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Fix CRC computation in ISM

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This commit is contained in:
Carles Fernandez 2024-09-20 14:50:31 +02:00
parent 557a7f7265
commit 583ae6df0d
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GPG Key ID: 4C583C52B0C3877D
4 changed files with 119 additions and 54 deletions
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40
src/core/system_parameters/galileo_ism.cc
View File

@ -15,7 +15,6 @@
*/
#include "galileo_ism.h"
#include <boost/crc.hpp>
#include <boost/dynamic_bitset.hpp>
#include <algorithm>
#include <vector>
@ -176,15 +175,12 @@ uint16_t Galileo_ISM::get_Tvalidity_hours() const
}
bool Galileo_ISM::check_ism_crc(const std::bitset<GALILEO_DATA_JK_BITS>& bits) const
bool Galileo_ISM::check_ism_crc(const std::bitset<GALILEO_DATA_JK_BITS>& bits)
{
boost::dynamic_bitset<unsigned char> frame_bits(bits.to_string().substr(0, GALILEO_ISM_CRC_DATA_BITS));
std::vector<unsigned char> bytes;
boost::to_block_range(frame_bits, std::back_inserter(bytes));
std::reverse(bytes.begin(), bytes.end());
boost::crc_optimal<32, 0xC0A0A0D5, 0xFFFFFFFF, 0xFFFFFFFF, true, true> crc32_ism;
crc32_ism.process_bytes(bytes.data(), GALILEO_ISM_CRC_DATA_BYTES);
const uint32_t crc_computed = crc32_ism.checksum();
if (this->ism_crc == crc_computed)
@ -196,33 +192,9 @@ bool Galileo_ISM::check_ism_crc(const std::bitset<GALILEO_DATA_JK_BITS>& bits) c
}
bool Galileo_ISM::ism_apply_to_sat(uint32_t prn) const
uint32_t Galileo_ISM::compute_crc(const std::vector<uint8_t>& data)
{
if (prn == 0 || prn > 63)
{
return false;
}
std::bitset<32> bs(this->ism_mask);
if (this->ism_mask_msb == 0)
{
if (prn <= 32)
{
return bs[prn - 1];
}
else
{
return false;
}
}
else
{
if (prn > 32)
{
return bs[prn - 32];
}
else
{
return false;
}
}
}
crc32_ism.process_bytes(data.data(), data.size());
uint32_t result = crc32_ism.checksum();
return result;
}

28
src/core/system_parameters/galileo_ism.h
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@ -19,9 +19,11 @@
#define GNSS_SDR_GALILEO_ISM_H
#include "Galileo_INAV.h"
#include <boost/crc.hpp>
#include <bitset>
#include <cstdint>
#include <unordered_map>
#include <vector>
/** \addtogroup Core
* \{ */
@ -41,7 +43,7 @@ public:
/*!
* Default constructor
*/
Galileo_ISM() = default;
Galileo_ISM() : crc32_ism(0x814141AB, 0, 0, false, false) {};
void set_ism_constellation_id(uint8_t const_id);
void set_ism_service_level_id(uint8_t sl_id);
@ -57,19 +59,21 @@ public:
void set_ism_Tvalidity(uint8_t tvalidity);
void set_ism_crc(uint32_t crc);
bool check_ism_crc(const std::bitset<GALILEO_DATA_JK_BITS>& bits) const; //!< Requires ism_crc to be already set
bool ism_apply_to_sat(uint32_t prn) const; //!< Returns true if ISM parameters apply to the prn satellite, false otherwise
bool check_ism_crc(const std::bitset<GALILEO_DATA_JK_BITS>& bits);
double get_pconst_value() const; //!< A priori constellation fault probability
double get_psat_value() const; //!< A priori satellite fault probability
float get_ura_m() const; //!< User Range Accuracy, in m, used for integrity
float get_ure_m() const; //!< User Range Error, in m, used for accuracy
float get_bnom_m() const; //!< Maximum nominal bias for a satellite, in m
uint16_t get_WN_ISM() const; //!< ISM Week Number, in weeks
uint16_t get_t0_ISM() const; //!< ISM Time of Week, in seconds
uint16_t get_Tvalidity_hours() const; //!< Validity duration of ISM content, in hours
double get_pconst_value() const;
double get_psat_value() const;
float get_ura_m() const;
float get_ure_m() const;
float get_bnom_m() const;
uint16_t get_WN_ISM() const;
uint16_t get_t0_ISM() const;
uint16_t get_Tvalidity_hours() const;
uint32_t compute_crc(const std::vector<uint8_t>& data);
private:
boost::crc_basic<32> crc32_ism;
// ICD 2.1 Table 97
std::unordered_map<uint8_t, double> ISM_PCONST_MAP = {
{0, 1.0e-8},
@ -146,7 +150,6 @@ private:
{14, 3.75},
{15, 4.00}};
// ICD 2.1 Table 101
std::unordered_map<uint8_t, float> ISM_BNOM_MAP = {
{0, 0.0},
@ -166,7 +169,6 @@ private:
{14, 2.0},
{15, 2.4}};
// ICD 2.1 Table 102
std::unordered_map<uint8_t, uint16_t> ISM_TVALIDITY_MAP = {
{0, 1},

62
src/tests/test_main.cc
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@ -18,19 +18,59 @@
#include "concurrent_map.h"
#include "concurrent_queue.h"
#include "gps_acq_assist.h"
#include <gtest/gtest.h>
#include <fstream>
#include <iostream>
#include <ostream>
#include <string>
#if USE_GLOG_AND_GFLAGS
#include <gflags/gflags.h>
#include <glog/logging.h>
#include <gtest/gtest.h>
#include <iostream>
#if GFLAGS_OLD_NAMESPACE
namespace gflags
{
using namespace google;
}
DECLARE_string(log_dir);
#endif
#else
#include "gnss_sdr_flags.h"
#include <absl/flags/flag.h>
#include <absl/flags/parse.h>
#include <absl/log/flags.h>
#include <absl/log/globals.h>
#include <absl/log/initialize.h>
#include <absl/log/log.h>
#include <absl/log/log_sink.h>
#include <absl/log/log_sink_registry.h>
class TestingLogSink : public absl::LogSink
{
public:
TestingLogSink()
{
if (!absl::GetFlag(FLAGS_log_dir).empty())
{
filename = std::string(absl::GetFlag(FLAGS_log_dir) + "/run_tests.log");
}
else
{
filename = std::string(GetTempDir() + "/run_tests.log");
}
logfile.open(filename);
}
void Send(const absl::LogEntry &entry) override
{
logfile << entry.text_message_with_prefix_and_newline() << std::flush;
}
private:
std::ofstream logfile;
std::string filename;
};
#endif
DECLARE_string(log_dir);
#if UNIT_TESTING_MINIMAL
#include "unit-tests/arithmetic/matio_test.cc"
@ -95,9 +135,6 @@ DECLARE_string(log_dir);
#include "unit-tests/system-parameters/glonass_gnav_ephemeris_test.cc"
#include "unit-tests/system-parameters/glonass_gnav_nav_message_test.cc"
#include "unit-tests/system-parameters/has_decoding_test.cc"
#include "unit-tests/system-parameters/galileo_ism_test.cc"
#ifndef EXCLUDE_TESTS_REQUIRING_BINARIES
#include "unit-tests/control-plane/control_thread_test.cc"
@ -177,8 +214,15 @@ int main(int argc, char **argv)
catch (...)
{
} // catch the "testing::internal::<unnamed>::ClassUniqueToAlwaysTrue" from gtest
#if USE_GLOG_AND_GFLAGS
gflags::ParseCommandLineFlags(&argc, &argv, true);
google::InitGoogleLogging(argv[0]);
#else
absl::ParseCommandLine(argc, argv);
absl::LogSink *testLogSink = new TestingLogSink;
absl::AddLogSink(testLogSink);
absl::InitializeLog();
#endif
try
{
res = RUN_ALL_TESTS();
@ -187,6 +231,10 @@ int main(int argc, char **argv)
{
LOG(WARNING) << "Unexpected catch";
}
#if USE_GLOG_AND_GFLAGS
gflags::ShutDownCommandLineFlags();
#else
absl::FlushLogSinks();
#endif
return res;
}

43
src/tests/unit-tests/system-parameters/galileo_ism_test.cc Normal file
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@ -0,0 +1,43 @@
/*!
* \file galileo_ism_test.cc
* \brief Tests for Galileo Integrity Support Message
* \author Carles Fernandez-Prades, 2024. cfernandez(at)cttc.es
*
*
* -----------------------------------------------------------------------------
*
* GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
* This file is part of GNSS-SDR.
*
* Copyright (C) 2010-2023 (see AUTHORS file for a list of contributors)
* SPDX-License-Identifier: GPL-3.0-or-later
*
* -----------------------------------------------------------------------------
*/
#include "galileo_ism.h"
#include <gtest/gtest.h>
#include <algorithm>
#include <bitset>
#include <vector>
TEST(GalileoISMTest, CRC)
{
Galileo_ISM gal_ism{};
uint32_t expected_crc = 3002390191;
std::bitset<96> input{"010110000010101010101010101010101010101010101010101010101010101010101010101010101010101010101010"};
std::vector<uint8_t> data_bytes;
for (size_t i = 0; i < input.size(); i += 8)
{
std::bitset<8> byte;
for (size_t j = 0; j < 8; j++)
{
byte[j] = input[i + j];
}
data_bytes.push_back(static_cast<uint8_t>(byte.to_ulong()));
}
std::reverse(data_bytes.begin(), data_bytes.end());
auto computed_crc = gal_ism.compute_crc(data_bytes);
EXPECT_TRUE(computed_crc == expected_crc);
}