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GLONASS Observables: Fixes bug in TOW updating

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Fixes bug in TOW update when a new value has been computed. This adds a
new flag to keep track of TOW update given the tk component. The code
fix improves the pseudorange measurement for code
This commit is contained in:
Damian Miralles 2017-10-02 23:00:45 -06:00 committed by Carles Fernandez
parent e5e9cc97ad
commit c5a690cf1e
5 changed files with 14 additions and 16 deletions
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2
conf/gnss-sdr_GLONASS_L1_CA_ibyte.conf
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@ -62,6 +62,8 @@ TelemetryDecoder_1G.implementation=GLONASS_L1_CA_Telemetry_Decoder
;######### OBSERVABLES CONFIG ############
Observables.implementation=Hybrid_Observables
Observables.dump=true;
Observables.dump_filename=/archive/glo_observables.dat
;######### PVT CONFIG ############
PVT.implementation=RTKLIB_PVT

5
src/algorithms/telemetry_decoder/gnuradio_blocks/glonass_l1_ca_telemetry_decoder_cc.cc
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@ -351,10 +351,11 @@ int glonass_l1_ca_telemetry_decoder_cc::general_work (int noutput_items __attrib
// UPDATE GNSS SYNCHRO DATA
//2. Add the telemetry decoder information
if (this->d_flag_preamble == true and d_nav.flag_TOW_set == true)
if (this->d_flag_preamble == true and d_nav.flag_TOW_new == true)
//update TOW at the preamble instant
{
d_TOW_at_current_symbol = floor((d_nav.d_TOW + 2*GLONASS_L1_CA_CODE_PERIOD + GLONASS_GNAV_PREAMBLE_DURATION_S)*1000.0)/1000.0;
d_TOW_at_current_symbol = floor((d_nav.d_TOW - GLONASS_GNAV_PREAMBLE_DURATION_S)*1000.0)/1000.0;
d_nav.flag_TOW_new = false;
}
else //if there is not a new preamble, we define the TOW of the current symbol

10
src/core/system_parameters/glonass_gnav_navigation_message.cc
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@ -73,12 +73,8 @@ void Glonass_Gnav_Navigation_Message::reset()
//broadcast orbit 1
flag_TOW_set = false;
flag_TOW_new = false;
d_TOW = 0.0; //!< Time of GPS Week of the ephemeris set (taken from subframes TOW) [s]
d_TOW_F1 = 0.0; //!< Time of GPS Week from HOW word of Subframe 1 [s]
d_TOW_F2 = 0.0; //!< Time of GPS Week from HOW word of Subframe 2 [s]
d_TOW_F3 = 0.0; //!< Time of GPS Week from HOW word of Subframe 3 [s]
d_TOW_F4 = 0.0; //!< Time of GPS Week from HOW word of Subframe 4 [s]
d_TOW_F5 = 0.0; //!< Time of GPS Week from HOW word of Subframe 5 [s]
flag_CRC_test = false;
d_frame_ID = 0;
@ -366,7 +362,8 @@ double Glonass_Gnav_Navigation_Message::get_TOW()
int i = 0;
// tk is relative to UTC(SU) + 3.00 hrs, so we need to convert to utc and add corrections
TOD = gnav_ephemeris.d_t_k - glot2utcsu - utcsu2utc + gnav_utc_model.d_tau_c + gnav_utc_model.d_tau_gps;
// tk plus 10 sec is the true tod since get_TOW is called when in str5
TOD = (gnav_ephemeris.d_t_k + 10) - glot2utcsu - utcsu2utc + gnav_utc_model.d_tau_c + gnav_utc_model.d_tau_gps;
boost::gregorian::date glo_date(gnav_ephemeris.d_yr, 1, 1);
@ -521,6 +518,7 @@ int Glonass_Gnav_Navigation_Message::string_decoder(std::string frame_string)
gnav_ephemeris.d_TOW = d_TOW;
gnav_ephemeris.d_WN = get_WN();
flag_TOW_set = true;
flag_TOW_new = true;
}
}

8
src/core/system_parameters/glonass_gnav_navigation_message.h
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@ -95,13 +95,9 @@ public:
bool flag_utc_model_str_5; //!< Clock info send in string 5 of navigation data
bool flag_utc_model_str_15; //!< Clock info send in string 15 of frame 5 of navigation data
bool flag_TOW_set;
bool flag_TOW_set; //!< Flag indicating when the TOW has been set
bool flag_TOW_new; //!< Flag indicating when a new TOW has been computed
double d_TOW; //!< Time of GPS Week of the ephemeris set (taken from subframes TOW) [s]
double d_TOW_F1; //!< Time of GPS Week from HOW word of Subframe 1 [s]
double d_TOW_F2; //!< Time of GPS Week from HOW word of Subframe 2 [s]
double d_TOW_F3; //!< Time of GPS Week from HOW word of Subframe 3 [s]
double d_TOW_F4; //!< Time of GPS Week from HOW word of Subframe 4 [s]
double d_TOW_F5; //!< Time of GPS Week from HOW word of Subframe 5 [s]
// Clock terms
double d_satClkCorr; // Satellite clock error

5
src/utils/matlab/hybrid_observables_plot_sample.m
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@ -7,16 +7,17 @@ addpath('./libs');
samplingFreq = 6625000; %[Hz]
channels=5;
path='/archive/';
observables_log_path=[path 'glo_observables'];
observables_log_path=[path 'glo_observables.dat'];
GNSS_observables= read_hybrid_observables_dump(channels,observables_log_path);
%%
%optional:
%search all channels having good satellite simultaneously
min_idx=1;
for n=1:1:channels
idx=find(GNSS_observables.valid(n,:)>0,1,'first');
if min_idx<idx
min_idx=idx;
min_idx=idx
end
end