RapidScat Level 2B Climate Ocean Wind Vectors in 12.5km Footprints

This dataset contains the RapidScat Level 2B 12.5km Version 1.0 Climate quality ocean surface wind vectors. The Level 2B wind vectors are binned on a 12.5 km Wind Vector Cell (WVC) grid and processed using the using the "full aperture" normalized radar cross-section (NRCS, a.k.a. Sigma-0) from the L1B dataset. RapidScat is a Ku-band dual beam circular rotating scatterometer retaining much of the same hardware and functionality of QuikSCAT, with exception of the antenna sub-system and digital interface to the International Space Station (ISS) Columbus module, which is where RapidScat is mounted. The NASA mission is officially referred to as ISS-RapidScat. Unlike QuikSCAT, ISS-RapidScat is not in sun-synchronous orbit, and flies at roughly half the altitude with a low inclination angle that restricts data coverage to the tropics and mid-latitude regions; the extent of latitudinal coverage stretches from approximately 61 degrees North to 61 degrees South. Furthermore, there is no consistent local time of day retrieval. This dataset is provided in a netCDF-3 file format that follows the netCDF-4 classic model (i.e., generated by the netCDF-4 API) and made available via Direct Download and OPeNDAP. For data access, please click on the "Data Access" tab above. This climate quality data set differs from the nominal "slice" L2B dataset as follows: 1) it uses full antenna footprint measurements (~20-km) without subdividing by range (~7-km) and 2) the absolute calibration has been modified for the two different low signal-to-noise ratio (SNR) mode data sets: LowSNR1 14 August 2015 to 18 September 2015; LowSNR2 6 October 2015 to 7 February 2016. The above enhancements allow this dataset to provide consistent calibration across all SNR states. Low SNR periods and other key quality control (QC) issues are tracked and kept up-to-date in PO.DAAC Drive at https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/rapidscat/open/L1B/docs/revtime.csv. If you have any questions, please visit our user forums: https://podaac.jpl.nasa.gov/forum/.

本数据集囊括了RapidScat Level 2B版本1.0的12.5公里气候质量海洋表面风速矢量。Level 2B风速矢量以12.5公里风速矢量单元（WVC）网格进行分箱，并利用L1B数据集的“全孔径”归一化雷达截面积（NRCS，亦称Sigma-0）进行处理。RapidScat是一款Ku波段双波束圆形旋转散射计，保留了QuikSCAT的大部分硬件和功能，但天线子系统及与国际空间站（ISS）哥伦布模块的数字接口有所区别，RapidScat即安装于此模块。NASA的这项任务正式命名为ISS-RapidScat。与QuikSCAT不同，ISS-RapidScat不在太阳同步轨道上，其飞行高度约为前者的一半，且倾角较低，限制了数据覆盖范围仅限于热带和中纬度地区；纬度覆盖范围大致从北纬61度延伸至南纬61度。此外，该任务不存在一致的地方时日间检索。本数据集以netCDF-3文件格式提供，遵循netCDF-4经典模型（即由netCDF-4 API生成）并通过直接下载和OPeNDAP方式提供。数据访问请点击上方的“数据访问”标签。此气候质量数据集与常规的“切片”L2B数据集存在以下差异：1）它使用完整的天线足迹测量（约20公里），而不按距离（约7公里）进行细分；2）对两种不同的低信噪比（SNR）模式数据集进行了绝对校准的修改：LowSNR1（2015年8月14日至2015年9月18日）；LowSNR2（2015年10月6日至2016年2月7日）。上述改进使得本数据集能够提供所有SNR状态下的统一校准。低信噪比期间及其他关键质量控制（QC）问题均被追踪并保持最新状态，可在PO.DAAC Drive的https://archive.podaac.earthdata.nasa.gov/podaac-ops-cumulus-docs/rapidscat/open/L1B/docs/revtime.csv中查找到。如有任何疑问，请访问我们的用户论坛：https://podaac.jpl.nasa.gov/forum/。