Field of view analysis of SeaWinds reflector antenna

Antennas are often mounted among many other instruments on the spacecraft (S/C) platform. The electromagnetic interference (EMI) and compatibility (EMC) issues are of great concern to the antenna and S/C system design engineers. Considering the rotating reflector antenna of the NASA SeaWinds scatterometer on the Japanese ADEOS II S/C, it is desirable to determine the antenna´s field of view (FOV) performance. In other words, how far should the other boxes be kept away from the reflector antenna to minimize the blockage/diffraction effects on the antenna´s performance requirements. Since the antenna is rotating around an axis parallel to the z-axis, the problem may now be interpreted as determining a limiting FOV cone angle such that no boxes should be placed inside. One could find the solution to this FOV problem by experimenting with a scale model. However, it is quicker and more cost effective to develop a numerical approach. Therefore, the high frequency technique of shooting and bouncing rays is applied to determine this antenna´s FOV cone angle.