Network Approach versus State-space Approach for Strapdown Inertial Kinematic Gravimetry

The extraction of gravity anomalies from airborne strapdown INS gravimetry has been mainly based on state-space approach (SSA), which has many advantages but displays a serious disadvantage, namely, its very limited capacity to handle space correlations (like the rigorous treatment of cross-over points). This paper examines an alternative through the well known geodetic approach, where the INS differential mechanization equations are interpreted as a least-squares network parameter estimation problem. The authors believe that the above approach has some potential advantages that are worth exploring. Mainly, that modelling of the Earth gravity field can be more rigorous than with SSA and that external observation equations can be better exploited.