Nisar S-Sar Echo Data Simulation

NASA ISRO Synthetic Aperture Radar (NISAR), a multi-frequency multi-polarization wide swath high-resolution SAR system, which is based on SweepSAR imaging technique, is a joint SAR mission between NASA and ISRO. NISAR, with a well-defined observation plan, will acquire high quality SAR data catering to various science disciplines such as deformation, ecosystem, cryosphere, agriculture and oceanic studies at 12 days repeat cycle over entire globe enabling time series analysis. This paper deals with the SAR echo data simulation while considering the NISAR specific complexities like DBF Digital Beam Forming (DBF), dead range gaps across swath and staggering of Pulse Repetition Interval (PRI). Additionally, Digital Elevation Model (DEM) and antenna pattern characteristics are incorporated in simulation for ascertaining the radiometric & geometric fidelity of the data products. Maximum perturbation of 100mdeg (1 sigma) in pointing is used during simulation.