Eigenstructure methods for direction of arrival estimation have become well established for radar, sonar and radio array applications for which coherent (i.e. amplitude and phase) measurements are available. In many IR and optical applications incoherent detectors are used that measure the power rather than signal amplitude/phase. In this paper, we derive a subspace algorithm for high resolution direction of arrival estimation for such measurement models. Results of computer simulation that verify the performance of our proposed algorithm are also presented.