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gpssim.c
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#define _CRT_SECURE_NO_DEPRECATE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <time.h>
#include <omp.h>
#ifdef _WIN32
#include "getopt.h"
#else
#include <unistd.h>
#endif
#include "gpssim.h"
int sinTable512[] = {
2, 5, 8, 11, 14, 17, 20, 23, 26, 29, 32, 35, 38, 41, 44, 47,
50, 53, 56, 59, 62, 65, 68, 71, 74, 77, 80, 83, 86, 89, 91, 94,
97, 100, 103, 105, 108, 111, 114, 116, 119, 122, 125, 127, 130, 132, 135, 138,
140, 143, 145, 148, 150, 153, 155, 157, 160, 162, 164, 167, 169, 171, 173, 176,
178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 205, 207,
209, 210, 212, 214, 215, 217, 218, 220, 221, 223, 224, 225, 227, 228, 229, 230,
232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 241, 242, 243, 244, 244, 245,
245, 246, 247, 247, 248, 248, 248, 249, 249, 249, 249, 250, 250, 250, 250, 250,
250, 250, 250, 250, 250, 249, 249, 249, 249, 248, 248, 248, 247, 247, 246, 245,
245, 244, 244, 243, 242, 241, 241, 240, 239, 238, 237, 236, 235, 234, 233, 232,
230, 229, 228, 227, 225, 224, 223, 221, 220, 218, 217, 215, 214, 212, 210, 209,
207, 205, 204, 202, 200, 198, 196, 194, 192, 190, 188, 186, 184, 182, 180, 178,
176, 173, 171, 169, 167, 164, 162, 160, 157, 155, 153, 150, 148, 145, 143, 140,
138, 135, 132, 130, 127, 125, 122, 119, 116, 114, 111, 108, 105, 103, 100, 97,
94, 91, 89, 86, 83, 80, 77, 74, 71, 68, 65, 62, 59, 56, 53, 50,
47, 44, 41, 38, 35, 32, 29, 26, 23, 20, 17, 14, 11, 8, 5, 2,
-2, -5, -8, -11, -14, -17, -20, -23, -26, -29, -32, -35, -38, -41, -44, -47,
-50, -53, -56, -59, -62, -65, -68, -71, -74, -77, -80, -83, -86, -89, -91, -94,
-97,-100,-103,-105,-108,-111,-114,-116,-119,-122,-125,-127,-130,-132,-135,-138,
-140,-143,-145,-148,-150,-153,-155,-157,-160,-162,-164,-167,-169,-171,-173,-176,
-178,-180,-182,-184,-186,-188,-190,-192,-194,-196,-198,-200,-202,-204,-205,-207,
-209,-210,-212,-214,-215,-217,-218,-220,-221,-223,-224,-225,-227,-228,-229,-230,
-232,-233,-234,-235,-236,-237,-238,-239,-240,-241,-241,-242,-243,-244,-244,-245,
-245,-246,-247,-247,-248,-248,-248,-249,-249,-249,-249,-250,-250,-250,-250,-250,
-250,-250,-250,-250,-250,-249,-249,-249,-249,-248,-248,-248,-247,-247,-246,-245,
-245,-244,-244,-243,-242,-241,-241,-240,-239,-238,-237,-236,-235,-234,-233,-232,
-230,-229,-228,-227,-225,-224,-223,-221,-220,-218,-217,-215,-214,-212,-210,-209,
-207,-205,-204,-202,-200,-198,-196,-194,-192,-190,-188,-186,-184,-182,-180,-178,
-176,-173,-171,-169,-167,-164,-162,-160,-157,-155,-153,-150,-148,-145,-143,-140,
-138,-135,-132,-130,-127,-125,-122,-119,-116,-114,-111,-108,-105,-103,-100, -97,
-94, -91, -89, -86, -83, -80, -77, -74, -71, -68, -65, -62, -59, -56, -53, -50,
-47, -44, -41, -38, -35, -32, -29, -26, -23, -20, -17, -14, -11, -8, -5, -2
};
int cosTable512[] = {
250, 250, 250, 250, 250, 249, 249, 249, 249, 248, 248, 248, 247, 247, 246, 245,
245, 244, 244, 243, 242, 241, 241, 240, 239, 238, 237, 236, 235, 234, 233, 232,
230, 229, 228, 227, 225, 224, 223, 221, 220, 218, 217, 215, 214, 212, 210, 209,
207, 205, 204, 202, 200, 198, 196, 194, 192, 190, 188, 186, 184, 182, 180, 178,
176, 173, 171, 169, 167, 164, 162, 160, 157, 155, 153, 150, 148, 145, 143, 140,
138, 135, 132, 130, 127, 125, 122, 119, 116, 114, 111, 108, 105, 103, 100, 97,
94, 91, 89, 86, 83, 80, 77, 74, 71, 68, 65, 62, 59, 56, 53, 50,
47, 44, 41, 38, 35, 32, 29, 26, 23, 20, 17, 14, 11, 8, 5, 2,
-2, -5, -8, -11, -14, -17, -20, -23, -26, -29, -32, -35, -38, -41, -44, -47,
-50, -53, -56, -59, -62, -65, -68, -71, -74, -77, -80, -83, -86, -89, -91, -94,
-97,-100,-103,-105,-108,-111,-114,-116,-119,-122,-125,-127,-130,-132,-135,-138,
-140,-143,-145,-148,-150,-153,-155,-157,-160,-162,-164,-167,-169,-171,-173,-176,
-178,-180,-182,-184,-186,-188,-190,-192,-194,-196,-198,-200,-202,-204,-205,-207,
-209,-210,-212,-214,-215,-217,-218,-220,-221,-223,-224,-225,-227,-228,-229,-230,
-232,-233,-234,-235,-236,-237,-238,-239,-240,-241,-241,-242,-243,-244,-244,-245,
-245,-246,-247,-247,-248,-248,-248,-249,-249,-249,-249,-250,-250,-250,-250,-250,
-250,-250,-250,-250,-250,-249,-249,-249,-249,-248,-248,-248,-247,-247,-246,-245,
-245,-244,-244,-243,-242,-241,-241,-240,-239,-238,-237,-236,-235,-234,-233,-232,
-230,-229,-228,-227,-225,-224,-223,-221,-220,-218,-217,-215,-214,-212,-210,-209,
-207,-205,-204,-202,-200,-198,-196,-194,-192,-190,-188,-186,-184,-182,-180,-178,
-176,-173,-171,-169,-167,-164,-162,-160,-157,-155,-153,-150,-148,-145,-143,-140,
-138,-135,-132,-130,-127,-125,-122,-119,-116,-114,-111,-108,-105,-103,-100, -97,
-94, -91, -89, -86, -83, -80, -77, -74, -71, -68, -65, -62, -59, -56, -53, -50,
-47, -44, -41, -38, -35, -32, -29, -26, -23, -20, -17, -14, -11, -8, -5, -2,
2, 5, 8, 11, 14, 17, 20, 23, 26, 29, 32, 35, 38, 41, 44, 47,
50, 53, 56, 59, 62, 65, 68, 71, 74, 77, 80, 83, 86, 89, 91, 94,
97, 100, 103, 105, 108, 111, 114, 116, 119, 122, 125, 127, 130, 132, 135, 138,
140, 143, 145, 148, 150, 153, 155, 157, 160, 162, 164, 167, 169, 171, 173, 176,
178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 205, 207,
209, 210, 212, 214, 215, 217, 218, 220, 221, 223, 224, 225, 227, 228, 229, 230,
232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 241, 242, 243, 244, 244, 245,
245, 246, 247, 247, 248, 248, 248, 249, 249, 249, 249, 250, 250, 250, 250, 250
};
// Receiver antenna attenuation in dB for boresight angle = 0:5:180 [deg]
double ant_pat_db[37] = {
0.00, 0.00, 0.22, 0.44, 0.67, 1.11, 1.56, 2.00, 2.44, 2.89, 3.56, 4.22,
4.89, 5.56, 6.22, 6.89, 7.56, 8.22, 8.89, 9.78, 10.67, 11.56, 12.44, 13.33,
14.44, 15.56, 16.67, 17.78, 18.89, 20.00, 21.33, 22.67, 24.00, 25.56, 27.33, 29.33,
31.56
};
int allocatedSat[MAX_SAT];
/*! \brief Subtract two vectors of double
* \param[out] y Result of subtraction
* \param[in] x1 Minuend of subtracion
* \param[in] x2 Subtrahend of subtracion
*/
void subVect(double *y, const double *x1, const double *x2)
{
y[0] = x1[0]-x2[0];
y[1] = x1[1]-x2[1];
y[2] = x1[2]-x2[2];
return;
}
/*! \brief Compute Norm of Vector
* \param[in] x Input vector
* \returns Length (Norm) of the input vector
*/
double normVect(const double *x)
{
return(sqrt(x[0]*x[0]+x[1]*x[1]+x[2]*x[2]));
}
/*! \brief Compute dot-product of two vectors
* \param[in] x1 First multiplicand
* \param[in] x2 Second multiplicand
* \returns Dot-product of both multiplicands
*/
double dotProd(const double *x1, const double *x2)
{
return(x1[0]*x2[0]+x1[1]*x2[1]+x1[2]*x2[2]);
}
/* !\brief generate the C/A code sequence for a given Satellite Vehicle PRN
* \param[in] prn PRN nuber of the Satellite Vehicle
* \param[out] ca Caller-allocated integer array of 1023 bytes
*/
void codegen(int *ca, int prn)
{
int delay[] = {
5, 6, 7, 8, 17, 18, 139, 140, 141, 251,
252, 254, 255, 256, 257, 258, 469, 470, 471, 472,
473, 474, 509, 512, 513, 514, 515, 516, 859, 860,
861, 862};
int g1[CA_SEQ_LEN], g2[CA_SEQ_LEN];
int r1[N_DWRD_SBF], r2[N_DWRD_SBF];
int c1, c2;
int i,j;
if (prn<1 || prn>32)
return;
for (i=0; i<N_DWRD_SBF; i++)
r1[i] = r2[i] = -1;
for (i=0; i<CA_SEQ_LEN; i++)
{
g1[i] = r1[9];
g2[i] = r2[9];
c1 = r1[2]*r1[9];
c2 = r2[1]*r2[2]*r2[5]*r2[7]*r2[8]*r2[9];
for (j=9; j>0; j--)
{
r1[j] = r1[j-1];
r2[j] = r2[j-1];
}
r1[0] = c1;
r2[0] = c2;
}
for (i=0,j=CA_SEQ_LEN-delay[prn-1]; i<CA_SEQ_LEN; i++,j++)
ca[i] = (1-g1[i]*g2[j%CA_SEQ_LEN])/2;
return;
}
/*! \brief Convert a UTC date into a GPS date
* \param[in] t input date in UTC form
* \param[out] g output date in GPS form
*/
void date2gps(const datetime_t *t, gpstime_t *g)
{
int doy[12] = {0,31,59,90,120,151,181,212,243,273,304,334};
int ye;
int de;
int lpdays;
ye = t->y - 1980;
// Compute the number of leap days since Jan 5/Jan 6, 1980.
lpdays = ye/4 + 1;
if ((ye%4)==0 && t->m<=2)
lpdays--;
// Compute the number of days elapsed since Jan 5/Jan 6, 1980.
de = ye*365 + doy[t->m-1] + t->d + lpdays - 6;
// Convert time to GPS weeks and seconds.
g->week = de / 7;
g->sec = (double)(de%7)*SECONDS_IN_DAY + t->hh*SECONDS_IN_HOUR
+ t->mm*SECONDS_IN_MINUTE + t->sec;
return;
}
/*! \brief Convert Earth-centered Earth-fixed (ECEF) into Lat/Long/Heighth
* \param[in] xyz Input Array of X, Y and Z ECEF coordinates
* \param[out] llh Output Array of Latitude, Longitude and Height
*/
void xyz2llh(const double *xyz, double *llh)
{
double a,eps,e,e2;
double x,y,z;
double rho2,dz,zdz,nh,slat,n,dz_new;
a = WGS84_RADIUS;
e = WGS84_ECCENTRICITY;
eps = 1.0e-3;
e2 = e*e;
if (normVect(xyz)<eps)
{
// Invalid ECEF vector
llh[0] = 0.0;
llh[1] = 0.0;
llh[2] = -a;
return;
}
x = xyz[0];
y = xyz[1];
z = xyz[2];
rho2 = x*x + y*y;
dz = e2*z;
while (1)
{
zdz = z + dz;
nh = sqrt(rho2 + zdz*zdz);
slat = zdz / nh;
n = a / sqrt(1.0-e2*slat*slat);
dz_new = n*e2*slat;
if (fabs(dz-dz_new) < eps)
break;
dz = dz_new;
}
llh[0] = atan2(zdz, sqrt(rho2));
llh[1] = atan2(y, x);
llh[2] = nh - n;
return;
}
/*! \brief Convert Lat/Long/Height into Earth-centered Earth-fixed (ECEF)
* \param[in] llh Input Array of Latitude, Longitude and Height
* \param[out] xyz Output Array of X, Y and Z ECEF coordinates
*/
void llh2xyz(const double *llh, double *xyz)
{
double n;
double a;
double e;
double e2;
double clat;
double slat;
double clon;
double slon;
double d,nph;
double tmp;
a = WGS84_RADIUS;
e = WGS84_ECCENTRICITY;
e2 = e*e;
clat = cos(llh[0]);
slat = sin(llh[0]);
clon = cos(llh[1]);
slon = sin(llh[1]);
d = e*slat;
n = a/sqrt(1.0-d*d);
nph = n + llh[2];
tmp = nph*clat;
xyz[0] = tmp*clon;
xyz[1] = tmp*slon;
xyz[2] = ((1.0-e2)*n + llh[2])*slat;
return;
}
/*! \brief Compute the intermediate matrix for LLH to ECEF
* \param[in] llh Input position in Latitude-Longitude-Height format
* \param[out] t Three-by-Three output matrix
*/
void ltcmat(const double *llh, double t[3][3])
{
double slat, clat;
double slon, clon;
slat = sin(llh[0]);
clat = cos(llh[0]);
slon = sin(llh[1]);
clon = cos(llh[1]);
t[0][0] = -slat*clon;
t[0][1] = -slat*slon;
t[0][2] = clat;
t[1][0] = -slon;
t[1][1] = clon;
t[1][2] = 0.0;
t[2][0] = clat*clon;
t[2][1] = clat*slon;
t[2][2] = slat;
return;
}
/*! \brief Convert Earth-centered Earth-Fixed to ?
* \param[in] xyz Input position as vector in ECEF format
* \param[in] t Intermediate matrix computed by \ref ltcmat
* \param[out] neu Output position as North-East-Up format
*/
void ecef2neu(const double *xyz, double t[3][3], double *neu)
{
neu[0] = t[0][0]*xyz[0] + t[0][1]*xyz[1] + t[0][2]*xyz[2];
neu[1] = t[1][0]*xyz[0] + t[1][1]*xyz[1] + t[1][2]*xyz[2];
neu[2] = t[2][0]*xyz[0] + t[2][1]*xyz[1] + t[2][2]*xyz[2];
return;
}
/*! \brief Convert North-Eeast-Up to Azimuth + Elevation
* \param[in] neu Input position in North-East-Up format
* \param[out] azel Output array of azimuth + elevation as double
*/
void neu2azel(double *azel, const double *neu)
{
double ne;
azel[0] = atan2(neu[1],neu[0]);
if (azel[0]<0.0)
azel[0] += (2.0*PI);
ne = sqrt(neu[0]*neu[0] + neu[1]*neu[1]);
azel[1] = atan2(neu[2], ne);
return;
}
/*! \brief Compute Satellite position, velocity and clock at given time
* \param[in] eph Ephemeris data of the satellite
* \param[in] g GPS time at which position is to be computed
* \param[out] pos Computed position (vector)
* \param[out] vel Computed velociy (vector)
* \param[clk] clk Computed clock
*/
void satpos(ephem_t eph, gpstime_t g, double *pos, double *vel, double *clk)
{
// Computing Satellite Velocity using the Broadcast Ephemeris
// http://www.ngs.noaa.gov/gps-toolbox/bc_velo.htm
double tk;
double mk;
double ek;
double ekold;
double ekdot;
double cek,sek;
double pk;
double pkdot;
double c2pk,s2pk;
double uk;
double ukdot;
double cuk,suk;
double ok;
double sok,cok;
double ik;
double ikdot;
double sik,cik;
double rk;
double rkdot;
double xpk,ypk;
double xpkdot,ypkdot;
double relativistic, OneMinusecosE, tmp;
tk = g.sec - eph.toe.sec;
if(tk>SECONDS_IN_HALF_WEEK)
tk -= SECONDS_IN_WEEK;
else if(tk<-SECONDS_IN_HALF_WEEK)
tk += SECONDS_IN_WEEK;
mk = eph.m0 + eph.n*tk;
ek = mk;
ekold = ek + 1.0;
OneMinusecosE = 0; // Suppress the uninitialized warning.
while(fabs(ek-ekold)>1.0E-14)
{
ekold = ek;
OneMinusecosE = 1.0-eph.ecc*cos(ekold);
ek = ek + (mk-ekold+eph.ecc*sin(ekold))/OneMinusecosE;
}
sek = sin(ek);
cek = cos(ek);
ekdot = eph.n/OneMinusecosE;
relativistic = -4.442807633E-10*eph.ecc*eph.sqrta*sek;
pk = atan2(eph.sq1e2*sek,cek-eph.ecc) + eph.aop;
pkdot = eph.sq1e2*ekdot/OneMinusecosE;
s2pk = sin(2.0*pk);
c2pk = cos(2.0*pk);
uk = pk + eph.cus*s2pk + eph.cuc*c2pk;
suk = sin(uk);
cuk = cos(uk);
ukdot = pkdot*(1.0 + 2.0*(eph.cus*c2pk - eph.cuc*s2pk));
rk = eph.A*OneMinusecosE + eph.crc*c2pk + eph.crs*s2pk;
rkdot = eph.A*eph.ecc*sek*ekdot + 2.0*pkdot*(eph.crs*c2pk - eph.crc*s2pk);
ik = eph.inc0 + eph.idot*tk + eph.cic*c2pk + eph.cis*s2pk;
sik = sin(ik);
cik = cos(ik);
ikdot = eph.idot + 2.0*pkdot*(eph.cis*c2pk - eph.cic*s2pk);
xpk = rk*cuk;
ypk = rk*suk;
xpkdot = rkdot*cuk - ypk*ukdot;
ypkdot = rkdot*suk + xpk*ukdot;
ok = eph.omg0 + tk*eph.omgkdot - OMEGA_EARTH*eph.toe.sec;
sok = sin(ok);
cok = cos(ok);
pos[0] = xpk*cok - ypk*cik*sok;
pos[1] = xpk*sok + ypk*cik*cok;
pos[2] = ypk*sik;
tmp = ypkdot*cik - ypk*sik*ikdot;
vel[0] = -eph.omgkdot*pos[1] + xpkdot*cok - tmp*sok;
vel[1] = eph.omgkdot*pos[0] + xpkdot*sok + tmp*cok;
vel[2] = ypk*cik*ikdot + ypkdot*sik;
// Satellite clock correction
tk = g.sec - eph.toc.sec;
if(tk>SECONDS_IN_HALF_WEEK)
tk -= SECONDS_IN_WEEK;
else if(tk<-SECONDS_IN_HALF_WEEK)
tk += SECONDS_IN_WEEK;
clk[0] = eph.af0 + tk*(eph.af1 + tk*eph.af2) + relativistic - eph.tgd;
clk[1] = eph.af1 + 2.0*tk*eph.af2;
return;
}
/*! \brief Compute Subframe from Ephemeris
* \param[in] eph Ephemeris of given SV
* \param[out] sbf Array of five sub-frames, 10 long words each
*/
void eph2sbf(const ephem_t eph, unsigned long sbf[5][N_DWRD_SBF])
{
unsigned long wn;
unsigned long toe;
unsigned long toc;
unsigned long iode;
unsigned long iodc;
long deltan;
long cuc;
long cus;
long cic;
long cis;
long crc;
long crs;
unsigned long ecc;
unsigned long sqrta;
long m0;
long omg0;
long inc0;
long aop;
long omgdot;
long idot;
long af0;
long af1;
long af2;
long tgd;
unsigned long ura = 2UL;
unsigned long dataId = 1UL;
unsigned long sbf4_page25_svId = 63UL;
unsigned long sbf5_page25_svId = 51UL;
unsigned long wna;
unsigned long toa;
wn = (unsigned long)(eph.toe.week%1024);
toe = (unsigned long)(eph.toe.sec/16.0);
toc = (unsigned long)(eph.toc.sec/16.0);
iode = (unsigned long)(eph.iode);
iodc = (unsigned long)(eph.iodc);
deltan = (long)(eph.deltan/POW2_M43/PI);
cuc = (long)(eph.cuc/POW2_M29);
cus = (long)(eph.cus/POW2_M29);
cic = (long)(eph.cic/POW2_M29);
cis = (long)(eph.cis/POW2_M29);
crc = (long)(eph.crc/POW2_M5);
crs = (long)(eph.crs/POW2_M5);
ecc = (unsigned long)(eph.ecc/POW2_M33);
sqrta = (unsigned long)(eph.sqrta/POW2_M19);
m0 = (long)(eph.m0/POW2_M31/PI);
omg0 = (long)(eph.omg0/POW2_M31/PI);
inc0 = (long)(eph.inc0/POW2_M31/PI);
aop = (long)(eph.aop/POW2_M31/PI);
omgdot = (long)(eph.omgdot/POW2_M43/PI);
idot = (long)(eph.idot/POW2_M43/PI);
af0 = (long)(eph.af0/POW2_M31);
af1 = (long)(eph.af1/POW2_M43);
af2 = (long)(eph.af2/POW2_M55);
tgd = (long)(eph.tgd/POW2_M31);
wna = (unsigned long)(eph.toe.week%256);
toa = (unsigned long)(eph.toe.sec/4096.0);
// Subframe 1
sbf[0][0] = 0x8B0000UL<<6;
sbf[0][1] = 0x1UL<<8;
sbf[0][2] = ((wn&0x3FFUL)<<20) | (ura<<14) | (((iodc>>8)&0x3UL)<<6);
sbf[0][3] = 0UL;
sbf[0][4] = 0UL;
sbf[0][5] = 0UL;
sbf[0][6] = (tgd&0xFFUL)<<6;
sbf[0][7] = ((iodc&0xFFUL)<<22) | ((toc&0xFFFFUL)<<6);
sbf[0][8] = ((af2&0xFFUL)<<22) | ((af1&0xFFFFUL)<<6);
sbf[0][9] = (af0&0x3FFFFFUL)<<8;
// Subframe 2
sbf[1][0] = 0x8B0000UL<<6;
sbf[1][1] = 0x2UL<<8;
sbf[1][2] = ((iode&0xFFUL)<<22) | ((crs&0xFFFFUL)<<6);
sbf[1][3] = ((deltan&0xFFFFUL)<<14) | (((m0>>24)&0xFFUL)<<6);
sbf[1][4] = (m0&0xFFFFFFUL)<<6;
sbf[1][5] = ((cuc&0xFFFFUL)<<14) | (((ecc>>24)&0xFFUL)<<6);
sbf[1][6] = (ecc&0xFFFFFFUL)<<6;
sbf[1][7] = ((cus&0xFFFFUL)<<14) | (((sqrta>>24)&0xFFUL)<<6);
sbf[1][8] = (sqrta&0xFFFFFFUL)<<6;
sbf[1][9] = (toe&0xFFFFUL)<<14;
// Subframe 3
sbf[2][0] = 0x8B0000UL<<6;
sbf[2][1] = 0x3UL<<8;
sbf[2][2] = ((cic&0xFFFFUL)<<14) | (((omg0>>24)&0xFFUL)<<6);
sbf[2][3] = (omg0&0xFFFFFFUL)<<6;
sbf[2][4] = ((cis&0xFFFFUL)<<14) | (((inc0>>24)&0xFFUL)<<6);
sbf[2][5] = (inc0&0xFFFFFFUL)<<6;
sbf[2][6] = ((crc&0xFFFFUL)<<14) | (((aop>>24)&0xFFUL)<<6);
sbf[2][7] = (aop&0xFFFFFFUL)<<6;
sbf[2][8] = (omgdot&0xFFFFFFUL)<<6;
sbf[2][9] = ((iode&0xFFUL)<<22) | ((idot&0x3FFFUL)<<8);
// Subframe 4, page 25
sbf[3][0] = 0x8B0000UL<<6;
sbf[3][1] = 0x4UL<<8;
sbf[3][2] = (dataId<<28) | (sbf4_page25_svId<<22);
sbf[3][3] = 0UL;
sbf[3][4] = 0UL;
sbf[3][5] = 0UL;
sbf[3][6] = 0UL;
sbf[3][7] = 0UL;
sbf[3][8] = 0UL;
sbf[3][9] = 0UL;
// Subframe 5, page 25
sbf[4][0] = 0x8B0000UL<<6;
sbf[4][1] = 0x5UL<<8;
sbf[4][2] = (dataId<<28) | (sbf5_page25_svId<<22) | ((toa&0xFFUL)<<14) | ((wna&0xFFUL)<<6);
sbf[4][3] = 0UL;
sbf[4][4] = 0UL;
sbf[4][5] = 0UL;
sbf[4][6] = 0UL;
sbf[4][7] = 0UL;
sbf[4][8] = 0UL;
sbf[4][9] = 0UL;
return;
}
/*! \brief Count number of bits set to 1
* \param[in] v long word in whihc bits are counted
* \returns Count of bits set to 1
*/
unsigned long countBits(unsigned long v)
{
unsigned long c;
const int S[] = {1, 2, 4, 8, 16};
const unsigned long B[] = {
0x55555555, 0x33333333, 0x0F0F0F0F, 0x00FF00FF, 0x0000FFFF};
c = v;
c = ((c >> S[0]) & B[0]) + (c & B[0]);
c = ((c >> S[1]) & B[1]) + (c & B[1]);
c = ((c >> S[2]) & B[2]) + (c & B[2]);
c = ((c >> S[3]) & B[3]) + (c & B[3]);
c = ((c >> S[4]) & B[4]) + (c & B[4]);
return(c);
}
/*! \brief Compute the Checksum for one given word of a subframe
* \param[in] source The input data
* \param[in] nib Does this word contain non-information-bearing bits?
* \returns Computed Checksum
*/
unsigned long computeChecksum(unsigned long source, int nib)
{
/*
Bits 31 to 30 = 2 LSBs of the previous transmitted word, D29* and D30*
Bits 29 to 6 = Source data bits, d1, d2, ..., d24
Bits 5 to 0 = Empty parity bits
*/
/*
Bits 31 to 30 = 2 LSBs of the previous transmitted word, D29* and D30*
Bits 29 to 6 = Data bits transmitted by the SV, D1, D2, ..., D24
Bits 5 to 0 = Computed parity bits, D25, D26, ..., D30
*/
/*
1 2 3
bit 12 3456 7890 1234 5678 9012 3456 7890
--- -------------------------------------
D25 11 1011 0001 1111 0011 0100 1000 0000
D26 01 1101 1000 1111 1001 1010 0100 0000
D27 10 1110 1100 0111 1100 1101 0000 0000
D28 01 0111 0110 0011 1110 0110 1000 0000
D29 10 1011 1011 0001 1111 0011 0100 0000
D30 00 1011 0111 1010 1000 1001 1100 0000
*/
unsigned long bmask[6] = {
0x3B1F3480UL, 0x1D8F9A40UL, 0x2EC7CD00UL,
0x1763E680UL, 0x2BB1F340UL, 0x0B7A89C0UL };
unsigned long D;
unsigned long d = source & 0x3FFFFFC0UL;
unsigned long D29 = (source>>31)&0x1UL;
unsigned long D30 = (source>>30)&0x1UL;
if (nib) // Non-information bearing bits for word 2 and 10
{
/*
Solve bits 23 and 24 to presearve parity check
with zeros in bits 29 and 30.
*/
if ((D30 + countBits(bmask[4] & d)) % 2)
d ^= (0x1UL<<6);
if ((D29 + countBits(bmask[5] & d)) % 2)
d ^= (0x1UL<<7);
}
D = d;
if (D30)
D ^= 0x3FFFFFC0UL;
D |= ((D29 + countBits(bmask[0] & d)) % 2) << 5;
D |= ((D30 + countBits(bmask[1] & d)) % 2) << 4;
D |= ((D29 + countBits(bmask[2] & d)) % 2) << 3;
D |= ((D30 + countBits(bmask[3] & d)) % 2) << 2;
D |= ((D30 + countBits(bmask[4] & d)) % 2) << 1;
D |= ((D29 + countBits(bmask[5] & d)) % 2);
D &= 0x3FFFFFFFUL;
//D |= (source & 0xC0000000UL); // Add D29* and D30* from source data bits
return(D);
}
/*! \brief Replace all 'E' exponential designators to 'D'
* \param str String in which all occurrences of 'E' are replaced with * 'D'
* \param len Length of input string in bytes
* \returns Number of characters replaced
*/
int replaceExpDesignator(char *str, int len)
{
int i,n=0;
for (i=0; i<len; i++)
{
if (str[i]=='D')
{
n++;
str[i] = 'E';
}
}
return(n);
}
double subGpsTime(gpstime_t g1, gpstime_t g0)
{
double dt;
dt = g1.sec - g0.sec;
dt += (double)(g1.week - g0.week) * SECONDS_IN_WEEK;
return(dt);
}
/*! \brief Read Ephemersi data from the RINEX Navigation file */
/* \param[out] eph Array of Output SV ephemeris data
* \param[in] fname File name of the RINEX file
* \returns Number of sets of ephemerides in the file
*/
int readRinexNavAll(ephem_t eph[][MAX_SAT], const char *fname)
{
FILE *fp;
int ieph;
int sv;
char str[MAX_CHAR];
char tmp[20];
datetime_t t;
gpstime_t g;
gpstime_t g0;
double dt;
if (NULL==(fp=fopen(fname, "rt")))
return(-1);
// Clear valid flag
for (ieph=0; ieph<EPHEM_ARRAY_SIZE; ieph++)
for (sv=0; sv<MAX_SAT; sv++)
eph[ieph][sv].vflg = 0;
// Skip header lines
while (1)
{
if (NULL==fgets(str, MAX_CHAR, fp))
break;
if (strncmp(str+60, "END OF HEADER", 13)==0)
break;
}
g0.week = -1;
ieph = 0;
while (1)
{
if (NULL==fgets(str, MAX_CHAR, fp))
break;
// EPOCH
strncpy(tmp, str+3, 2);
tmp[2] = 0;
t.y = atoi(tmp) + 2000;
strncpy(tmp, str+6, 2);
tmp[2] = 0;
t.m = atoi(tmp);
strncpy(tmp, str+9, 2);
tmp[2] = 0;
t.d = atoi(tmp);
strncpy(tmp, str+12, 2);
tmp[2] = 0;
t.hh = atoi(tmp);
strncpy(tmp, str+15, 2);
tmp[2] = 0;
t.mm = atoi(tmp);
strncpy(tmp, str+18, 4);
tmp[2] = 0;
t.sec = atof(tmp);
date2gps(&t, &g);
if (g0.week==-1)
g0 = g;
// Check current time of clock
dt = subGpsTime(g, g0);
if (dt>SECONDS_IN_HOUR)
{
g0 = g;
ieph++; // a new set of ephemerides
if (ieph>=EPHEM_ARRAY_SIZE)
break;
}
// Date and time
eph[ieph][sv].t = t;
// PRN
strncpy(tmp, str, 2);
tmp[2] = 0;
sv = atoi(tmp)-1;
// SV CLK
eph[ieph][sv].toc = g;
strncpy(tmp, str+22, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19); // tmp[15]='E';
eph[ieph][sv].af0 = atof(tmp);
strncpy(tmp, str+41, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].af1 = atof(tmp);
strncpy(tmp, str+60, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].af2 = atof(tmp);
// BROADCAST ORBIT - 1
if (NULL==fgets(str, MAX_CHAR, fp))
break;
strncpy(tmp, str+3, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].iode = (int)atof(tmp);
strncpy(tmp, str+22, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].crs = atof(tmp);
strncpy(tmp, str+41, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].deltan = atof(tmp);
strncpy(tmp, str+60, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].m0 = atof(tmp);
// BROADCAST ORBIT - 2
if (NULL==fgets(str, MAX_CHAR, fp))
break;
strncpy(tmp, str+3, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].cuc = atof(tmp);
strncpy(tmp, str+22, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].ecc = atof(tmp);
strncpy(tmp, str+41, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].cus = atof(tmp);
strncpy(tmp, str+60, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].sqrta = atof(tmp);
// BROADCAST ORBIT - 3
if (NULL==fgets(str, MAX_CHAR, fp))
break;
strncpy(tmp, str+3, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].toe.sec = atof(tmp);
strncpy(tmp, str+22, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].cic = atof(tmp);
strncpy(tmp, str+41, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].omg0 = atof(tmp);
strncpy(tmp, str+60, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].cis = atof(tmp);
// BROADCAST ORBIT - 4
if (NULL==fgets(str, MAX_CHAR, fp))
break;
strncpy(tmp, str+3, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].inc0 = atof(tmp);
strncpy(tmp, str+22, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].crc = atof(tmp);
strncpy(tmp, str+41, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].aop = atof(tmp);
strncpy(tmp, str+60, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].omgdot = atof(tmp);
// BROADCAST ORBIT - 5
if (NULL==fgets(str, MAX_CHAR, fp))
break;
strncpy(tmp, str+3, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].idot = atof(tmp);
strncpy(tmp, str+41, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].toe.week = (int)atof(tmp);
// BROADCAST ORBIT - 6
if (NULL==fgets(str, MAX_CHAR, fp))
break;
strncpy(tmp, str+41, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].tgd = atof(tmp);
strncpy(tmp, str+60, 19);
tmp[19] = 0;
replaceExpDesignator(tmp, 19);
eph[ieph][sv].iodc = (int)atof(tmp);
// BROADCAST ORBIT - 7
if (NULL==fgets(str, MAX_CHAR, fp))
break;
// Set valid flag
eph[ieph][sv].vflg = 1;
// Update the working variables
eph[ieph][sv].A = eph[ieph][sv].sqrta * eph[ieph][sv].sqrta;
eph[ieph][sv].n = sqrt(GM_EARTH/(eph[ieph][sv].A*eph[ieph][sv].A*eph[ieph][sv].A)) + eph[ieph][sv].deltan;
eph[ieph][sv].sq1e2 = sqrt(1.0 - eph[ieph][sv].ecc*eph[ieph][sv].ecc);
eph[ieph][sv].omgkdot = eph[ieph][sv].omgdot - OMEGA_EARTH;
}
fclose(fp);
if (g0.week>=0)
ieph += 1; // Number of sets of ephemerides
return(ieph);
}
/*! \brief Compute range between a satellite and the receiver
* \param[out] rho The computed range
* \param[in] eph Ephemeris data of the satellite
* \param[in] g GPS time at time of receiving the signal
* \param[in] xyz position of the receiver
*/
void computeRange(range_t *rho, ephem_t eph, gpstime_t g, double xyz[])
{
double pos[3],vel[3],clk[2];
double los[3];
double tau;
double range,rate;
double xrot,yrot;
double llh[3],neu[3];
double tmat[3][3];
// SV position at time of the pseudorange observation.
satpos(eph, g, pos, vel, clk);
// Receiver to satellite vector and light-time.