All, I have an odd one that I've been pulling my hair out on for a month. I was able to finally able to isolate the problem. For the longest time I thought it was an intermittent sync problem and never noticed the pattern.
So, When I generate a .bin file using the newest BRDC file available running this command
gps-sdr-sim -e /home/pi/HOURLY_BRDC/current_brdc -l 36.515811,-89.748672,100 -b 8
The .bin file is created fine. The problem is when I issue the transmit to a hack RF ( with txco) using the command below..
hackrf_transfer -t gpssim.bin -f 1575420000 -s 2600000 -a 1 -x 0 -R
It transmits the signal, I see all the SAT populate on a GPS app. after about 60 to 120 seconds I get sync and can see apps like google maps show me in the spoofed location.. so far so good...
The problem is as soon as the transmission reaches its time limit ( about 500 seconds in my case) it REPEATS the signal like it should with the -R option. On the second run of the transmission I can still see all the SATs signal, but will Never receive sync during the ENTIRE cycle of the second repeat. I have ran this several times and it is consistent ONLY THE ODD cycle or repeats of the signal will give a GPS SYNC. Every time it is on the EVEN cycle it will NOT sync.
Any Ideas? I'm using a raspberry pi 3 and a hack RF as my setup.
All, I have an odd one that I've been pulling my hair out on for a month. I was able to finally able to isolate the problem. For the longest time I thought it was an intermittent sync problem and never noticed the pattern.
So, When I generate a .bin file using the newest BRDC file available running this command gps-sdr-sim -e /home/pi/HOURLY_BRDC/current_brdc -l 36.515811,-89.748672,100 -b 8
The .bin file is created fine. The problem is when I issue the transmit to a hack RF ( with txco) using the command below.. hackrf_transfer -t gpssim.bin -f 1575420000 -s 2600000 -a 1 -x 0 -R
It transmits the signal, I see all the SAT populate on a GPS app. after about 60 to 120 seconds I get sync and can see apps like google maps show me in the spoofed location.. so far so good...
The problem is as soon as the transmission reaches its time limit ( about 500 seconds in my case) it REPEATS the signal like it should with the -R option. On the second run of the transmission I can still see all the SATs signal, but will Never receive sync during the ENTIRE cycle of the second repeat. I have ran this several times and it is consistent ONLY THE ODD cycle or repeats of the signal will give a GPS SYNC. Every time it is on the EVEN cycle it will NOT sync.
Any Ideas? I'm using a raspberry pi 3 and a hack RF as my setup.