Assessment of the sensitivity of the South African KAT-7 and MeerKAT/SKA radio telescope reflector antennas

This paper assesses and compares the sensitivities of the antenna gain, cross-polarization and sidelobe levels with respect to feed and/or subreflector displacements due to estimated operational conditions as well as manufacturing tolerances. The probabilistic assessment is evaluated with the Unscented Transform, deemed computationally more efficient than other similar techniques, and employs physical optics computer simulations performed with the WebPRAC and GRASP computer codes. The procedure is applied to the KAT-7 prime focus parabolic reflector antenna, and to a proposed design for the MeerKAT offset Gregorian reflector antenna.