Merge pull request #235 from jacobmcnamee/prn_generalize

remove indexing by PRN

Author: jacobmcnamee

include/libswiftnav/observation.h

@@ -48,14 +48,14 @@ u8 make_propagated_sdiffs_wip(u8 n_local, navigation_measurement_t *m_local,
 u8 make_propagated_sdiffs(u8 n_local, navigation_measurement_t *m_local,
                           u8 n_remote, navigation_measurement_t *m_remote,
                           double *remote_dists, double remote_pos_ecef[3],
-                          ephemeris_t *es, gps_time_t t,
+                          const ephemeris_t *e[], gps_time_t t,
                           sdiff_t *sds);
 
 s8 make_dd_measurements_and_sdiffs(gnss_signal_t ref_sid, const gnss_signal_t *non_ref_sids, u8 num_dds,
                                    u8 num_sdiffs, const sdiff_t *sdiffs_in,
                                    double *dd_meas, sdiff_t *sdiffs_out);
 
-u8 check_lock_counters(u8 n_sds, const sdiff_t *sds, u16 *lock_counters,
+u8 check_lock_counters(u8 n_sds, const sdiff_t *sds, u16 *lock_counters[],
                        gnss_signal_t *sats_to_drop);
 
 s8 copy_sdiffs_put_ref_first(const gnss_signal_t ref_sid, const u8 num_sdiffs,

include/libswiftnav/track.h

@@ -233,10 +233,7 @@ float cn0_est(cn0_est_state_t *s, float I, float Q);
 
 void calc_navigation_measurement(u8 n_channels, channel_measurement_t meas[],
                                  navigation_measurement_t nav_meas[],
-                                 double nav_time, ephemeris_t ephemerides[]);
-void calc_navigation_measurement_(u8 n_channels, channel_measurement_t* meas[],
-                                  navigation_measurement_t* nav_meas[],
-                                  double nav_time, ephemeris_t* ephemerides[]);
+                                 double nav_time, const ephemeris_t* e[]);
 
 int nav_meas_cmp(const void *a, const void *b);
 u8 tdcp_doppler(u8 n_new, navigation_measurement_t *m_new,

src/observation.c

@@ -58,7 +58,7 @@ static void single_diff_(void *context, u32 n, const void *a, const void *b)
   const navigation_measurement_t *m_b = (const navigation_measurement_t *)b;
   sdiff_t *sds = (sdiff_t *)context;
 
-  sds[n].sid.sat = m_a->sid.sat;
+  sds[n].sid = m_a->sid;
   sds[n].pseudorange = m_a->raw_pseudorange - m_b->raw_pseudorange;
   sds[n].carrier_phase = m_a->carrier_phase - m_b->carrier_phase;
   sds[n].doppler = m_a->raw_doppler - m_b->raw_doppler;
@@ -168,15 +168,16 @@ int cmp_sid_sdiff(const void *a, const void *b)
  *                           correspond to the i-th element of m_remote).
  * \param remote_pos_ecef   The position of the remote receiver (presumed
  *                           constant in ecef).
- * \param es
+ * \param e                 Array of pointers to ephemerides corresponding
+ *                          to the signals in m_local
  * \param t
  * \param sds               The single differenced propagated measurements.
  * \return The number of sats common in both local and remote sdiffs.
  */
 u8 make_propagated_sdiffs(u8 n_local, navigation_measurement_t *m_local,
                           u8 n_remote, navigation_measurement_t *m_remote,
                           double *remote_dists, double remote_pos_ecef[3],
-                          ephemeris_t *es, gps_time_t t,
+                          const ephemeris_t *e[], gps_time_t t,
                           sdiff_t *sds)
 {
   u8 i, j, n = 0;
@@ -187,12 +188,12 @@ u8 make_propagated_sdiffs(u8 n_local, navigation_measurement_t *m_local,
       j--;
     else if (sid_compare(m_local[i].sid, m_remote[j].sid) > 0)
       i--;
-    else if (ephemeris_good(&es[m_local[i].sid.sat], t)) {
+    else if (ephemeris_good(e[i], t)) {
       double clock_err;
       double clock_rate_err;
       double local_sat_pos[3];
       double local_sat_vel[3];
-      calc_sat_state(&es[m_local[i].sid.sat], t, local_sat_pos, local_sat_vel,
+      calc_sat_state(e[i], t, local_sat_pos, local_sat_vel,
                      &clock_err, &clock_rate_err);
       sds[n].sid = m_local[i].sid;
       double dx = local_sat_pos[0] - remote_pos_ecef[0];
@@ -245,14 +246,15 @@ u8 make_propagated_sdiffs(u8 n_local, navigation_measurement_t *m_local,
  *
  * The lock counter values are then updated to reflect their changed values.
  *
- * \param n_sds        Number of single difference observations passed in
- * \param sds          Array of single difference observations
- * \param lock_counter Array of lock counter values, indexed by PRN
- * \param sats_to_drop Output array of PRNs for which the lock counter value
- *                     has changed
+ * \param n_sds         Number of single difference observations passed in
+ * \param sds           Array of single difference observations
+ * \param lock_counters Array of lock counter values corresponding to signals
+ *                      in sds
+ * \param sats_to_drop  Output array of signals for which the lock counter value
+ *                      has changed
  * \return Number of sats with changed lock counter
  */
-u8 check_lock_counters(u8 n_sds, const sdiff_t *sds, u16 *lock_counters,
+u8 check_lock_counters(u8 n_sds, const sdiff_t *sds, u16 *lock_counters[],
                        gnss_signal_t *sats_to_drop)
 {
   assert(sds != NULL);
@@ -261,11 +263,10 @@ u8 check_lock_counters(u8 n_sds, const sdiff_t *sds, u16 *lock_counters,
 
   u8 num_sats_to_drop = 0;
   for (u8 i = 0; i<n_sds; i++) {
-    gnss_signal_t sid = sds[i].sid;
     u16 new_count = sds[i].lock_counter;
-    if (new_count != lock_counters[sid.sat]) {
-      sats_to_drop[num_sats_to_drop++] = sid;
-      lock_counters[sid.sat] = new_count;
+    if (new_count != *lock_counters[i]) {
+      sats_to_drop[num_sats_to_drop++] = sds[i].sid;
+      *lock_counters[i] = new_count;
     }
   }
   return num_sats_to_drop;

src/track.c

@@ -746,50 +746,35 @@ float cn0_est(cn0_est_state_t *s, float I, float Q)
 }
 
 void calc_navigation_measurement(u8 n_channels, channel_measurement_t meas[],
-                                 navigation_measurement_t nav_meas[], double nav_time,
-                                 ephemeris_t ephemerides[])
-{
-  channel_measurement_t* meas_ptrs[n_channels];
-  navigation_measurement_t* nav_meas_ptrs[n_channels];
-  ephemeris_t* ephemerides_ptrs[n_channels];
-
-  for (u8 i=0; i<n_channels; i++) {
-    meas_ptrs[i] = &meas[i];
-    nav_meas_ptrs[i] = &nav_meas[i];
-    ephemerides_ptrs[i] = &ephemerides[meas[i].sid.sat];
-  }
-
-  calc_navigation_measurement_(n_channels, meas_ptrs, nav_meas_ptrs, nav_time, ephemerides_ptrs);
-}
-
-void calc_navigation_measurement_(u8 n_channels, channel_measurement_t* meas[], navigation_measurement_t* nav_meas[], double nav_time, ephemeris_t* ephemerides[])
+                                 navigation_measurement_t nav_meas[],
+                                 double nav_time, const ephemeris_t* e[])
 {
   double TOTs[n_channels];
   double min_TOF = -DBL_MAX;
   double clock_err[n_channels], clock_rate_err[n_channels];
 
   for (u8 i=0; i<n_channels; i++) {
-    TOTs[i] = 1e-3 * meas[i]->time_of_week_ms;
-    TOTs[i] += meas[i]->code_phase_chips / 1.023e6;
-    TOTs[i] += (nav_time - meas[i]->receiver_time) * meas[i]->code_phase_rate / 1.023e6;
+    TOTs[i] = 1e-3 * meas[i].time_of_week_ms;
+    TOTs[i] += meas[i].code_phase_chips / 1.023e6;
+    TOTs[i] += (nav_time - meas[i].receiver_time) * meas[i].code_phase_rate / 1.023e6;
 
     /** \todo Maybe keep track of week number in tracking channel
         state or derive it from system time. */
-    nav_meas[i]->tot.tow = TOTs[i];
-    gps_time_match_weeks(&nav_meas[i]->tot, &ephemerides[i]->toe);
+    nav_meas[i].tot.tow = TOTs[i];
+    gps_time_match_weeks(&nav_meas[i].tot, &e[i]->toe);
 
-    nav_meas[i]->raw_doppler = meas[i]->carrier_freq;
-    nav_meas[i]->snr = meas[i]->snr;
-    nav_meas[i]->sid.sat = meas[i]->sid.sat;
+    nav_meas[i].raw_doppler = meas[i].carrier_freq;
+    nav_meas[i].snr = meas[i].snr;
+    nav_meas[i].sid = meas[i].sid;
 
-    nav_meas[i]->carrier_phase = meas[i]->carrier_phase;
-    nav_meas[i]->carrier_phase += (nav_time - meas[i]->receiver_time) * meas[i]->carrier_freq;
+    nav_meas[i].carrier_phase = meas[i].carrier_phase;
+    nav_meas[i].carrier_phase += (nav_time - meas[i].receiver_time) * meas[i].carrier_freq;
 
-    nav_meas[i]->lock_counter = meas[i]->lock_counter;
+    nav_meas[i].lock_counter = meas[i].lock_counter;
 
     /* calc sat clock error */
-    calc_sat_state(ephemerides[i], nav_meas[i]->tot,
-                   nav_meas[i]->sat_pos, nav_meas[i]->sat_vel,
+    calc_sat_state(e[i], nav_meas[i].tot,
+                   nav_meas[i].sat_pos, nav_meas[i].sat_vel,
                    &clock_err[i], &clock_rate_err[i]);
 
     /* remove clock error to put all tots within the same time window */
@@ -798,14 +783,14 @@ void calc_navigation_measurement_(u8 n_channels, channel_measurement_t* meas[],
   }
 
   for (u8 i=0; i<n_channels; i++) {
-    nav_meas[i]->raw_pseudorange = (min_TOF - TOTs[i])*GPS_C + GPS_NOMINAL_RANGE;
+    nav_meas[i].raw_pseudorange = (min_TOF - TOTs[i])*GPS_C + GPS_NOMINAL_RANGE;
 
-    nav_meas[i]->pseudorange = nav_meas[i]->raw_pseudorange \
+    nav_meas[i].pseudorange = nav_meas[i].raw_pseudorange \
                                + clock_err[i]*GPS_C;
-    nav_meas[i]->doppler = nav_meas[i]->raw_doppler + clock_rate_err[i]*GPS_L1_HZ;
+    nav_meas[i].doppler = nav_meas[i].raw_doppler + clock_rate_err[i]*GPS_L1_HZ;
 
-    nav_meas[i]->tot.tow -= clock_err[i];
-    nav_meas[i]->tot = normalize_gps_time(nav_meas[i]->tot);
+    nav_meas[i].tot.tow -= clock_err[i];
+    nav_meas[i].tot = normalize_gps_time(nav_meas[i].tot);
   }
 }