A novel method is presented to estimate the direction of arrival (DOA) for coherent signals in the environment of small number snapshots. According to the statistical characteristics of the signal source, the Bootstrap algorithm reconstructs the new Eigen-space, and expands element numbers of covariance matrix. The amount of information to be extended after the reconstruction, and to maximize the use of the noise subspace and signal subspace information. At the same time, Block sampling for coherent signal has good filtering to coherence function, which solves the problem of coherent signal smoothing. The simulation results show that the method in a small number of snapshots of direction of arrival estimation has good estimation performance.
