[time-nuts] Raw GPS signal samples

[Azelio Boriani]

>For our timing niche, SDGPS (Software-Defined GPS) doesn't even need to be real-time. It's the after-the-fact corrections to the LO that are of interest.

Can you elaborate the "after-the-fact corrections to the LO" point? I
understand that: I can correct the LO after a sample cycle, then use
the corrected LO to take other samples and correct again and so on.

On Wed, Sep 4, 2013 at 11:05 PM, Tom Van Baak <tvb at leapsecond.com> wrote:
> Hi John,
>
> It's not off-topic at all. Thanks for posting. Someday it would be cool if an amateur precise time project emerged from this effort.
>
> What is not clear from your link is the accuracy or stability of the LO that was used. It seems to me, for timing purposes, that one would want to have a very precise timebase for the binary samples that are collected.
>
> I suppose it depends if someone just wants to make a homebrew (50 baud) GPS subcode decoder and navigation receiver, or if someone is interested in extracting as much precise time from the code and carrier phase as possible. For our timing niche, SDGPS (Software-Defined GPS) doesn't even need to be real-time. It's the after-the-fact corrections to the LO that are of interest.
>
> Do keep us posted.
>
> /tvb
>
> ----- Original Message -----
> From: "John Seamons" <jks at jks.com>
> To: "Discussion of precise time and frequency measurement" <time-nuts at febo.com>
> Sent: Tuesday, September 03, 2013 1:30 PM
> Subject: [time-nuts] Raw GPS signal samples
>
>
>> Somewhat off-topic but it might help someone out: I've had a tough time finding, and using, files on the net containing raw GPS signal samples to be used with the various software-only (or software-mostly) GPS receivers out there. I finally got a file of data that works and have have posted it plus a description of the file format here: <http://www.jks.com/gps/gps.html> I've used it successfully with Andrew Holme's excellent homemade GPS receiver. Now on to building an actual RF front-end to get some real signals..
>>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.