X-Band Scanning ARM Precipitation Radar (XSAPR); Vertically-Pointing Scan - xsaprcfrvpt

The X-band Scanning ARM Precipitation Radar (X-SAPR) is an X-band dual-polarization Doppler weather radar. The X-SAPR operates in a simultaneous transmit and receive (STAR) mode, meaning that the transmit signal is split so that power is transmitted on both horizontal and vertical polarizations at the same time. The X-SAPR transmitter is a 200 kW (peak power) magnetron. The receiver is based upon the Vaisala RVP-900 and runs Vaisala s IRIS software. \n \nIn addition to the first three Doppler moments (reflectivity, radial velocity, and spectra width), the X-SAPR also provides differential reflectivity, correlation coefficient, and specific differential phases. The dual-polarization variables enable estimates of rainfall rates and identification of precipitation types. At the Southern Great Plains site, three X-SAPRs surround the Central Facility, allowing the use of multi-Doppler velocity retrievals to estimate wind fields.

X波段扫描式ARM降水雷达（X-band Scanning ARM Precipitation Radar，X-SAPR）是一款X波段双偏振多普勒天气雷达。该雷达采用同时收发（simultaneous transmit and receive，STAR）模式，其工作原理为通过拆分发射信号，实现水平与垂直偏振方向的同步功率发射。X-SAPR的发射机为峰值功率200千瓦的磁控管（magnetron），其接收机基于维萨拉RVP-900平台开发，并搭载维萨拉IRIS软件。

除前三项多普勒矩量（反射率、径向速度与谱宽）外，X-SAPR还可提供差分反射率、相关系数以及比差分相位（specific differential phases）。双偏振参量可用于降雨率估算与降水类型识别。在南部大平原观测场，三台X-SAPR环绕中央设施部署，可通过多多普勒速度反演实现风场估算。