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mirror of https://github.com/gnss-sdr/gnss-sdr synced 2024-07-01 17:33:15 +00:00

Temporary bug fix related to the GPS L1 C/A symbol TOW assignation. Position accuracy improvement confirmed. In-deep review is being done

This commit is contained in:
Javier Arribas 2017-08-01 17:03:31 +02:00
parent 94a4a0fdcf
commit 1574e277d7
3 changed files with 81 additions and 17 deletions

View File

@ -230,22 +230,25 @@ int hybrid_observables_cc::general_work (int noutput_items,
int distance = std::distance(d_gnss_synchro_history_queue[i].begin(), gnss_synchro_deque_iter);
if (distance > 0)
{
double T_rx_channel_prev = (double)d_gnss_synchro_history_queue[i].at(distance - 1).Tracking_sample_counter / (double)gnss_synchro_deque_iter->fs;
double delta_T_rx_s_prev = T_rx_channel_prev - T_rx_s;
if (fabs(delta_T_rx_s_prev) < fabs(delta_T_rx_s))
{
realigned_gnss_synchro_map.insert(std::pair<int, Gnss_Synchro>(
d_gnss_synchro_history_queue[i].at(distance-1).Channel_ID,
d_gnss_synchro_history_queue[i].at(distance-1)));
adjacent_gnss_synchro_map.insert(std::pair<int, Gnss_Synchro>(gnss_synchro_deque_iter->Channel_ID, *gnss_synchro_deque_iter));
}
else
{
realigned_gnss_synchro_map.insert(std::pair<int, Gnss_Synchro>(gnss_synchro_deque_iter->Channel_ID, *gnss_synchro_deque_iter));
adjacent_gnss_synchro_map.insert(std::pair<int, Gnss_Synchro>(
d_gnss_synchro_history_queue[i].at(distance-1).Channel_ID,
d_gnss_synchro_history_queue[i].at(distance-1)));
}
if (d_gnss_synchro_history_queue[i].at(distance-1).Flag_valid_word)
{
double T_rx_channel_prev = (double)d_gnss_synchro_history_queue[i].at(distance - 1).Tracking_sample_counter / (double)gnss_synchro_deque_iter->fs;
double delta_T_rx_s_prev = T_rx_channel_prev - T_rx_s;
if (fabs(delta_T_rx_s_prev) < fabs(delta_T_rx_s))
{
realigned_gnss_synchro_map.insert(std::pair<int, Gnss_Synchro>(
d_gnss_synchro_history_queue[i].at(distance-1).Channel_ID,
d_gnss_synchro_history_queue[i].at(distance-1)));
adjacent_gnss_synchro_map.insert(std::pair<int, Gnss_Synchro>(gnss_synchro_deque_iter->Channel_ID, *gnss_synchro_deque_iter));
}
else
{
realigned_gnss_synchro_map.insert(std::pair<int, Gnss_Synchro>(gnss_synchro_deque_iter->Channel_ID, *gnss_synchro_deque_iter));
adjacent_gnss_synchro_map.insert(std::pair<int, Gnss_Synchro>(
d_gnss_synchro_history_queue[i].at(distance-1).Channel_ID,
d_gnss_synchro_history_queue[i].at(distance-1)));
}
}
}
else
{

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@ -350,7 +350,7 @@ int gps_l1_ca_telemetry_decoder_cc::general_work (int noutput_items __attribute_
//double decoder_latency_ms=(double)(current_symbol.Tracking_sample_counter-d_symbol_history.at(0).Tracking_sample_counter)
// /(double)current_symbol.fs;
// update TOW at the preamble instant (account with decoder latency)
d_TOW_at_Preamble = d_GPS_FSM.d_nav.d_TOW + GPS_L1_CA_CODE_PERIOD + GPS_CA_PREAMBLE_DURATION_S;
d_TOW_at_Preamble = d_GPS_FSM.d_nav.d_TOW + 2*GPS_L1_CA_CODE_PERIOD + GPS_CA_PREAMBLE_DURATION_S;
d_TOW_at_current_symbol = floor(d_TOW_at_Preamble*1000.0)/1000.0;
flag_TOW_set = true;

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@ -0,0 +1,61 @@
% Javier Arribas 2011
function [observables] = read_true_sim_observables_dump (filename, count)
%% usage: read_true_sim_observables_dump (filename, [count])
%%
%% open gnss-sdr-sim observables dump and read all chennels
%%
m = nargchk (1,2,nargin);
channels=12; %Simulator always use 12 channels
num_double_vars=6;
double_size_bytes=8;
skip_bytes_each_read=double_size_bytes*num_double_vars*channels;
bytes_shift=0;
if (m)
usage (m);
end
if (nargin < 2)
count = Inf;
end
%loops_counter = fread (f, count, 'uint32',4*12);
f = fopen (filename, 'rb');
if (f < 0)
else
for N=1:1:channels
observables.RX_time(N,:) = fread (f, count, 'float64',skip_bytes_each_read-double_size_bytes);
bytes_shift=bytes_shift+double_size_bytes;
fseek(f,bytes_shift,'bof'); % move to next interleaved
observables.Carrier_Doppler_hz(N,:) = fread (f, count, 'float64',skip_bytes_each_read-double_size_bytes);
bytes_shift=bytes_shift+double_size_bytes;
fseek(f,bytes_shift,'bof'); % move to next interleaved
observables.Carrier_phase_hz(N,:) = fread (f, count, 'float64',skip_bytes_each_read-double_size_bytes);
bytes_shift=bytes_shift+double_size_bytes;
fseek(f,bytes_shift,'bof'); % move to next interleaved
observables.Pseudorange_m(N,:) = fread (f, count, 'float64',skip_bytes_each_read-double_size_bytes);
bytes_shift=bytes_shift+double_size_bytes;
fseek(f,bytes_shift,'bof'); % move to next interleaved
observables.Carrier_phase_hz_v2(N,:) = fread (f, count, 'float64',skip_bytes_each_read-double_size_bytes);
bytes_shift=bytes_shift+double_size_bytes;
fseek(f,bytes_shift,'bof'); % move to next interleaved
observables.PRN(N,:) = fread (f, count, 'float64',skip_bytes_each_read-double_size_bytes);
bytes_shift=bytes_shift+double_size_bytes;
fseek(f,bytes_shift,'bof'); % move to next interleaved
end
fclose (f);
% %%%%%%%% output vars %%%%%%%%
% for(int i=0;i<12;i++)
% {
% d_dump_file.read((char *) &gps_time_sec[i], sizeof(double));
% d_dump_file.read((char *) &doppler_l1_hz, sizeof(double));
% d_dump_file.read((char *) &acc_carrier_phase_l1_cycles[i], sizeof(double));
% d_dump_file.read((char *) &dist_m[i], sizeof(double));
% d_dump_file.read((char *) &carrier_phase_l1_cycles[i], sizeof(double));
% d_dump_file.read((char *) &prn[i], sizeof(double));
% }
end