OLCI/Sentinel-3A L1 Full Resolution Top of Atmosphere Reflectance

The OLCI/Sentinel-3A L1 Full Resolution Top of Atmosphere Reflectance product, S3A_OL_1_EFR is generated from the data aquired by the Ocean and Land Colour Instrument (OLCI) on board European Earth Observation satellite mission, SENTINEL-3. The OLCI is a push-broom imaging spectrometer that measures solar radiation reflected by the Earth at a ground spatial resolution of around 300m, over all surfaces, in 21 spectral bands. OLCI is based on the imaging design of ENVISAT's Medium Resolution Imaging Spectrometer (MERIS). It has a 1270km wide swath.

For more information about the instrument and the mission, visit "Sentinel Online" at https://sentinel.esa.int/web/sentinel/home.

The S3A_OL_1_EFR is a Level-1B product. This is composed of an information package map, called a manifest, 22 measurement data files, and seven annotation data files. The 21 measurement data files (one for each band) consist of Top Of Atmosphere (TOA) radiances, calibrated to geophysical units (W.m-2. sr-1 Micro meter-1), georeferenced onto the Earth's surface, and spatially resampled onto an evenly spaced grid. Seven annotation files provide information on illumination and observation geometry, environment data (meteorological data) and quality and classification flags. Both measurement data files and annotation data files are written in netCDF 4 format. The manifest file is in XML format and contains metadata associated with the instrument and the processing. The S3A_OL_1_EFR is generated in Earth Observation (EO) processing mode and all parameters in this product are provided for each re-gridded pixel on the product image and for each removed pixel.

The OL_1_EFR product package is described below:

Element name Description
Manifest.safe SENTINEL-SAFE product manifest
Oa##_radiance.nc Radiance for OLCI acquisition bands 01 to 21
Removed_pixels.nc Removed pixels information needed for Level-1C generation
Time_coordinates.nc Time stamp annotations
Geo_coordinates.nc High resolution georeferencing data
Quality_flags.nc Classification and quality flags
Tie_geo_coordinates.nc Low resolution georeferencing data
Tie_geometries.nc Sun and view angles
Tie_meteo.nc ECMWF meteorology data
Instrument_data.nc Instrument data

note: Oa## represents all the OLCI channels (Oa1 to Oa21).

For more information about the product, read the SENTINEL-3 OLCI User Guide at https://sentinel.esa.int/web/sentinel/user-guides/sentinel-3-olci.

S3A_OL_1_EFR（海洋与陆地色彩仪器（OLCI）在欧空局地球观测卫星任务 SENTINEL-3上获取的数据生成的全分辨率大气顶反射率产品）是一项基于欧空局ENVISAT中分辨率成像光谱仪（MERIS）成像设计的推帚式成像光谱仪。该仪器测量地球表面在约300米地面空间分辨率下，由21个光谱带反射的太阳辐射，涵盖所有表面。该产品是以地球观测（EO）处理模式生成的，其中所有参数均针对产品图像上的每个重采样的像素以及每个移除的像素提供。S3A_OL_1_EFR是一级B产品，由信息包地图（称为清单）、22个测量数据文件和7个注释数据文件组成。21个测量数据文件（每个波段一个）包含大气顶（TOA）辐射亮度，校准至地球物理单位（W.m-2. sr-1 微米-1），地理参考至地球表面，并在均匀分布的网格上空间重采样。7个注释文件提供关于照明和观测几何形状、环境数据（气象数据）以及质量和分类标志的信息。测量数据文件和注释数据文件均采用netCDF 4格式编写，清单文件采用XML格式，包含与仪器和加工相关的元数据。关于该产品的更多信息，请参阅https://sentinel.esa.int/web/sentinel/user-guides/sentinel-3-olci上的 SENTINEL-3 OLCI用户指南。