RSS SMAP Level 3 Sea Surface Salinity Standard Mapped Image 8-Day Running Mean V6.0 Validated Dataset

The RSS SMAP Level 3 Sea Surface Salinity Standard Mapped Image 8-Day Running Mean V6.0 Validated Dataset produced by the Remote Sensing Systems (RSS) and sponsored by the NASA Ocean Salinity Science Team, is a validated product that provides orbital/swath data on sea surface salinity (SSS) derived from the NASA's Soil Moisture Active Passive (SMAP) mission. The SMAP satellite was launched on 31 January 2015
with a near-polar orbit at an inclination of 98 degrees and an altitude of 685 km. It has an ascending node time of 6 pm and is sun-synchronous. With its 1000km swath, SMAP achieves global coverage in approximately 3 days, but has an exact orbit repeat cycle of 8 days. Malfunction of the SMAP scatterometer on 7 July, 2015, has necessitated the use of collocated wind speed, primarily from WindSat, for the surface roughness correction required for the surface salinity retrieval.
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The major changes in Version 6.0 from Version 5.0 are: (1) Removal of biases during the first few months of the SMAP mission that are related to the operation of the SMAP radar during that time. (2) Mitigation of biases that depend on the SMAP look angle. (3) Mitigation of salty biases at high Northern latitudes. (4) Revised sun-glint flag.
The RSS SMAP 8-Day running mean product is based on SSS averages spanning an 8-day moving time window, it includes data for a range of parameters: derived sea surface salinity (SSS) with SSS-uncertainty, rain filtered SMAP sea surface salinity, collocated wind speed, data and ancillary reference surface salinity data from HYCOM.
Each data file is available in netCDF-4 file format with about 7-day latency (after the end of the averaging period).
Data begins on April 1,2015 and is ongoing. Observations are global in extent with an approximate spatial resolution of 40KM. Note that while a SSS 40KM variable is also included in the product for most open ocean applications, The standard product of the SMAP Version 6.0 release is the smoothed salinity product with a spatial resolution of approximately 70 km.

由遥感系统公司（RSS）生产并由美国国家航空航天局（NASA）海洋盐度科学团队资助的RSS SMAP Level 3 海面盐度标准映射图像8日滚动平均值V6.0验证数据集，是一项经过验证的产品，它提供了由NASA的土壤湿度主动被动（SMAP）任务得出的海面盐度（SSS）的轨道/扫描数据。SMAP卫星于2015年1月31日发射，位于近极地轨道，倾斜角为98度，轨道高度为685公里。其上升节点时间为下午6点，且为太阳同步轨道。SMAP卫星的扫描宽度为1000公里，大约3天内实现全球覆盖，但确切的轨道重复周期为8天。2015年7月7日SMAP散射仪的故障，迫使我们使用来自WindSat的风速数据，以进行表面粗糙度校正，这对于表面盐度恢复至关重要。

版本6.0与版本5.0的主要变化包括：（1）移除了与SMAP雷达在该时期运行相关的偏差；（2）缓解了依赖于SMAP观测角度的偏差；（3）缓解了高纬度地区的盐分偏差；（4）修订了太阳耀斑标志。

RSS SMAP 8日滚动平均值产品基于8日移动时间窗口的海面盐度（SSS）平均值，它包含了一系列参数的数据：衍生的海面盐度（SSS）及其不确定性、雨过滤的SMAP海面盐度、同位风速以及来自HYCOM的辅助参考表面盐度数据。

每个数据文件均以netCDF-4文件格式提供，具有约7天的延迟（在平均值周期结束后）。数据始于2015年4月1日，并持续进行。观测范围全球，空间分辨率约为40公里。请注意，虽然产品中也包含了一个SSS 40公里变量，适用于大多数开阔海域的应用，但SMAP版本6.0发布的标准产品是经过平滑处理的盐度产品，其空间分辨率约为70公里。