[time-nuts] GPS SDR (was: FE-.5680A trimming resolution)
davidwhess at gmail.com
Wed Feb 1 17:38:12 UTC 2012
On Wed, 1 Feb 2012 09:27:30 -0800, Chris Albertson
<albertson.chris at gmail.com> wrote:
>On Wed, Feb 1, 2012 at 8:19 AM, Attila Kinali <attila at kinali.ch> wrote:
>> On Wed, 01 Feb 2012 09:07:23 -0500
>> John Ackermann N8UR <jra at febo.com> wrote:
>>> There've been numerous threads on the Gnuradio mailing list about code
>>> to receive GPS using the Ettus Research USRP hardware. I don't know
>>> whether anyone has actually made it work, but it appears that it's been
>>> the subject of quite a few academic projects.
>That is the problem with an academic projects typically something like
>this would be part of a Master's theses or a senior project. and then
>the student graduates and was no more interrest in supporting it.
>I thought it might be interresting but then found out you need to buy
>$2,000+ worth of hardware for even start experimenting. Open Source
>SDR needs to run on a common affordable platform or it will never gain
>the critical mass of users that it take to make the project live
>longer then a few months.
>I think the way to go is to find a commercial GPS chip that has a low
>level interface and then build the uP controller using a common
>development system. Both the chip and the uP board need to be,
>common, well documented and cheap. Then with this you build an open
>source thunderbolt type device. An SDR that samples the microwave
>RF is going to be un-affordable, even mixing and down converting
>microwaves is not so simple as doing the same on HF ham bands. But
>there might be low level GPS chip available for cheap.
One of the projects did just this but then the integrated circuit or
module that handled the RF and low level functions was discontinued.
For a while they scavenged the hardware from other products that used
it but then those dried up as well.
I believe the best option now would be to find a ubiquitous and well
documented receiver that provides low level access but I suspect they
no longer exist.
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