GPS Software Correlator for the USRP

Well, thanks to Google's summer of code and student Isaac Carroll at Portland State University, the foundation of a GPS software receiver for the USRP has been laid. For his project he developed a working GPS software correlator that works on captured data from the USRP. A link to the project page is here. Although, there is a lot of work to be done to bring it into the gnuradio framework (i.e. C++ blocks), its great to have some working python code to test feasibility. Speed is really the major roadblock for the python code. After profiling the code, determination of the threshold based on standard deviation of data is a major slowdown. Using the acquire.py code is quite simple and an example for the data found on KD7LMO's website can be downloaded here. After all the python code has been downloaded from the trak page (first link) you can run the example by

python acquire.py gps_4m_complex.dat