/* decode Galileo navigation data (I/NAV word 10) -------------------------------
*
* args : uint8_t *buff I navigation data bits
* sdreph_t *eph I/O sdr ephemeris structure
* return : none
*-----------------------------------------------------------------------------*/
void decode_word10(const uint8_t *buff, sdrnav_t *nav)
{
// 0 | 6
// 6 | 4
// 10 | 16
// 26 | 11
// 37 | 16
// 53 | 16
// 69 | 13
// 82 | 2
// 84 | 2
// 86 | 16 A_0G
// 102 | 12 A_1G
// 112 - ---
// 114, 2 | 8 t_0G
// 122,10 | 6 WN_0G
// 128,16
sdreph_t *eph = &nav->sdreph;
Ephemeris[nav->sat].A_0G = getbits (buff, OFFSET1+ 86, 16)*P2_35;
Ephemeris[nav->sat].A_1G = getbits2(buff, OFFSET1+102, 10, OFFSET2+0, 2)*P2_30*P2_21;
Ephemeris[nav->sat].t_0G = getbitu (buff, OFFSET2+ 2, 8)*3600;
Ephemeris[nav->sat].WN_0G = getbitu (buff, OFFSET2+ 10, 6);
//printf("word10 GST-GPS %s: %e %e %d %d\n", PRN(nav->sat),
// Ephemeris[nav->sat].A_0G, Ephemeris[nav->sat].A_1G,
// Ephemeris[nav->sat].t_0G, Ephemeris[nav->sat].WN_0G);
}
/* decode Galileo navigation data (I/NAV word 4) -------------------------------
*
* args : uint8_t *buff I navigation data bits
* sdreph_t *eph I/O sdr ephemeris structure
* return : none
*-----------------------------------------------------------------------------*/
void decode_word4(const uint8_t *buff, sdrnav_t *nav)
{
sdreph_t *eph = &nav->sdreph;
int oldiodc=eph->eph.iodc;
eph->eph.iodc =getbitu( buff,OFFSET1+ 6,10);
eph->eph.cic =getbits( buff,OFFSET1+22,16)*P2_29;
eph->eph.cis =getbits( buff,OFFSET1+38,16)*P2_29;
eph->toc_gst =getbitu( buff,OFFSET1+54,14)*60;
eph->eph.f0 =getbits( buff,OFFSET1+68,31)*P2_34;
eph->eph.f1 =getbits2(buff,OFFSET1+99,13,OFFSET2+ 0, 8)*P2_46;
eph->eph.f2 =getbits( buff,OFFSET2+ 8, 6)*P2_59;
eph->eph.iode =eph->eph.iodc;
/* compute time of clock */
if (eph->week_gst!=0) {
eph->eph.toc=gst2time(eph->week_gst,eph->toc_gst);
Ephemeris[nav->sat].Page4(eph->eph.iodc, eph->eph.cic, eph->eph.cis, eph->eph.f0, eph->eph.f1, eph->eph.f2, time2gpst(eph->eph.toc, NULL));
} else {
Ephemeris[nav->sat].Page4(eph->eph.iodc, eph->eph.cic, eph->eph.cis, eph->eph.f0, eph->eph.f1, eph->eph.f2);
}
/* ephemeris update flag */
if (oldiodc-eph->eph.iodc!=0) eph->update=ON;
/* subframe counter */
eph->cnt++;
}
/* decode GPS/QZS navigation data (subframe 3) ---------------------------------
*
* args : uint8_t *buff I navigation data bits
* sdreph_t *eph I/O sdr ephemeris structure
* return : none
*-----------------------------------------------------------------------------*/
void decode_subfrm3(const uint8_t *buff, sdreph_t *eph)
{
int oldiode=eph->eph.iode;
eph->tow_gpst=getbitu( buff, 30,17)*6.0;
eph->eph.cic =getbits( buff, 60,16)*P2_29;
eph->eph.OMG0=getbits2(buff, 76, 8, 90,24)*P2_31*SC2RAD;
eph->eph.cis =getbits( buff,120,16)*P2_29;
eph->eph.i0 =getbits2(buff,136, 8,150,24)*P2_31*SC2RAD;
eph->eph.crc =getbits( buff,180,16)*P2_5;
eph->eph.omg =getbits2(buff,196, 8,210,24)*P2_31*SC2RAD;
eph->eph.OMGd=getbits( buff,240,24)*P2_43*SC2RAD;
eph->eph.iode=getbitu( buff,270, 8);
eph->eph.idot=getbits( buff,278,14)*P2_43*SC2RAD;
/* ephemeris update flag */
if (oldiode-eph->eph.iode!=0) eph->update=ON;
/* subframe counter */
eph->cnt++;
}
/* decode Galileo navigation data (I/NAV word 3) -------------------------------
*
* args : uint8_t *buff I navigation data bits
* sdreph_t *eph I/O sdr ephemeris structure
* return : none
*-----------------------------------------------------------------------------*/
void decode_word3(const uint8_t *buff, sdrnav_t *nav)
{
sdreph_t *eph = &nav->sdreph;
int oldiodc=eph->eph.iodc;
eph->eph.iodc =getbitu( buff,OFFSET1+ 6,10);
eph->eph.OMGd =getbits( buff,OFFSET1+ 16,24)*P2_43*SC2RAD;
eph->eph.deln =getbits( buff,OFFSET1+ 40,16)*P2_43*SC2RAD;
eph->eph.cuc =getbits( buff,OFFSET1+ 56,16)*P2_29;
eph->eph.cus =getbits( buff,OFFSET1+ 72,16)*P2_29;
eph->eph.crc =getbits( buff,OFFSET1+ 88,16)*P2_5;
eph->eph.crs =getbits2(buff,OFFSET1+104, 8,OFFSET2+ 0, 8)*P2_5;
eph->eph.sva =0; /*getbitu( buff,OFFSET2+ 8,8); (undefined) */
eph->eph.iode =eph->eph.iodc;
Ephemeris[nav->sat].Page3(eph->eph.iodc, eph->eph.OMGd, eph->eph.deln, eph->eph.cuc, eph->eph.cus, eph->eph.crc, eph->eph.crs);
/* ephemeris update flag */
if (oldiodc-eph->eph.iodc!=0) eph->update=ON;
/* ephemeris counter */
eph->cnt++;
}
/* decode GPS/QZS navigation data (subframe 2) ---------------------------------
*
* args : uint8_t *buff I navigation data bits
* sdreph_t *eph I/O sdr ephemeris structure
* return : none
*-----------------------------------------------------------------------------*/
void decode_subfrm2(const uint8_t *buff, sdreph_t *eph)
{
double sqrtA;
int oldiode=eph->eph.iode;
eph->tow_gpst=getbitu( buff, 30,17)*6.0;
eph->eph.iode=getbitu( buff, 60, 8);
eph->eph.crs =getbits( buff, 68,16)*P2_5;
eph->eph.deln=getbits( buff, 90,16)*P2_43*SC2RAD;
eph->eph.M0 =getbits2(buff,106, 8,120,24)*P2_31*SC2RAD;
eph->eph.cuc =getbits( buff,150,16)*P2_29;
eph->eph.e =getbitu2(buff,166, 8,180,24)*P2_33;
eph->eph.cus =getbits( buff,210,16)*P2_29;
sqrtA =getbitu2(buff,226, 8,240,24)*P2_19;
eph->eph.toes=getbitu( buff,270,16)*16.0;
eph->eph.fit =getbitu( buff,286, 1);
eph->eph.A =sqrtA*sqrtA;
/* ephemeris update flag */
if (oldiode-eph->eph.iode!=0) eph->update=ON;
/* subframe counter */
eph->cnt++;
}
/* decode BeiDou D1 ephemeris --------------------------------------------------
* decode BeiDou D1 ephemeris (IGSO/MEO satellites) (ref [3] 5.2)
* args : unsigned char *buff I beidou D1 subframe bits
* buff[ 0- 37]: subframe 1 (300 bits)
* buff[38- 75]: subframe 2
* buff[76-113]: subframe 3
* eph_t *eph IO ephemeris structure
* return : status (1:ok,0:error)
*-----------------------------------------------------------------------------*/
extern int decode_bds_d1(const unsigned char *buff, eph_t *eph)
{
double toc_bds,sqrtA;
unsigned int toe1,toe2,sow1,sow2,sow3;
int i,frn1,frn2,frn3;
trace(3,"decode_bds_d1:\n");
i=8*38*0; /* subframe 1 */
frn1 =getbitu (buff,i+ 15, 3);
sow1 =getbitu2(buff,i+ 18, 8,i+30,12);
eph->svh =getbitu (buff,i+ 42, 1); /* SatH1 */
eph->iodc =getbitu (buff,i+ 43, 5); /* AODC */
eph->sva =getbitu (buff,i+ 48, 4);
eph->week =getbitu (buff,i+ 60,13); /* week in BDT */
toc_bds =getbitu2(buff,i+ 73, 9,i+ 90, 8)*8.0;
eph->tgd[0]=getbits (buff,i+ 98,10)*0.1*1E-9;
eph->tgd[1]=getbits2(buff,i+108, 4,i+120, 6)*0.1*1E-9;
eph->f2 =getbits (buff,i+214,11)*P2_66;
eph->f0 =getbits2(buff,i+225, 7,i+240,17)*P2_33;
eph->f1 =getbits2(buff,i+257, 5,i+270,17)*P2_50;
eph->iode =getbitu (buff,i+287, 5); /* AODE */
i=8*38*1; /* subframe 2 */
frn2 =getbitu (buff,i+ 15, 3);
sow2 =getbitu2(buff,i+ 18, 8,i+30,12);
eph->deln =getbits2(buff,i+ 42,10,i+ 60, 6)*P2_43*SC2RAD;
eph->cuc =getbits2(buff,i+ 66,16,i+ 90, 2)*P2_31;
eph->M0 =getbits2(buff,i+ 92,20,i+120,12)*P2_31*SC2RAD;
eph->e =getbitu2(buff,i+132,10,i+150,22)*P2_33;
eph->cus =getbits (buff,i+180,18)*P2_31;
eph->crc =getbits2(buff,i+198, 4,i+210,14)*P2_6;
eph->crs =getbits2(buff,i+224, 8,i+240,10)*P2_6;
sqrtA =getbitu2(buff,i+250,12,i+270,20)*P2_19;
toe1 =getbitu (buff,i+290, 2); /* TOE 2-MSB */
eph->A =sqrtA*sqrtA;
i=8*38*2; /* subframe 3 */
frn3 =getbitu (buff,i+ 15, 3);
sow3 =getbitu2(buff,i+ 18, 8,i+30,12);
toe2 =getbitu2(buff,i+ 42,10,i+ 60, 5); /* TOE 5-LSB */
eph->i0 =getbits2(buff,i+ 65,17,i+ 90,15)*P2_31*SC2RAD;
eph->cic =getbits2(buff,i+105, 7,i+120,11)*P2_31;
eph->OMGd =getbits2(buff,i+131,11,i+150,13)*P2_43*SC2RAD;
eph->cis =getbits2(buff,i+163, 9,i+180, 9)*P2_31;
eph->idot =getbits2(buff,i+189,13,i+210, 1)*P2_43*SC2RAD;
eph->OMG0 =getbits2(buff,i+211,21,i+240,11)*P2_31*SC2RAD;
eph->omg =getbits2(buff,i+251,11,i+270,21)*P2_31*SC2RAD;
eph->toes =merge_two_u(toe1,toe2,15)*8.0;
/* check consistency of subframe numbers, sows and toe/toc */
if (frn1!=1||frn2!=2||frn3!=3) {
trace(3,"decode_bds_d1 error: frn=%d %d %d\n",frn1,frn2,frn3);
return 0;
}
if (sow2!=sow1+6||sow3!=sow2+6) {
trace(3,"decode_bds_d1 error: sow=%d %d %d\n",sow1,sow2,sow3);
return 0;
}
if (toc_bds!=eph->toes) {
trace(3,"decode_bds_d1 error: toe=%.0f toc=%.0f\n",eph->toes,toc_bds);
return 0;
}
eph->ttr=bdt2gpst(bdt2time(eph->week,sow1)); /* bdt -> gpst */
if (eph->toes>sow1+302400.0) eph->week++;
else if (eph->toes<sow1-302400.0) eph->week--;
eph->toe=bdt2gpst(bdt2time(eph->week,eph->toes)); /* bdt -> gpst */
eph->toc=bdt2gpst(bdt2time(eph->week,toc_bds)); /* bdt -> gpst */
return 1;
}
/* decode BeiDou D2 ephemeris --------------------------------------------------
* decode BeiDou D2 ephemeris (GEO satellites) (ref [3] 5.3)
* args : unsigned char *buff I beidou D2 subframe 1 page bits
* buff[ 0- 37]: page 1 (300 bits)
* buff[ 38- 75]: page 2
* ...
* buff[342-379]: page 10
* eph_t *eph IO ephemeris structure
* return : status (1:ok,0:error)
*-----------------------------------------------------------------------------*/
extern int decode_bds_d2(const unsigned char *buff, eph_t *eph)
{
double toc_bds,sqrtA;
unsigned int f1p4,cucp5,ep6,cicp7,i0p8,OMGdp9,omgp10;
unsigned int sow1,sow3,sow4,sow5,sow6,sow7,sow8,sow9,sow10;
int i,f1p3,cucp4,ep5,cicp6,i0p7,OMGdp8,omgp9;
int pgn1,pgn3,pgn4,pgn5,pgn6,pgn7,pgn8,pgn9,pgn10;
trace(3,"decode_bds_d2:\n");
i=8*38*0; /* page 1 */
pgn1 =getbitu (buff,i+ 42, 4);
sow1 =getbitu2(buff,i+ 18, 8,i+ 30,12);
eph->svh =getbitu (buff,i+ 46, 1); /* SatH1 */
eph->iodc =getbitu (buff,i+ 47, 5); /* AODC */
eph->sva =getbitu (buff,i+ 60, 4);
eph->week =getbitu (buff,i+ 64,13); /* week in BDT */
toc_bds =getbitu2(buff,i+ 77, 5,i+ 90,12)*8.0;
eph->tgd[0]=getbits (buff,i+102,10)*0.1*1E-9;
eph->tgd[1]=getbits (buff,i+120,10)*0.1*1E-9;
i=8*38*2; /* page 3 */
pgn3 =getbitu (buff,i+ 42, 4);
sow3 =getbitu2(buff,i+ 18, 8,i+ 30,12);
eph->f0 =getbits2(buff,i+100,12,i+120,12)*P2_33;
f1p3 =getbits (buff,i+132,4);
i=8*38*3; /* page 4 */
pgn4 =getbitu (buff,i+ 42, 4);
sow4 =getbitu2(buff,i+ 18, 8,i+ 30,12);
f1p4 =getbitu2(buff,i+ 46, 6,i+ 60,12);
eph->f2 =getbits2(buff,i+ 72,10,i+ 90, 1)*P2_66;
eph->iode =getbitu (buff,i+ 91, 5); /* AODE */
eph->deln =getbits (buff,i+ 96,16)*P2_43*SC2RAD;
cucp4 =getbits (buff,i+120,14);
i=8*38*4; /* page 5 */
pgn5 =getbitu (buff,i+ 42, 4);
sow5 =getbitu2(buff,i+ 18, 8,i+ 30,12);
cucp5 =getbitu (buff,i+ 46, 4);
eph->M0 =getbits3(buff,i+ 50, 2,i+ 60,22,i+ 90, 8)*P2_31*SC2RAD;
eph->cus =getbits2(buff,i+ 98,14,i+120, 4)*P2_31;
ep5 =getbits (buff,i+124,10);
i=8*38*5; /* page 6 */
pgn6 =getbitu (buff,i+ 42, 4);
sow6 =getbitu2(buff,i+ 18, 8,i+ 30,12);
ep6 =getbitu2(buff,i+ 46, 6,i+ 60,16);
sqrtA =getbitu3(buff,i+ 76, 6,i+ 90,22,i+120,4)*P2_19;
cicp6 =getbits (buff,i+124,10);
eph->A =sqrtA*sqrtA;
i=8*38*6; /* page 7 */
pgn7 =getbitu (buff,i+ 42, 4);
sow7 =getbitu2(buff,i+ 18, 8,i+ 30,12);
cicp7 =getbitu2(buff,i+ 46, 6,i+ 60, 2);
eph->cis =getbits (buff,i+ 62,18)*P2_31;
eph->toes =getbitu2(buff,i+ 80, 2,i+ 90,15)*8.0;
i0p7 =getbits2(buff,i+105, 7,i+120,14);
i=8*38*7; /* page 8 */
pgn8 =getbitu (buff,i+ 42, 4);
sow8 =getbitu2(buff,i+ 18, 8,i+ 30,12);
i0p8 =getbitu2(buff,i+ 46, 6,i+ 60, 5);
eph->crc =getbits2(buff,i+ 65,17,i+ 90, 1)*P2_6;
eph->crs =getbits (buff,i+ 91,18)*P2_6;
OMGdp8 =getbits2(buff,i+109, 3,i+120,16);
i=8*38*8; /* page 9 */
pgn9 =getbitu (buff,i+ 42, 4);
sow9 =getbitu2(buff,i+ 18, 8,i+ 30,12);
OMGdp9 =getbitu (buff,i+ 46, 5);
eph->OMG0 =getbits3(buff,i+ 51, 1,i+ 60,22,i+ 90, 9)*P2_31*SC2RAD;
omgp9 =getbits2(buff,i+ 99,13,i+120,14);
i=8*38*9; /* page 10 */
pgn10 =getbitu (buff,i+ 42, 4);
sow10 =getbitu2(buff,i+ 18, 8,i+ 30,12);
omgp10 =getbitu (buff,i+ 46, 5);
eph->idot =getbits2(buff,i+ 51, 1,i+ 60,13)*P2_43*SC2RAD;
/* check consistency of page numbers, sows and toe/toc */
if (pgn1!=1||pgn3!=3||pgn4!=4||pgn5!=5||pgn6!=6||pgn7!=7||pgn8!=8||pgn9!=9||
pgn10!=10) {
trace(3,"decode_bds_d2 error: pgn=%d %d %d %d %d %d %d %d %d\n",
pgn1,pgn3,pgn4,pgn5,pgn6,pgn7,pgn8,pgn9,pgn10);
return 0;
}
if (sow3!=sow1+6||sow4!=sow3+3||sow5!=sow4+3||sow6!=sow5+3||
sow7!=sow6+3||sow8!=sow7+3||sow9!=sow8+3||sow10!=sow9+3) {
trace(3,"decode_bds_d2 error: sow=%d %d %d %d %d %d %d %d %d\n",
sow1,sow3,sow4,sow5,sow6,sow7,sow8,sow9,sow10);
return 0;
}
if (toc_bds!=eph->toes) {
trace(3,"decode_bds_d2 error: toe=%.0f toc=%.0f\n",eph->toes,toc_bds);
return 0;
}
eph->f1 =merge_two_s(f1p3 ,f1p4 ,18)*P2_50;
eph->cuc =merge_two_s(cucp4 ,cucp5 , 4)*P2_31;
eph->e =merge_two_s(ep5 ,ep6 ,22)*P2_33;
eph->cic =merge_two_s(cicp6 ,cicp7 , 8)*P2_31;
eph->i0 =merge_two_s(i0p7 ,i0p8 ,11)*P2_31*SC2RAD;
eph->OMGd=merge_two_s(OMGdp8,OMGdp9, 5)*P2_43*SC2RAD;
eph->omg =merge_two_s(omgp9 ,omgp10, 5)*P2_31*SC2RAD;
eph->ttr=bdt2gpst(bdt2time(eph->week,sow1)); /* bdt -> gpst */
if (eph->toes>sow1+302400.0) eph->week++;
else if (eph->toes<sow1-302400.0) eph->week--;
eph->toe=bdt2gpst(bdt2time(eph->week,eph->toes)); /* bdt -> gpst */
eph->toc=bdt2gpst(bdt2time(eph->week,toc_bds)); /* bdt -> gpst */
return 1;
}
