Accuracy of FPGA receiver

July 03, 2012  •  Leave comment (1)

On the figure below coordinates variations are plotted. They are taken from FPGA+ARM receiver. The measurements were made during aproximately 1 hour with the speed of 1 measurement per second.

PVT_FPGA_variance.PNG

Variation of coordinates across each axis is about 80 meters that approximately corresponds to software GPS receiver SoftGNSS.

FPGA + ARM = new results with hardware receiver

July 02, 2012  •  Leave comment (1)

On the figure below result of hardware receiver (FPGA+ARM-based) work is shown. The same demoboard as in the note From software receiver to hardware receiver or what can be achieved from a bundle of OSGPS and NAMURU was used. Now the software part of the project is running under real time operating system TNKernel. The project is based on correlator Namuru and software gpl-gps/namuru-gpl.

PVT_FPGA.png

For the moment the program works not stable. Sometimes incorrect synchronization for some channels happens and hence pseudoranges are calculated incorrectly. As a result wrong coordinates are calculated.