Effect of Temperature on RCS Measure and Calibration of Standard Metal Ball up to 800°C

Abstract

Metal balls are often used as standard bodies in the target RCS measure based on precise theoretical calculations, and the accuracy of RCS measure data is directly related to the experiment measure. This paper mainly studies the calibration of metal balls at high temperatures in target RCS measure. Firstly, the high temperature field of targets is analyzed, and it is found that the changes of amplitude and phase distributions of the electromagnetic field surrounding the heated target. Then the echo of the standard metal ball at the ambient temperature is obtained through experiments, and the data is used as the calibration. Several temperature points of the target ranging from 30° to 800°C are selected for RCS measure to obtain the standard body RCS data, and get the experiment error less than 0.5 dB based on the temperature dependence of RCS data of 200 mm diameter metal ball. Therefore, RCS data are not sensitive to the temperature below 800°C, so the high temperature performance measure of the stealth targets can be calibrated at ambient temperature, which can obviously improve the efficiency at the high temperature.