Google Earth Engine ——数据全解析专辑（COPERNICUS/S2_SR）20154至今哨兵-2号(SR) 数据集

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发布于 2024-02-02 09:03:33

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发布于 2024-02-02 09:03:33

Sentinel-2 is a wide-swath, high-resolution, multi-spectral imaging mission supporting Copernicus Land Monitoring studies, including the monitoring of vegetation, soil and water cover, as well as observation of inland waterways and coastal areas.

The Sentinel-2 L2 data are downloaded from scihub. They were computed by running sen2cor. WARNING: ESA did not produce L2 data for all L1 assets, and earlier L2 coverage is not global.

The assets contain 12 UINT16 spectral bands representing SR scaled by 10000 (unlike in L1 data, there is no B10). There are also several more L2-specific bands (see band list for details). See the Sentinel-2 User Handbook for details. In addition, three QA bands are present where one (QA60) is a bitmask band with cloud mask information. For more details, see the full explanation of how cloud masks are computed.

EE asset ids for Sentinel-2 L2 assets have the following format: COPERNICUS/S2_SR/20151128T002653_20151128T102149_T56MNN. Here the first numeric part represents the sensing date and time, the second numeric part represents the product generation date and time, and the final 6-character string is a unique granule identifier indicating its UTM grid reference (see MGRS).

Clouds can be removed by using COPERNICUS/S2_CLOUD_PROBABILITY. See this tutorial explaining how to apply the cloud mask.

For more details on Sentinel-2 radiometric resolution, see this page.

Sentinel-2 是一个宽幅、高分辨率、多光谱成像任务，支持哥白尼土地监测研究，包括监测植被、土壤和水覆盖，以及观察内陆水道和沿海地区。

Sentinel-2 L2 数据从 scihub 下载。它们是通过运行 sen2cor 来计算的。警告：ESA 没有为所有 L1 资产生成 L2 数据，早期的 L2 覆盖范围不是全球性的。

资产包含 12 个 UINT16 光谱带，代表按 10000 缩放的 SR（与 L1 数据不同，没有 B10）。还有几个特定于 L2 的频段（有关详细信息，请参阅频段列表）。有关详细信息，请参阅 Sentinel-2 用户手册。此外，存在三个 QA 带，其中一个 (QA60) 是具有云掩码信息的位掩码带。有关更多详细信息，请参阅有关如何计算云掩码的完整说明。

Sentinel-2 L2 资产的 EE 资产 ID 具有以下格式：COPERNICUS/S2_SR/20151128T002653_20151128T102149_T56MNN。这里的第一个数字部分表示感应日期和时间，第二个数字部分表示产品生成日期和时间，最后的 6 个字符串是一个唯一的颗粒标识符，表示其 UTM 网格参考（参见 MGRS）。

可以使用 COPERNICUS/S2_CLOUD_PROBABILITY 去除云。请参阅本教程，解释如何应用云遮罩。

有关 Sentinel-2 辐射分辨率的更多详细信息，请参阅此页面。

Dataset Availability

2017-03-28T00:00:00 - 2021-09-04T00:00:00

Dataset Provider

European Union/ESA/Copernicus

Collection Snippet

ee.ImageCollection("COPERNICUS/S2_SR")

Bands Table

Name	Description	Min	Max	Resolution	Units	Wavelength	Scale
B1	Aerosols			60 meters		443.9nm (S2A) / 442.3nm (S2B)	0.0001
B2	Blue			10 meters		496.6nm (S2A) / 492.1nm (S2B)	0.0001
B3	Green			10 meters		560nm (S2A) / 559nm (S2B)	0.0001
B4	Red			10 meters		664.5nm (S2A) / 665nm (S2B)	0.0001
B5	Red Edge 1			20 meters		703.9nm (S2A) / 703.8nm (S2B)	0.0001
B6	Red Edge 2			20 meters		740.2nm (S2A) / 739.1nm (S2B)	0.0001
B7	Red Edge 3			20 meters		782.5nm (S2A) / 779.7nm (S2B)	0.0001
B8	NIR			10 meters		835.1nm (S2A) / 833nm (S2B)	0.0001
B8A	Red Edge 4			20 meters		864.8nm (S2A) / 864nm (S2B)	0.0001
B9	Water vapor			60 meters		945nm (S2A) / 943.2nm (S2B)	0.0001
B11	SWIR 1			20 meters		1613.7nm (S2A) / 1610.4nm (S2B)	0.0001
B12	SWIR 2			20 meters		2202.4nm (S2A) / 2185.7nm (S2B)	0.0001
AOT	Aerosol Optical Thickness			10 meters			0.001
WVP	Water Vapor Pressure. The height the water would occupy if the vapor were condensed into liquid and spread evenly across the column.			10 meters	cm		0.001
SCL	Scene Classification Map (The "No Data" value of 0 is masked out)	1	11	20 meters			0
TCI_R	True Color Image, Red channel			10 meters			0
TCI_G	True Color Image, Green channel			10 meters			0
TCI_B	True Color Image, Blue channel			10 meters			0
MSK_CLDPRB	Cloud Probability Map (missing in some products)	0	100	20 meters			0
MSK_SNWPRB	Snow Probability Map (missing in some products)	0	100	10 meters			0
QA10	Always empty			10 meters			0
QA20	Always empty			20 meters			0
QA60	Cloud mask			60 meters			0
QA60 Bitmask	Bit 10: Opaque clouds 0: No opaque clouds1: Opaque clouds presentBit 11: Cirrus clouds 0: No cirrus clouds1: Cirrus clouds present

Bit 10: Opaque clouds
- 0: No opaque clouds
- 1: Opaque clouds present
Bit 11: Cirrus clouds
- 0: No cirrus clouds
- 1: Cirrus clouds present

Class Table: SCL

Value	Color Value	Description
1	#ff0004	Saturated or defective
2	#868686	Dark Area Pixels
3	#774b0a	Cloud Shadows
4	#10d22c	Vegetation
5	#ffff52	Bare Soils
6	#0000ff	Water
7	#818181	Clouds Low Probability / Unclassified
8	#c0c0c0	Clouds Medium Probability
9	#f1f1f1	Clouds High Probability
10	#bac5eb	Cirrus
11	#52fff9	Snow / Ice

影像属性：

Name	Type	Description
AOT_RETRIEVAL_ACCURACY	Double	Accuracy of Aerosol Optical thickness model
CLOUDY_PIXEL_PERCENTAGE	Double	Granule-specific cloudy pixel percentage taken from the original metadata
CLOUD_COVERAGE_ASSESSMENT	Double	Cloudy pixel percentage for the whole archive that contains this granule. Taken from the original metadata
CLOUDY_SHADOW_PERCENTAGE	Double	Percentage of pixels classified as cloud shadow
DARK_FEATURES_PERCENTAGE	Double	Percentage of pixels classified as dark features or shadows
DATASTRIP_ID	String	Unique identifier of the datastrip Product Data Item (PDI)
DATATAKE_IDENTIFIER	String	Uniquely identifies a given Datatake. The ID contains the Sentinel-2 satellite, start date and time, absolute orbit number, and processing baseline.
DATATAKE_TYPE	String	MSI operation mode
DEGRADED_MSI_DATA_PERCENTAGE	Double	Percentage of degraded MSI and ancillary data
FORMAT_CORRECTNESS	String	Synthesis of the On-Line Quality Control (OLQC) checks performed at granule (Product_Syntax) and datastrip (Product Syntax and DS_Consistency) levels
GENERAL_QUALITY	String	Synthesis of the OLQC checks performed at the datastrip level (Relative_Orbit_Number)
GENERATION_TIME	Double	Product generation time
GEOMETRIC_QUALITY	String	Synthesis of the OLQC checks performed at the datastrip level (Attitude_Quality_Indicator)
GRANULE_ID	String	Unique identifier of the granule PDI (PDI_ID)
HIGH_PROBA_CLOUDS_PERCENTAGE	Double	Percentage of pixels classified as high probability clouds
MEAN_INCIDENCE_AZIMUTH_ANGLE_B1	Double	Mean value containing viewing incidence azimuth angle average for band B1 and for all detectors
MEAN_INCIDENCE_AZIMUTH_ANGLE_B2	Double	Mean value containing viewing incidence azimuth angle average for band B2 and for all detectors
MEAN_INCIDENCE_AZIMUTH_ANGLE_B3	Double	Mean value containing viewing incidence azimuth angle average for band B3 and for all detectors
MEAN_INCIDENCE_AZIMUTH_ANGLE_B4	Double	Mean value containing viewing incidence azimuth angle average for band B4 and for all detectors
MEAN_INCIDENCE_AZIMUTH_ANGLE_B5	Double	Mean value containing viewing incidence azimuth angle average for band B5 and for all detectors
MEAN_INCIDENCE_AZIMUTH_ANGLE_B6	Double	Mean value containing viewing incidence azimuth angle average for band B6 and for all detectors
MEAN_INCIDENCE_AZIMUTH_ANGLE_B7	Double	Mean value containing viewing incidence azimuth angle average for band B7 and for all detectors
MEAN_INCIDENCE_AZIMUTH_ANGLE_B8	Double	Mean value containing viewing incidence azimuth angle average for band B8 and for all detectors
MEAN_INCIDENCE_AZIMUTH_ANGLE_B8A	Double	Mean value containing viewing incidence azimuth angle average for band B8a and for all detectors
MEAN_INCIDENCE_AZIMUTH_ANGLE_B9	Double	Mean value containing viewing incidence azimuth angle average for band B9 and for all detectors
MEAN_INCIDENCE_AZIMUTH_ANGLE_B10	Double	Mean value containing viewing incidence azimuth angle average for band B10 and for all detectors
MEAN_INCIDENCE_AZIMUTH_ANGLE_B11	Double	Mean value containing viewing incidence azimuth angle average for band B11 and for all detectors
MEAN_INCIDENCE_AZIMUTH_ANGLE_B12	Double	Mean value containing viewing incidence azimuth angle average for band B12 and for all detectors
MEAN_INCIDENCE_ZENITH_ANGLE_B1	Double	Mean value containing viewing incidence zenith angle average for band B1 and for all detectors
MEAN_INCIDENCE_ZENITH_ANGLE_B2	Double	Mean value containing viewing incidence zenith angle average for band B2 and for all detectors
MEAN_INCIDENCE_ZENITH_ANGLE_B3	Double	Mean value containing viewing incidence zenith angle average for band B3 and for all detectors
MEAN_INCIDENCE_ZENITH_ANGLE_B4	Double	Mean value containing viewing incidence zenith angle average for band B4 and for all detectors
MEAN_INCIDENCE_ZENITH_ANGLE_B5	Double	Mean value containing viewing incidence zenith angle average for band B5 and for all detectors
MEAN_INCIDENCE_ZENITH_ANGLE_B6	Double	Mean value containing viewing incidence zenith angle average for band B6 and for all detectors
MEAN_INCIDENCE_ZENITH_ANGLE_B7	Double	Mean value containing viewing incidence zenith angle average for band B7 and for all detectors
MEAN_INCIDENCE_ZENITH_ANGLE_B8	Double	Mean value containing viewing incidence zenith angle average for band B8 and for all detectors
MEAN_INCIDENCE_ZENITH_ANGLE_B8A	Double	Mean value containing viewing incidence zenith angle average for band B8a and for all detectors
MEAN_INCIDENCE_ZENITH_ANGLE_B9	Double	Mean value containing viewing incidence zenith angle average for band B9 and for all detectors
MEAN_INCIDENCE_ZENITH_ANGLE_B10	Double	Mean value containing viewing incidence zenith angle average for band B10 and for all detectors
MEAN_INCIDENCE_ZENITH_ANGLE_B11	Double	Mean value containing viewing incidence zenith angle average for band B11 and for all detectors
MEAN_INCIDENCE_ZENITH_ANGLE_B12	Double	Mean value containing viewing incidence zenith angle average for band B12 and for all detectors
MEAN_SOLAR_AZIMUTH_ANGLE	Double	Mean value containing sun azimuth angle average for all bands and detectors
MEAN_SOLAR_ZENITH_ANGLE	Double	Mean value containing sun zenith angle average for all bands and detectors
MEDIUM_PROBA_CLOUDS_PERCENTAGE	Double	Percentage of pixels classified as medium probability clouds
MGRS_TILE	String	US-Military Grid Reference System (MGRS) tile
NODATA_PIXEL_PERCENTAGE	Double	Percentage of No Data pixels
NOT_VEGETATED_PERCENTAGE	Double	Percentage of pixels classified as non-vegetated
PROCESSING_BASELINE	String	Configuration baseline used at the time of the product generation in terms of processor software version and major Ground Image Processing Parameters (GIPP) version
PRODUCT_ID	String	The full id of the original Sentinel-2 product
RADIATIVE_TRANSFER_ACCURACY	Double	Accuracy of radiative transfer model
RADIOMETRIC_QUALITY	String	Based on the OLQC reports contained in the Datastrips/QI_DATA with RADIOMETRIC_QUALITY checklist name
REFLECTANCE_CONVERSION_CORRECTION	Double	Earth-Sun distance correction factor
SATURATED_DEFECTIVE_PIXEL_PERCENTAGE	Double	Percentage of saturated or defective pixels
SENSING_ORBIT_DIRECTION	String	Imaging orbit direction
SENSING_ORBIT_NUMBER	Double	Imaging orbit number
SENSOR_QUALITY	String	Synthesis of the OLQC checks performed at granule (Missing_Lines, Corrupted_ISP, and Sensing_Time) and datastrip (Degraded_SAD and Datation_Model) levels
SOLAR_IRRADIANCE_B1	Double	Mean solar exoatmospheric irradiance for band B1
SOLAR_IRRADIANCE_B2	Double	Mean solar exoatmospheric irradiance for band B2
SOLAR_IRRADIANCE_B3	Double	Mean solar exoatmospheric irradiance for band B3
SOLAR_IRRADIANCE_B4	Double	Mean solar exoatmospheric irradiance for band B4
SOLAR_IRRADIANCE_B5	Double	Mean solar exoatmospheric irradiance for band B5
SOLAR_IRRADIANCE_B6	Double	Mean solar exoatmospheric irradiance for band B6
SOLAR_IRRADIANCE_B7	Double	Mean solar exoatmospheric irradiance for band B7
SOLAR_IRRADIANCE_B8	Double	Mean solar exoatmospheric irradiance for band B8
SOLAR_IRRADIANCE_B8A	Double	Mean solar exoatmospheric irradiance for band B8a
SOLAR_IRRADIANCE_B9	Double	Mean solar exoatmospheric irradiance for band B9
SOLAR_IRRADIANCE_B10	Double	Mean solar exoatmospheric irradiance for band B10
SOLAR_IRRADIANCE_B11	Double	Mean solar exoatmospheric irradiance for band B11
SOLAR_IRRADIANCE_B12	Double	Mean solar exoatmospheric irradiance for band B12
SNOW_ICE_PERCENTAGE	Double	Percentage of pixels classified as snow or ice
SPACECRAFT_NAME	String	Sentinel-2 spacecraft name: Sentinel-2A, Sentinel-2B
THIN_CIRRUS_PERCENTAGE	Double	Percentage of pixels classified as thin cirrus clouds
UNCLASSIFIED_PERCENTAGE	Double	Percentage of unclassified pixels
VEGETATION_PERCENTAGE	Double	Percentage of pixels classified as vegetation
WATER_PERCENTAGE	Double	Percentage of pixels classified as water
WATER_VAPOUR_RETRIEVAL_ACCURACY	Double	Declared accuracy of the Water Vapor model

代码：

function maskS2clouds(image) {
  var qa = image.select('QA60');

  // Bits 10 and 11 are clouds and cirrus, respectively.
  var cloudBitMask = 1 << 10;
  var cirrusBitMask = 1 << 11;

  // Both flags should be set to zero, indicating clear conditions.去云操作
  var mask = qa.bitwiseAnd(cloudBitMask).eq(0)
      .and(qa.bitwiseAnd(cirrusBitMask).eq(0));

  return image.updateMask(mask).divide(10000);
}

// Map the function over one year of data and take the median.
// Load Sentinel-2 TOA reflectance data.
var dataset = ee.ImageCollection('COPERNICUS/S2')
                  .filterDate('2018-01-01', '2018-06-30')
                  // Pre-filter to get less cloudy granules.
                  .filter(ee.Filter.lt('CLOUDY_PIXEL_PERCENTAGE', 20))
                  .map(maskS2clouds);

var rgbVis = {
  min: 0.0,
  max: 0.3,
  bands: ['B4', 'B3', 'B2'],
};

Map.setCenter(-9.1695, 38.6917, 12);
Map.addLayer(dataset.median(), rgbVis, 'RGB');

影像：