High-Resolution Radar Imaging of Space Debris Based on Sparse Representation

Short data and large Doppler bandwidth in a low-pulse-repetition-frequency system is a challenging problem for space debris imaging. Meanwhile, space debris usually rotates at a high speed so that the echo suffers from the shadow effect during the observation. To solve the problem, we propose a new 2-D inverse synthetic aperture radar imaging algorithm. Based on the fact that space debris usually rotates for several periods during the observation and the scattering field presents strong spatial sparsity, the proposed method can efficiently improve the imaging quality by constructing the measurement matrix to utilize the support data in multiple cycles. Theoretical analysis confirms that the methodology can obtain a well-focused image. Numerical simulations demonstrate the effectiveness of the proposed algorithm for space debris imaging.