kasacrppi (a1)

The Ka-Band Scanning ARM Cloud Radar (KASACR) records cloud properties. ARM's scanning cloud radars are dual-frequency, dual-polarization Doppler radars mounted on a common scanning pedestal. Each pedestal includes a Ka-band radar (2kW peak power) and the deployment location determines whether the second radar is a W-band (1.7 kW peak power) or an X-band (20 kW peak power). Beamwidths for Ka-bands paired with W-bands are roughly matched at 0.3 degrees. The X-band beamwidth is approximately 1 degree. Due to the narrow antenna beamwidth, ARM’s scanning cloud radars use scanning strategies unlike typical weather radars. Rather than focusing on plan position indicator, or PPI, scans, the KASACR uses range height indicator, or RHI, scans at numerous azimuths to obtain cloud volume data. Measurements collected with the KASACR are copolar and cross-polar radar reflectivity, Doppler velocity, spectra width and spectra when not scanning, and linear depolarization ratio. KASACR data from the 2018–2019 Cloud, Aerosol, and Complex Terrain Interactions (CACTI) field campaign in Argentina are now available as b1-level products. Building on the original CACTI operational data, the b1-level products feature improved data quality resulting from extensive analyses and corrections. The data are cross-calibrated to a common point, datastreams are corrected for operational issues that occurred during the campaign, and several data quality masks and basic derived products are incorporated. For more information, read the CACTI radar b1-level processing report.

Ka波段扫描式ARM云雷达（Ka-Band Scanning ARM Cloud Radar，KASACR）用于记录云属性参数。ARM旗下的扫描式云雷达均为搭载于统一扫描转台的双频双极化多普勒雷达，每套转台均配备一台Ka波段雷达（峰值功率2千瓦），且根据部署位置的不同，第二台雷达可选配W波段（峰值功率1.7千瓦）或X波段雷达（峰值功率20千瓦）。与W波段配对的Ka波段波束宽度均约为0.3度，二者波束宽度基本匹配；X波段波束宽度则约为1度。鉴于天线波束宽度较窄，ARM扫描式云雷达采用的扫描策略与常规气象雷达存在显著差异。KASACR并未侧重平面位置显示器（Plan Position Indicator，PPI）扫描模式，而是在多个方位角上执行距离高度显示器（Range Height Indicator，RHI）扫描，以此获取云体三维数据。该雷达采集的测量参数包括同极化与交叉极化雷达反射率、多普勒速度、谱宽，以及非扫描模式下的频谱与线性退极化比。目前，2018-2019年在阿根廷开展的云、气溶胶与复杂地形相互作用（Cloud, Aerosol, and Complex Terrain Interactions，CACTI）外场试验所获取的KASACR数据，已以b1级产品形式对外发布。该b1级产品基于原始CACTI业务数据构建，通过全面的分析与校正实现了数据质量的提升：将所有数据交叉定标至统一基准点，对试验期间出现的各类业务问题对应的数据流进行校正，并整合了多套数据质量掩码与基础衍生产品。如需获取更多详细信息，请参阅《CACTI雷达b1级处理报告》。