bugfix: Fixes bugs with units in GNAV Almanac decoding

Forces conversion of semicircles to radians units  in some GNAV Almanac
parameters. In addition, adds safeguards in code to avoid invalid
slot number identification.

conf/gnss-sdr_GLONASS_L1_CA_ibyte.conf

@@ -25,20 +25,15 @@ Resampler.sample_freq_out=6625000
 Resampler.item_type=gr_complex
 
 ;######### CHANNELS GLOBAL CONFIG ############
+Channel.signal=1G
+Channels.in_acquisition=1
 Channels_1G.count=5
-Channels.in_acquisition=5
-Channel0.signal=1G
-Channel1.signal=1G
-Channel2.signal=1G
-Channel3.signal=1G
-Channel4.signal=1G
 
 Channel0.satellite=11
 Channel1.satellite=2
 Channel2.satellite=18
 Channel3.satellite=12
 Channel4.satellite=21
-; Possible list includes 2, 12, 21, 22
 
 ;######### ACQUISITION GLOBAL CONFIG ############
 Acquisition_1G.implementation=GLONASS_L1_CA_PCPS_Acquisition
@@ -53,9 +48,9 @@ Acquisition_1G.dump_filename=/archive/glo_acquisition.dat
 ;Acquisition_1G.coherent_integration_time_ms=10
 
 ;######### TRACKING GLOBAL CONFIG ############
-Tracking_1G.implementation=GLONASS_L1_CA_DLL_PLL_C_Aid_Tracking
+Tracking_1G.implementation=GLONASS_L1_CA_DLL_PLL_Tracking
 Tracking_1G.item_type=gr_complex
-Tracking_1G.if=1
+Tracking_1G.if=0
 Tracking_1G.early_late_space_chips=0.5
 Tracking_1G.pll_bw_hz=25.0;
 Tracking_1G.dll_bw_hz=3.0;
@@ -63,7 +58,7 @@ Tracking_1G.dump=true;
 Tracking_1G.dump_filename=/archive/glo_tracking_ch_
 
 ;######### TELEMETRY DECODER GPS CONFIG ############
-TelemetryDecoder_1G.implementation=GPS_L1_CA_Telemetry_Decoder
+TelemetryDecoder_1G.implementation=GLONASS_L1_CA_Telemetry_Decoder
 
 ;######### OBSERVABLES CONFIG ############
 Observables.implementation=Hybrid_Observables

src/algorithms/telemetry_decoder/gnuradio_blocks/glonass_l1_ca_telemetry_decoder_cc.cc

@@ -200,6 +200,7 @@ void glonass_l1_ca_telemetry_decoder_cc::decode_string(double *frame_symbols,int
             // get object for this SV (mandatory)
             std::shared_ptr<Glonass_Gnav_Ephemeris> tmp_obj = std::make_shared<Glonass_Gnav_Ephemeris>(d_nav.get_ephemeris());
             this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj));
+            LOG(INFO) << "GLONASS GNAV Ephemeris have been received on channel" << d_channel << " from satellite " << d_satellite;
 
         }
     if (d_nav.have_new_utc_model() == true)
@@ -207,12 +208,14 @@ void glonass_l1_ca_telemetry_decoder_cc::decode_string(double *frame_symbols,int
             // get object for this SV (mandatory)
             std::shared_ptr<Glonass_Gnav_Utc_Model> tmp_obj = std::make_shared<Glonass_Gnav_Utc_Model>(d_nav.get_utc_model());
             this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj));
+            LOG(INFO) << "GLONASS GNAV UTC Model have been received on channel" << d_channel << " from satellite " << d_satellite;
         }
     if (d_nav.have_new_almanac() == true)
         {
             unsigned int slot_nbr = d_nav.i_alm_satellite_slot_number;
             std::shared_ptr<Glonass_Gnav_Almanac> tmp_obj= std::make_shared<Glonass_Gnav_Almanac>(d_nav.get_almanac(slot_nbr));
             this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj));
+            LOG(INFO) << "GLONASS GNAV Almanac have been received on channel" << d_channel << " in slot number " << slot_nbr;
         }
     // 5. Update satellite information on system
     if(d_nav.flag_update_slot_number == true)

src/core/system_parameters/glonass_gnav_navigation_message.cc

@@ -385,6 +385,8 @@ int Glonass_Gnav_Navigation_Message::string_decoder(std::string frame_string)
 
         case 3:
             // --- It is string 3 ----------------------------------------------
+            if (flag_ephemeris_str_2 == true)
+                {
                     gnav_ephemeris.d_P_3 = static_cast<bool>(read_navigation_bool(string_bits, P3));
                     gnav_ephemeris.d_gamma_n = static_cast<double>(read_navigation_signed(string_bits, GAMMA_N)) * TWO_N40;
                     gnav_ephemeris.d_P = static_cast<double>(read_navigation_unsigned(string_bits, P));
@@ -394,11 +396,14 @@ int Glonass_Gnav_Navigation_Message::string_decoder(std::string frame_string)
                     gnav_ephemeris.d_Zn = static_cast<double>(read_navigation_signed(string_bits, Z_N)) * TWO_N11;
 
                     flag_ephemeris_str_3 = true;
+                }
 
             break;
 
         case 4:
             // --- It is string 4 ----------------------------------------------
+            if (flag_ephemeris_str_3 == true)
+                {
                     gnav_ephemeris.d_tau_n = static_cast<double>(read_navigation_signed(string_bits, TAU_N)) * TWO_N30;
                     gnav_ephemeris.d_Delta_tau_n = static_cast<double>(read_navigation_signed(string_bits, DELTA_TAU_N)) * TWO_N30;
                     gnav_ephemeris.d_E_n = static_cast<double>(read_navigation_unsigned(string_bits, E_N));
@@ -414,11 +419,14 @@ int Glonass_Gnav_Navigation_Message::string_decoder(std::string frame_string)
                     gnav_ephemeris.i_satellite_PRN = static_cast<unsigned int>(gnav_ephemeris.d_n);
 
                     flag_ephemeris_str_4 = true;
+                }
 
             break;
 
         case 5:
             // --- It is string 5 ----------------------------------------------
+            if (flag_ephemeris_str_4 == true)
+                {
                     gnav_utc_model.d_N_A = static_cast<double>(read_navigation_unsigned(string_bits, N_A));
                     gnav_utc_model.d_tau_c = static_cast<double>(read_navigation_signed(string_bits, TAU_C)) * TWO_N31;
                     gnav_utc_model.d_N_4 = static_cast<double>(read_navigation_unsigned(string_bits, N_4));
@@ -426,10 +434,9 @@ int Glonass_Gnav_Navigation_Message::string_decoder(std::string frame_string)
                     gnav_ephemeris.d_l5th_n = static_cast<bool>(read_navigation_bool(string_bits, ALM_L_N));
 
                     flag_utc_model_str_5 = true;
+
                     // Compute Year and DoY based on Algorithm A3.11 of GLONASS ICD
-            if (flag_ephemeris_str_4 == true)
+                    // 1). Current year number J in the four-year interval is calculated
-                {
-                    //Current year number J in the four-year interval is calculated:
                     if (gnav_ephemeris.d_N_T >= 1 && gnav_ephemeris.d_N_T <= 366)
                     {
                         J = 1;
@@ -455,16 +462,20 @@ int Glonass_Gnav_Navigation_Message::string_decoder(std::string frame_string)
                     {
                         d_TOW = get_TOW();
                         flag_TOW_set = true;
-
                     }
 
                 }
+
+
             break;
 
         case 6:
             // --- It is string 6 ----------------------------------------------
             i_alm_satellite_slot_number = static_cast<unsigned int>(read_navigation_unsigned(string_bits, n_A));
             d_frame_ID = get_frame_number(i_alm_satellite_slot_number);
+            // Make sure a valid frame_ID or satellite slot number is returned
+            if(d_frame_ID == 0)
+                return 0;
 
             gnav_almanac[i_alm_satellite_slot_number - 1].d_C_n = static_cast<bool>(read_navigation_bool(string_bits, C_N));
             gnav_almanac[i_alm_satellite_slot_number - 1].d_M_n_A = static_cast<double>(read_navigation_unsigned(string_bits, M_N_A));
@@ -510,6 +521,9 @@ int Glonass_Gnav_Navigation_Message::string_decoder(std::string frame_string)
             // --- It is string 8 ----------------------------------------------
             i_alm_satellite_slot_number = static_cast<unsigned int>(read_navigation_unsigned(string_bits, n_A));
             d_frame_ID = get_frame_number(i_alm_satellite_slot_number);
+            // Make sure a valid frame_ID or satellite slot number is returned
+            if(d_frame_ID == 0)
+                return 0;
 
             gnav_almanac[i_alm_satellite_slot_number - 1].d_C_n = static_cast<bool>(read_navigation_bool(string_bits, C_N));
             gnav_almanac[i_alm_satellite_slot_number - 1].d_M_n_A = static_cast<double>(read_navigation_unsigned(string_bits, M_N_A));
@@ -548,6 +562,9 @@ int Glonass_Gnav_Navigation_Message::string_decoder(std::string frame_string)
             // --- It is string 10 ---------------------------------------------
             i_alm_satellite_slot_number = static_cast<unsigned int>(read_navigation_unsigned(string_bits, n_A));
             d_frame_ID = get_frame_number(i_alm_satellite_slot_number);
+            // Make sure a valid frame_ID or satellite slot number is returned
+            if(d_frame_ID == 0)
+                return 0;
 
             gnav_almanac[i_alm_satellite_slot_number - 1].d_C_n = static_cast<bool>(read_navigation_bool(string_bits, C_N));
             gnav_almanac[i_alm_satellite_slot_number - 1].d_M_n_A = static_cast<double>(read_navigation_unsigned(string_bits, M_N_A));
@@ -587,7 +604,9 @@ int Glonass_Gnav_Navigation_Message::string_decoder(std::string frame_string)
             // --- It is string 12 ---------------------------------------------
             i_alm_satellite_slot_number = static_cast<unsigned int>(read_navigation_unsigned(string_bits, n_A));
             d_frame_ID = get_frame_number(i_alm_satellite_slot_number);
-
+            // Make sure a valid frame_ID or satellite slot number is returned
+            if(d_frame_ID == 0)
+                return 0;
             gnav_almanac[i_alm_satellite_slot_number - 1].d_C_n = static_cast<bool>(read_navigation_bool(string_bits, C_N));
             gnav_almanac[i_alm_satellite_slot_number - 1].d_M_n_A = static_cast<double>(read_navigation_unsigned(string_bits, M_N_A));
             gnav_almanac[i_alm_satellite_slot_number - 1].d_n_A = static_cast<double>(read_navigation_unsigned(string_bits, n_A));
@@ -633,7 +652,9 @@ int Glonass_Gnav_Navigation_Message::string_decoder(std::string frame_string)
                 {
                     i_alm_satellite_slot_number = static_cast<unsigned int>(read_navigation_unsigned(string_bits, n_A));
                     d_frame_ID = get_frame_number(i_alm_satellite_slot_number);
-
+                    // Make sure a valid frame_ID or satellite slot number is returned
+                    if(d_frame_ID == 0)
+                        return 0;
                     gnav_almanac[i_alm_satellite_slot_number - 1].d_C_n = static_cast<bool>(read_navigation_bool(string_bits, C_N));
                     gnav_almanac[i_alm_satellite_slot_number - 1].d_M_n_A = static_cast<double>(read_navigation_unsigned(string_bits, M_N_A));
                     gnav_almanac[i_alm_satellite_slot_number - 1].d_n_A = static_cast<double>(read_navigation_unsigned(string_bits, n_A));
@@ -644,12 +665,10 @@ int Glonass_Gnav_Navigation_Message::string_decoder(std::string frame_string)
 
                     flag_almanac_str_14 = true;
                 }
-
-
             break;
 
         case 15:
-            // --- It is string 9 ----------------------------------------------
+            // --- It is string 15 ----------------------------------------------
             if (d_frame_ID != 5 and flag_almanac_str_14 == true) {
                 gnav_almanac[i_alm_satellite_slot_number - 1].d_omega_n_A = static_cast<double>(read_navigation_signed(string_bits, OMEGA_N_A)) * TWO_N15 * GLONASS_PI;
                 gnav_almanac[i_alm_satellite_slot_number - 1].d_t_lambda_n_A = static_cast<double>(read_navigation_unsigned(string_bits, T_LAMBDA_N_A)) * TWO_N5;
@@ -711,23 +730,17 @@ Glonass_Gnav_Almanac Glonass_Gnav_Navigation_Message::get_almanac(unsigned int s
 
 bool Glonass_Gnav_Navigation_Message::have_new_ephemeris() //Check if we have a new ephemeris stored in the galileo navigation class
 {
-    if ((flag_ephemeris_str_1 == true) and (flag_ephemeris_str_2 == true) and (flag_ephemeris_str_3 == true) and (flag_ephemeris_str_4 == true))
+    // We need to make sure we have received the ephemeris info plus the time info
-        {
+    if ((flag_ephemeris_str_1 == true) and (flag_ephemeris_str_2 == true) and
-            if (gnav_ephemeris.d_P_4 == 1)
+        (flag_ephemeris_str_3 == true) and (flag_ephemeris_str_4 == true) and
+        (flag_utc_model_str_5 == true))
         {
             flag_ephemeris_str_1 = false;// clear the flag
             flag_ephemeris_str_2 = false;// clear the flag
             flag_ephemeris_str_3 = false;// clear the flag
             flag_ephemeris_str_4 = false;// clear the flag
             flag_all_ephemeris = true;
-                    DLOG(INFO) << "Ephemeris (1, 2, 3, 4) have been received and belong to the same batch" << std::endl;
+            DLOG(INFO) << "GLONASS GNAV Ephemeris (1, 2, 3, 4) have been received and belong to the same batch" << std::endl;
-
-                    return true;
-                }
-            else
-                {
-                    return false;
-                }
         }
     else
         return false;