The physics of compressive sensing (CS) and the gradient-based recovery
algorithms are presented. First, the different forms for CS are summarized.
Second, the physical meanings of coherence and measurement are given. Third,
the gradient-based recovery algorithms and their geometry explanations are
provided. Finally, we conclude the report and give some suggestion for future
work.Comment: 7 pages, 11 Figures. It is a research report which has not been
published in any Journal or Conferenc
