Advances in Strapdown Systems for Geodetic Applications

Abstract

This paper discusses recent developments in strapdown inertial navigation systems that have been pursued to obtain high accuracy. In particular a strapdown system with a single gimbal axis to obtain controlled rotation of the inertial sensor assembly is discussed. An approximate theoretical error model of this hybrid, strapdown inertial system is derived which permits its error characteristics to be compared with those of a conventional strapdown system in the vehicle coordinate frame. The high accuracy potential of the hybrid mechanization relative to a conventional strapdown inertial system is evident from a comparison of the respective error models. Testing of single and multiple gimbal hybrid strapdown inertial systems has confirmed the high accuracy potential of such systems in certain applications.