A comprehensive study of the rational function model for photogrammetric processing

Abstract

The rational function model (RFM) has gained considerable interest recently mainly due to the fact that Space Imaging Inc. (Thornton, Colorado) has adopted the RFM1 as an alternative sensor model for image exploitation. The RFM has also been implemented in some digital photogrammetric systems to replace the physical sensor mode for photogrammetric processing. However, there have been few publications addressing the theoretical properties and practical aspects of the RFM until recently. In this paper a comprehensive study of the RFM is reported upon. Technical issues such as the solutions, feasibility, accuracy, numerical stability, and requirements for control information are addressed. Both the direct and iterative least-squares solutions to the RFM are derived, and the solutions under terrain-dependent and terrain-independent computation scenarios are discussed. Finally, evaluations of the numerous tests with different data sets are analyzed. The objective of this study is to provide readers with a comprehensive understanding of the issues pertaining to applications of the RFM.