/* decode gps navigation data subframe 5 -------------------------------------*/
static void decode_gps_subfrm5(const unsigned char *buff, alm_t *alm)
{
double toas;
int i,sat,week,svid=getbitu(buff,50,6);
if (1<=svid&&svid<=24) { /* page 1-24 */
/* decode almanac */
sat=getbitu(buff,50,6);
if (1<=sat&&sat<=32) decode_almanac(buff,sat,alm);
}
else if (svid==51) { /* page 25 */
if (alm) {
i=56;
toas=getbitu(buff,i,8)*4096; i+=8;
week=getbitu(buff,i,8); i+=8;
week=adjgpsweek(week);
/* decode sv health */
for (sat=1;sat<=24;sat++) {
alm[sat-1].svh=getbitu(buff,i,6); i+=6;
}
for (sat=1;sat<=32;sat++) {
alm[sat-1].toas=toas;
alm[sat-1].week=week;
alm[sat-1].toa=gpst2time(week,toas);
}
}
}
}
/* decode gps navigation data subframe 4 -------------------------------------*/
static void decode_gps_subfrm4(const unsigned char *buff, alm_t *alm,
double *ion, double *utc, int *leaps)
{
int i,sat,svid=getbitu(buff,50,6);
if (25<=svid&&svid<=32) { /* page 2,3,4,5,7,8,9,10 */
/* decode almanac */
sat=getbitu(buff,50,6);
if (1<=sat&&sat<=32) decode_almanac(buff,sat,alm);
}
else if (svid==63) { /* page 25 */
/* decode as and sv config */
i=56;
for (sat=1;sat<=32;sat++) {
if (alm) alm[sat-1].svconf=getbitu(buff,i,4); i+=4;
}
/* decode sv health */
i=186;
for (sat=25;sat<=32;sat++) {
if (alm) alm[sat-1].svh =getbitu(buff,i,6); i+=6;
}
}
else if (svid==56) { /* page 18 */
/* decode ion/utc parameters */
if (ion) {
i=56;
ion[0]=getbits(buff,i, 8)*P2_30; i+= 8;
ion[1]=getbits(buff,i, 8)*P2_27; i+= 8;
ion[2]=getbits(buff,i, 8)*P2_24; i+= 8;
ion[3]=getbits(buff,i, 8)*P2_24; i+= 8;
ion[4]=getbits(buff,i, 8)*pow(2,11); i+= 8;
ion[5]=getbits(buff,i, 8)*pow(2,14); i+= 8;
ion[6]=getbits(buff,i, 8)*pow(2,16); i+= 8;
ion[7]=getbits(buff,i, 8)*pow(2,16);
}
if (utc) {
i=120;
utc[1]=getbits(buff,i,24)*P2_50; i+=24;
utc[0]=getbits(buff,i,32)*P2_30; i+=32;
utc[2]=getbits(buff,i, 8)*pow(2,12); i+= 8;
utc[3]=getbitu(buff,i, 8);
}
if (leaps) {
i=192;
*leaps=getbits(buff,i,8);
}
}
}
/* decode qzss navigation data subframe 4/5 ----------------------------------*/
static void decode_qzs_subfrm45(const unsigned char *buff, alm_t *alm,
double *ion, double *utc, int *leaps)
{
int i,j,sat,toas,week,svid=getbitu(buff,50,6);
if (1<=svid&&svid<=5) { /* qzss almanac */
if (!(sat=satno(SYS_QZS,192+svid))) return;
decode_almanac(buff,sat,alm);
}
else if (svid==51) { /* qzss health */
if (alm) {
i=56;
toas=getbitu(buff,i,8)*4096; i+=8;
week=getbitu(buff,i,8); i+=8;
week=adjgpsweek(week);
for (j=0;j<5;j++) {
if (!(sat=satno(SYS_QZS,193+j))) continue;
alm[sat-1].toas=toas;
alm[sat-1].week=week;
alm[sat-1].toa=gpst2time(week,toas);
alm[sat-1].svh=getbitu(buff,i,6); i+=6;
}
}
}
else if (svid==56) { /* ion/utc parameters */
if (ion) {
i=56;
ion[0]=getbits(buff,i, 8)*P2_30; i+= 8;
ion[1]=getbits(buff,i, 8)*P2_27; i+= 8;
ion[2]=getbits(buff,i, 8)*P2_24; i+= 8;
ion[3]=getbits(buff,i, 8)*P2_24; i+= 8;
ion[4]=getbits(buff,i, 8)*pow(2,11); i+= 8;
ion[5]=getbits(buff,i, 8)*pow(2,14); i+= 8;
ion[6]=getbits(buff,i, 8)*pow(2,16); i+= 8;
ion[7]=getbits(buff,i, 8)*pow(2,16);
}
if (utc) {
i=120;
utc[1]=getbits(buff,i,24)*P2_50; i+=24;
utc[0]=getbits(buff,i,32)*P2_30; i+=32;
utc[2]=getbits(buff,i, 8)*pow(2,12); i+= 8;
utc[3]=getbitu(buff,i, 8);
}
}
}
/* decode navigation data subframe 5 -----------------------------------------*/
static int decode_subfrm5(const unsigned char *buff, alm_t *alm)
{
double toas;
int i,sat,week,svid=getbitu(buff,50,6);
trace(4,"decode_subfrm5: svid=%d\n",svid);
trace(5,"decode_subfrm5: buff=");
traceb(5,buff,30);
if (1<=svid&&svid<=24) { /* page 1-24 */
/* decode almanac */
decode_almanac(buff,alm);
}
else if (svid==51) { /* page 25 */
if (alm) {
i=56;
toas=getbitu(buff,i,8)*4096;
i+=8;
week=getbitu(buff,i,8);
i+=8;
week=adjgpsweek(week);
/* decode sv health */
for (sat=1; sat<=24; sat++) {
alm[sat-1].svh=getbitu(buff,i,6);
i+=6;
}
for (sat=1; sat<=32; sat++) {
alm[sat-1].toas=toas;
alm[sat-1].week=week;
alm[sat-1].toa=gpst2time(week,toas);
}
}
}
return 5;
}
