Receiving the L2C signal with "Namuru" GPS L1 receiver

Abstract

L2C is the first modernised GPS signal for civilians, broadcast by the new generation of satellites, designated Block IIR-M. Currently three of these satellites (PRN-17, PRN-31 and PRN-12) have been declared operational by the Air Force Space Command at Schriever Air Force Base, Colorado. The structure of the L2C signal is designed such that it achieves a number of advantages over the GPS L1 signal alone. This includes weak signal acquisition, ionospheric error elimination when both L1 and L2C are used, quicker operations and improved tracking performance. It was suggested that it would be interesting as well as challenging to acquire and track the L2C signal with a standard GPS L1 receiver. "Namuru" is an FPGA-based GPS L1 receiver, developed at School of Surveying & Spatial Information Systems, UNSW.