Time-shared fitting method of Doppler parameters and the implementation on FPGA

An essential part of SAR processing is the fitting of Doppler parameters, including the Doppler centroid frequency and the Doppler frequency rate. The traditional least squares fitting method is not practically used due to its heavy calculation burden. In this paper, we propose an improved time-shared fitting method of the Doppler parameters, which can reduce the resources and the time delay. The Doppler centroid frequency and the Doppler frequency rate need linear and quadratic fitting respectively. In this paper, only linear and quadratic fitting methods are discussed. Then the paper presents the implementation of the time-shared fitting method on FPGA. At last, the author analyzes the resources and time delay of the time-shared fitting method, and compares them with other fitting methods. The time-shared fitting method can save a lot of hardware resources and can reduce the time delay.