Computer-aided design of the Green Bank radio telescope reflector antenna

This paper summarizes the results of a computational study performed to evaluate the electrical performance of the Green Bank telescope reflector antenna. All computed patterns were obtained with the PRAC (Parabolic Reflector Analysis Code) program, developed by the authors, and with the GRASP7 commercial code. In addition, calculations on the single and dual offset Gregorian configurations were conducted to optimize the performance for low cross polarization (XPOL). The patterns and performance values indicate that low cross polarization (XPOL) performance for the GBT reflector can be achieved with a dual offset configuration, provided that a low XPOL feed is employed.