IMOS - Satellite Remote Sensing - Surface Waves Sub-Facility - Gridded SAR wind - Delayed mode data

Sentinel-1 A, B and C satellites are part of Europe's Copernicus Earth Observation program and carry identical C-band Synthetic Aperture Radar (SAR) instruments. This dataset contains regularly gridded (0.01 x 0.01 deg) daily 10m neutral stability wind speed and direction derived from Sentinel-1 SARs in the wider Australian nearshore regions. In these regions, the satellites normally operate in interferometric wide (IW) swath mode. The winds are derived using a consistent geophysical model function (gmf), CMOD5N, and variational Bayesian inversion approach as proposed in Portabella et al. (2002) and Sentinel-1 Ocean wind (owi) algorithm definition document. The input SAR and model (ECMWF) data used in the inversion are sourced from owi Level-2 product, and the resulting derived winds are approximately at 1km horizontal spatial resolution as in the source product. Wind speeds are also calibrated against Metop-A and B scatterometer wind database of Ribal and Young, 2020 (JTECH). For each day, all available derived wind field swaths (available as separate wind product: IMOS - Satellite Remote Sensing - Surface Waves Sub-Facility - SAR wind - Delayed mode data) are combined and interpolated to a nominal 0.01 x 0.01-degree regular grid. The final data are thus arranged in a rectilinear grid with dimensions defined by TIME, LATITUDE and LONGITUDE.The data represented by this record, are presented in delayed mode.

Sentinel-1 A、B、C卫星是欧洲哥白尼地球观测计划（Copernicus Earth Observation Program）的组成部分，搭载完全相同的C波段合成孔径雷达（Synthetic Aperture Radar, SAR）载荷。本数据集包含经0.01°×0.01°规则网格化的每日10米高度中性稳定风速与风向数据，其源自澳大利亚近岸广阔区域内的Sentinel-1 SAR观测数据。该区域内的卫星通常采用干涉宽幅（IW）条带模式工作。数据反演采用统一的地球物理模型函数（geophysical model function, GMF）CMOD5N，以及Portabella等（2002）提出的变分贝叶斯反演方法，并结合《Sentinel-1海洋风（owi）算法定义文档》完成。反演所用的SAR与欧洲中期天气预报中心（European Centre for Medium-Range Weather Forecasts, ECMWF）模式数据，均源自owi二级产品；反演得到的风速风向数据的水平空间分辨率约为1km，与源产品保持一致。风速数据还参照Ribal与Young于2020年发表在《Journal of Atmospheric and Oceanic Technology》（简称JTECH）中的Metop-A、B散射计风速数据库完成校准。每日所有可用的反演风场条带数据（以独立风产品形式发布：IMOS - Satellite Remote Sensing - Surface Waves Sub-Facility - SAR wind - Delayed mode data）均会被合并，并插值至标称0.01°×0.01°的规则网格中。最终数据以由时间、纬度、经度定义的直角坐标网格形式组织。本记录所表征的数据采用延迟模式发布。