国产MWP967KV型地基微波辐射计探测精度

MWP967KV型地基微波辐射计是我国自主研发，拥有完整自主知识产权的新型大气微波遥感探测设备，为了实现国产设备在气象业务中的应用，需对设备的探测精度进行对比分析。利用2015年8月—2018年3月四川盆地南部山区的无线电探空数据和地基微波辐射计数据，分析晴空和有云天气条件下温度廓线、相对湿度廓线和水汽密度廓线及相关物理参数的精度。结果表明：晴空、层积云和高积云的微波辐射计与探空仪的温度、水汽密度和相对湿度相关系数整体上分别在0.9890，0.9665，0.5868以上，均达到0.01显著性水平。3种参数廓线的相关系数整体均呈地面大于高空，仅温度廓线相关系数达到0.01显著性水平，相对湿度廓线和水汽密度廓线在高空的相关系数未达到0.01显著性水平。3种参数的相关性整体上温度最高，水汽密度次之，相对湿度最低。温度、相对湿度和水汽密度的均方根误差平均值分别为2.8℃，22%和1.38 g·m-3，温度廓线和相对湿度廓线在层积云和高积云的云中及云上的精度明显降低，均方根误差较云层下温度升高1℃~2℃，相对湿度增大10%~20%。逆温层会影响廓线及物理参数的精度。晴天或云天等大范围相似天气条件下，探空气球飘移距离与温度廓线、相对湿度廓线和水汽密度廓线偏差的相关性较弱。

The Observational Precision of Domestic MWP967KV Ground-based Microwave Radiometer

MWP967KV ground-based microwave radiometer is an atmospheric microwave remote sensing equipment, which is jointly developed by institutes and universities in China with complete independent intellectual property rights. The microwave profiler includes 21 K-band (22-30 GHz) and 14 V-band (51-59 GHz) microwave channels. The radiometer receives radiation emitted by atmospheric oxygen, water vapor molecules and liquid water in multiple channels. The microwave, infrared and surface meteorological observations are automatically converted into continuous temperature, humidity and liquid profiles using radiative transfer equations and neural networks.In order to apply ground-based microwave radiometer MWP967KV in meteorological services, it is necessary to make comparative test analysis on its detection accuracy. The comparative test is carried out in the southern mountainous area of the Sichuan Basin from August 2015 to March 2018. The ground-based microwave radiometer MWP967KV is located at Yibin County station (28.7°N, 104.57°E) and radiosonde is located at Yibin Station (28.77°N, 104.6°E). The precision of microwave profilers and physical indexes in clear-sky, stratocumulus-sky and altocumulus-sky are analyzed and evaluated using radiosonde data as reference data and combining with ground precipitation data and cloud amount data.Results show that correlation coefficients of temperature, vapor density and relative humidity between radiometer and radiosonde in clear-sky, stratocumulus-sky and altocumulus-sky are 0.9890, 0.9665 and 0.5868, respectively, all passing 0.01 significant test. The correlation is more significant at the bottom than that in the upper air.The detection precision of temperature and relative humidity profile is obviously higher below clouds. The maximum deviation of water vapor density is on the ground and the deviation above 5 km height is close to 0.The fitted temperature profile is good, especially for high temperature. The fitted vapor density profile is also good, especially for low vapor density. However, the fitted relative humidity profile is not satisfying. For samples without temperature inversion layer, the precision of microwave profilers is higher and physical indexes are more accurate.There is no significant difference in correlation coefficient of the balloon drift distance to the deviation between radiometer and radiosonde for temperature, relative humidity and vapor density profiles under a wide range similar weather background, such as clear-sky and cloudy-sky.