/*!
* satellite-js v3.0.1
* (c) 2013 Shashwat Kandadai and UCSC
* https://github.com/shashwatak/satellite-js
* License: MIT
*/
var pi = Math.PI;
var twoPi = pi * 2;
var deg2rad = pi / 180.0;
var rad2deg = 180 / pi;
var minutesPerDay = 1440.0;
var mu = 398600.5; // in km3 / s2
var earthRadius = 6378.137; // in km
var xke = 60.0 / Math.sqrt(earthRadius * earthRadius * earthRadius / mu);
var vkmpersec = earthRadius * xke / 60.0;
var tumin = 1.0 / xke;
var j2 = 0.00108262998905;
var j3 = -0.00000253215306;
var j4 = -0.00000161098761;
var j3oj2 = j3 / j2;
var x2o3 = 2.0 / 3.0;
var constants = /*#__PURE__*/Object.freeze({
pi: pi,
twoPi: twoPi,
deg2rad: deg2rad,
rad2deg: rad2deg,
minutesPerDay: minutesPerDay,
mu: mu,
earthRadius: earthRadius,
xke: xke,
vkmpersec: vkmpersec,
tumin: tumin,
j2: j2,
j3: j3,
j4: j4,
j3oj2: j3oj2,
x2o3: x2o3
});
/* -----------------------------------------------------------------------------
*
* procedure days2mdhms
*
* this procedure converts the day of the year, days, to the equivalent month
* day, hour, minute and second.
*
* algorithm : set up array for the number of days per month
* find leap year - use 1900 because 2000 is a leap year
* loop through a temp value while the value is < the days
* perform int conversions to the correct day and month
* convert remainder into h m s using type conversions
*
* author : david vallado 719-573-2600 1 mar 2001
*
* inputs description range / units
* year - year 1900 .. 2100
* days - julian day of the year 0.0 .. 366.0
*
* outputs :
* mon - month 1 .. 12
* day - day 1 .. 28,29,30,31
* hr - hour 0 .. 23
* min - minute 0 .. 59
* sec - second 0.0 .. 59.999
*
* locals :
* dayofyr - day of year
* temp - temporary extended values
* inttemp - temporary int value
* i - index
* lmonth[12] - int array containing the number of days per month
*
* coupling :
* none.
* --------------------------------------------------------------------------- */
function days2mdhms(year, days) {
var lmonth = [31, year % 4 === 0 ? 29 : 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
var dayofyr = Math.floor(days); // ----------------- find month and day of month ----------------
var i = 1;
var inttemp = 0;
while (dayofyr > inttemp + lmonth[i - 1] && i < 12) {
inttemp += lmonth[i - 1];
i += 1;
}
var mon = i;
var day = dayofyr - inttemp; // ----------------- find hours minutes and seconds -------------
var temp = (days - dayofyr) * 24.0;
var hr = Math.floor(temp);
temp = (temp - hr) * 60.0;
var minute = Math.floor(temp);
var sec = (temp - minute) * 60.0;
return {
mon: mon,
day: day,
hr: hr,
minute: minute,
sec: sec
};
}
/* -----------------------------------------------------------------------------
*
* procedure jday
*
* this procedure finds the julian date given the year, month, day, and time.
* the julian date is defined by each elapsed day since noon, jan 1, 4713 bc.
*
* algorithm : calculate the answer in one step for efficiency
*
* author : david vallado 719-573-2600 1 mar 2001
*
* inputs description range / units
* year - year 1900 .. 2100
* mon - month 1 .. 12
* day - day 1 .. 28,29,30,31
* hr - universal time hour 0 .. 23
* min - universal time min 0 .. 59
* sec - universal time sec 0.0 .. 59.999
*
* outputs :
* jd - julian date days from 4713 bc
*
* locals :
* none.
*
* coupling :
* none.
*
* references :
* vallado 2007, 189, alg 14, ex 3-14
*
* --------------------------------------------------------------------------- */
function jdayInternal(year, mon, day, hr, minute, sec) {
var msec = arguments.length > 6 && arguments[6] !== undefined ? arguments[6] : 0;
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
// # - 0.5*sgn(100.0*year + mon - 190002.5) + 0.5;
;
}
function jday(year, mon, day, hr, minute, sec, msec) {
if (year instanceof Date) {
var date = year;
return jdayInternal(date.getUTCFullYear(), date.getUTCMonth() + 1, // Note, this function requires months in range 1-12.
date.getUTCDate(), date.getUTCHours(), date.getUTCMinutes(), date.getUTCSeconds(), date.getUTCMilliseconds());
}
return jdayInternal(year, mon, day, hr, minute, sec, msec);
}
/* -----------------------------------------------------------------------------
*
* procedure invjday
*
* this procedure finds the year, month, day, hour, minute and second
* given the julian date. tu can be ut1, tdt, tdb, etc.
*
* algorithm : set up starting values
* find leap year - use 1900 because 2000 is a leap year
* find the elapsed days through the year in a loop
* call routine to find each individual value
*
* author : david vallado 719-573-2600 1 mar 2001
*
* inputs description range / units
* jd - julian date days from 4713 bc
*
* outputs :
* year - year 1900 .. 2100
* mon - month 1 .. 12
* day - day 1 .. 28,29,30,31
* hr - hour 0 .. 23
* min - minute 0 .. 59
* sec - second 0.0 .. 59.999
*
* locals :
* days - day of year plus fractional
* portion of a day days
* tu - julian centuries from 0 h
* jan 0, 1900
* temp - temporary double values
* leapyrs - number of leap years from 1900
*
* coupling :
* days2mdhms - finds month, day, hour, minute and second given days and year
*
* references :
* vallado 2007, 208, alg 22, ex 3-13
* --------------------------------------------------------------------------- */
function invjday(jd, asArray) {
// --------------- find year and days of the year -
var temp = jd - 2415019.5;
var tu = temp / 365.25;
var year = 1900 + Math.floor(tu);
var leapyrs = Math.floor((year - 1901) * 0.25); // optional nudge by 8.64x10-7 sec to get even outputs
var days = temp - ((year - 1900) * 365.0 + leapyrs) + 0.00000000001; // ------------ check for case of beginning of a year -----------
if (days < 1.0) {
year -= 1;
leapyrs = Math.floor((year - 1901) * 0.25);
days = temp - ((year - 1900) * 365.0 + leapyrs);
} // ----------------- find remaing data -------------------------
var mdhms = days2mdhms(year, days);
var mon = mdhms.mon,
day = mdhms.day,
hr = mdhms.hr,
minute = mdhms.minute;
var sec = mdhms.sec - 0.00000086400;
if (asArray) {
return [year, mon, day, hr, minute, Math.floor(sec)];
}
return new Date(Date.UTC(year, mon - 1, day, hr, minute, Math.floor(sec)));
}
/* -----------------------------------------------------------------------------
*
* procedure dpper
*
* this procedure provides deep space long period periodic contributions
* to the mean elements. by design, these periodics are zero at epoch.
* this used to be dscom which included initialization, but it's really a
* recurring function.
*
* author : david vallado 719-573-2600 28 jun 2005
*
* inputs :
* e3 -
* ee2 -
* peo -
* pgho -
* pho -
* pinco -
* plo -
* se2 , se3 , sgh2, sgh3, sgh4, sh2, sh3, si2, si3, sl2, sl3, sl4 -
* t -
* xh2, xh3, xi2, xi3, xl2, xl3, xl4 -
* zmol -
* zmos -
* ep - eccentricity 0.0 - 1.0
* inclo - inclination - needed for lyddane modification
* nodep - right ascension of ascending node
* argpp - argument of perigee
* mp - mean anomaly
*
* outputs :
* ep - eccentricity 0.0 - 1.0
* inclp - inclination
* nodep - right ascension of ascending node
* argpp - argument of perigee
* mp - mean anomaly
*
* locals :
* alfdp -
* betdp -
* cosip , sinip , cosop , sinop ,
* dalf -
* dbet -
* dls -
* f2, f3 -
* pe -
* pgh -
* ph -
* pinc -
* pl -
* sel , ses , sghl , sghs , shl , shs , sil , sinzf , sis ,
* sll , sls
* xls -
* xnoh -
* zf -
* zm -
*
* 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 dpper(satrec, options) {
var 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,
t = satrec.t,
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 init = options.init,
opsmode = options.opsmode;
var ep = options.ep,
inclp = options.inclp,
nodep = options.nodep,
argpp = options.argpp,
mp = options.mp; // Copy satellite attributes into local variables for convenience
// and symmetry in writing formulae.
var alfdp;
var betdp;
var cosip;
var sinip;
var cosop;
var sinop;
var dalf;
var dbet;
var dls;
var f2;
var f3;
var pe;
var pgh;
var ph;
var pinc;
var pl;
var sinzf;
var xls;
var xnoh;
var zf;
var zm; // ---------------------- constants -----------------------------
var zns = 1.19459e-5;
var zes = 0.01675;
var znl = 1.5835218e-4;
var zel = 0.05490; // --------------- calculate time varying periodics -----------
zm = zmos + zns * t; // be sure that the initial call has time set to zero
if (init === 'y') {
zm = zmos;
}
zf = zm + 2.0 * zes * Math.sin(zm);
sinzf = Math.sin(zf);
f2 = 0.5 * sinzf * sinzf - 0.25;
f3 = -0.5 * sinzf * Math.cos(zf);
var ses = se2 * f2 + se3 * f3;
var sis = si2 * f2 + si3 * f3;
var sls = sl2 * f2 + sl3 * f3 + sl4 * sinzf;
var sghs = sgh2 * f2 + sgh3 * f3 + sgh4 * sinzf;
var shs = sh2 * f2 + sh3 * f3;
zm = zmol + znl * t;
if (init === 'y') {
zm = zmol;
}
zf = zm + 2.0 * zel * Math.sin(zm);
sinzf = Math.sin(zf);
f2 = 0.5 * sinzf * sinzf - 0.25;
f3 = -0.5 * sinzf * Math.cos(zf);
var sel = ee2 * f2 + e3 * f3;
var sil = xi2 * f2 + xi3 * f3;
var sll = xl2 * f2 + xl3 * f3 + xl4 * sinzf;
var sghl = xgh2 * f2 + xgh3 * f3 + xgh4 * sinzf;
var shll = xh2 * f2 + xh3 * f3;
pe = ses + sel;
pinc = sis + sil;
pl = sls + sll;
pgh = sghs + sghl;
ph = shs + shll;
if (init === 'n') {
pe -= peo;
pinc -= pinco;
pl -= plo;
pgh -= pgho;
ph -= pho;
inclp += pinc;
ep += pe;
sinip = Math.sin(inclp);
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) {
ph /= sinip;
pgh -= cosip * ph;
argpp += pgh;
nodep += ph;
mp += pl;
} else {
// ---- apply periodics with lyddane modification ----
sinop = Math.sin(nodep);
cosop = Math.cos(nodep);
alfdp = sinip * sinop;
betdp = sinip * cosop;
dalf = ph * cosop + pinc * cosip * sinop;
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;
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 :
* d - 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() {
if ((arguments.length <= 0 ? undefined : arguments[0]) instanceof Date || arguments.length > 1) {
return gstimeInternal(jday.apply(void 0, arguments));
}
return gstimeInternal.apply(void 0, arguments);
}
/*-----------------------------------------------------------------------------
*
* 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;
var thgr70 = 1.7321343856509374;
var fk5r = 5.07551419432269442e-15;
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;
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
};
}
/*----------------------------------------------------------------------------
*
* 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) {
/* eslint-disable no-param-reassign */
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 = 0; // ------- 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 = 2; // sgp4fix add return
return [false, false];
}
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 = 1; // sgp4fix to return if there is an error in eccentricity
return [false, false];
} // 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; // ----------------- 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 = 3; // sgp4fix add return
return [false, false];
}
} // -------------------- 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 = 4; // sgp4fix add return
return [false, false];
}
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 = 6;
return {
position: false,
velocity: false
};
}
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
};
/* eslint-enable no-param-reassign */
}
/*-----------------------------------------------------------------------------
*
* 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(satrec, options) {
/* eslint-disable no-param-reassign */
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; // ----------- 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.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, 0);
satrec.init = 'n';
/* eslint-enable no-param-reassign */
}
/* -----------------------------------------------------------------------------
*
* function twoline2rv
*
* 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 `longstr1` and `longstr2`,
* 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 xpdotp = 1440.0 / (2.0 * pi); // 229.1831180523293;
var year = 0;
var satrec = {};
satrec.error = 0;
satrec.satnum = longstr1.substring(2, 7);
satrec.epochyr = parseInt(longstr1.substring(18, 20), 10);
satrec.epochdays = parseFloat(longstr1.substring(20, 32));
satrec.ndot = parseFloat(longstr1.substring(33, 43));
satrec.nddot = parseFloat(".".concat(parseInt(longstr1.substring(44, 50), 10), "E").concat(longstr1.substring(50, 52)));
satrec.bstar = parseFloat("".concat(longstr1.substring(53, 54), ".").concat(parseInt(longstr1.substring(54, 59), 10), "E").concat(longstr1.substring(59, 61))); // satrec.satnum = longstr2.substring(2, 7);
satrec.inclo = parseFloat(longstr2.substring(8, 16));
satrec.nodeo = parseFloat(longstr2.substring(17, 25));
satrec.ecco = parseFloat(".".concat(longstr2.substring(26, 33)));
satrec.argpo = parseFloat(longstr2.substring(34, 42));
satrec.mo = parseFloat(longstr2.substring(43, 51));
satrec.no = parseFloat(longstr2.substring(52, 63)); // ---- find no, ndot, nddot ----
satrec.no /= xpdotp; // rad/min
// satrec.nddot= satrec.nddot * Math.pow(10.0, nexp);
// satrec.bstar= satrec.bstar * Math.pow(10.0, ibexp);
// ---- convert to sgp4 units ----
satrec.a = Math.pow(satrec.no * tumin, -2.0 / 3.0);
satrec.ndot /= xpdotp * 1440.0; // ? * minperday
satrec.nddot /= xpdotp * 1440.0 * 1440; // ---- find standard orbital elements ----
satrec.inclo *= deg2rad;
satrec.nodeo *= deg2rad;
satrec.argpo *= deg2rad;
satrec.mo *= deg2rad;
satrec.alta = satrec.a * (1.0 + satrec.ecco) - 1.0;
satrec.altp = satrec.a * (1.0 - satrec.ecco) - 1.0; // ----------------------------------------------------------------
// 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 ---------
if (satrec.epochyr < 57) {
year = satrec.epochyr + 2000;
} else {
year = satrec.epochyr + 1900;
}
var mdhmsResult = days2mdhms(year, satrec.epochdays);
var mon = mdhmsResult.mon,
day = mdhmsResult.day,
hr = mdhmsResult.hr,
minute = mdhmsResult.minute,
sec = mdhmsResult.sec;
satrec.jdsatepoch = jday(year, mon, day, hr, minute, sec); // ---------------- 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 _toConsumableArray(arr) {
return _arrayWithoutHoles(arr) || _iterableToArray(arr) || _nonIterableSpread();
}
function _arrayWithoutHoles(arr) {
if (Array.isArray(arr)) {
for (var i = 0, arr2 = new Array(arr.length); i < arr.length; i++) arr2[i] = arr[i];
return arr2;
}
}
function _iterableToArray(iter) {
if (Symbol.iterator in Object(iter) || Object.prototype.toString.call(iter) === "[object Arguments]") return Array.from(iter);
}
function _nonIterableSpread() {
throw new TypeError("Invalid attempt to spread non-iterable instance");
}
function propagate() {
for (var _len = arguments.length, args = new Array(_len), _key = 0; _key < _len; _key++) {
args[_key] = arguments[_key];
}
// Return a position and velocity vector for a given date and time.
var satrec = args[0];
var date = Array.prototype.slice.call(args, 1);
var j = jday.apply(void 0, _toConsumableArray(date));
var m = (j - satrec.jdsatepoch) * minutesPerDay;
return sgp4(satrec, m);
}
function dopplerFactor(location, position, velocity) {
var currentRange = Math.sqrt(Math.pow(position.x - location.x, 2) + Math.pow(position.y - location.y, 2) + Math.pow(position.z - location.z, 2));
var nextPos = {
x: position.x + velocity.x,
y: position.y + velocity.y,
z: position.z + velocity.z
};
var nextRange = Math.sqrt(Math.pow(nextPos.x - location.x, 2) + Math.pow(nextPos.y - location.y, 2) + Math.pow(nextPos.z - location.z, 2));
var rangeRate = nextRange - currentRange;
function sign(value) {
return value >= 0 ? 1 : -1;
}
rangeRate *= sign(rangeRate);
var c = 299792.458; // Speed of light in km/s
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(geodetic) {
var longitude = geodetic.longitude,
latitude = geodetic.latitude,
height = geodetic.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);
k += 1;
}
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
};
}
/**
* @param {Object} tc
* @param {Number} tc.topS Positive horizontal vector S due south.
* @param {Number} tc.topE Positive horizontal vector E due east.
* @param {Number} tc.topZ Vector Z normal to the surface of the earth (up).
* @returns {Object}
*/
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);
}
export { constants, propagate, sgp4, twoline2satrec, gstime, jday, invjday, dopplerFactor, radiansToDegrees, degreesToRadians, degreesLat, degreesLong, radiansLat, radiansLong, geodeticToEcf, eciToGeodetic, eciToEcf, ecfToEci, ecfToLookAngles };