Abstract:The accuracy of MWR measurements obtained at Baoshan Station of Shanghai from July 2018 to July 2019 are evaluated by comparing brightness temperature of MWR against those calculated from radiosonde soundings at the same site with radiative transfer model. Beyond that, the performances of the MWR calibrations techniques and the effects of radome replacement are estimated. Results show that the observed brightness temperature from MWR agrees well with the simulated ones of radiosonde soundings in clear-sky conditions. The correlation coefficients between two datasets are over 0.96 in all channels, with root mean square errors 0.15-2.68 K. The performances of the V band channels are better than those of K band channels. Moreover, the features of brightness temperature bias vary with channels, including systematic biases, random deviations and biases with significant seasonal variations. The LN2 calibration could significantly reduce the systematic drifts in most of K-band channels. But the brightness temperature from V-band channels do not change obviously after LN2 calibration. By replacing the radome periodically, brightness temperature biases in the rainy conditions might be reduced significantly. And the recovery time of brightness temperature might also be shortened. Results also indicate that the radome made of new material used in this study is more efficient than the original one in reducing the negative impacts of precipitation in MWR accuracy. It works for about 4 months.