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Tips and questions relating to the GPS modules from SFE
By usman889
#50390
Hello!

Has any one succesfully performed the GPS raw data acquisition with the new SiGe GN3S Sampler v2 USB module.

Any suggestions for an alternate device that captures data with IF of few MHz rather than the I and Q samples.

Regards

Usman
By fpgapro
#57171
Hi, i'm having the same problem with GN3S v2. I've changed fs to 8183800, IF is 38400 Hz, the rest is as default (except 12 channles, ischar...) but I'm not able to acquire any satellites. I've used 2 diff antennas and checked signal with Magellan GPS. Did You find something new.

Thanks
By 3849
#58396
the Matlab code soll also new upload. but there are also filetype =2 to set .
By Rob5
#75854
Hello,

I have followed the instructions given in http://ccar.colorado.edu/gnss and installed the interface they provide to operate the GN3Sv2 front end

But when I run the application the Buffer Overrun rises:

C:\GN3Sv2\gn3sv2 -s 32

———-

GN3S v2 - GNSS IF Streamer for Windows

———-

Saving data to gnss.bin

Collecting data IQ samples at Fs=8.1838 MHz

Streaming data to disk.

Buffer overrun…

Captured 0 MB in 0 seconds.

Changing the parameters of the acquisition doesn't make any difference, the problem is always the same.
My computer is a Vaio FW21E Laptop with an Intel core 2 Duo P8400 2,26 GHz processor and a 320 GB Serial ATA 5400 rpm hard drive. I have also portable hard Drive from LaCie with 250 GB, with maximum transfer rate from 28-32 MB/s and average access time minor than 12 ms. The problem rise using both disks. The OS I am working with is Vista.
I don't know if the problem is due to the speed of the hard drives or it has something to do with some configuration in Vista.

Any suggestions?
Thank you in advance,
Best Regards
Roberto de Lezaeta
By marx83
#134526
fpgapro wrote:Hi, i'm having the same problem with GN3S v2. I've changed fs to 8183800, IF is 38400 Hz, the rest is as default (except 12 channles, ischar...) but I'm not able to acquire any satellites. I've used 2 diff antennas and checked signal with Magellan GPS. Did You find something new.

Thanks
Hello,

We have been experiencing a probable malfunctioning of the SiGe GN3S Sampler v2: data seem properly acquired (no SW errors), but no satellite acquisition has been ever performed by using our SiGe Sampler.

Last month (sep 11) we have purchased a SiGe GN3S Sampler v2 from Sparkfun together with the antenna advertised on the same page.

We have been using the matlab code from "A software-defined GPS and Galileo Receiver- A single frequency approach" (Kai Borre) both on a Windows 7 and Windows XP machine

For SiGe version 2 we replaced the .m files contained in the SDR with the updated ones downloaded by the GNSS web site of Colorado University for the processing of the I/Q data and we used the parameters indicated on the same web site : (in order to validate this SW, we have also generated a proper sample IQ file and the SDR properly acquired the GPS satellites we had coded into the IQ file).

Sampling frequency : 8.1838 MHz
Intermediate frequency : 38.400 KHz

Again, all the software runs smooth but no satellites have ever been acquired in a clear sky view (i.e. no trees, no buildings, at Rome-Italy latitude) and the University of Colorado still did not provide any hint to solve the problem.

I noticed you have experienced a similar issue; did you manage to fix it?