Collaborative Research: Development of RADAP-II Radar Database for the United States

小行星9419103 拟议工作的主要目标是开发一个雷达数据库，供水文和气象界使用。 这些数据来自国家气象局运行的数字RADAP-II雷达，这些雷达正在逐步淘汰，并被新的NEXRAD技术所取代，并得到降雨网络的补充。 该数据库将包括高质量的基于雷达的降雨量估计，这些降雨量估计是基于由国家气象局（NWS）运营的几台配备RADAP-II数字处理器的WSR-57和WSR-74 S雷达。 该数据库将包括从瞬时到每日累积的时间尺度的降雨量估计，以及4公里乘4公里、15公里乘15公里和50公里乘50公里的空间尺度。 为了从雷达数据获得降雨量估计值，需要若干处理步骤。 首先，将使用修改的高斯分类方法来去除异常传播（AP）回波。 需要进行距离修正以消除由于距离效应而引起的系统误差。 雷达反射率到降雨率（Z-R）转换的基础上雨滴尺寸分布的应用，以实现物理为基础的数据，极坐标到直角坐标的转换进行，然后消除平流的影响。 累积计算和偏差消除完成了估计过程。 最后一步是执行前面步骤的错误传播分析。 该建议计划的工作包括三个主要部分：（1）建立一个质量控制的雷达反射率数据库;（2）根据雷达数据提供降雨量估计;（3）制定不确定性传播程序，并为上述降雨量产品提供误差方差估计。 如果进行雷达-雨量计联合分析，则拟议产品的质量将大大提高。 这是由于各种技术困难以及潜在的雷达校准问题造成的雷达数据的时间覆盖范围存在重大差距。 另一方面，雷达数据将有助于澄清某些质量控制问题的降雨量数据，并在估计的误差结构的降雨量为基础的估计，特别是误差成分，由于一个空闲的空间采样的降雨量网络。 我们的研究的主要产品将是结合雷达和降雨观测的降雨网格分析，辅之以定量评估其不确定性。 该分析将针对阿肯色州河流域进行，特别关注俄克拉荷马州和堪萨斯的ARM/CART实验场地。 该项目的基本要素将是数据分析的概念设计开发，误差传播的模拟研究，以及我们产品的独立交叉验证。

9419103 Krajewski The main goal of the proposed work is to develop a radar database for use by the hydrological and meteorological community. The data are from digital RADAP-II radars operated by the National Weather Service and which are being phased out and replaced by the new NEXRAD technology, complemented by the raingage networks. The database will consist of high quality radar-based rainfall estimates based on several WSR-57 and WSR-74S radars equipped with RADAP-II digital processors, operated by the National Weather Service (NWS). The data base will include rainfall estimates at temporal scale that range from instantaneous to daily accumulations, and a spatial scales of 4 km by 4 km, 15 km by 15 km, and 50 by 50 km. In order to obtain rainfall estimates from radar data, several processing steps are required. First, removal of anomalous propagation (AP) echoes will be done with a modified Gaussian classification approach. Range correction is required to remove systematic errors due to range effects. Radar reflectivity to rainfall rate (Z-R) conversion based on raindrop size distributions is applied to achieve physically-based data, and polar to rectangular coordinate conversion is carried out followed by removal of advection effects. Accumulation calculations and bias removal complete the estimation procedure. The final step is to perform an error propagation analysis of the preceding steps. The work planned under the proposal includes three main elements: (1) development of a quality-controlled radar reflectivity database; (2) providing estimates of rainfall based on the radar data; and (3) developing procedures for uncertainly propagation and providing estimates of error variance for the above rainfall products. The quality of the proposed products would be greatly enhanced if a combined radar-raingage analysis was conducted. This is due to significant gaps in the temporal coverage by the radar data caused by various technical difficulties as well as the potential rad ar calibration problems. On the other hand, the radar data will be helpful in clarifying certain quality control problems in the raingage data, and in estimating the error structure of the raingage-based estimates, particularly the error component due to a spare spatial sampling by the raingage network. The main product of our research will be grided analysis of rainfall based on combined radar and raingage observations, complemented by a quantitative assessment of its uncertainty. This analysis will be performed for the Arkansas River Basin with a particular focus on the ARM/CART experimental site in Oklahoma and Kansas. Essential elements of the project will be development of conceptual design for data analysis, simulation studies of error propagation, and independent cross-validation of our products.