I am using fastGPS to do the correlation as well as writing my own MATLAB correlation scripts.
Nick On Fri, Nov 25, 2011 at 8:40 PM, Nick Foster <n...@ettus.com> wrote: > On Fri, Nov 25, 2011 at 7:01 AM, Nick Othieno <nickothi...@gmail.com> > wrote: > > Hi Ryan, > > > > What did you use for your setup, ie daughterboards, antenna and LNA (if > you > > do not mind my asking). I have been trying a setup for months that uses a > > DBSRX2 and a mighty mouse 2 antenna only, but I have never been able to > > acquire the L1 signal. I am wondering where I have gone wrong in the > setup. > > I've successfully used a DBSRX + active antenna to receive GPS signals > before. What software are you using to do the correlation and find the > L1 signal? > > --n > > > > > Nick > > > > On Fri, Nov 18, 2011 at 9:47 AM, Wolfarth, Ryan <wolfa...@muohio.edu> > wrote: > >> > >> Hi folks, > >> > >> My group is using USRPs to do the task Kouki described, although our > flow > >> diagram is a little different. We only use the USRP2 to receive the > raw RF > >> data which is written to file. This data is processed to the point > where we > >> decode the navigation bits, but no position is ever found. We're more > >> interested in the effects of ionosphere scintillations on GNSS signal > >> structure so we don't need to calculate antenna position. > >> > >> I can recommend two books that have helped me immensely. The Kaplan > "blue > >> book:" > >> > >> > >> > http://www.amazon.com/Understanding-GPS-Principles-Applications-Second/dp/1580538940/ref=sr_1_1?ie=UTF8&qid=1321627222&sr=8-1 > >> > >> And the Kaplan "blue book:" > >> > >> http://www.gpstextbook.com/ > >> > >> I do know of a group that has used a USRP1 to develop a 4 channel L1 > >> receiver, but they had to modify the FPGA to do all the real time > >> processing. Let me know if you have additional questions! > >> > >> -Ryan > >> > >> On Fri, Nov 18, 2011 at 7:56 AM, Brian Padalino <bpadal...@gmail.com> > >> wrote: > >>> > >>> 2011/11/18 山本弘貴 <k.yamamoto.0...@gmail.com>: > >>> > Hi, All > >>> > I have very trouble > >>> > My experiment enviroment isUBUNTU 11.04 , USRP N200, DBSRX2 ,active > >>> > antenna and gnuradio > >>> > I am worrying about good software GPS receiver is not exist . > >>> > I want to receive L1 signal , and want to demodulate that signal > >>> > However GPS signal is used Spread spectrum modulation scheme. > >>> > I try to creating gnuradio-companion's blocks.(use to Spread spectrum > >>> > demodulation blocks) > >>> > but that is very difficult so Now I think method is > >>> > > >>> > GPS L1 signal → USRP N200 → gnuradio-companion(UHD_source→File_sink) > >>> > → software decode soft → output(Location data) > >>> > > >>> > > >>> > Eventually I want to Calculate location data, > >>> > Please let me know if you're a good this way > >>> > >>> I recently came across this product listing at Spark Fun: > >>> > >>> http://www.sparkfun.com/products/10981 > >>> > >>> Which has a link to a book all about GPS receiving and even comes with > >>> MATLAB source code: > >>> > >>> > >>> > http://www.amazon.com/Software-Defined-GPS-Galileo-Receiver-Single-Frequency/dp/0817643907 > >>> > >>> I am sure, with the source, you could adapt it to use the USRP > >>> recorded signal, and then possibly port the MATLAB over to either > >>> Python (using Josh's signal processing in Python blocks) or straight > >>> C++. > >>> > >>> > I am sorry that My English is not good > >>> > > >>> > Kouki > >>> > >>> Good luck - it's definitely not a trivial task, but it sounds extremely > >>> fun. > >>> > >>> Brian > >>> > >>> _______________________________________________ > >>> Discuss-gnuradio mailing list > >>> Discuss-gnuradio@gnu.org > >>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > >> > >> > >> _______________________________________________ > >> Discuss-gnuradio mailing list > >> Discuss-gnuradio@gnu.org > >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > >> > > > > > > _______________________________________________ > > Discuss-gnuradio mailing list > > Discuss-gnuradio@gnu.org > > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > > > >
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