In this paper, we present a new direction of arrival (DOA) estimation algorithm for coherent wideband signals. This algorithm is based on the test of orthogonality of projected subspaces (TOPS) method which will fail to work in real environments where signals are highly correlated or coherent due to multipath propagation. In order to overcome the disadvantage, we combine spatial smoothing techniques with TOPS method so that the rank of covariance matrix is equal to the number of signal sources even signals received are coherent. Unlike other coherent wideband methods, such as the coherent signal subspace method (CSSM) and WAVES, the new method does not require any initial DOA estimation, thus avoiding errors brought by incorrect initial values. Simulations on computer and experiments in the anechoic chamber based on an 8-elements digital array radar test-bed operating at L & S band are carried out. Simulation and experimental results validate the effectiveness of proposed algorithm.