An Improved Adaptive Monopulse Algorithm Based on Subspace Projection

Adaptive monopulse technique is widely used in surveillance and tracking radar due to its interference cancelling and angle estimation ability. In classical adaptive monopulse, the first-order linear approximation is adopted and the high-order items are ignored, which causes angle estimation error. To solve this issue, constraints to make the high-order items approach zero are proposed and combined to interference subspace to calculate weights of sum and difference beams. Finally, the obtained weights are applied to classical adaptive monopulse method to estimate the angle location while making equations more concise. Some rules and regulations on the locations of the constraints are also made in this paper. By using the method proposed in this paper, adaptive monopulse estimation can be applied to a larger area and angle estimation error can be reduced further. Simulation results show the effectiveness and correctness of the algorithm proposed in this paper.