On the accurate calibration of the SeaWinds radar antenna: a cylindrical near-field measurement approach

A multipolarization, multi-incidence angle conical scanning Ku-band radar antenna is being designed and calibrated at the Jet Propulsion Laboratory (JPL) for the SeaWinds Scatterometer instrument. To calibrate the radar´s performance, it is essential to accurately determine the antenna gain and radiation pattern characteristics over wide angular range. Such characterizations may be performed on a far-field range or in an indoor near-field measurement facility. Among the advantage of the latter is that the antenna is in a controlled environment. This paper demonstrates the utility of a cylindrical near-field measurement approach for the SeaWinds radar antenna calibration. Both generalized measurement error models and measured tests on a standard gain horn and NASA Scatterometer instrument antenna have been performed to achieve and verify the desired calibration accuracy. A comparison between far-field measured data and those obtained from cylindrical near-field measurements was found in excellent agreement