High-Precision Kinematic GPS Differential Positioning and Integration of GPS with a Ring Laser Strapdown Inertial System

Abstract

Many fields, such as geodetic surveying, positioning of airborne sensors (photogrammetric cameras), laser bathymetry, airborne gravimetry, and hydrographic surveys, require accuracies in the decimeter or even centimeter range in differential positioning. Using the full potential of the GPS in a dynamic environment, the Institute of Astronomical and Physical Geodesy (IAPG) has carried out several kinematic tests with respect to land-based, shipborne, and airborne applications. After reviewing the main concepts in differential GPS kinematic positioning, this paper presents experiences with and practical results of kinematic GPS tests. Results of a Kalman filter covariance analysis are shown for the integration of GPS phase and pseudorange data with ring laser strapdown inertial systems in order to recover cycle slips and short-time loss of lock in GPS. In particular, the question is discussed of the extent to which inertial strapdown systems can be used to bridge these times and to maintain centimeter accuracy.