Challenges in High-Resolution Multidimensional Radar Signal Processing

Author(s):

Traian Dogaru

Abstract:

Surveillance radar systems equipped with active electronically scanned antenna arrays (AESAs) typically operate with low spatial resolution. Under these conditions, the data transformation from the radar signal in the frequency, array position, and slow time dimensions to the reflectivity map in the range, angle, and Doppler dimensions is conventionally performed by a 3-D fast Fourier transform. However, the ability to apply this conventional processing scheme relies on certain approximations, the validity of which becomes questionable as we try to improve the radar system’s resolution. In this report, we analyze the conditions when the radar measurement dimensions (frequency, array position, and slow time) become coupled, and we point out to the signal processing challenges posed by this coupling in creating the radar reflectivity map. We discuss possible algorithmic approaches to creating a high-resolution reflectivity map with an AESA radar system and illustrate several simple numerical examples.