Frequency-Optimized Joint Sparse Recovery for Grating-Lobe Suppression in Distributed Radar

This letter proposes a frequency-optimized multi-frequency joint sparse recovery method for grating-lobe suppression in distributed radar. Single-frequency sparse recovery in distributed large-baseline arrays may suffer from highly correlated grating-lobe atoms, resulting in unstable angular support estimation. To address this problem, a grating-lobe consistency metric is constructed from frequency-dependent observation matrices, and an optimized frequency set is selected to reduce the cross-frequency consistency of ambiguous lobes. A multi-frequency joint sparse reconstruction model is then developed to recover the common angular support of true targets. Simulation results demonstrate that the proposed method effectively suppresses residual grating lobes and improves angular support stability.