Application downloads navigation data in RINEX format from NASA ftp server and generates data samples for GPS simulation using HackRF PortaPack
Usage:
python gps_sim.py <email>where email - registration email on https://cddis.nasa.gov
Output example:
Downloading navigation file for 010723 from gdc.cddis.eosdis.nasa.gov ...
Navigation file saved as brdc1820.23n
Generating data samples for GPS signal simulation ...
Data samples saved as loc_010723.C8The file https://cddis.gsfc.nasa.gov/archive/gnss/data/daily/yyyy/ddd/yyn/brdcddd0.yyn.Z
is the daily broadcast ephemeris file. This file is a merge of the individual site navigation files into one, non-redundant file that can be utilized by users instead of the many individual navigation files.
yyyy is the 4-digit year
ddd is the three-digit day of year and yy is the two-digit year
These files are also available in yearly subdirectories of https://cddis.nasa.gov/archive/gnss/data/daily/yyyy/brdc/.
Example: https://cddis.nasa.gov/archive/gnss/data/daily/2023/brdc/brdc1800.23n.gz
https://cddis.nasa.gov/Data_and_Derived_Products/CDDIS_Archive_Access.html
https://www.unavco.org/data/gps-gnss/file-server/file-server.html
https://incors.in.gov/data.aspx
https://pypi.org/project/RinexParser/
https://pypi.org/project/georinex/
gps-sdr-sim.exe source code https://github.com/osqzss/gps-sdr-sim
Just use gnss-sdr :) https://gnss-sdr.org/
gnss-sdr --config_file=./rec.conf
Initializing GNSS-SDR v0.0.16 ... Please wait.
Logging will be written at "/tmp"
Use gnss-sdr --log_dir=/path/to/log to change that.
RF Channels: 1
Starting a TCP/IP server of RTCM messages on port 2101
The TCP/IP server of RTCM messages is up and running. Accepting connections ...
Processing file ./loc_120823.C8, which contains 1247480000 samples (1247480000 bytes)
<skipped>
First position fix at 2023-Aug-12 00:01:54.100000 UTC is Lat = 40.197 [deg], Long = 29.0602 [deg], Height= 89.7712 [m]
Current receiver time: 2 min 14 s
Position at 2023-Aug-12 00:01:54.500000 UTC using 7 observations is Lat = 40.197006776 [deg], Long = 29.060217486 [deg], Height = 91.299 [m]
Velocity: East: 0.228 [m/s], North: -0.256 [m/s], Up = -0.307 [m/s]
Position at 2023-Aug-12 00:01:55.000000 UTC using 7 observations is Lat = 40.196991180 [deg], Long = 29.060181830 [deg], Height = 88.543 [m]
Velocity: East: -0.042 [m/s], North: 0.208 [m/s], Up = 0.061 [m/s]
Position at 2023-Aug-12 00:01:55.500000 UTC using 7 observations is Lat = 40.197015512 [deg], Long = 29.060195598 [deg], Height = 90.012 [m]
Velocity: East: 0.151 [m/s], North: -0.097 [m/s], Up = 0.535 [m/s]
Position at 2023-Aug-12 00:01:56.000000 UTC using 7 observations is Lat = 40.197001863 [deg], Long = 29.060196420 [deg], Height = 95.545 [m]
Velocity: East: 0.180 [m/s], North: -0.052 [m/s], Up = -0.447 [m/s]
Position at 2023-Aug-12 00:01:56.500000 UTC using 7 observations is Lat = 40.197007071 [deg], Long = 29.060187157 [deg], Height = 90.483 [m]
Velocity: East: -0.110 [m/s], North: 0.143 [m/s], Up = 0.787 [m/s]
<skipped>Config file example for data samples file loc_120823.C8
rec.conf
[GNSS-SDR]
;######### GLOBAL OPTIONS ##################
GNSS-SDR.internal_fs_sps=2600000
;######### SIGNAL_SOURCE CONFIG ############
SignalSource.implementation=File_Signal_Source
SignalSource.filename=./loc_120823.C8
SignalSource.item_type=ibyte
SignalSource.sampling_frequency=2600000
SignalSource.samples=0
;######### SIGNAL_CONDITIONER CONFIG ############
SignalConditioner.implementation=Signal_Conditioner
DataTypeAdapter.implementation=Ibyte_To_Complex
;######### CHANNELS GLOBAL CONFIG ############
Channels_1C.count=10
Channels.in_acquisition=10
Channel.signal=1C
;######### ACQUISITION GLOBAL CONFIG ############
Acquisition_1C.implementation=GPS_L1_CA_PCPS_Acquisition
Acquisition_1C.item_type=gr_complex
Acquisition_1C.pfa=0.01
Acquisition_1C.doppler_max=10000
Acquisition_1C.doppler_step=250
Acquisition_1C.blocking=true
;######### TRACKING GLOBAL CONFIG ############
Tracking_1C.implementation=GPS_L1_CA_DLL_PLL_Tracking
Tracking_1C.item_type=gr_complex
Tracking_1C.pll_bw_hz=40.0;
Tracking_1C.dll_bw_hz=4.0;
;######### TELEMETRY DECODER GPS CONFIG ############
TelemetryDecoder_1C.implementation=GPS_L1_CA_Telemetry_Decoder
;######### OBSERVABLES CONFIG ############
Observables.implementation=Hybrid_Observables
;######### PVT CONFIG ############
PVT.implementation=RTKLIB_PVT
PVT.positioning_mode=Single
PVT.output_rate_ms=100
PVT.display_rate_ms=500
PVT.iono_model=Broadcast
PVT.trop_model=Saastamoinen
PVT.flag_rtcm_server=true
PVT.flag_rtcm_tty_port=false
PVT.rtcm_dump_devname=/dev/pts/1
PVT.rtcm_tcp_port=2101
PVT.rtcm_MT1019_rate_ms=5000
PVT.rtcm_MT1077_rate_ms=1000
PVT.rinex_version=2