In this work, the direction finding of coherently distributed (CD) sources using a uniform linear array (ULA) is investigated. Conventional DSPE algorithm for localization of CD sources requires an extensive two-dimensional search of nominal DOAs and angular spreads. The proposed algorithm exploits the propagator, which is a linear operator that can be easily estimated from the received data, to identify the subspace. Then it constructs a decoupled one-dimensional spectrum estimator for nominal DOAs with the aid of the characteristic of ULA and the rank reduction criterion. The proposed algorithm can dispense the high-complexity two-dimensional search and the eigen-decomposition operation. Hence, it exhibits an advantage of low complexity. When compared to the DSPE and CD-GESPRIT algorithms, the proposed algorithm has close estimation accuracy. Numerical simulation results demonstrate the performance and improvement of the proposed algorithm.