SAR Imaging and Interferometry Using Parameters Estimated from Raw Data

Abstract

Due to the costs, sensitivity, and export policies of many governments, universities, and research institutions, particularly in developing countries, the ability to purchase, install and maintain high-accuracy inertial navigation system (INS) and global positioning system (GPS) is restricted. This paper presents a new method for SAR imaging and interferometry using parameters estimated from raw data. First, methods for determining the order of real and imaginary parts within the raw data images, and for determining chirp rate polarity are proposed. Second, a selection of parameters, including the forward effective velocities of the sensor, the near range distance, and the squint angle, are extracted using the Doppler centroid and Doppler rate. Finally, we create single look complex (SLC) images, coherence maps, digital elevation models (DEMs), and dual-pass differential unwrapped phase maps. The level of accuracy shown in this comparative study suggests that the proposed method is acceptable for creating the featured SAR products and is suitable for real world applications. This method and result is particularly relevant for systems which suffer from a lack of high-accuracy positional metadata.