Improving and extending GPS L1 CA observables unit test

src/tests/common-files/observable_tests_flags.h

@@ -0,0 +1,40 @@
+/*!
+ * \file tracking_tests_flags.h
+ * \brief Helper file for unit testing
+ * \author Javier Arribas, 2018. jarribas(at)cttc.es
+ *
+ * -------------------------------------------------------------------------
+ *
+ * Copyright (C) 2010-2018  (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 <https://www.gnu.org/licenses/>.
+ *
+ * -------------------------------------------------------------------------
+ */
+
+#ifndef GNSS_SDR_OBSERVABLE_TESTS_FLAGS_H_
+#define GNSS_SDR_OBSERVABLE_TESTS_FLAGS_H_
+
+#include <gflags/gflags.h>
+#include <limits>
+
+DEFINE_double(skip_obs_transitory_s, 30.0, "Skip the initial observable outputs to avoid transitory results [s]");
+
+
+#endif

src/tests/common-files/signal_generator_flags.h

@@ -45,6 +45,7 @@ DEFINE_string(filename_raw_data, "signal_out.bin", "Filename of output raw data
 DEFINE_int32(fs_gen_sps, 2600000, "Sampling frequency [sps]");
 DEFINE_int32(test_satellite_PRN, 1, "PRN of the satellite under test (must be visible during the observation time)");
 DEFINE_int32(test_satellite_PRN2, 2, "PRN of the satellite under test (must be visible during the observation time)");
+DEFINE_string(test_satellite_PRN_list, "1,2,3,6,9,10,12,17,20,23,28", "List of PRN of the satellites under test (must be visible during the observation time)");
 DEFINE_double(CN0_dBHz, std::numeric_limits<double>::infinity(), "Enable noise generator and set the CN0 [dB-Hz]");
 
 #endif

src/tests/unit-tests/signal-processing-blocks/observables/hybrid_observables_test.cc

@@ -59,6 +59,7 @@
 #include "gnss_sdr_sample_counter.h"
 #include <matio.h>
 #include "test_flags.h"
+#include "observable_tests_flags.h"
 #include "gnuplot_i.h"
 
 
@@ -188,24 +189,27 @@ public:
     bool save_mat_xy(std::vector<double>& x, std::vector<double>& y, std::string filename);
     void check_results_carrier_phase(
         arma::mat& true_ch0,
-        arma::mat& true_ch1,
         arma::vec& true_tow_s,
         arma::mat& measured_ch0,
-        arma::mat& measured_ch1);
+        std::string data_title);
-    void check_results_code_psudorange(
+    void check_results_carrier_doppler(
+        arma::mat& true_ch0,
+        arma::vec& true_tow_s,
+        arma::mat& measured_ch0,
+        std::string data_title);
+    void check_results_code_pseudorange(
         arma::mat& true_ch0,
         arma::mat& true_ch1,
         arma::vec& true_tow_s,
         arma::mat& measured_ch0,
-        arma::mat& measured_ch1);
+        arma::mat& measured_ch1,
+        std::string data_title);
 
     HybridObservablesTest()
     {
         factory = std::make_shared<GNSSBlockFactory>();
         config = std::make_shared<InMemoryConfiguration>();
         item_size = sizeof(gr_complex);
-        gnss_synchro_ch0 = Gnss_Synchro();
-        gnss_synchro_ch1 = Gnss_Synchro();
     }
 
     ~HybridObservablesTest()
@@ -217,8 +221,7 @@ public:
     gr::top_block_sptr top_block;
     std::shared_ptr<GNSSBlockFactory> factory;
     std::shared_ptr<InMemoryConfiguration> config;
-    Gnss_Synchro gnss_synchro_ch0;
+    std::vector<Gnss_Synchro> gnss_synchro_vec;
-    Gnss_Synchro gnss_synchro_ch1;
     size_t item_size;
 };
 
@@ -268,18 +271,6 @@ int HybridObservablesTest::generate_signal()
 
 void HybridObservablesTest::configure_receiver()
 {
-    gnss_synchro_ch0.Channel_ID = 0;
-    gnss_synchro_ch0.System = 'G';
-    std::string signal = "1C";
-    signal.copy(gnss_synchro_ch0.Signal, 2, 0);
-    gnss_synchro_ch0.PRN = FLAGS_test_satellite_PRN;
-
-    gnss_synchro_ch1.Channel_ID = 1;
-    gnss_synchro_ch1.System = 'G';
-    signal.copy(gnss_synchro_ch1.Signal, 2, 0);
-    gnss_synchro_ch1.PRN = FLAGS_test_satellite_PRN2;
-
-
     config->set_property("GNSS-SDR.internal_fs_sps", std::to_string(baseband_sampling_freq));
 
     // Set Tracking
@@ -290,7 +281,7 @@ void HybridObservablesTest::configure_receiver()
     config->set_property("Tracking_1C.dll_bw_hz", "0.20");
     config->set_property("Tracking_1C.pll_bw_narrow_hz", "1.0");
     config->set_property("Tracking_1C.dll_bw_narrow_hz", "0.1");
-    config->set_property("Tracking_1C.extend_correlation_symbols", "20");
+    config->set_property("Tracking_1C.extend_correlation_symbols", "1");
     config->set_property("Tracking_1C.early_late_space_chips", "0.5");
 
     config->set_property("TelemetryDecoder_1C.dump", "true");
@@ -299,36 +290,31 @@ void HybridObservablesTest::configure_receiver()
 
 void HybridObservablesTest::check_results_carrier_phase(
     arma::mat& true_ch0,
-    arma::mat& true_ch1,
     arma::vec& true_tow_s,
     arma::mat& measured_ch0,
-    arma::mat& measured_ch1)
+    std::string data_title)
 {
     //1. True value interpolation to match the measurement times
 
-    double t0 = std::max(measured_ch0(0, 0), measured_ch1(0, 0));
+    double t0 = measured_ch0(0, 0);
     int size1 = measured_ch0.col(0).n_rows;
-    int size2 = measured_ch1.col(0).n_rows;
+    double t1 = measured_ch0(size1 - 1, 0);
-    double t1 = std::min(measured_ch0(size1 - 1, 0), measured_ch1(size2 - 1, 0));
     arma::vec t = arma::linspace<arma::vec>(t0, t1, floor((t1 - t0) * 1e3));
+    //conversion between arma::vec and std:vector
+    arma::vec t_from_start = arma::linspace<arma::vec>(0, t1 - t0, floor((t1 - t0) * 1e3));
+    std::vector<double> time_vector(t_from_start.colptr(0), t_from_start.colptr(0) + t_from_start.n_rows);
 
     arma::vec true_ch0_phase_interp;
-    arma::vec true_ch1_phase_interp;
     arma::interp1(true_tow_s, true_ch0.col(3), t, true_ch0_phase_interp);
-    arma::interp1(true_tow_s, true_ch1.col(3), t, true_ch1_phase_interp);
 
     arma::vec meas_ch0_phase_interp;
-    arma::vec meas_ch1_phase_interp;
     arma::interp1(measured_ch0.col(0), measured_ch0.col(3), t, meas_ch0_phase_interp);
-    arma::interp1(measured_ch1.col(0), measured_ch1.col(3), t, meas_ch1_phase_interp);
 
     //2. RMSE
     arma::vec err_ch0_cycles;
-    arma::vec err_ch1_cycles;
 
     //compute error without the accumulated carrier phase offsets (which depends on the receiver starting time)
     err_ch0_cycles = meas_ch0_phase_interp - true_ch0_phase_interp - meas_ch0_phase_interp(0) + true_ch0_phase_interp(0);
-    err_ch1_cycles = meas_ch1_phase_interp - true_ch1_phase_interp - meas_ch1_phase_interp(0) + true_ch1_phase_interp(0);
 
     arma::vec err2_ch0 = arma::square(err_ch0_cycles);
     double rmse_ch0 = sqrt(arma::mean(err2_ch0));
@@ -341,21 +327,9 @@ void HybridObservablesTest::check_results_carrier_phase(
     double max_error_ch0 = arma::max(err_ch0_cycles);
     double min_error_ch0 = arma::min(err_ch0_cycles);
 
-    arma::vec err2_ch1 = arma::square(err_ch1_cycles);
-    double rmse_ch1 = sqrt(arma::mean(err2_ch1));
-
-    //3. Mean err and variance
-    double error_mean_ch1 = arma::mean(err_ch1_cycles);
-    double error_var_ch1 = arma::var(err_ch1_cycles);
-
-    // 4. Peaks
-    double max_error_ch1 = arma::max(err_ch1_cycles);
-    double min_error_ch1 = arma::min(err_ch1_cycles);
-
-
     //5. report
     std::streamsize ss = std::cout.precision();
-    std::cout << std::setprecision(10) << "Channel 0 Carrier phase RMSE = "
+    std::cout << std::setprecision(10) << data_title << " Accumulated Carrier phase RMSE = "
               << rmse_ch0 << ", mean = " << error_mean_ch0
               << ", stdev = " << sqrt(error_var_ch0)
               << " (max,min) = " << max_error_ch0
@@ -363,31 +337,115 @@ void HybridObservablesTest::check_results_carrier_phase(
               << " [cycles]" << std::endl;
     std::cout.precision(ss);
 
+    //plots
+    Gnuplot g3("linespoints");
+    g3.set_title(data_title + "Accumulated Carrier phase error [cycles]");
+    g3.set_grid();
+    g3.set_xlabel("Time [s]");
+    g3.set_ylabel("Carrier Phase error [cycles]");
+    //conversion between arma::vec and std:vector
+    std::vector<double> error_vec(err_ch0_cycles.colptr(0), err_ch0_cycles.colptr(0) + err_ch0_cycles.n_rows);
+    g3.cmd("set key box opaque");
+    g3.plot_xy(time_vector, error_vec,
+        "Delta pseudorrange error");
+    g3.set_legend();
+    g3.savetops(data_title + "Carrier_phase_error");
+    if (FLAGS_show_plots)
+        {
+            g3.showonscreen();  // window output
+        }
+    else
+        {
+            g3.disablescreen();
+        }
+
+
     ASSERT_LT(rmse_ch0, 5e-2);
     ASSERT_LT(error_mean_ch0, 5e-2);
     ASSERT_GT(error_mean_ch0, -5e-2);
     ASSERT_LT(error_var_ch0, 5e-2);
     ASSERT_LT(max_error_ch0, 5e-2);
     ASSERT_GT(min_error_ch0, -5e-2);
-
-    //5. report
-    ss = std::cout.precision();
-    std::cout << std::setprecision(10) << "Channel 1 Carrier phase RMSE = "
-              << rmse_ch1 << ", mean = " << error_mean_ch1
-              << ", stdev = " << sqrt(error_var_ch1)
-              << " (max,min) = " << max_error_ch1
-              << "," << min_error_ch1
-              << " [cycles]" << std::endl;
-    std::cout.precision(ss);
-
-    ASSERT_LT(rmse_ch1, 5e-2);
-    ASSERT_LT(error_mean_ch1, 5e-2);
-    ASSERT_GT(error_mean_ch1, -5e-2);
-    ASSERT_LT(error_var_ch1, 5e-2);
-    ASSERT_LT(max_error_ch1, 5e-2);
-    ASSERT_GT(min_error_ch1, -5e-2);
 }
 
+void HybridObservablesTest::check_results_carrier_doppler(
+    arma::mat& true_ch0,
+    arma::vec& true_tow_s,
+    arma::mat& measured_ch0,
+    std::string data_title)
+{
+    //1. True value interpolation to match the measurement times
+
+    double t0 = measured_ch0(0, 0);
+    int size1 = measured_ch0.col(0).n_rows;
+    double t1 = measured_ch0(size1 - 1, 0);
+    arma::vec t = arma::linspace<arma::vec>(t0, t1, floor((t1 - t0) * 1e3));
+    //conversion between arma::vec and std:vector
+    arma::vec t_from_start = arma::linspace<arma::vec>(0, t1 - t0, floor((t1 - t0) * 1e3));
+    std::vector<double> time_vector(t_from_start.colptr(0), t_from_start.colptr(0) + t_from_start.n_rows);
+
+    arma::vec true_ch0_doppler_interp;
+    arma::interp1(true_tow_s, true_ch0.col(2), t, true_ch0_doppler_interp);
+
+    arma::vec meas_ch0_doppler_interp;
+    arma::interp1(measured_ch0.col(0), measured_ch0.col(2), t, meas_ch0_doppler_interp);
+
+    //2. RMSE
+    arma::vec err_ch0_hz;
+
+    //compute error
+    err_ch0_hz = meas_ch0_doppler_interp - true_ch0_doppler_interp;
+
+    arma::vec err2_ch0 = arma::square(err_ch0_hz);
+    double rmse_ch0 = sqrt(arma::mean(err2_ch0));
+
+    //3. Mean err and variance
+    double error_mean_ch0 = arma::mean(err_ch0_hz);
+    double error_var_ch0 = arma::var(err_ch0_hz);
+
+    // 4. Peaks
+    double max_error_ch0 = arma::max(err_ch0_hz);
+    double min_error_ch0 = arma::min(err_ch0_hz);
+
+    //5. report
+    std::streamsize ss = std::cout.precision();
+    std::cout << std::setprecision(10) << data_title << "Carrier Doppler RMSE = "
+              << rmse_ch0 << ", mean = " << error_mean_ch0
+              << ", stdev = " << sqrt(error_var_ch0)
+              << " (max,min) = " << max_error_ch0
+              << "," << min_error_ch0
+              << " [Hz]" << std::endl;
+    std::cout.precision(ss);
+
+    //plots
+    Gnuplot g3("linespoints");
+    g3.set_title(data_title + "Carrier Doppler error [Hz]");
+    g3.set_grid();
+    g3.set_xlabel("Time [s]");
+    g3.set_ylabel("Carrier Doppler error [Hz]");
+    //conversion between arma::vec and std:vector
+    std::vector<double> error_vec(err_ch0_hz.colptr(0), err_ch0_hz.colptr(0) + err_ch0_hz.n_rows);
+    g3.cmd("set key box opaque");
+    g3.plot_xy(time_vector, error_vec,
+        "Delta pseudorrange error");
+    g3.set_legend();
+    g3.savetops(data_title + "Carrier_doppler_error");
+    if (FLAGS_show_plots)
+        {
+            g3.showonscreen();  // window output
+        }
+    else
+        {
+            g3.disablescreen();
+        }
+
+    ASSERT_LT(rmse_ch0, 5);
+    ASSERT_LT(error_mean_ch0, 5);
+    ASSERT_GT(error_mean_ch0, -5);
+    ASSERT_LT(error_var_ch0, 10);
+    ASSERT_LT(max_error_ch0, 10);
+    ASSERT_GT(min_error_ch0, -5);
+}
 
 bool HybridObservablesTest::save_mat_xy(std::vector<double>& x, std::vector<double>& y, std::string filename)
 {
@@ -424,12 +482,13 @@ bool HybridObservablesTest::save_mat_xy(std::vector<double>& x, std::vector<doub
         }
 }
 
-void HybridObservablesTest::check_results_code_psudorange(
+void HybridObservablesTest::check_results_code_pseudorange(
     arma::mat& true_ch0,
     arma::mat& true_ch1,
     arma::vec& true_tow_s,
     arma::mat& measured_ch0,
-    arma::mat& measured_ch1)
+    arma::mat& measured_ch1,
+    std::string data_title)
 {
     //1. True value interpolation to match the measurement times
 
@@ -475,7 +534,7 @@ void HybridObservablesTest::check_results_code_psudorange(
 
     //5. report
     std::streamsize ss = std::cout.precision();
-    std::cout << std::setprecision(10) << "Delta Observables RMSE = "
+    std::cout << std::setprecision(10) << data_title << "Delta Observables RMSE = "
               << rmse << ", mean = " << error_mean
               << ", stdev = " << sqrt(error_var)
               << " (max,min) = " << max_error
@@ -484,9 +543,8 @@ void HybridObservablesTest::check_results_code_psudorange(
     std::cout.precision(ss);
 
     //plots
-
     Gnuplot g3("linespoints");
-    g3.set_title("Delta Pseudorange error [m]");
+    g3.set_title(data_title + "Delta Pseudorange error [m]");
     g3.set_grid();
     g3.set_xlabel("Time [s]");
     g3.set_ylabel("Pseudorange error [m]");
@@ -496,8 +554,7 @@ void HybridObservablesTest::check_results_code_psudorange(
     g3.plot_xy(time_vector, range_error_m,
         "Delta pseudorrange error");
     g3.set_legend();
-    g3.savetops("Delta_pseudorrange_error");
+    g3.savetops(data_title + "Delta_pseudorrange_error");
-    g3.savetopdf("Delta_pseudorrange_error", 18);
     if (FLAGS_show_plots)
         {
             g3.showonscreen();  // window output
@@ -531,135 +588,125 @@ TEST_F(HybridObservablesTest, ValidationOfResults)
     std::chrono::time_point<std::chrono::system_clock> start, end;
     std::chrono::duration<double> elapsed_seconds(0);
 
+    Gnss_Synchro tmp_gnss_synchro;
+    tmp_gnss_synchro.System = 'G';
+    std::string signal = "1C";
+    signal.copy(tmp_gnss_synchro.Signal, 2, 0);
+
+    std::istringstream ss(FLAGS_test_satellite_PRN_list);
+    std::string token;
+
+    while (std::getline(ss, token, ','))
+        {
+            tmp_gnss_synchro.PRN = boost::lexical_cast<int>(token);
+            gnss_synchro_vec.push_back(tmp_gnss_synchro);
+        }
+
     configure_receiver();
 
     //open true observables log file written by the simulator
-    tracking_true_obs_reader true_obs_data_ch0;
+    std::vector<std::shared_ptr<tracking_true_obs_reader>> true_reader_vec;
-    tracking_true_obs_reader true_obs_data_ch1;
+    std::vector<std::shared_ptr<TrackingInterface>> tracking_ch_vec;
-    int test_satellite_PRN = FLAGS_test_satellite_PRN;
+    std::vector<std::shared_ptr<TelemetryDecoderInterface>> tlm_ch_vec;
-    int test_satellite_PRN2 = FLAGS_test_satellite_PRN2;
-    std::cout << "Testing satellite PRNs " << test_satellite_PRN << "," << test_satellite_PRN2 << std::endl;
-    std::string true_obs_file = std::string("./gps_l1_ca_obs_prn");
-    true_obs_file.append(std::to_string(test_satellite_PRN));
-    true_obs_file.append(".dat");
-    ASSERT_NO_THROW({
-        if (true_obs_data_ch0.open_obs_file(true_obs_file) == false)
-            {
-                throw std::exception();
-            };
-    }) << "Failure opening true observables file";
 
-    true_obs_file = std::string("./gps_l1_ca_obs_prn");
+    std::vector<gr::blocks::null_sink::sptr> null_sink_vec;
-    true_obs_file.append(std::to_string(test_satellite_PRN2));
+    for (unsigned int n = 0; n < gnss_synchro_vec.size(); n++)
-    true_obs_file.append(".dat");
+        {
-    ASSERT_NO_THROW({
+            //set channels ids
-        if (true_obs_data_ch1.open_obs_file(true_obs_file) == false)
+            gnss_synchro_vec.at(n).Channel_ID = n;
-            {
+            //read true data from the generator logs
-                throw std::exception();
+            true_reader_vec.push_back(std::make_shared<tracking_true_obs_reader>());
-            };
+            std::cout << "Loading true observable data for PRN " << gnss_synchro_vec.at(n).PRN << std::endl;
-    }) << "Failure opening true observables file";
+            std::string true_obs_file = std::string("./gps_l1_ca_obs_prn");
+            true_obs_file.append(std::to_string(gnss_synchro_vec.at(n).PRN));
+            true_obs_file.append(".dat");
+            ASSERT_NO_THROW({
+                if (true_reader_vec.back()->open_obs_file(true_obs_file) == false)
+                    {
+                        throw std::exception();
+                    };
+            }) << "Failure opening true observables file";
+
+            // load acquisition data based on the first epoch of the true observations
+            ASSERT_NO_THROW({
+                if (true_reader_vec.back()->read_binary_obs() == false)
+                    {
+                        throw std::exception();
+                    };
+            }) << "Failure reading true observables file";
+
+            //restart the epoch counter
+            true_reader_vec.back()->restart();
+
+            std::cout << "Initial Doppler [Hz]=" << true_reader_vec.back()->doppler_l1_hz << " Initial code delay [Chips]="
+                      << true_reader_vec.back()->prn_delay_chips << std::endl;
+
+            gnss_synchro_vec.at(n).Acq_delay_samples = (GPS_L1_CA_CODE_LENGTH_CHIPS - true_reader_vec.back()->prn_delay_chips / GPS_L1_CA_CODE_LENGTH_CHIPS) * baseband_sampling_freq * GPS_L1_CA_CODE_PERIOD;
+            gnss_synchro_vec.at(n).Acq_doppler_hz = true_reader_vec.back()->doppler_l1_hz;
+            gnss_synchro_vec.at(n).Acq_samplestamp_samples = 0;
+
+
+            //create the tracking channels
+            tracking_ch_vec.push_back(std::make_shared<GpsL1CaDllPllTracking>(config.get(), "Tracking_1C", 1, 1));
+            //create the telemetry decoders
+            tlm_ch_vec.push_back(std::make_shared<GpsL1CaTelemetryDecoder>(config.get(), "TelemetryDecoder_1C", 1, 1));
+            //create null sinks for observables output
+            null_sink_vec.push_back(gr::blocks::null_sink::make(sizeof(Gnss_Synchro)));
+
+            ASSERT_NO_THROW({
+                tlm_ch_vec.back()->set_channel(gnss_synchro_vec.at(n).Channel_ID);
+                tlm_ch_vec.back()->set_satellite(Gnss_Satellite(std::string("GPS"), gnss_synchro_vec.at(n).PRN));
+            }) << "Failure setting gnss_synchro.";
+
+            ASSERT_NO_THROW({
+                tracking_ch_vec.back()->set_channel(gnss_synchro_vec.at(n).Channel_ID);
+            }) << "Failure setting channel.";
+
+            ASSERT_NO_THROW({
+                tracking_ch_vec.back()->set_gnss_synchro(&gnss_synchro_vec.at(n));
+            }) << "Failure setting gnss_synchro.";
+        }
 
     top_block = gr::make_top_block("Telemetry_Decoder test");
-    std::shared_ptr<TrackingInterface> tracking_ch0 = std::make_shared<GpsL1CaDllPllTracking>(config.get(), "Tracking_1C", 1, 1);
+    boost::shared_ptr<HybridObservablesTest_msg_rx> dummy_msg_rx_trk = HybridObservablesTest_msg_rx_make();
-    std::shared_ptr<TrackingInterface> tracking_ch1 = std::make_shared<GpsL1CaDllPllTracking>(config.get(), "Tracking_1C", 1, 1);
+    boost::shared_ptr<HybridObservablesTest_tlm_msg_rx> dummy_tlm_msg_rx = HybridObservablesTest_tlm_msg_rx_make();
-
-    boost::shared_ptr<HybridObservablesTest_msg_rx> msg_rx_ch0 = HybridObservablesTest_msg_rx_make();
-    boost::shared_ptr<HybridObservablesTest_msg_rx> msg_rx_ch1 = HybridObservablesTest_msg_rx_make();
-
-    // load acquisition data based on the first epoch of the true observations
-    ASSERT_NO_THROW({
-        if (true_obs_data_ch0.read_binary_obs() == false)
-            {
-                throw std::exception();
-            };
-    }) << "Failure reading true observables file";
-
-    ASSERT_NO_THROW({
-        if (true_obs_data_ch1.read_binary_obs() == false)
-            {
-                throw std::exception();
-            };
-    }) << "Failure reading true observables file";
-
-    //restart the epoch counter
-    true_obs_data_ch0.restart();
-    true_obs_data_ch1.restart();
-
-    std::cout << "Initial Doppler [Hz]=" << true_obs_data_ch0.doppler_l1_hz << " Initial code delay [Chips]=" << true_obs_data_ch0.prn_delay_chips << std::endl;
-
-    gnss_synchro_ch0.Acq_delay_samples = (GPS_L1_CA_CODE_LENGTH_CHIPS - true_obs_data_ch0.prn_delay_chips / GPS_L1_CA_CODE_LENGTH_CHIPS) * baseband_sampling_freq * GPS_L1_CA_CODE_PERIOD;
-    gnss_synchro_ch0.Acq_doppler_hz = true_obs_data_ch0.doppler_l1_hz;
-    gnss_synchro_ch0.Acq_samplestamp_samples = 0;
-
-    std::cout << "Initial Doppler [Hz]=" << true_obs_data_ch1.doppler_l1_hz << " Initial code delay [Chips]=" << true_obs_data_ch1.prn_delay_chips << std::endl;
-
-    gnss_synchro_ch1.Acq_delay_samples = (GPS_L1_CA_CODE_LENGTH_CHIPS - true_obs_data_ch1.prn_delay_chips / GPS_L1_CA_CODE_LENGTH_CHIPS) * baseband_sampling_freq * GPS_L1_CA_CODE_PERIOD;
-    gnss_synchro_ch1.Acq_doppler_hz = true_obs_data_ch1.doppler_l1_hz;
-    gnss_synchro_ch1.Acq_samplestamp_samples = 0;
-
-    //telemetry decoders
-    std::shared_ptr<TelemetryDecoderInterface> tlm_ch0(new GpsL1CaTelemetryDecoder(config.get(), "TelemetryDecoder_1C", 1, 1));
-    std::shared_ptr<TelemetryDecoderInterface> tlm_ch1(new GpsL1CaTelemetryDecoder(config.get(), "TelemetryDecoder_1C", 1, 1));
-
-    ASSERT_NO_THROW({
-        tlm_ch0->set_channel(0);
-        tlm_ch1->set_channel(1);
-
-        tlm_ch0->set_satellite(Gnss_Satellite(std::string("GPS"), gnss_synchro_ch0.PRN));
-        tlm_ch1->set_satellite(Gnss_Satellite(std::string("GPS"), gnss_synchro_ch1.PRN));
-    }) << "Failure setting gnss_synchro.";
-
-    boost::shared_ptr<HybridObservablesTest_tlm_msg_rx> tlm_msg_rx_ch1 = HybridObservablesTest_tlm_msg_rx_make();
-    boost::shared_ptr<HybridObservablesTest_tlm_msg_rx> tlm_msg_rx_ch2 = HybridObservablesTest_tlm_msg_rx_make();
-
     //Observables
-    std::shared_ptr<ObservablesInterface> observables(new HybridObservables(config.get(), "Observables", 3, 2));
+    std::shared_ptr<ObservablesInterface> observables(new HybridObservables(config.get(), "Observables", tracking_ch_vec.size() + 1, tracking_ch_vec.size()));
 
-    ASSERT_NO_THROW({
+    for (unsigned int n = 0; n < tracking_ch_vec.size(); n++)
-        tracking_ch0->set_channel(gnss_synchro_ch0.Channel_ID);
+        {
-        tracking_ch1->set_channel(gnss_synchro_ch1.Channel_ID);
+            ASSERT_NO_THROW({
-    }) << "Failure setting channel.";
+                tracking_ch_vec.at(n)->connect(top_block);
+            }) << "Failure connecting tracking to the top_block.";
+        }
 
-    ASSERT_NO_THROW({
-        tracking_ch0->set_gnss_synchro(&gnss_synchro_ch0);
-        tracking_ch1->set_gnss_synchro(&gnss_synchro_ch1);
-    }) << "Failure setting gnss_synchro.";
-
-    ASSERT_NO_THROW({
-        tracking_ch0->connect(top_block);
-        tracking_ch1->connect(top_block);
-    }) << "Failure connecting tracking to the top_block.";
 
     ASSERT_NO_THROW({
         std::string file = "./" + filename_raw_data;
         const char* file_name = file.c_str();
         gr::blocks::file_source::sptr file_source = gr::blocks::file_source::make(sizeof(int8_t), file_name, false);
         gr::blocks::interleaved_char_to_complex::sptr gr_interleaved_char_to_complex = gr::blocks::interleaved_char_to_complex::make();
-        gr::blocks::null_sink::sptr sink_ch0 = gr::blocks::null_sink::make(sizeof(Gnss_Synchro));
-        gr::blocks::null_sink::sptr sink_ch1 = gr::blocks::null_sink::make(sizeof(Gnss_Synchro));
         gnss_sdr_sample_counter_sptr samp_counter = gnss_sdr_make_sample_counter(static_cast<double>(baseband_sampling_freq), sizeof(gr_complex));
         top_block->connect(file_source, 0, gr_interleaved_char_to_complex, 0);
         top_block->connect(gr_interleaved_char_to_complex, 0, samp_counter, 0);
 
-        //ch0
+        for (unsigned int n = 0; n < tracking_ch_vec.size(); n++)
-        top_block->connect(gr_interleaved_char_to_complex, 0, tracking_ch0->get_left_block(), 0);
+            {
-        top_block->connect(tracking_ch0->get_right_block(), 0, tlm_ch0->get_left_block(), 0);
+                top_block->connect(gr_interleaved_char_to_complex, 0, tracking_ch_vec.at(n)->get_left_block(), 0);
-        top_block->connect(tlm_ch0->get_right_block(), 0, observables->get_left_block(), 0);
+                top_block->connect(tracking_ch_vec.at(n)->get_right_block(), 0, tlm_ch_vec.at(n)->get_left_block(), 0);
-        top_block->msg_connect(tracking_ch0->get_right_block(), pmt::mp("events"), msg_rx_ch0, pmt::mp("events"));
+                top_block->connect(tlm_ch_vec.at(n)->get_right_block(), 0, observables->get_left_block(), n);
-        //ch1
+                top_block->msg_connect(tracking_ch_vec.at(n)->get_right_block(), pmt::mp("events"), dummy_msg_rx_trk, pmt::mp("events"));
-        top_block->connect(gr_interleaved_char_to_complex, 0, tracking_ch1->get_left_block(), 0);
+                top_block->connect(observables->get_right_block(), n, null_sink_vec.at(n), 0);
-        top_block->connect(tracking_ch1->get_right_block(), 0, tlm_ch1->get_left_block(), 0);
+            }
-        top_block->connect(tlm_ch1->get_right_block(), 0, observables->get_left_block(), 1);
+        //connect sample counter and timmer to the last channel in observables block (extra channel)
-        top_block->msg_connect(tracking_ch1->get_right_block(), pmt::mp("events"), msg_rx_ch1, pmt::mp("events"));
+        top_block->connect(samp_counter, 0, observables->get_left_block(), tracking_ch_vec.size());
-
-        top_block->connect(observables->get_right_block(), 0, sink_ch0, 0);
-        top_block->connect(observables->get_right_block(), 1, sink_ch1, 0);
-        top_block->connect(samp_counter, 0, observables->get_left_block(), 2);
 
     }) << "Failure connecting the blocks.";
 
-    tracking_ch0->start_tracking();
+    for (unsigned int n = 0; n < tracking_ch_vec.size(); n++)
-    tracking_ch1->start_tracking();
+        {
+            tracking_ch_vec.at(n)->start_tracking();
+        }
 
     EXPECT_NO_THROW({
         start = std::chrono::system_clock::now();
@@ -684,40 +731,36 @@ TEST_F(HybridObservablesTest, ValidationOfResults)
 
     std::cout << "True observation epochs = " << nepoch << std::endl;
     // Matrices for storing columnwise true GPS time, Range, Doppler and Carrier phase
-    arma::mat true_ch0 = arma::zeros<arma::mat>(nepoch, 4);
+    std::vector<arma::mat> true_obs_vec;
-    arma::mat true_ch1 = arma::zeros<arma::mat>(nepoch, 4);
-
     true_observables.restart();
     long int epoch_counter = 0;
+    for (unsigned int n = 0; n < tracking_ch_vec.size(); n++)
+        {
+            true_obs_vec.push_back(arma::zeros<arma::mat>(nepoch, 4));
+        }
+
     ASSERT_NO_THROW({
         while (true_observables.read_binary_obs())
             {
-                if (round(true_observables.prn[0]) != gnss_synchro_ch0.PRN)
+                for (unsigned int n = 0; n < true_obs_vec.size(); n++)
                     {
-                        std::cout << "True observables SV PRN does not match " << round(true_observables.prn[1]) << std::endl;
+                        if (round(true_observables.prn[n]) != gnss_synchro_vec.at(n).PRN)
-                        throw std::exception();
+                            {
+                                std::cout << "True observables SV PRN does not match measured ones: "
+                                          << round(true_observables.prn[n]) << " vs. " << gnss_synchro_vec.at(n).PRN << std::endl;
+                                throw std::exception();
+                            }
+                        true_obs_vec.at(n)(epoch_counter, 0) = true_observables.gps_time_sec[n];
+                        true_obs_vec.at(n)(epoch_counter, 1) = true_observables.dist_m[n];
+                        true_obs_vec.at(n)(epoch_counter, 2) = true_observables.doppler_l1_hz[n];
+                        true_obs_vec.at(n)(epoch_counter, 3) = true_observables.acc_carrier_phase_l1_cycles[n];
                     }
-                if (round(true_observables.prn[1]) != gnss_synchro_ch1.PRN)
-                    {
-                        std::cout << "True observables SV PRN does not match " << round(true_observables.prn[1]) << std::endl;
-                        throw std::exception();
-                    }
-                true_ch0(epoch_counter, 0) = true_observables.gps_time_sec[0];
-                true_ch0(epoch_counter, 1) = true_observables.dist_m[0];
-                true_ch0(epoch_counter, 2) = true_observables.doppler_l1_hz[0];
-                true_ch0(epoch_counter, 3) = true_observables.acc_carrier_phase_l1_cycles[0];
-
-                true_ch1(epoch_counter, 0) = true_observables.gps_time_sec[1];
-                true_ch1(epoch_counter, 1) = true_observables.dist_m[1];
-                true_ch1(epoch_counter, 2) = true_observables.doppler_l1_hz[1];
-                true_ch1(epoch_counter, 3) = true_observables.acc_carrier_phase_l1_cycles[1];
-
                 epoch_counter++;
             }
     });
 
     //read measured values
-    observables_dump_reader estimated_observables(2);  //two channels
+    observables_dump_reader estimated_observables(tracking_ch_vec.size());
     ASSERT_NO_THROW({
         if (estimated_observables.open_obs_file(std::string("./observables.dat")) == false)
             {
@@ -726,96 +769,114 @@ TEST_F(HybridObservablesTest, ValidationOfResults)
     }) << "Failure opening dump observables file";
 
     nepoch = static_cast<unsigned int>(estimated_observables.num_epochs());
-    std::cout << "Measured observation epochs = " << nepoch << std::endl;
+    std::cout << "Measured observations epochs = " << nepoch << std::endl;
 
     // Matrices for storing columnwise measured RX_time, TOW, Doppler, Carrier phase and Pseudorange
-    arma::mat measured_ch0 = arma::zeros<arma::mat>(nepoch, 5);
+    std::vector<arma::mat> measured_obs_vec;
-    arma::mat measured_ch1 = arma::zeros<arma::mat>(nepoch, 5);
+    std::vector<long int> epoch_counters_vec;
+    for (unsigned int n = 0; n < tracking_ch_vec.size(); n++)
+        {
+            measured_obs_vec.push_back(arma::zeros<arma::mat>(nepoch, 5));
+            epoch_counters_vec.push_back(0);
+        }
 
     estimated_observables.restart();
-    epoch_counter = 0;
-    long int epoch_counter2 = 0;
     while (estimated_observables.read_binary_obs())
         {
-            if (static_cast<bool>(estimated_observables.valid[0]))
+            for (unsigned int n = 0; n < measured_obs_vec.size(); n++)
                 {
-                    measured_ch0(epoch_counter, 0) = estimated_observables.RX_time[0];
+                    if (static_cast<bool>(estimated_observables.valid[n]))
-                    measured_ch0(epoch_counter, 1) = estimated_observables.TOW_at_current_symbol_s[0];
+                        {
-                    measured_ch0(epoch_counter, 2) = estimated_observables.Carrier_Doppler_hz[0];
+                            measured_obs_vec.at(n)(epoch_counters_vec.at(n), 0) = estimated_observables.RX_time[n];
-                    measured_ch0(epoch_counter, 3) = estimated_observables.Acc_carrier_phase_hz[0];
+                            measured_obs_vec.at(n)(epoch_counters_vec.at(n), 1) = estimated_observables.TOW_at_current_symbol_s[n];
-                    measured_ch0(epoch_counter, 4) = estimated_observables.Pseudorange_m[0];
+                            measured_obs_vec.at(n)(epoch_counters_vec.at(n), 2) = estimated_observables.Carrier_Doppler_hz[n];
-                    epoch_counter++;
+                            measured_obs_vec.at(n)(epoch_counters_vec.at(n), 3) = estimated_observables.Acc_carrier_phase_hz[n];
-                }
+                            measured_obs_vec.at(n)(epoch_counters_vec.at(n), 4) = estimated_observables.Pseudorange_m[n];
-            if (static_cast<bool>(estimated_observables.valid[1]))
+                            epoch_counters_vec.at(n)++;
-                {
+                        }
-                    measured_ch1(epoch_counter2, 0) = estimated_observables.RX_time[1];
-                    measured_ch1(epoch_counter2, 1) = estimated_observables.TOW_at_current_symbol_s[1];
-                    measured_ch1(epoch_counter2, 2) = estimated_observables.Carrier_Doppler_hz[1];
-                    measured_ch1(epoch_counter2, 3) = estimated_observables.Acc_carrier_phase_hz[1];
-                    measured_ch1(epoch_counter2, 4) = estimated_observables.Pseudorange_m[1];
-                    epoch_counter2++;
                 }
         }
 
+
     //Cut measurement tail zeros
-    arma::uvec index = arma::find(measured_ch0.col(0) > 0.0, 1, "last");
+    arma::uvec index;
-    if ((index.size() > 0) and index(0) < (nepoch - 1))
+    for (unsigned int n = 0; n < measured_obs_vec.size(); n++)
         {
-            measured_ch0.shed_rows(index(0) + 1, nepoch - 1);
+            index = arma::find(measured_obs_vec.at(n).col(0) > 0.0, 1, "last");
-        }
+            if ((index.size() > 0) and index(0) < (nepoch - 1))
-    index = arma::find(measured_ch1.col(0) > 0.0, 1, "last");
+                {
-    if ((index.size() > 0) and index(0) < (nepoch - 1))
+                    measured_obs_vec.at(n).shed_rows(index(0) + 1, nepoch - 1);
-        {
+                }
-            measured_ch1.shed_rows(index(0) + 1, nepoch - 1);
         }
 
     //Cut measurement initial transitory of the measurements
 
-    double initial_transitory_s = 30.0;
+    double initial_transitory_s = FLAGS_skip_obs_transitory_s;
 
-    index = arma::find(measured_ch0.col(0) >= (measured_ch0(0, 0) + initial_transitory_s), 1, "first");
+    for (unsigned int n = 0; n < measured_obs_vec.size(); n++)
-    if ((index.size() > 0) and (index(0) > 0))
         {
-            measured_ch0.shed_rows(0, index(0));
+            index = arma::find(measured_obs_vec.at(n).col(0) >= (measured_obs_vec.at(n)(0, 0) + initial_transitory_s), 1, "first");
-        }
+            if ((index.size() > 0) and (index(0) > 0))
-    index = arma::find(measured_ch1.col(0) >= (measured_ch1(0, 0) + initial_transitory_s), 1, "first");
+                {
-    if ((index.size() > 0) and (index(0) > 0))
+                    measured_obs_vec.at(n).shed_rows(0, index(0));
-        {
+                }
-            measured_ch1.shed_rows(0, index(0));
+
+            index = arma::find(measured_obs_vec.at(n).col(0) >= true_obs_vec.at(n)(0, 0), 1, "first");
+            if ((index.size() > 0) and (index(0) > 0))
+                {
+                    measured_obs_vec.at(n).shed_rows(0, index(0));
+                }
         }
 
 
-    index = arma::find(measured_ch0.col(0) >= true_ch0(0, 0), 1, "first");
-    if ((index.size() > 0) and (index(0) > 0))
-        {
-            measured_ch0.shed_rows(0, index(0));
-        }
-    index = arma::find(measured_ch1.col(0) >= true_ch1(0, 0), 1, "first");
-    if ((index.size() > 0) and (index(0) > 0))
-        {
-            measured_ch1.shed_rows(0, index(0));
-        }
-
     //Correct the clock error using true values (it is not possible for a receiver to correct
     //the receiver clock offset error at the observables level because it is required the
     //decoding of the ephemeris data and solve the PVT equations)
 
     //Find the reference satellite (the nearest) and compute the receiver time offset at observable level
+
+    double min_pr = std::numeric_limits<double>::max();
+    unsigned int min_pr_ch_id = 0;
     arma::vec receiver_time_offset_s;
-    if (measured_ch0(0, 4) < measured_ch1(0, 4))
+    for (unsigned int n = 0; n < measured_obs_vec.size(); n++)
         {
-            receiver_time_offset_s = true_ch0.col(1) / GPS_C_m_s - GPS_STARTOFFSET_ms / 1000.0;
+            if (measured_obs_vec.at(n)(0, 4) < min_pr)
+                {
+                    min_pr = measured_obs_vec.at(n)(0, 4);
+                    min_pr_ch_id = n;
+                }
         }
-    else
+
+    receiver_time_offset_s = true_obs_vec.at(min_pr_ch_id).col(1) / GPS_C_m_s - GPS_STARTOFFSET_ms / 1000.0;
+
+    for (unsigned int n = 0; n < measured_obs_vec.size(); n++)
         {
-            receiver_time_offset_s = true_ch1.col(1) / GPS_C_m_s - GPS_STARTOFFSET_ms / 1000.0;
+            arma::vec corrected_reference_TOW_s = true_obs_vec.at(min_pr_ch_id).col(0) - receiver_time_offset_s;
+            std::cout << "[CH " << n << "] Receiver time offset " << receiver_time_offset_s(0) * 1e3 << " [ms]" << std::endl;
+
+            //Compare measured observables
+            if (min_pr_ch_id != n)
+                {
+                    check_results_code_pseudorange(true_obs_vec.at(n),
+                        true_obs_vec.at(min_pr_ch_id),
+                        corrected_reference_TOW_s,
+                        measured_obs_vec.at(n),
+                        measured_obs_vec.at(min_pr_ch_id),
+                        "[CH " + std::to_string(n) + "] PRN " + std::to_string(gnss_synchro_vec.at(n).PRN) + " ");
+                }
+            else
+                {
+                    std::cout << "[CH " << std::to_string(n) << "] PRN " << std::to_string(gnss_synchro_vec.at(n).PRN) << " is the reference satellite" << std::endl;
+                }
+            std::cout << "true_obs_vec.at(n): " << true_obs_vec.at(n)(0, 2) << std::endl;
+            check_results_carrier_phase(true_obs_vec.at(n),
+                corrected_reference_TOW_s,
+                measured_obs_vec.at(n),
+                "[CH " + std::to_string(n) + "] PRN " + std::to_string(gnss_synchro_vec.at(n).PRN) + " ");
+            check_results_carrier_doppler(true_obs_vec.at(n),
+                corrected_reference_TOW_s,
+                measured_obs_vec.at(n),
+                "[CH " + std::to_string(n) + "] PRN " + std::to_string(gnss_synchro_vec.at(n).PRN) + " ");
         }
-    arma::vec corrected_reference_TOW_s = true_ch0.col(0) - receiver_time_offset_s;
-    std::cout << "Receiver time offset: " << receiver_time_offset_s(0) * 1e3 << " [ms]" << std::endl;
-
-    //Compare measured observables
-    check_results_code_psudorange(true_ch0, true_ch1, corrected_reference_TOW_s, measured_ch0, measured_ch1);
-    check_results_carrier_phase(true_ch0, true_ch1, corrected_reference_TOW_s, measured_ch0, measured_ch1);
-
     std::cout << "Test completed in " << elapsed_seconds.count() << " [s]" << std::endl;
 }