Hello Harald,
On Sun, 12 Dec 2010 17:01:22 +0100, "Harald Welte" laforge@gnumonks.org wrote:
Pretty interesting. If only I had the time to implement it ;)
I don't think that implementing is the hard part, debugging is. You send data which might be wrong due to some bugs in your code into a "black-box" which does something with the data. The "black-box" will not tell you if your data are wrong, if they are, it might just take longer till any results are returned. So you are not sure if you are doing the things right.
I conclude the above from my experience so far: Even phones with very extensive tracing capabilities don't tell you much about what is going on during their GPS position calculations. And at least I am not aware of a GPS server I have access to who will provide those data required for an "MS-assisted" measurement so that one could compare the own calculation against a reference.
If someone know about a server providing those data (I am not talking of things like "almanac" or "ephemeris" here) or knows about existing source code to do the calculation, I would like to know.
BTW, the book "Server-Side GPS and Assisted-GPS in Java" contains a few nice chapters, one should not care about "Java" in the title, only the examples are written in Java.
Best regards, Dieter
Hi Dieter,
of a GPS server I have access to who will provide those data required for an "MS-assisted" measurement so that one could compare the own calculation against a reference.
There are a few. My Trimble Thunderbolt can give you doppler and codephase (gps often calls it "pseudorange").
If someone know about a server providing those data (I am not talking of things like "almanac" or "ephemeris" here) or knows about existing source code to do the calculation, I would like to know.
there are a few open-source GPS implementations out there. The "software defined radio" part only determines the pseudoranges (e.g. the chips' phase with respect to each other) to the part that does the actual trigonometric calculations, so every implementation should be useable for that purpose.
Sparkfun sells "only the frontend" (mixer, 1-bit ADC, USB) with sourcecode available in a book and on DVD (WTF?!)
---> http://www.sparkfun.com/products/8238
Then, I found a "GPL-GPS" Project at http://gps.psas.pdx.edu/ with a repository at http://svn.psas.pdx.edu/svn/psas/trunk/gps/gpl-gps/
There's actually quite a lot of information out there, but there also seem to be quite a lot of half-abandoned projects (and a few seem to have vanished since the last time I had an interest in it around 2005).
Chris
Selling the hardware and software separately is probably a tactic to avoid patent infringement.
On Dec 12, 2010, at 10:22 AM, Christian Vogel wrote:
Sparkfun sells "only the frontend" (mixer, 1-bit ADC, USB) with sourcecode available in a book and on DVD (WTF?!)
David A. Burgess Kestrel Signal Processing, Inc.
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Christian Vogel -
David A. Burgess -
Dieter Spaar