在相控陣雷達跟蹤低仰角目標時，采用頻率捷變技術可以有效地減小雷達回波中直射信號和反射信號的相關性，抑制多徑效應對目標到達方向估計造成的影響，提高角度估計的精度和性能。再用修正的AR模型算法，不僅可以在此基礎上進一步去掉這兩種信號的相關性，而且能正確估計出目標和鏡像的仰角。計算機仿真實驗結果驗證了頻率捷變和修正AR模型算法理論的正確性，以及在與其他方法比較的情況下，兩者結合在去相關性能上的優越性和工程實用性。

It is very effective that applying frequency agility to reduce the coherence of the direct and the reflect signal in phased array radar, which are contained in the echo of radar. This method can restrain the influence caused by multipath effect when estimating the target’s direction of arrival (DOA), and improve the precision and ability of angle’s estimation. Then the application of the modified AR model can not only reduce the coherence of the two signals further, but separate the elevations of the target and its image. The simulation results verify the validity of the theory of frequency agility and modified AR model, as well as the advantage and practicability with the combination of two methods when comparing with other methods.