基于梯度物理的压缩感知（CS）和恢复算法。对 CS形式进行了总结。介绍了物理意义的连贯性和测量。以及基于梯度的恢复算法及其几何解释。-The physics of compressive sensing (CS) and the gradient-based recovery algorithms are presented. First,the di® erent forms for CS are summarized. Second, the physical meanings of