Simulation of satellite-to-satellite tracking data of interferometric SAR based on GPS

Abstract

While space-borne synthetic aperture radar (SAR) has evolved into a mature technology over the past two decades, there is a growing interest in interferometric SAR applications. Precise relative state estimation is a necessary technique for the operation of multiple space vehicle on-orbit formation flying together, which is vitally important for the InSAR system. Carrier-phase Differential GPS (CDGPS) positioning has been proven to be an accurate technique for relative positioning and attitude determining between multiple vehicles. In order to analyze and assess the achievable accuracy based on satellite-to-satellite tracking (SST) by the US global positioning system (GPS), a modeling with corresponding simulation software is established to analyze relative state estimation of InSAR using CDGPS, which is a part of the InSAR Simulation System (ISSS). The models including SAR satellites model, GPS satellites model and observation error models are studied in this paper. The simulated observation data is obtained by employing these elaborately selected models, which can be used in the process of investigating orbit determination scheme, evaluating relative state estimation methods such as ambiguity resolution method, Kalman filtering technique and so on. The values of simulated model parameters can be customized to simulate satellites at different altitudes and tracking data with different errors.