Failed to acquire signal on identical file and config to successful gnss-sdr run

[asazernik]

I'm shifting from gnss-sdr to PocketSDR for working with recorded IQ files. As part of validation, I'm trying to reproduce a working gnss-sdr configuration in PocketSDR i.e. run PocketSDR with the same parameters and on the same input file as the gnss-sdr run and see if I get similar results.

Unfortunately, when I try this PocketSDR fails acquire satellites.

Is there any obvious mistake in my translation of gnss-sdr config to PocketSDR command, or some preprocessing step I need to take first?

PocketSDR command line:

python/pocket_acq.py -f 4 -sig L1CA -prn 1-63 -d 10000 -tint 1 /home/asa/Downloads/gpsl1.iq

GNSS-sdr signal and tracking configurations:

;######### GLOBAL OPTIONS ##################
GNSS-SDR.internal_fs_sps=4000000

;######### SIGNAL_SOURCE CONFIG ############
SignalSource.implementation=File_Signal_Source
SignalSource.filename=/home/asa/Downloads/gpsl1.iq
SignalSource.item_type=ibyte
SignalSource.sampling_frequency=4000000

;######### SIGNAL_CONDITIONER CONFIG ############
SignalConditioner.implementation=Signal_Conditioner

;######### DATA_TYPE_ADAPTER CONFIG ############
DataTypeAdapter.implementation=Ibyte_To_Complex

;######### INPUT_FILTER CONFIG ############
InputFilter.implementation=Freq_Xlating_Fir_Filter
InputFilter.decimation_factor=1
InputFilter.input_item_type=gr_complex
InputFilter.output_item_type=gr_complex
InputFilter.taps_item_type=float
InputFilter.number_of_taps=5
InputFilter.number_of_bands=2
InputFilter.band1_begin=0.0
InputFilter.band1_end=0.85
InputFilter.band2_begin=0.9
InputFilter.band2_end=1.0
InputFilter.ampl1_begin=1.0
InputFilter.ampl1_end=1.0
InputFilter.ampl2_begin=0.0
InputFilter.ampl2_end=0.0
InputFilter.band1_error=1.0
InputFilter.band2_error=1.0
InputFilter.filter_type=bandpass
InputFilter.grid_density=16

;######### RESAMPLER CONFIG ############
Resampler.implementation=Pass_Through

;######### CHANNELS GLOBAL CONFIG ############
Channels_1C.count=8
Channels.in_acquisition=1

;######### ACQUISITION GLOBAL CONFIG ############
Acquisition_1C.implementation=GPS_L1_CA_PCPS_Acquisition
Acquisition_1C.item_type=gr_complex
Acquisition_1C.coherent_integration_time_ms=1
Acquisition_1C.pfa=0.01
Acquisition_1C.doppler_max=10000
Acquisition_1C.doppler_step=250
Acquisition_1C.blocking=true

The file is a capture at 4MSPS on a baseband of 1575.42MHz.

Thanks!

[tomojitakasu]

The current version of Pocket SDR requires the input sampled IQ data to be in the specific format. For details, please refer to slide p.35. If your data do not conform to this format, you will need to convert them.

https://gpspp.sakura.ne.jp/paper2005/IPNTJ_Seminar_202505_revA.pdf