Antenna angle error correction to radome curvature

For many tactical mobile ground based tracking phased-array radar applications, the antenna system must be covered by a radome to permit capability in all weather conditions. While this radome provides environmental protection for the tracking antenna, it will affect the accuracy in estimating target direction caused by radome curvature and radome seam scattering. The antenna designer must then evaluate angle error due to radome effect so as to completely characterize performance parameters that meet the requirements of angle accuracy on the overall tracking radar system. The author presents the analysis of an angle error correction algorithm for the phased array inside a curved sandwich radome. The array´s dimension is 2 m/spl times/4.7 m (EL/spl times/AZ) and operates at X-band. The radome is assembled by three sandwich panels and has cylindrical shape with 4 m radius in elevation. Most angle error is contributed by radome curvature. The numerical radome simulation employs a ray tracing method to compute the transmission coefficients of the antenna´s rays at different incident angles through the radome which are dependent on array scan. Due to the cylindrical geometry of the radome, no angle error is obtained in azimuth.