Abstract: A method for determining the attitude of a stabilized platform having three or more antennae includes, for each antenna, front-end processing a GPS signal received, the front-end processing including down-converting a GPS source signal by heterodyning and direct sampling, then sampling the down-converted signal. For each antenna the GPS signal is acquired by faster-than-real-time correlating the down-converted signal with each of a number of stored codes and correlating with each of a number of Doppler frequencies. The correlation is repeated for a smaller range of Doppler frequencies, and for smaller intervals of code phases. The down converted signal is then stripped of its codes, and the phases of the resulting signals from each antenna are subtracted, providing the phase differences between antennas, which are converted into attitude angles.

Abstract: A digital receiver for receiving and interpreting navigational data in the global position system comprising faster-than-real-time correlators for correlating the code portions of individual signals with matching codes stored in memory thus creating a plurality of virtual channels for acquiring and tracking each visible satellite.