Calibration accuracy enhancement in the field experiment with a ground-based scatterometer

An improved field-measurement technique for enhancing the calibration accuracy of a ground-based scatterometer is proposed in this paper. The automatic two-dimensional (2-D) measurement of a calibration target, so-called ‘2-D target scanning technique (2DTST)’, gives a precise alignment between a point calibration target and an antenna bore-sight. Averaging of the calibration-target measurements increases further the accuracy and reliability of the automatic alignment. The measurement results show that the correlation among the measurements is larger than 0.95 and the error-rate is below 5% at a frequency range from 9.4 GHz to 9.9 GHz. The evaluation of the calibration accuracy using the STCT (Single Target Calibration Technique) shows that 2DTST in the field experiment can secure the precise calibration accuracy within 0.5 dB for magnitude correction and 4° for phase correction.