananomaly < 0.0 )
|
||
meananomaly= twopi + meananomaly;
|
||
end
|
||
|
||
eclplong_raw= meanlong + 1.914666471 *sin(meananomaly) ...
|
||
+ 0.019994643 *sin(2.0 *meananomaly); %deg
|
||
eclplong_raw= rem( eclplong_raw,360.0 ); %deg
|
||
|
||
obliquity= 23.439291 - 0.0130042 *ttdb; %deg
|
||
|
||
eclplong_raw = eclplong_raw *deg2rad;
|
||
obliquity= obliquity *deg2rad;
|
||
|
||
% --------- find magnitude of sun vector, ) components ------
|
||
magr= 1.000140612 - 0.016708617 *cos( meananomaly ) ...
|
||
- 0.000139589 *cos( 2.0 *meananomaly ); % in au's
|
||
|
||
rsun(1)= magr*cos( eclplong_raw );
|
||
rsun(2)= magr*cos(obliquity)*sin(eclplong_raw);
|
||
rsun(3)= magr*sin(obliquity)*sin(eclplong_raw);
|
||
|
||
if show == 'y'
|
||
fprintf(1,'meanlon %11.6f meanan %11.6f eclplon %11.6f obli %11.6f \n', ...
|
||
meanlong,meananomaly/deg2rad,eclplong_raw/deg2rad,obliquity/deg2rad);
|
||
fprintf(1,'rs %11.9f %11.9f %11.9f \n',rsun);
|
||
fprintf(1,'magr %14.7f \n',magr);
|
||
end
|
||
|
||
rtasc= atan( cos(obliquity)*tan(eclplong_raw) );
|
||
|
||
% --- check that rtasc is in the same quadrant as eclplong_raw ----
|
||
if ( eclplong_raw < 0.0 )
|
||
eclplong_raw= eclplong_raw + twopi; % make sure it's in 0 to 2pi range
|
||
end
|
||
if ( abs( eclplong_raw-rtasc ) > pi*0.5 )
|
||
rtasc= rtasc + 0.5 *pi*round( (eclplong_raw-rtasc)/(0.5 *pi));
|
||
end
|
||
decl = asin( sin(obliquity)*sin(eclplong_raw) );
|
||
*/
|
||
|
||
export { SatRecError, constants, degreesLat, degreesLong, degreesToRadians, dopplerFactor, ecfToEci, ecfToLookAngles, eciToEcf, eciToGeodetic, geodeticToEcf, gstime, invjday, jday, json2satrec, propagate, radiansLat, radiansLong, radiansToDegrees, sgp4, sunPos, twoline2satrec };
|