/*! * \file gps_l5_telemetry_decoder_gs.cc * \brief Implementation of a CNAV message demodulator block * \author Antonio Ramos, 2017. antonio.ramos(at)cttc.es * * ------------------------------------------------------------------------- * * Copyright (C) 2010-2019 (see AUTHORS file for a list of contributors) * * GNSS-SDR is a software defined Global Navigation * Satellite Systems receiver * * This file is part of GNSS-SDR. * * GNSS-SDR 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 3 of the License, or * (at your option) any later version. * * GNSS-SDR 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 GNSS-SDR. If not, see . * * ------------------------------------------------------------------------- */ #include "gps_l5_telemetry_decoder_gs.h" #include "display.h" #include "gnss_synchro.h" #include "gps_cnav_ephemeris.h" #include "gps_cnav_iono.h" #include "gps_cnav_utc_model.h" // for Gps_CNAV_Utc_Model #include #include #include // for make_any #include // for mp #include #include // for abs #include // for exception #include #include // for shared_ptr, make_shared gps_l5_telemetry_decoder_gs_sptr gps_l5_make_telemetry_decoder_gs(const Gnss_Satellite &satellite, bool dump) { return gps_l5_telemetry_decoder_gs_sptr(new gps_l5_telemetry_decoder_gs(satellite, dump)); } gps_l5_telemetry_decoder_gs::gps_l5_telemetry_decoder_gs( const Gnss_Satellite &satellite, bool dump) : gr::block("gps_l5_telemetry_decoder_gs", gr::io_signature::make(1, 1, sizeof(Gnss_Synchro)), gr::io_signature::make(1, 1, sizeof(Gnss_Synchro))) { // prevent telemetry symbols accumulation in output buffers this->set_max_noutput_items(1); // Ephemeris data port out this->message_port_register_out(pmt::mp("telemetry")); // Control messages to tracking block this->message_port_register_out(pmt::mp("telemetry_to_trk")); d_last_valid_preamble = 0; d_sent_tlm_failed_msg = false; d_max_symbols_without_valid_frame = GPS_L5_CNAV_DATA_PAGE_BITS * GPS_L5_SYMBOLS_PER_BIT * 10; // rise alarm if 20 consecutive subframes have no valid CRC // initialize internal vars d_dump = dump; d_satellite = Gnss_Satellite(satellite.get_system(), satellite.get_PRN()); DLOG(INFO) << "GPS L5 TELEMETRY PROCESSING: satellite " << d_satellite; d_channel = 0; d_flag_valid_word = false; d_TOW_at_current_symbol_ms = 0U; d_TOW_at_Preamble_ms = 0U; // initialize the CNAV frame decoder (libswiftcnav) cnav_msg_decoder_init(&d_cnav_decoder); d_sample_counter = 0; } gps_l5_telemetry_decoder_gs::~gps_l5_telemetry_decoder_gs() { if (d_dump_file.is_open() == true) { try { d_dump_file.close(); } catch (const std::exception &ex) { LOG(WARNING) << "Exception in destructor closing the dump file " << ex.what(); } } } void gps_l5_telemetry_decoder_gs::set_satellite(const Gnss_Satellite &satellite) { d_satellite = Gnss_Satellite(satellite.get_system(), satellite.get_PRN()); DLOG(INFO) << "GPS L5 CNAV telemetry decoder in channel " << this->d_channel << " set to satellite " << d_satellite; d_CNAV_Message.reset(); } void gps_l5_telemetry_decoder_gs::set_channel(int32_t channel) { d_channel = channel; d_CNAV_Message.reset(); DLOG(INFO) << "GPS L5 CNAV channel set to " << channel; // ############# ENABLE DATA FILE LOG ################# if (d_dump == true) { if (d_dump_file.is_open() == false) { try { d_dump_filename = "telemetry_L5_"; d_dump_filename.append(std::to_string(d_channel)); d_dump_filename.append(".dat"); d_dump_file.exceptions(std::ifstream::failbit | std::ifstream::badbit); d_dump_file.open(d_dump_filename.c_str(), std::ios::out | std::ios::binary); LOG(INFO) << "Telemetry decoder dump enabled on channel " << d_channel << " Log file: " << d_dump_filename.c_str(); } catch (const std::ifstream::failure &e) { LOG(WARNING) << "channel " << d_channel << " Exception opening Telemetry GPS L5 dump file " << e.what(); } } } } void gps_l5_telemetry_decoder_gs::reset() { d_last_valid_preamble = d_sample_counter; d_TOW_at_current_symbol_ms = 0; d_sent_tlm_failed_msg = false; d_flag_valid_word = false; DLOG(INFO) << "Telemetry decoder reset for satellite " << d_satellite; } int gps_l5_telemetry_decoder_gs::general_work(int noutput_items __attribute__((unused)), gr_vector_int &ninput_items __attribute__((unused)), gr_vector_const_void_star &input_items, gr_vector_void_star &output_items) { // get pointers on in- and output gnss-synchro objects auto *out = reinterpret_cast(output_items[0]); // Get the output buffer pointer const auto *in = reinterpret_cast(input_items[0]); // Get the input buffer pointer // UPDATE GNSS SYNCHRO DATA Gnss_Synchro current_synchro_data{}; // structure to save the synchronization information and send the output object to the next block // 1. Copy the current tracking output current_synchro_data = in[0]; consume_each(1); // one by one // check if there is a problem with the telemetry of the current satellite d_sample_counter++; // count for the processed symbols if (d_sent_tlm_failed_msg == false) { if ((d_sample_counter - d_last_valid_preamble) > d_max_symbols_without_valid_frame) { int message = 1; // bad telemetry this->message_port_pub(pmt::mp("telemetry_to_trk"), pmt::make_any(message)); d_sent_tlm_failed_msg = true; } } cnav_msg_t msg; uint32_t delay; uint8_t symbol_clip = static_cast(current_synchro_data.Prompt_Q > 0) * 255; // 2. Add the telemetry decoder information // check if new CNAV frame is available if (cnav_msg_decoder_add_symbol(&d_cnav_decoder, symbol_clip, &msg, &delay) == true) { std::bitset 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++) { raw_bits[GPS_L5_CNAV_DATA_PAGE_BITS - 1 - i] = ((msg.raw_msg[i / 8] >> (7 - i % 8)) & 1U); } d_CNAV_Message.decode_page(raw_bits); // Push the new navigation data to the queues if (d_CNAV_Message.have_new_ephemeris() == true) { // get ephemeris object for this SV std::shared_ptr tmp_obj = std::make_shared(d_CNAV_Message.get_ephemeris()); std::cout << TEXT_MAGENTA << "New GPS L5 CNAV message received in channel " << d_channel << ": ephemeris from satellite " << d_satellite << TEXT_RESET << std::endl; this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj)); } if (d_CNAV_Message.have_new_iono() == true) { std::shared_ptr tmp_obj = std::make_shared(d_CNAV_Message.get_iono()); std::cout << TEXT_MAGENTA << "New GPS L5 CNAV message received in channel " << d_channel << ": iono model parameters from satellite " << d_satellite << TEXT_RESET << std::endl; this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj)); } if (d_CNAV_Message.have_new_utc_model() == true) { std::shared_ptr tmp_obj = std::make_shared(d_CNAV_Message.get_utc_model()); std::cout << TEXT_MAGENTA << "New GPS L5 CNAV message received in channel " << d_channel << ": UTC model parameters from satellite " << d_satellite << TEXT_RESET << std::endl; this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj)); } // update TOW at the preamble instant d_TOW_at_Preamble_ms = msg.tow * 6000; // The time of the last input symbol can be computed from the message ToW and // delay by the formulae: // \code // symbolTime_ms = msg->tow * 6000 + *pdelay * 10 + (12 * 10); 12 symbols of the encoder's transitory // check TOW update consistency uint32_t last_d_TOW_at_current_symbol_ms = d_TOW_at_current_symbol_ms; d_TOW_at_current_symbol_ms = msg.tow * 6000 + (delay + 12) * GPS_L5I_SYMBOL_PERIOD_MS; if (last_d_TOW_at_current_symbol_ms != 0 and abs(static_cast(d_TOW_at_current_symbol_ms) - int64_t(last_d_TOW_at_current_symbol_ms)) > GPS_L5I_SYMBOL_PERIOD_MS) { DLOG(INFO) << "Warning: GPS L5 TOW update in ch " << d_channel << " does not match the TLM TOW counter " << static_cast(d_TOW_at_current_symbol_ms) - int64_t(last_d_TOW_at_current_symbol_ms) << " ms " << " with delay: " << delay << " msg tow: " << msg.tow * 6000 << " ms \n"; d_TOW_at_current_symbol_ms = 0; d_flag_valid_word = false; } else { d_last_valid_preamble = d_sample_counter; d_flag_valid_word = true; } } else { if (d_flag_valid_word) { d_TOW_at_current_symbol_ms += GPS_L5I_SYMBOL_PERIOD_MS; if (current_synchro_data.Flag_valid_symbol_output == false) { d_flag_valid_word = false; } } } if (d_flag_valid_word == true) { current_synchro_data.TOW_at_current_symbol_ms = d_TOW_at_current_symbol_ms; current_synchro_data.Flag_valid_word = d_flag_valid_word; if (d_dump == true) { // MULTIPLEXED FILE RECORDING - Record results to file try { double tmp_double; uint64_t tmp_ulong_int; tmp_double = static_cast(d_TOW_at_current_symbol_ms) / 1000.0; d_dump_file.write(reinterpret_cast(&tmp_double), sizeof(double)); tmp_ulong_int = current_synchro_data.Tracking_sample_counter; d_dump_file.write(reinterpret_cast(&tmp_ulong_int), sizeof(uint64_t)); tmp_double = static_cast(d_TOW_at_Preamble_ms) / 1000.0; d_dump_file.write(reinterpret_cast(&tmp_double), sizeof(double)); } catch (const std::ifstream::failure &e) { LOG(WARNING) << "Exception writing Telemetry GPS L5 dump file " << e.what(); } } // 3. Make the output (copy the object contents to the GNURadio reserved memory) out[0] = current_synchro_data; return 1; } return 0; }