gpssim.c

[robellebor]

in the gpssim.c file there is a brief that says "Read ephemersi data from the RINEX navigation file" .... where is the RINEX navigation file .... or is it fetching it from the internet ???

[osqzss]

You can find the RINEX navigation file of the daily GPS broadcast ephemeris (brdc) in the following archives: ftp://cddis.gsfc.nasa.gov/gnss/data/daily/

[robellebor]

so that means , we have to be online when we run the gps-sdr-sim ??

[Honky103]

Nope there is a file named "brdc0xxx.14n" in the directory alr. It will read from the same directory as ur gps-sdr-sim

[robellebor]

okay ... am just having a problem getting the gps signal in my phone "gps-test" mobile application .... i have tried by connecting the usrp to a spectrum analyzer and checked that the signal is being transmitted in the right frequency (1575.42 MHz) ,and it works fine, but still i cant get the signal in my phone ???

[Honky103]

Try in a gps-denied environment. Refer to issue #80. This was raised before

[IvanKor]

RINEX navigation file at this time can always be obtained using a GPS receiver, for example, u-blox --> now.nav

[Honky103]

Oh which ublox chip are you using?

[IvanKor]

u-blox 6,7,8

[Honky103]

Are you using the t-series or n-series

[IvanKor]

Any, u-blox 7.03 (45969) 00040007 --> NEO-6M-0-001 US $3.63

[Honky103]

Hmm i know this is a digression, but how do you get the RINEX navigation data file from the ublox chip?

[IvanKor]

UBX-AID-EPH & UBX-AID-HUI convert to now.nav UBX-AID-ALM convert to almanac.sem.txt Almanac is required for the synthesis of EPH satellites that could not take the GPS receiver.

[Honky103]

Oh thanks IvanKor for the information. I am able to save UBX-AID-ALM to almanac.sem.txt from ucenter. However, I can't extract UBX-AID-EPH and UBX-AID-HUI to a file from ucenter. Any idea how do I do that? I am using ucenter_v8.26

[IvanKor]

I do not use ucenter. I use my software.