Correct Carrier Phase observable for inverted PLL lock in L2,L5 E1, and E5

src/algorithms/telemetry_decoder/gnuradio_blocks/galileo_telemetry_decoder_gs.cc

@@ -757,6 +757,12 @@ int galileo_telemetry_decoder_gs::general_work(int noutput_items __attribute__((
             // todo: Galileo to GPS time conversion should be moved to observable block.
             // current_symbol.TOW_at_current_symbol_ms -= delta_t;  // Galileo to GPS TOW
 
+            if (flag_PLL_180_deg_phase_locked == true)
+                {
+                    // correct the accumulated phase for the Costas loop phase shift, if required
+                    current_symbol.Carrier_phase_rads += GALILEO_PI;
+                }
+
             if (d_dump == true)
                 {
                     // MULTIPLEXED FILE RECORDING - Record results to file

src/algorithms/telemetry_decoder/gnuradio_blocks/gps_l2c_telemetry_decoder_gs.cc

@@ -74,6 +74,7 @@ gps_l2c_telemetry_decoder_gs::gps_l2c_telemetry_decoder_gs(
     cnav_msg_decoder_init(&d_cnav_decoder);
 
     d_sample_counter = 0;
+    flag_PLL_180_deg_phase_locked = false;
 }
 
 
@@ -175,6 +176,14 @@ int gps_l2c_telemetry_decoder_gs::general_work(int noutput_items __attribute__((
     // check if new CNAV frame is available
     if (flag_new_cnav_frame == true)
         {
+            if (d_cnav_decoder.part1.invert == true or d_cnav_decoder.part1.invert == true)
+                {
+                    flag_PLL_180_deg_phase_locked = true;
+                }
+            else
+                {
+                    flag_PLL_180_deg_phase_locked = false;
+                }
             std::bitset<GPS_L2_CNAV_DATA_PAGE_BITS> raw_bits;
             // Expand packet bits to bitsets. Notice the reverse order of the bits sequence, required by the CNAV message decoder
             for (uint32_t i = 0; i < GPS_L2_CNAV_DATA_PAGE_BITS; i++)
@@ -225,6 +234,14 @@ int gps_l2c_telemetry_decoder_gs::general_work(int noutput_items __attribute__((
                     d_flag_valid_word = false;
                 }
         }
+
+
+    if (flag_PLL_180_deg_phase_locked == true)
+        {
+            // correct the accumulated phase for the Costas loop phase shift, if required
+            current_synchro_data.Carrier_phase_rads += GPS_L2_PI;
+        }
+
     current_synchro_data.TOW_at_current_symbol_ms = round(d_TOW_at_current_symbol * 1000.0);
     current_synchro_data.Flag_valid_word = d_flag_valid_word;
 

src/algorithms/telemetry_decoder/gnuradio_blocks/gps_l2c_telemetry_decoder_gs.h

@@ -83,6 +83,7 @@ private:
     uint64_t d_last_valid_preamble;
     uint32_t d_max_symbols_without_valid_frame;
 
+    bool flag_PLL_180_deg_phase_locked;
     double d_TOW_at_current_symbol;
     double d_TOW_at_Preamble;
     bool d_flag_valid_word;

src/algorithms/telemetry_decoder/gnuradio_blocks/gps_l5_telemetry_decoder_gs.cc

@@ -69,6 +69,7 @@ gps_l5_telemetry_decoder_gs::gps_l5_telemetry_decoder_gs(
     cnav_msg_decoder_init(&d_cnav_decoder);
 
     d_sample_counter = 0;
+    flag_PLL_180_deg_phase_locked = false;
 }
 
 
@@ -167,6 +168,14 @@ int gps_l5_telemetry_decoder_gs::general_work(int noutput_items __attribute__((u
     // check if new CNAV frame is available
     if (cnav_msg_decoder_add_symbol(&d_cnav_decoder, symbol_clip, &msg, &delay) == true)
         {
+            if (d_cnav_decoder.part1.invert == true or d_cnav_decoder.part1.invert == true)
+                {
+                    flag_PLL_180_deg_phase_locked = true;
+                }
+            else
+                {
+                    flag_PLL_180_deg_phase_locked = false;
+                }
             std::bitset<GPS_L5_CNAV_DATA_PAGE_BITS> raw_bits;
             // Expand packet bits to bitsets. Notice the reverse order of the bits sequence, required by the CNAV message decoder
             for (uint32_t i = 0; i < GPS_L5_CNAV_DATA_PAGE_BITS; i++)
@@ -238,6 +247,11 @@ int gps_l5_telemetry_decoder_gs::general_work(int noutput_items __attribute__((u
 
     if (d_flag_valid_word == true)
         {
+            if (flag_PLL_180_deg_phase_locked == true)
+                {
+                    // correct the accumulated phase for the Costas loop phase shift, if required
+                    current_synchro_data.Carrier_phase_rads += GPS_L5_PI;
+                }
             current_synchro_data.TOW_at_current_symbol_ms = d_TOW_at_current_symbol_ms;
             current_synchro_data.Flag_valid_word = d_flag_valid_word;
 

src/algorithms/telemetry_decoder/gnuradio_blocks/gps_l5_telemetry_decoder_gs.h

@@ -75,6 +75,7 @@ private:
 
     cnav_msg_decoder_t d_cnav_decoder{};
 
+    bool flag_PLL_180_deg_phase_locked;
     uint32_t d_TOW_at_current_symbol_ms;
     uint32_t d_TOW_at_Preamble_ms;
     bool d_flag_valid_word;