Early/Obsolete code for Location Service (LCS / SMLC / RRLP)
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osmocom-lcs/ubx-parse.c

246 lines
6.5 KiB

/*
* ubx-parse.c
*
* Implementation of parsing code converting UBX messages to GPS assist
* data
*
*
* Copyright (C) 2009 Sylvain Munaut <tnt@246tNt.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdio.h>
#include "gps.h"
#include "ubx.h"
#include "ubx-parse.h"
#define DEBUG 1
#if DEBUG
#define printd(x, args ...) printf(x, ## args)
#else
#define printd(x, args ...)
#endif
#define DEBUG1 0
#if DEBUG1
#define printd1(x, args ...) printf(x, ## args)
#else
#define printd1(x, args ...)
#endif
/* Helpers */
static int
float_to_fixedpoint(float f, int sf)
{
if (sf < 0) {
while (sf++ < 0)
f *= 2.0f;
} else {
while (sf-- > 0)
f *= 0.5f;
}
return (int)f;
}
static inline int
double_to_fixedpoint(double d, int sf)
{
if (sf < 0) {
while (sf++ < 0)
d *= 2.0;
} else {
while (sf-- > 0)
d *= 0.5;
}
return (int)d;
}
/* UBX message parsing to fill gps assist data */
static void
_ubx_msg_parse_nav_posllh(struct ubx_hdr *hdr, void *pl, int pl_len, void *ud)
{
struct ubx_nav_posllh *nav_posllh = pl;
struct gps_assist_data *gps = ud;
printd("[.] NAV_POSLLH\n");
gps->fields |= GPS_FIELD_REFPOS;
gps->ref_pos.latitude = (double)(nav_posllh->lat) * 1e-7;
gps->ref_pos.longitude = (double)(nav_posllh->lon) * 1e-7;
gps->ref_pos.altitude = (double)(nav_posllh->height) * 1e-3;
printd(" TOW %lu\n", nav_posllh->itow);
printd(" latitude %f\n", gps->ref_pos.latitude);
printd(" longitude %f\n", gps->ref_pos.longitude);
printd(" altitude %f\n", gps->ref_pos.altitude);
}
static void
_ubx_msg_parse_aid_ini(struct ubx_hdr *hdr, void *pl, int pl_len, void *ud)
{
struct ubx_aid_ini *aid_ini = pl;
struct gps_assist_data *gps = ud;
printd("[.] AID_INI\n");
/* Extract info for "Reference Time" */
gps->fields |= GPS_FIELD_REFTIME;
gps->ref_time.wn = aid_ini->wn;
gps->ref_time.tow = (double)aid_ini->tow * 1e-3;
gps->ref_time.when = time(NULL);
printd(" WN %d\n", gps->ref_time.wn);
printd(" TOW %ld\n", aid_ini->tow);
if((aid_ini->flags & 0x03) != 0x03) { /* time and pos valid ? */
fprintf(stderr, "Postion and/or time not valid (0x%lx)", aid_ini->flags);
}
// FIXME: We could extract ref position as well but we need it in
// WGS84 geodetic coordinates and it's provided as ecef, so
// we need a lot of math ...
}
static void
_ubx_msg_parse_aid_hui(struct ubx_hdr *hdr, void *pl, int pl_len, void *ud)
{
struct ubx_aid_hui *aid_hui = pl;
struct gps_assist_data *gps = ud;
printd("[.] AID_HUI\n");
if (aid_hui->flags & 0x2) { /* UTC parameters valid */
struct gps_utc_model *utc = &gps->utc;
printd(" UTC\n");
gps->fields |= GPS_FIELD_UTC;
utc->a0 = double_to_fixedpoint(aid_hui->utc_a0, -30);
utc->a1 = double_to_fixedpoint(aid_hui->utc_a1, -50);
utc->delta_t_ls = aid_hui->utc_ls;
utc->t_ot = aid_hui->utc_tot >> 12;
utc->wn_t = aid_hui->utc_wnt;
utc->wn_lsf = aid_hui->utc_wnf;
utc->dn = aid_hui->utc_dn;
utc->delta_t_lsf = aid_hui->utc_lsf;
}
if (aid_hui->flags & 0x04) { /* Klobuchar parameters valid */
struct gps_ionosphere_model *iono = &gps->ionosphere;
printd(" IONOSPHERE\n");
gps->fields |= GPS_FIELD_IONOSPHERE;
iono->alpha_0 = float_to_fixedpoint(aid_hui->klob_a0, -30);
iono->alpha_1 = float_to_fixedpoint(aid_hui->klob_a1, -27);
iono->alpha_2 = float_to_fixedpoint(aid_hui->klob_a2, -24);
iono->alpha_3 = float_to_fixedpoint(aid_hui->klob_a3, -24);
iono->beta_0 = float_to_fixedpoint(aid_hui->klob_b0, 11);
iono->beta_1 = float_to_fixedpoint(aid_hui->klob_b1, 14);
iono->beta_2 = float_to_fixedpoint(aid_hui->klob_b2, 16);
iono->beta_3 = float_to_fixedpoint(aid_hui->klob_b3, 16);
}
}
static void
_ubx_msg_parse_aid_alm(struct ubx_hdr *hdr, void *pl, int pl_len, void *ud)
{
struct ubx_aid_alm *aid_alm = pl;
struct gps_assist_data *gps = ud;
if(pl_len == 8) /* length if not available */
return;
if(pl_len != sizeof(struct ubx_aid_alm)) {
fprintf(stderr, "pl_len != sizeof(struct ubx_aid_alm) (%d)\n", pl_len);
return;
}
printd("[.] AID_ALM %2ld - %ld (nsv = %d)\n", aid_alm->sv_id, aid_alm->gps_week, gps->almanac.n_sv);
if (aid_alm->gps_week) {
int i = gps->almanac.n_sv++;
gps->fields |= GPS_FIELD_ALMANAC;
gps->almanac.wna = aid_alm->gps_week & 0xff;
gps_unpack_sf45_almanac(aid_alm->alm_words, &gps->almanac.svs[i]);
/* set satellite ID this way, otherwise it will be wrong */
gps->almanac.svs[i].sv_id = aid_alm->sv_id;
}
}
static void
_ubx_msg_parse_aid_eph(struct ubx_hdr *hdr, void *pl, int pl_len, void *ud)
{
struct ubx_aid_eph *aid_eph = pl;
struct gps_assist_data *gps = ud;
if(pl_len == 8) /* length if not available */
return;
if(pl_len != sizeof(struct ubx_aid_eph)) {
fprintf(stderr, "pl_len != sizeof(struct ubx_aid_eph) (%d)\n", pl_len);
return;
}
printd("[.] AID_EPH %2ld - %s (nsv = %d)\n", aid_eph->sv_id, aid_eph->present ? "present" : "", gps->ephemeris.n_sv);
if (aid_eph->present) {
int i = gps->ephemeris.n_sv++;
gps->fields |= GPS_FIELD_EPHEMERIS;
gps->ephemeris.svs[i].sv_id = aid_eph->sv_id;
gps_unpack_sf123(aid_eph->eph_words, &gps->ephemeris.svs[i]);
}
}
static void
_ubx_msg_parse_nav_timegps(struct ubx_hdr *hdr, void *pl, int pl_len, void *ud)
{
struct ubx_nav_timegps *nav_timegps = pl;
struct gps_assist_data *gps = ud;
printd1("[.] NAV_TIMEGPS\n");
/* Extract info for "Reference Time" */
gps->fields |= GPS_FIELD_REFTIME;
gps->ref_time.wn = nav_timegps->week;
gps->ref_time.tow = (double)nav_timegps->itow * 1e-3;
gps->ref_time.when = time(NULL);
printd1(" WN %d\n", nav_timegps->week);
printd1(" TOW %ld\n", nav_timegps->itow);
}
/* Dispatch table */
struct ubx_dispatch_entry ubx_parse_dt[] = {
UBX_DISPATCH(NAV, POSLLH, _ubx_msg_parse_nav_posllh),
UBX_DISPATCH(AID, INI, _ubx_msg_parse_aid_ini),
UBX_DISPATCH(AID, HUI, _ubx_msg_parse_aid_hui),
UBX_DISPATCH(AID, ALM, _ubx_msg_parse_aid_alm),
UBX_DISPATCH(AID, EPH, _ubx_msg_parse_aid_eph),
UBX_DISPATCH(NAV, TIMEGPS, _ubx_msg_parse_nav_timegps),
};