Abstract: In joint angle and Doppler estimation, an improved propagator method is proposed to solve the problem that the accuracy of the traditional propagator method is poor at low signal-to-noise ratio (SNR). Firstly, by applying temporal smoothing technique a new array steering matrix is constructed which has a double Vandermonde structure, and then the rotational invariance technique is utilized to obtain the coarse estimation of angles. Secondly, a new propagator matrix is constructed which is orthogonal to the extended array steering matrix, and then a quadratic optimization function is formulated. Finally, with the use of the Frobenius norm constraint of the steering vector, the 2-dimensional optimization problem is decomposed into 1-dimensional optimization problem which can be solved by 1-dimensional local searching. Both eigenvalue decomposition (EVD) of the covariance matrix and pair matching are not required in the proposed algorithm. Simulation results show that the proposed algorithm exhibits superior accuracy and resolution ratio.