Extended Targets Modelling and Block Agnostic Sparse Reconstruction in Through-the-Wall Radar Imaging: A Different Perspective

摘要

A common target model in through-the-wall radar (TWRI) imaging literature obeys the point target (PT) assumption in which, a target is hypothesized to occupy a single pixel. Unlike PTs, the received signal reflected from extended target (ET) is an integration of the scattered signals from various parts of the same target. For high resolution images, a generalized model is needed to encompass the ETs. The ET modelling and reconstruction under compressive sensing (CS) framework have not been studied comprehensively yet. Existing reconstruction methods for ETs assume that when the scene is vectorized, target pixels form blocks with constant block sizes, also, assume that the size and number of the blocks and their sizes are known in priori and they follow Gaussian distributions. These assumptions rarely mimic the practical TWRI scenarios. In this paper, we suggest a different but realistic ET reconstruction approach based on agnostic block sparsity. The algorithm does not impose any assumption on the length, number, or the distribution of the blocks.? Results based on MATLAB simulation and experimental data show the effectiveness of the proposed reconstruction approach.