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gnss-sdr
Rapid Tracking and Loss of Lock w/ Hackrf
Good Morning, Having gone through he previous related issues and coming up empty, I figured I'd post here to see if I'm doing anything wrong.
Operating Environment Free and clear view of sky
GNSS-SDR Version GNSS-SDR v0.0.10
Machine Specs: Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz 32GB RAM
Hackrf Info: hackrf_info version: unknown libhackrf version: unknown (0.5) Board ID Number: 2 (HackRF One) Firmware Version: 2018.01.1 (API:1.02) Part ID Number: 0xa000cb3c 0x00674757
Antenna Info: Mfg: PulseLarsen Antennas Model: RAZ62311MM Notes: GNSS Beidou-GPS-Glonass Frequency 1561.098±2.046,1575.42±1.023,1602.5625±4 MHz VSWR 2:1 Nominal Impedance 50 ohms Gain (Radiating element) 1 dBic +/- 1dB Gain (LNA gain) 30 dB +/- 2 dB Polarization RHCP Specs Sheet: https://productfinder.pulseeng.com/doc_type/WEB301/doc_num/RAZXXXXXMM/doc_part/RAZXXXXXMM.pdf
Config File [GNSS-SDR]
;######### GLOBAL OPTIONS ################## GNSS-SDR.internal_fs_sps=2000000
;######### SIGNAL_SOURCE CONFIG ############ SignalSource.implementation=Osmosdr_Signal_Source SignalSource.item_type=gr_complex SignalSource.sampling_frequency=2000000 SignalSource.freq=1575420000 SignalSource.gain=40 SignalSource.rf_gain=40 SignalSource.if_gain=30 SignalSource.AGC_enabled=false SignalSource.samples=0 SignalSource.repeat=false ;# Next line enables the internal HackRF One bias (3.3 VDC) SignalSource.osmosdr_args=hackrf,bias=1 SignalSource.enable_throttle_control=false SignalSource.dump=false SignalSource.dump_filename=./signal_source.dat
;######### SIGNAL_CONDITIONER CONFIG ############ SignalConditioner.implementation=Signal_Conditioner
;######### DATA_TYPE_ADAPTER CONFIG ############ DataTypeAdapter.implementation=Pass_Through
;######### 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 InputFilter.dump=false InputFilter.dump_filename=../data/input_filter.dat
;######### RESAMPLER CONFIG ############ Resampler.implementation=Pass_Through
;######### CHANNELS GLOBAL CONFIG ############ Channels_1C.count=8 Channels.in_acquisition=1 Channel.signal=1C
;######### ACQUISITION GLOBAL CONFIG ############ Acquisition_1C.implementation=GPS_L1_CA_PCPS_Acquisition_Fine_Doppler Acquisition_1C.item_type=gr_complex Acquisition_1C.if=0 Acquisition_1C.sampled_ms=1 Acquisition_1C.threshold=0.015 Acquisition_1C.doppler_max=10000 Acquisition_1C.doppler_min=-10000 Acquisition_1C.doppler_step=500 Acquisition_1C.max_dwells=15 Acquisition_1C.dump=false Acquisition_1C.dump_filename=./acq_dump.dat
;######### TRACKING GLOBAL CONFIG ############ Tracking_1C.implementation=GPS_L1_CA_DLL_PLL_Tracking Tracking_1C.item_type=gr_complex Tracking_1C.if=0 Tracking_1C.pll_bw_hz=40.0; Tracking_1C.dll_bw_hz=2.0; Tracking_1C.order=3; Tracking_1C.early_late_space_chips=0.5; Tracking_1C.dump=false Tracking_1C.dump_filename=./tracking_ch_
;######### TELEMETRY DECODER GPS CONFIG ############ TelemetryDecoder_1C.implementation=GPS_L1_CA_Telemetry_Decoder TelemetryDecoder_1C.dump=false TelemetryDecoder_1C.decimation_factor=1;
;######### OBSERVABLES CONFIG ############ Observables.implementation=Hybrid_Observables Observables.dump=false Observables.dump_filename=./observables.dat
;######### PVT CONFIG ############ PVT.implementation=RTKLIB_PVT PVT.positioning_mode=Single PVT.output_rate_ms=10 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
Observed Behavior gnss-sdr --config_file=/SDR/gps/configs/hackrf_GPS_L1v2.conf Initializing GNSS-SDR v0.0.10 ... Please wait. Logging will be written at "/tmp" Use gnss-sdr --log_dir=/path/to/log to change that. OsmoSdr arguments: hackrf,bias=1 gr-osmosdr 0.1.4 (0.1.4) gnuradio 3.7.13.4 built-in source types: file osmosdr fcd rtl rtl_tcp uhd miri hackrf bladerf rfspace airspy airspyhf soapy redpitaya freesrp Using HackRF One with firmware 2018.01.1 Enabled antenna bias voltage Actual RX Rate: 2000000.000000 [SPS]... Actual RX Freq: 1575420000.000000 [Hz]... PLL Frequency tune error 0.000000 [Hz]... Actual RX Gain: 14.000000 dB... Actual Bandwidth: 6000000.000000 [Hz]... Starting a TCP/IP server of RTCM messages on port 2101 The TCP/IP server of RTCM messages is up and running. Accepting connections ... Current receiver time: 1 s Tracking of GPS L1 C/A signal started on channel 0 for satellite GPS PRN 01 (Block IIF) Tracking of GPS L1 C/A signal started on channel 1 for satellite GPS PRN 09 (Block IIF) Tracking of GPS L1 C/A signal started on channel 2 for satellite GPS PRN 10 (Block IIF) Tracking of GPS L1 C/A signal started on channel 3 for satellite GPS PRN 11 (Block IIR) Tracking of GPS L1 C/A signal started on channel 4 for satellite GPS PRN 12 (Block IIR-M) Tracking of GPS L1 C/A signal started on channel 5 for satellite GPS PRN 13 (Block IIR) Tracking of GPS L1 C/A signal started on channel 6 for satellite GPS PRN 14 (Block IIR) Tracking of GPS L1 C/A signal started on channel 7 for satellite GPS PRN 15 (Block IIR-M) Current receiver time: 2 s Loss of lock in channel 0! Tracking of GPS L1 C/A signal started on channel 0 for satellite GPS PRN 01 (Block IIF) Loss of lock in channel 1! Loss of lock in channel 2! Tracking of GPS L1 C/A signal started on channel 1 for satellite GPS PRN 09 (Block IIF) Tracking of GPS L1 C/A signal started on channel 2 for satellite GPS PRN 16 (Block IIR) Loss of lock in channel 4! Loss of lock in channel 5! Tracking of GPS L1 C/A signal started on channel 4 for satellite GPS PRN 12 (Block IIR-M) Loss of lock in channel 6! Tracking of GPS L1 C/A signal started on channel 5 for satellite GPS PRN 17 (Block IIR-M) Loss of lock in channel 7! Tracking of GPS L1 C/A signal started on channel 6 for satellite GPS PRN 18 (Block IIR) Tracking of GPS L1 C/A signal started on channel 7 for satellite GPS PRN 19 (Block IIR) Current receiver time: 3 s Loss of lock in channel 1! Loss of lock in channel 2! Tracking of GPS L1 C/A signal started on channel 1 for satellite GPS PRN 09 (Block IIF) Tracking of GPS L1 C/A signal started on channel 2 for satellite GPS PRN 20 (Block IIR) Loss of lock in channel 4! Tracking of GPS L1 C/A signal started on channel 4 for satellite GPS PRN 12 (Block IIR-M) Loss of lock in channel 6! Tracking of GPS L1 C/A signal started on channel 6 for satellite GPS PRN 18 (Block IIR) Current receiver time: 4 s Loss of lock in channel 2! Loss of lock in channel 1! Tracking of GPS L1 C/A signal started on channel 2 for satellite GPS PRN 20 (Block IIR) Loss of lock in channel 4! Tracking of GPS L1 C/A signal started on channel 1 for satellite GPS PRN 21 (Block IIR) Tracking of GPS L1 C/A signal started on channel 4 for satellite GPS PRN 22 (Block IIR) Loss of lock in channel 6! Tracking of GPS L1 C/A signal started on channel 6 for satellite GPS PRN 18 (Block IIR) Current receiver time: 5 s Loss of lock in channel 2! Tracking of GPS L1 C/A signal started on channel 2 for satellite GPS PRN 20 (Block IIR) Loss of lock in channel 1! Tracking of GPS L1 C/A signal started on channel 1 for satellite GPS PRN 21 (Block IIR) Current receiver time: 6 s Loss of lock in channel 6! Tracking of GPS L1 C/A signal started on channel 6 for satellite GPS PRN 18 (Block IIR) Loss of lock in channel 2! Tracking of GPS L1 C/A signal started on channel 2 for satellite GPS PRN 20 (Block IIR) Loss of lock in channel 1! Tracking of GPS L1 C/A signal started on channel 1 for satellite GPS PRN 21 (Block IIR) Current receiver time: 7 s Loss of lock in channel 6! Tracking of GPS L1 C/A signal started on channel 6 for satellite GPS PRN 18 (Block IIR) Loss of lock in channel 2! Tracking of GPS L1 C/A signal started on channel 2 for satellite GPS PRN 20 (Block IIR) Current receiver time: 8 s Loss of lock in channel 1! Tracking of GPS L1 C/A signal started on channel 1 for satellite GPS PRN 21 (Block IIR) Loss of lock in channel 6! Tracking of GPS L1 C/A signal started on channel 6 for satellite GPS PRN 18 (Block IIR) Current receiver time: 9 s Loss of lock in channel 2! Tracking of GPS L1 C/A signal started on channel 2 for satellite GPS PRN 20 (Block IIR) Loss of lock in channel 1! Tracking of GPS L1 C/A signal started on channel 1 for satellite GPS PRN 21 (Block IIR) Current receiver time: 10 s Loss of lock in channel 2! Tracking of GPS L1 C/A signal started on channel 2 for satellite GPS PRN 20 (Block IIR) Loss of lock in channel 1! Tracking of GPS L1 C/A signal started on channel 1 for satellite GPS PRN 21 (Block IIR) Current receiver time: 11 s Loss of lock in channel 2! Tracking of GPS L1 C/A signal started on channel 2 for satellite GPS PRN 20 (Block IIR) Loss of lock in channel 1! Tracking of GPS L1 C/A signal started on channel 1 for satellite GPS PRN 21 (Block IIR) qCurrent receiver time: 12 s Loss of lock in channel 2! Tracking of GPS L1 C/A signal started on channel 2 for satellite GPS PRN 20 (Block IIR)
Quit keystroke order received, stopping GNSS-SDR !! Stopping GNSS-SDR, please wait! OOOOOOOOOOOTotal GNSS-SDR run time: 13.1425 [seconds] GNSS-SDR program ended. Stopping TCP/IP server on port 2101
Notes If it runs long enough (10-15min), I am able to receive some sporadic navigation message data, but they are not consistent.
Thoughts?
I may be wrong as I'm still learning, but it was my understanding that the hackrf is able to do that once the proper setting was set "SignalSource.osmosdr_args=hackrf,bias=1"
UPDATE: I've removed my previous install (installed via sudo apt-get install gnss-sdr) and build it via the Clone, build and install GNSS-SDR instructions...with the cmake -DENABLE_OSMOSDR=ON ../ option
The results seem better I'll get a series of tracking and loss of lock messages every 5-15 seconds vs the constant lock and loss of lock I had before. I am also now receiving "New GPS NAV messages"
Yes, but you have also to phisically connect a bias-tee, that is a simple three way component useful to fed the active antenna. In the first port you connect the front end with a RF cable, in the second you connect a DC cable with a 5 volt input(USB port of a pc) and you get in output of the third port the sum RF+DC where you will connect the antenna. Without this hardware configuration you will have a poor gain and it will be difficult to get a suitable number of NAV messages from different satellites. MC
Thanks matteo, but doesn't the hackrf have an internal bias-tee? According to the feature documentation "Software-controlled antenna port power (50 mA at 3.3 V)."
https://github.com/mossmann/hackrf/wiki/HackRF-One
If you check the documentation here you'll see that setting the bias=1 flag only has an effect if the version of gr-osmosdr that you are using is >= 0.1.4-13. If you are using an older version either upgrade it or use an external bias tee as suggested by @matteocutugno
Thanks @matteocutugno and @odrisci. It is my understanding that I'm on a newest version, at least one greater than 0.1.4-13.
When running "sudo apt install gr-osmosdr"
Reading package lists... Done
Building dependency tree
Reading state information... Done
gr-osmosdr is already the newest version (0.1.4-14build7).
UPDATE: After updating and running 'next' along with the supplied hackrf config, I'm now getting a few between 1-4 channel locks and New GPS NAV messages. After running long enough, (~20min) I had also started to receive positional information, that positional information was also sporadic.
If I set Channels_1C.count to 20...I start receiving New GPS nav messages from 5 channels and positions (green messages) within 2min.
Hi @gooroo363 ,
Since you are receiving NAV messages and obtaining PVT information it looks like is not a bias-tee issue.
It seems that your acquisition configuration is not quite accurate. The channels start tracking and loss the lock very easily. You should try to find a proper threshold or PFA (probability of false alarm) since it looks like you are obtaining many false alarms. A very low threshold (or high PFA) will declare a satellite present even when it is not there (I think it's your case). On the other hand, a very high threshold (or low PFA) will not declare a satellite present even being there.
You could also try to make narrower Doppler steps or apply a Doppler refinement (using "Acquisition_1C.make_two_steps=true") to obtain more accurate Doppler estimations for the tracking phase.
If the problem persists, you should verify if the receiver is trying to track the satellites in view or just random satellites. Here you can check the GNSS satellites in view at your location.
Hope it helps!
Thanks @luisrho. I'll give those settings a try. I also have another active antenna arriving in a few days to see if I can learn more about my hardware configuration. I also stumbled upon Trimble's GNSS planning tool. For those that are interested. https://www.gnssplanning.com/#/settings
@luisrho Early testing looks like the hackrf is trying to track some random satellites :-/ I can't tell if the ones that are in view that are being tracked are just dumb luck or if some are actually getting through. I'll continue adjusting the gain and Acquisition settings and see how it goes. I've also verified that the USB3 ports are not providing "Supplemental charging power"
Whats interesting is that at 1s in it claims to track on all channels, and always the same sats (01,09-15)...and always at 17s is when the losses start to appear.
gnss-sdr --config_file=/home/x/SDR/gnss-sdr/conf/gnss-sdr_GPS_L1_hackrf.conf
Initializing GNSS-SDR v0.0.10.git-next-ad389f7b1 ... Please wait. Logging will be written at "/tmp" Use gnss-sdr --log_dir=/path/to/log to change that. OsmoSdr arguments: hackrf,bias=1 gr-osmosdr 0.1.4 (0.1.4) gnuradio 3.7.13.4 built-in source types: file osmosdr fcd rtl rtl_tcp uhd miri hackrf bladerf rfspace airspy airspyhf soapy redpitaya freesrp Using HackRF One with firmware 2018.01.1 Enabled antenna bias voltage Actual RX Rate: 2000000.000000 [SPS]... Actual RX Freq: 1575420000.000000 [Hz]... PLL Frequency tune error 0.000000 [Hz]... AGC enabled Actual Bandwidth: 6000000.000000 [Hz]... Starting a TCP/IP server of RTCM messages on port 2101 The TCP/IP server of RTCM messages is up and running. Accepting connections ... Current receiver time: 1 s Tracking of GPS L1 C/A signal started on channel 0 for satellite GPS PRN 01 (Block IIF) Tracking of GPS L1 C/A signal started on channel 1 for satellite GPS PRN 09 (Block IIF) Tracking of GPS L1 C/A signal started on channel 2 for satellite GPS PRN 10 (Block IIF) Tracking of GPS L1 C/A signal started on channel 3 for satellite GPS PRN 11 (Block IIR) Tracking of GPS L1 C/A signal started on channel 4 for satellite GPS PRN 12 (Block IIR-M) Tracking of GPS L1 C/A signal started on channel 5 for satellite GPS PRN 13 (Block IIR) Tracking of GPS L1 C/A signal started on channel 6 for satellite GPS PRN 14 (Block IIR) Tracking of GPS L1 C/A signal started on channel 7 for satellite GPS PRN 15 (Block IIR-M) Current receiver time: 2 s Current receiver time: 3 s Current receiver time: 4 s Current receiver time: 5 s Current receiver time: 6 s Current receiver time: 7 s Current receiver time: 8 s Current receiver time: 9 s Current receiver time: 10 s Current receiver time: 11 s Current receiver time: 12 s Current receiver time: 13 s Current receiver time: 14 s Current receiver time: 15 s Current receiver time: 16 s Current receiver time: 17 s Loss of lock in channel 1! Tracking of GPS L1 C/A signal started on channel 1 for satellite GPS PRN 09 (Block IIF) Current receiver time: 18 s Current receiver time: 19 s Loss of lock in channel 0! Tracking of GPS L1 C/A signal started on channel 0 for satellite GPS PRN 01 (Block IIF) Current receiver time: 20 s Current receiver time: 21 s Current receiver time: 22 s Current receiver time: 23 s Current receiver time: 24 s Current receiver time: 25 s Current receiver time: 26 s Current receiver time: 27 s Current receiver time: 28 s Current receiver time: 29 s Current receiver time: 30 s Current receiver time: 31 s Current receiver time: 32 s Current receiver time: 33 s Loss of lock in channel 1! Tracking of GPS L1 C/A signal started on channel 1 for satellite GPS PRN 09 (Block IIF)
This is similar behavior to issue #233 "Loss of lock in channel while using bladeRF for real time acquisiton #233" same sats are trying to be acquired right off the bat. It might be expected behavior, I just haven't seen any documentation highlighting it.
UPDATE: Received and tested new active antenna, same results. Will continue to debug. Here is what the spectrum looks like in GQRX
@gooroo363
I feel these configuration values below may not make much sense ...
Acquisition_1C.doppler_max=10000 Acquisition_1C.doppler_min=-10000 Acquisition_1C.doppler_step=500
If I remember this correctly, the doppler due to the satellites should be +/-2.7 ppm or so. What is the ppm of your receiver clock?
In general, the search windows should be
half search window = max satellite doppler + max receiver doppler + clock drifting ...
@gooroo363
Also the step size of 500Hz may be too large ... what is your coherence integration size here? I see ... it is 1 ms. As such the step size = 1 / 0.001 / 2 = 500 Hz.
I think you should set
Acquisition_1C.sampled_ms=2
and then
Acquisition_1C.doppler_step=250
to improve your doppler estimation
Hello
I have very similar problems using the Hack RF with an ublox multiband active GNSS antenna. Did you manage to solve the problem?
Thank you, Daniel.
HI, I'm having the same issue with my HackRF One. It starts tracking on a channel, then loses it about 10 sec later. Has anyone creates a good conf file that works (better than the demo one on the main page)? Thx! Don
Hi Don, I never managed to solve that issue. I would be interested as well in a work-around / solution to this. I tried it on a virtual machine first, and then with a physical linux machine, but it did not work in both cases.
Thx. I just get this repeated:
Tracking of GPS L1 C/A signal started on channel 0 for satellite GPS PRN 17 (Block IIR-M) Current receiver time: 22 min 31 s Current receiver time: 22 min 32 s Current receiver time: 22 min 33 s Current receiver time: 22 min 34 s Tracking of GPS L1 C/A signal started on channel 6 for satellite GPS PRN 23 (Block IIR) Current receiver time: 22 min 35 s Current receiver time: 22 min 36 s Current receiver time: 22 min 37 s Current receiver time: 22 min 38 s Current receiver time: 22 min 39 s Current receiver time: 22 min 40 s Current receiver time: 22 min 41 s Current receiver time: 22 min 42 s Current receiver time: 22 min 43 s Current receiver time: 22 min 44 s Current receiver time: 22 min 45 s Current receiver time: 22 min 46 s Loss of lock in channel 0!
And I get this when I run the front-end-cal: Searching for GPS Satellites in L1 band... [ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 ] Total signal acquisition run time 9.37991 [seconds] Unable to get Ephemeris SUPL assistance. TOW is unknown! GNSS-SDR Front-end calibration program ended.
So I'm guessing it's either the signal is too weak for the HackRF, or I need a higher quality external clock for it to lock, or maybe there are some settings I can improve to get lock.
Frustrating that I can't seem to find some good info on others trying and having success witht he HackRF and gnss-sdr.
Don
same issue here I've tried several other osmosdr receivers (limesdr, bladerf, and rtlsdr)
Got both the hackrf and an rtl-sdr processing L1. Had to drop the gains to 30, 30, 22 for my particular antenna. Both lock in about 45 sec. Got the rtl-sdr also locking on L2, but its a bit sporatic. It would be nice if the software provided more clues as to whats going on, or whats happening in the acquisition or tracking phases so we’d know what parameters we might try to vary.
Can you please share what antenna and configuration file you are using and whether you have a biast, I see the author of this paper https://www.mdpi.com/2076-3263/10/2/79 managed to get it working but with a ridiculously expensive antenna “low cost solution”
I’m enabling the power to the antenna via software (in the conf file). Two antenna work equally well for me, the ublox multiband antenna (about$60 from Sparkfun) or a high-gain base station antenna (probably about $400) that’s on my roof.
The conf file i used is the example conf file for the hackrf that’s provided on the My First Fix page on the gnss-sdr org site. I just had to lower the three gains as i mention above. I think the original gains were too high and were saturating the front end. I also bought an Nooelec LNA for the antenna, but not thinking i need it. I also have A couple Cheap bandpass (L1, L2) filters Coming from etsy, so will try those as well when they arrive. So far, it seems the rtl-sdr v3 acquires quicker for me than the hackrf, and I can get the rtl-sdr v3 to also lock on L2 sporatically. Would be nice to view the fft of the exact gnss-sdr gain settings i’m using, but not seeing how to do that in gnuradio as the gains are named differently.
This config file shows the respective gains from gnss-sdr to osmosdr: https://github.com/gnss-sdr/gnss-sdr/blob/master/conf/gnss-sdr_GPS_L1_bladeRF.conf
;# RF Gain: LNA Gain {0, 3, 6} SignalSource.gain=6 ;# IF Gain: N/A SignalSource.rf_gain=40 ;# BB Gain: RX VGA1 + VGA2 [5, 60] SignalSource.if_gain=48
That would be nice to see what the spectrum looks like when the system is working, perhaps a waterfall plot. I will also be trying the ublox multiband antenna and two other antennas provided with the products below:
Assuming these are working systems we'd be able to compare the acquired signals from rtl-sdr against the ones here:
https://www.amazon.com/gp/product/B07TZVQDHQ/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1
https://anavs.de/multi-sensor-rtk-module/
The conf file you're referring to is for a BladeRF front end, and they likely are using a powered-T with a LNA amplifier, so thus the relatively low (6 db) gain level.
Yes the specific values are for bladerf and the ranges shown are the ones supported by the bladerf. But the naming of the gains apply to all osmosdr receivers. So in gnuradio using the osmsosdr sink block you would do RG Gain: 30 (lna) IF Gain : 30 (rf gain) BB Gain : 20 (if gain). To me it would make sense that the IF gain in osmo wouldn't apply because the signal would be at baseband for that same reason it could also make sense that the IF gain used in the config file is the same as the BB gain in osmo. Below is the documentation from the gnuradio source block.
On the gr-osmosdr source block documentation it has: RF Gain: Overall RF gain of the device.
IF Gain: Overall intermediate frequency gain of the device. This setting is available for RTL-SDR and OsmoSDR devices with E4000 tuners and HackRF in receive and transmit mode. Observations lead to a reasonable gain range from 15 to 30dB.
BB Gain: Overall baseband gain of the device. This setting is available for HackRF in receive mode. Observations lead to a reasonable gain range from 15 to 30dB.
Ahh for me it was the antenna, below are the results I'm obtaining for with the rtl-sdr and this antenna: https://www.tersus-gnss.com/product/antenna-ax3703 as you see multiple location and velocity estimates are provided every second. The ublox antenna also worked but not as frequent and with much larger variances in the estimates.
First position fix at 2020-Jun-07 21:28:30.100000 UTC is Lat = 33.4932 [deg], Long = -111.901 [deg], Height= 335.778 [m] Position at 2020-Jun-07 21:28:30.500000 UTC using 4 observations is Lat = 33.492972657 [deg], Long = -111.901343224 [deg], Height = 323.726 [m] Velocity: East: 0.019 [m/s], North: -0.009 [m/s], Up = -0.015 [m/s] Position at 2020-Jun-07 21:28:31.000000 UTC using 4 observations is Lat = 33.492928189 [deg], Long = -111.901407454 [deg], Height = 311.270 [m] Velocity: East: -0.160 [m/s], North: -0.274 [m/s], Up = -0.177 [m/s] Current receiver time: 1 min 16 s Loss of lock in channel 2! Position at 2020-Jun-07 21:28:31.500000 UTC using 4 observations is Lat = 33.493143300 [deg], Long = -111.901250488 [deg], Height = 325.975 [m] Velocity: East: -0.137 [m/s], North: -0.262 [m/s], Up = -0.204 [m/s] Position at 2020-Jun-07 21:28:32.000000 UTC using 4 observations is Lat = 33.492882622 [deg], Long = -111.901437965 [deg], Height = 312.867 [m] Velocity: East: 0.260 [m/s], North: 0.420 [m/s], Up = 0.353 [m/s] Current receiver time: 1 min 17 s Position at 2020-Jun-07 21:28:32.500000 UTC using 4 observations is Lat = 33.492754477 [deg], Long = -111.901515597 [deg], Height = 303.042 [m] Velocity: East: 0.056 [m/s], North: 0.086 [m/s], Up = 0.100 [m/s] Loss of lock in channel 5! Position at 2020-Jun-07 21:28:33.000000 UTC using 4 observations is Lat = 33.492873955 [deg], Long = -111.901417349 [deg], Height = 317.635 [m] Velocity: East: -0.146 [m/s], North: -0.279 [m/s], Up = -0.297 [m/s] Current receiver time: 1 min 18 s Position at 2020-Jun-07 21:28:33.500000 UTC using 4 observations is Lat = 33.492898695 [deg], Long = -111.901420803 [deg], Height = 308.615 [m] Velocity: East: -0.009 [m/s], North: 0.006 [m/s], Up = -0.172 [m/s] Position at 2020-Jun-07 21:28:34.000000 UTC using 4 observations is Lat = 33.492763118 [deg], Long = -111.901534764 [deg], Height = 289.685 [m] Velocity: East: -0.113 [m/s], North: -0.214 [m/s], Up = -0.166 [m/s] Current receiver time: 1 min 19 s Tracking of GPS L1 C/A signal started on channel 2 for satellite GPS PRN 01 (Block IIF) Position at 2020-Jun-07 21:28:34.500000 UTC using 4 observations is Lat = 33.492769029 [deg], Long = -111.901549834 [deg], Height = 301.402 [m] Velocity: East: 0.164 [m/s], North: 0.220 [m/s], Up = 0.192 [m/s] Position at 2020-Jun-07 21:28:35.000000 UTC using 4 observations is Lat = 33.492762633 [deg], Long = -111.901559209 [deg], Height = 303.480 [m] Velocity: East: -0.041 [m/s], North: -0.093 [m/s], Up = -0.180 [m/s] Current receiver time: 1 min 20 s Position at 2020-Jun-07 21:28:35.500000 UTC using 4 observations is Lat = 33.492762038 [deg], Long = -111.901560661 [deg], Height = 291.675 [m] Velocity: East: -0.164 [m/s], North: -0.260 [m/s], Up = -0.242 [m/s] New GPS NAV message received in channel 4: subframe 4 from satellite GPS PRN 12 (Block IIR-M) New GPS NAV message received in channel 0: subframe 4 from satellite GPS PRN 05 (Block IIR-M) New GPS NAV message received in channel 3: subframe 4 from satellite GPS PRN 25 (Block IIF) New GPS NAV message received in channel 7: subframe 4 from satellite GPS PRN 29 (Block IIR-M) Position at 2020-Jun-07 21:28:36.000000 UTC using 4 observations is Lat = 33.492893764 [deg], Long = -111.901471985 [deg], Height = 300.273 [m] Velocity: East: -0.288 [m/s], North: -0.546 [m/s], Up = -0.452 [m/s] Current receiver time: 1 min 21 s Loss of lock in channel 1! Position at 2020-Jun-07 21:28:36.500000 UTC using 4 observations is Lat = 33.493170679 [deg], Long = -111.901252689 [deg], Height = 345.440 [m] Velocity: East: 0.005 [m/s], North: 0.071 [m/s], Up = 0.017 [m/s] Position at 2020-Jun-07 21:28:37.000000 UTC using 4 observations is Lat = 33.492930981 [deg], Long = -111.901431459 [deg], Height = 318.693 [m] Velocity: East: 0.044 [m/s], North: 0.076 [m/s], Up = 0.000 [m/s] Current receiver time: 1 min 22 s Position at 2020-Jun-07 21:28:37.500000 UTC using 4 observations is Lat = 33.492945078 [deg], Long = -111.901410141 [deg], Height = 310.442 [m] Velocity: East: 0.014 [m/s], North: 0.044 [m/s], Up = -0.067 [m/s] Position at 2020-Jun-07 21:28:38.000000 UTC using 4 observations is Lat = 33.492685327 [deg], Long = -111.901601419 [deg], Height = 276.741 [m] Velocity: East: 0.177 [m/s], North: 0.274 [m/s], Up = 0.236 [m/s] Current receiver time: 1 min 23 s Position at 2020-Jun-07 21:28:38.500000 UTC using 4 observations is Lat = 33.492664226 [deg], Long = -111.901605926 [deg], Height = 291.993 [m] Velocity: East: 0.002 [m/s], North: -0.069 [m/s], Up = -0.107 [m/s] Position at 2020-Jun-07 21:28:39.000000 UTC using 4 observations is Lat = 33.492635828 [deg], Long = -111.901595628 [deg], Height = 292.733 [m] Velocity: East: 0.022 [m/s], North: 0.078 [m/s], Up = -0.103 [m/s] Current receiver time: 1 min 24 s Tracking of GPS L1 C/A signal started on channel 5 for satellite GPS PRN 13 (Block IIR) Position at 2020-Jun-07 21:28:39.500000 UTC using 4 observations is Lat = 33.492762380 [deg], Long = -111.901514818 [deg], Height = 303.636 [m] Velocity: East: 0.165 [m/s], North: 0.272 [m/s], Up = 0.247 [m/s] Position at 2020-Jun-07 21:28:40.000000 UTC using 4 observations is Lat = 33.492838552 [deg], Long = -111.901491665 [deg], Height = 306.510 [m] Velocity: East: -0.099 [m/s], North: -0.211 [m/s], Up = -0.190 [m/s] Current receiver time: 1 min 25 s Position at 2020-Jun-07 21:28:40.500000 UTC using 4 observations is Lat = 33.492902809 [deg], Long = -111.901414238 [deg], Height = 308.465 [m] Velocity: East: 0.024 [m/s], North: 0.026 [m/s], Up = -0.032 [m/s] Position at 2020-Jun-07 21:28:41.000000 UTC using 4 observations is Lat = 33.492775020 [deg], Long = -111.901509179 [deg], Height = 301.006 [m] Velocity: East: 0.049 [m/s], North: 0.047 [m/s], Up = -0.019 [m/s] Current receiver time: 1 min 26 s Position at 2020-Jun-07 21:28:41.500000 UTC using 4 observations is Lat = 33.492901436 [deg], Long = -111.901399995 [deg], Height = 310.869 [m] Velocity: East: 0.120 [m/s], North: 0.216 [m/s], Up = 0.126 [m/s]
Looks like you're getting a good solution. I experimented around with the HackRf and was able to go up to 8MS/S and 12 sats tracked on my CPU. Have you tried tracking on L2 or E1? I tried both, but GNSS-SDR seemed to see the sats but kept losing them with out getting a PVT solution.
@Abdob would mind sending over your conf file.....i still can't get it to work.....3 different machines and two different antennas.
@gooroo363 I can send you one I use for HackRF and RTL-SDR front ends, but am out of pocket for a week. Please get back to me after Jun 28th and ping me if you still need it. Once HUGE factor is making sure you have a good oscillator. I like the $25 NooElec Tiny TCXO for the HackRF for example (or a high end GPSDO if I want high timing accuracy for test).