Microwave pulse Doppler radar systems are useful tools for airplane tracking and velocity estimation in all-weather situations. However, Doppler radar often suffers from intrinsic difficulty when the target Doppler spectrum is buried amongst a cluttered background from clouds as lower pulse repetition frequencies (PRF) cause ambiguity in the Doppler spectrum. To address this issue, we propose a novel target detection method based on the independent component analysis (ICA) scheme. The results from numerical simulations validate the effectiveness of our method compared with those obtained by conventional methods based on principal component analysis (PCA