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osqzss / gps-sdr-sim

Software-Defined GPS Signal Simulator
MIT License
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receiving GPS ephemeries data direct from satellite #182

Open bikilay opened 5 years ago

bikilay commented 5 years ago

hey Guys Iwant to receive GPS ephemeries data directly from satellite as it is transmitting i open air and want to save it....I used the downloaded one and able to spoof or fix my position by using USRP.....How I can do that?? I need any open source or command that enable me to receive direct data from GPS satellite

IvanKor commented 5 years ago

I use u-blox https://raw.githubusercontent.com/IvanKor/hrfGPS/master/screenshot3.png and ... https://raw.githubusercontent.com/IvanKor/hrfGPS/master/screenshot2.png https://github.com/IvanKor/hrfGPS

bikilay commented 5 years ago

It is not clear Ivankor, how I could receive ephemeris data directly from satellite by using laptop, USRP and antenna in open air....I have gps-sdr sim open source code and by using this code I have fixed the position by transmitting downloaded ephemeries data over USRP and receiving the transmitted signal by using my phone...gps data app....But now I need to receive ephemeris data in open air by using laptop, antenna and USRP and want to save it in to my laptop.......any code or command that enables me to do this on ubuntu.......

IvanKor commented 5 years ago

If "laptop + USRP + antenna " then recompile for USRP https://github.com/taroz/GNSS-SDRLIB This is a hard task for a laptop. Rewriting the GNSS-SDRLIB I use it only to set the exact frequency of the hackrf crystal oscillator. https://github.com/IvanKor/hrfGPS/blob/master/GNSS-SDRLIB.jpg

bikilay commented 5 years ago

okay thanks.... i need to generate latest ephemeris data other than .14n, like brdc3540.17n and brdc3540.18n...........how can I do that?? $ ./gps-sdr-sim -e brdc3540.14n -l 5,10,15 -d 60 -s 2500000 -b 8...this is for .14n.

when i use this command $ ./gps-sdr-sim -e brdc3540.17n -l 5,10,15 -d 60 -s 2500000 -b 8 it says an error no ephemeries data found..

osqzss commented 5 years ago

BRDC files are available at ftp://cddis.gsfc.nasa.gov/gnss/data/daily/

bikilay commented 5 years ago

okay thanks....is there any way that i can generate using terminal instead of downloading. ./gps-sdr-sim -e brdc3540.14n -l 5,10,15 -d 60 -s 2500000 -b 8....like this...i need the command that i will write on terminal to generate those ephemeries data....

bitdust commented 5 years ago

I use ublox M-8T and receive the .ubx form of RAW data. then use RTKlib tool to transform the .ubx to *.nav file. the nav file is what you want.