Target and Image Elevation Angles Separation Algorithm for Low-Angle Tracking with Monopulse Antenna

The multipath phenomenon causes error in elevation angle tracking operation of low altitude targets. Returning signals from the target after reflecting from the surface enter the antenna main beam. In such circumstances, the surface acts like a mirror and creates an image of the real target beneath the surface. Multipath effect elimination is a major challenge in tracking systems. In an attempt to decrease the multipath effects, the authors extended the elevation geometric mean method and presented the target and image elevation angles separation algorithm with monopulse antenna. The proposed method presents two equations for calculating the real and image elevation angles. These two equations are expressing the summation and the multiplication of the target and its image angle. This method presents low computational complexity and simple implementation on the monopulse tracking system. The computer simulation results show that the proposed method is able to mitigate the multipath effect and estimate the elevation angle with high accuracy.