“…Over the past few years, in order to interpolate (or model) the distance-dependent residual biases, several interpolation methods have been proposed. They include the Linear Combination Model (Han & Rizos, 1996;Han, 1997), the Distance-Based Linear Interpolation Method (Gao & Li, 1998), the Linear Interpolation Method (Wanninger, 1995), the Low-Order Surface Model (Wübbena et al, 1996;Fotopoulos & Cannon, 2001), and the Least Squares Collocation Method (Raquet, 1998;Marel, 1998). The theoretical and numerical comparison of the various interpolation algorithms has been made by Dai et al (2003), and there is no obviously 'superior' technique.…”