Design and implementation of portable GNSS baseband logger

Abstract

The design and the implementation of a portable GNSS baseband logging system which can log raw GPS L1 baseband more than one hour or longer is presented. In addition, the design covers GPS (L1, L2)/GLONASS/Galileo/Compass frequency and the maximal sample frequency is about 50MHz.The system is based on Blackfin DSP and uses CompactFlash card for storage. The data is extracted by reading the CompactFlash card to store as a data file. The recorded data file is analyzed by using the FFT to acquire the GPS satellites signals and the position is calculated by using the open source GPS positioning software. The system is very portable because of the CF+DSP design and can also be used on missile and satellite. It provides a good research and development platform for the GNSS software receiver.