  Orthogonal Matching Pursuit (OMP) is the canonical greedy algorithm for
sparse approximation. In this paper we demonstrate that the restricted isometry
property (RIP) can be used for a very straightforward analysis of OMP. Our main
conclusion is that the RIP of order $K+1$ (with isometry constant $\delta <
\frac{1}{3\sqrt{K}}$) is sufficient for OMP to exactly recover any $K$-sparse
signal. Our analysis relies on simple and intuitive observations about OMP and
matrices which satisfy the RIP. For restricted classes of $K$-sparse signals
(those that are highly compressible), a relaxed bound on the isometry constant
is also established. A deeper understanding of OMP may benefit the analysis of
greedy algorithms in general. To demonstrate this, we also briefly revisit the
analysis of the Regularized OMP (ROMP) algorithm.
