Sentinel-2 Surface Reflectance Analysis Ready Data 2020-Q4

Data for 2020-Q4
This dataset is the Sentinel-2 Surface Reflectance Analysis Ready Data (ARD) archive for Switzerland, generated sen2cor 2.5 (http://step.esa.int/main/third-party-plugins-2/sen2cor/).

Detailed description about the Sentinel-2 A & B missions can be found in the CEOS Earth Observation Handbook:
http://database.eohandbook.com/database/missionsummary.aspx?missionID=552
http://database.eohandbook.com/database/missionsummary.aspx?missionID=553

Sentinel-2 (S2) is a constellation of two sun-synchronous satellites operated by ESA respectively from 2015 to 2022 (Sentinel-2A) and 2017-2024 (Sentinel-2B). Switzerland is covered by twelve Sentinel-2 scenes (ID: 31TGM, 31TGN, 32TLR, 32TLS, 32TLT, 32TMR, 32TMS, 32TMT, 32TNS, 32TNT, 32TPS, 32TPT). This corresponds to a spatial extent of latitude 45.0 to 47.9N, longitude 5.5 to 11.8E. Data are downloaded as L1C products corresponding to 100x100km2 geometrically corrected Top Of the Atmosphere (TOA) tiles.It supports land monitoring related services, including generation of generic land cover maps, risk mapping and fast images for disaster relief, generation of leaf coverage leaf chlorophyll content and leaf water content42,43. Both satellites carry the MultiSpectral Instrument (MSI).

Sentinel-2 processed to level 2A with Sen2Cor comes with a scene classification (similar to the pixel_qa band provided by USGS for Landsat data) with 12 classes as described at: https://earth.esa.int/web/sentinel/technical-guides/sentinel-2-msi/level-2a/algorithm. It helps identifying pixels that are saturated or defective as well as cloud and cloud shadows that may affect the quality of the images. In addition, ESA provides a monthly status of the quality of Sentinel-2 data through Data Quality Reports (DQR). These reports document geometric and radiometric performances against initial sensor specifications together with observed anomalies and issues. DQR are available at: https://sentinels.copernicus.eu/web/sentinel/data-product-quality-reports.

2020年第四季度数据集
本数据集为瑞士区域的Sentinel-2地表反射率分析就绪数据（Analysis Ready Data, ARD）存档文件，由sen2cor 2.5版本生成（生成工具地址：http://step.esa.int/main/third-party-plugins-2/sen2cor/）。

关于Sentinel-2A与Sentinel-2B任务的详细说明可参阅CEOS地球观测手册：
http://database.eohandbook.com/database/missionsummary.aspx?missionID=552
http://database.eohandbook.com/database/missionsummary.aspx?missionID=553

Sentinel-2（简称S2）是由欧洲空间局（ESA）运营的两颗太阳同步卫星组成的星座，其中Sentinel-2A的运营时段为2015年至2022年，Sentinel-2B为2017年至2024年。瑞士全境覆盖12景Sentinel-2影像幅宽（影像ID：31TGM、31TGN、32TLR、32TLS、32TLT、32TMR、32TMS、32TMT、32TNS、32TNT、32TPS、32TPT），对应的空间范围为北纬45.0°至47.9°、东经5.5°至11.8°。本数据集以L1C产品形式下载，其对应100km×100km的经几何校正的大气顶层（Top Of the Atmosphere, TOA）瓦片。该数据集可支撑各类土地监测相关服务，包括通用土地覆盖图生成、风险制图与灾害救援快速影像生成，以及叶面积覆盖度、叶片叶绿素含量与叶片水分含量的反演[42,43]。两颗卫星均搭载多光谱仪器（MultiSpectral Instrument, MSI）。

通过Sen2Cor处理至2A级的Sentinel-2数据附带场景分类图层（与美国地质调查局USGS为Landsat数据提供的pixel_qa波段类似），共包含12类像元类别，详细分类规则可参阅：https://earth.esa.int/web/sentinel/technical-guides/sentinel-2-msi/level-2a/algorithm。该分类图层可用于识别饱和像元、瑕疵像元，以及可能影响影像质量的云与云阴影像元。此外，欧洲空间局ESA会通过数据质量报告（Data Quality Reports, DQR）按月发布Sentinel-2数据的质量状态，此类报告将对照传感器初始规格文档，记录数据的几何与辐射性能表现，同时说明观测到的异常与问题。数据质量报告DQR的获取地址为：https://sentinels.copernicus.eu/web/sentinel/data-product-quality-reports.