Enhanced Narrow-band radar imaging of rotating objects: Application to Long Baseline Bistatic Radar (LBBR) for Space Domain Awareness (SDA)

Abstract:
This paper explores spectral enhancement techniques for Doppler Tomography (DT) and Doppler Back Projection (DBP) in order to achieve improved 2D imaging of rotating space objects observed using bistatic radar. DT and DBP are utilized in narrowband radar systems for imaging targets rotating about single and multiple axes, respectively. However, the limited range information, the small angular displacement for coherent computations and additional rotations in the targets lead to less detailed 2D images. To address this limitation, we investigate spectral enhancement methods to obtain sharper images, enabling better Space Domain Awareness (SDA). The paper provides an introduction to key concepts such as bistatic geometry, signal modeling for rotating targets, and the processing sequence. This sequence encompasses preprocessing steps, the implementation of DT/DBP techniques, and a thorough consideration of resolution-related factors. Each technique is closely associated with specific image enhancement approaches, accompanied by a detailed analysis of their advantages and disadvantages. The effectiveness of these enhancements is quantitatively evaluated using performance metrics, and practical validation is demonstrated through real-world measurements presented in the results section.