Multi-channel GPS RF data logging and playback facility

Abstract

The development and initial testing of a GPS data logging facility is described. The main purpose of the facility is to record digital data from a GPS L-band antenna array during field trials and later play the data back through different antenna electronics units. The hardware can also be used as a multi-channel GPS signal generator which could prove very useful for evaluating adaptive antenna arrays. The current system can log raw RF data from four antenna channels at a 20 MHz bandwidth at either L1 and/or L2 for a duration of 2 hours. The data is stored on hard-drives and can then be played back on four antenna channels. As this system is designed for testing high dynamic range anti-jam units, the overall dynamic range had to be maximised and the mismatch between antenna channels minimised. The overall system design as well as initial test results of the dynamic range and mismatch obtained in the current system will be presented.