gps-stack-sim icon indicating copy to clipboard operation
gps-stack-sim copied to clipboard

Can I use ephemeris data to generate IF signal and record it in a bin file?

Open Imtiaz08 opened this issue 3 years ago • 3 comments

Hi I would like to generate a signal using this code and then transmit the signal using USRP N200. Is it possible with this code?

Imtiaz08 avatar May 20 '22 15:05 Imtiaz08

Hi,

The short answer is no.

With this code you can generate some signals which given some additional encoding software (which is not in this repo) you could potentially transmit with that SDR.

Hope this is helpful, Javier

JavierAntoran avatar May 20 '22 15:05 JavierAntoran

Thank you so much for the answer

Here's what I have done so far:

  1. I have extracted the ephemeris from the RINEX.nav file and calculated the satellite position
  2. I have determined the satellite visibility for the target spoofing location based on the elevation angles
  3. Generated 5 subframes and put the data extracted from the RINEX.nav file in those subframes according to the GPS ICD
  4. calculated the pseudorange between each satellite and determined the code phases for each satellite based on those pseudoranges

Now the problem is I can't build a signal from the calculated data. I have generated a BIN file containing the GPS L1 C/A IF data but when I read it using GNSS SDR it says invalid preamble.

I know you must be a very busy person but if you could provide me with some insights in this regard I will be very thankful to you for this act of kindness as my thesis is stuck from two months and I am very much depressed

Imtiaz08 avatar May 22 '22 08:05 Imtiaz08

I am afraid I am not knowledgeable about how to interact with your hardware. Perhaps you have access to a manual that tells you how to pass your signals to the sdr?

JavierAntoran avatar May 31 '22 14:05 JavierAntoran