The use of maximum likelihood estimation for forming images of diffuse radar targets from delay-Doppler data

Abs,stract-A new approach to high-resolution radar imaging is presented. The starting point is a model of the radar echo signal based on the physics governing radar reflections. This model has been used several times in the past for describing radar targets that are rough compared to the wavelength of the transmitted radiation. Without specifying precisely what the transmitted signal is, a general estimation-based procedure is derived for obtaining images. After discretizing the model, the radar imaging problem reduces to the task of estimating discretized second-order statistics of the reflectance process of the target Maximum likelihood estimates of these statistics are obtained as the limit point of an expectation-maximization algorithm.