Integration of GPS and Strapdown Inertial Subsystems into a Single Unit

Abstract

Most GPS receivers are designed for stand-alone operation. Single-channel, slow-sequencing receivers are recognized to be lowest cost, but lack dynamic capability, while multiplexed and multichannel designs allow operation during acceleration, but add cost, weight and power. It is also well recognized that a marriage of GPS data with strapdown inertial data enhances the quality of both, and many people are looking at integration of available GPS receivers with various available inertial systems. However, direct design at the outset of a tightly integrated GPS and strapdown INS allows optimization of both for performance and cost. Using this approach, a properly designed slow-sequencing, single-channel receiver, married to a low-cost strapdown inertial unit, provides satellite tracking during 10-g acceleration, very high jamming suppression, improved strapdown inertial outputs, and improved GPS navigation accuracy. Packaging this “GPS/I” in a single unit reduces software and hardware redundancies, and results in a very low-cost design.