轉譯選項組態
此轉譯組態會定義數種方式,以可視化 Explorer 中的 Sentinel-2 衛星影像。 每個項目都會描述不同的風格或科學產品,例如 自然色彩 (您眼睛看到的)、 彩色紅外 (以醒目提示 植被),或標準化差異植被指數(NDVI) (植被健康指數)。
字串 options 會指定如何將資料視覺化:
assets=B04&assets=B03&assets=B02:
這個 assets 參數會告訴系統要用於影像的帶狀帶(衛星數據層)。 例如,B04 是紅色,B03 是綠色,B02 是藍色,它們一起製作真色影像。
nodata=0:
任何值為 0 的像素都會被視為遺漏或透明。
color_formula=Gamma RGB 3.2 Saturation 0.8 Sigmoidal RGB 25 0.35:
此伽瑪調整會套用色彩修正,讓影像看起來更自然或更具視覺吸引力。
-
Gamma 調整亮度
-
飽和度 會變更色彩強度
-
Sigmoidal 調整對比
expression=(B08-B04)/(B08+B04):
對於 NDVI 和 NDWI,這個運算式參數會使用帶狀來計算數學公式,以建立醒目提示植被或水分的新影像。
rescale=-1,1:
這個重新調整參數會延展計算值以符合色階,因此結果很容易解譯。
colormap_name=rdylgn:
此 colormap 參數會將調色盤(紅色-黃色-綠色)套用至結果,讓您更容易看到差異。
[
{
"id": "natural-color",
"name": "Natural color",
"description": "True color composite of visible bands (B04, B03, B02)",
"type": "raster-tile",
"options": "assets=B04&assets=B03&assets=B02&nodata=0&color_formula=Gamma RGB 3.2 Saturation 0.8 Sigmoidal RGB 25 0.35",
"minZoom": 9
},
{
"id": "natural-color-pre-feb-2022",
"name": "Natural color (pre Feb, 2022)",
"description": "Pre-Feb 2022 true color composite of visible bands (B04, B03, B02)",
"type": "raster-tile",
"options": "assets=B04&assets=B03&assets=B02&nodata=0&color_formula=Gamma RGB 3.7 Saturation 1.5 Sigmoidal RGB 15 0.35",
"minZoom": 9
},
{
"id": "color-infrared",
"name": "Color infrared",
"description": "Highlights healthy (red) and unhealthy (blue/gray) vegetation (B08, B04, B03).",
"type": "raster-tile",
"options": "assets=B08&assets=B04&assets=B03&nodata=0&color_formula=Gamma RGB 3.7 Saturation 1.5 Sigmoidal RGB 15 0.35",
"minZoom": 9
},
{
"id": "short-wave-infrared",
"name": "Short wave infrared",
"description": "Darker shades of green indicate denser vegetation. Brown is indicative of bare soil and built-up areas (B12, B8A, B04).",
"type": "raster-tile",
"options": "assets=B12&assets=B8A&assets=B04&nodata=0&color_formula=Gamma RGB 3.7 Saturation 1.5 Sigmoidal RGB 15 0.35",
"minZoom": 9
},
{
"id": "agriculture",
"name": "Agriculture",
"description": "Darker shades of green indicate denser vegetation (B11, B08, B02).",
"type": "raster-tile",
"options": "assets=B11&assets=B08&assets=B02&nodata=0&color_formula=Gamma RGB 3.7 Saturation 1.5 Sigmoidal RGB 15 0.35",
"minZoom": 9
},
{
"id": "normalized-difference-veg-inde",
"name": "Normalized Difference Veg. Index (NDVI)",
"description": "Normalized Difference Vegetation Index (B08-B04)/(B08+B04), darker green indicates healthier vegetation.",
"type": "raster-tile",
"options": "nodata=0&expression=(B08-B04)/(B08+B04)&rescale=-1,1&colormap_name=rdylgn&asset_as_band=true",
"minZoom": 9
},
{
"id": "moisture-index-ndwi",
"name": "Moisture Index (NDWI)",
"description": "Index indicating water stress in plants (B8A-B11)/(B8A+B11)",
"type": "raster-tile",
"options": "nodata=0&expression=(B8A-B11)/(B8A+B11)&rescale=-1,1&colormap_name=rdbu&asset_as_band=true",
"minZoom": 9
},
{
"id": "atmospheric-penetration",
"name": "Atmospheric penetration",
"description": "False color rendering with non-visible bands to reduce effects of atmospheric particles (B12, B11, B8A).",
"type": "raster-tile",
"options": "nodata=0&assets=B12&assets=B11&assets=B8A&color_formula=Gamma RGB 3.7 Saturation 1.5 Sigmoidal RGB 15 0.35",
"minZoom": 9
}
]
STAC 集合組態
STAC 集合組態會定義這個 Sentinel-2 集合的核心元數據。
STAC 集合 JSON 中的 區 item_assets 段可作為集合中所有可用數據資產的重要目錄。 它會定義每個光譜波段(B01-B12、B8A 等)及其屬性,包括:
- 資產密鑰 (例如轉譯組態所參考的 “B04”、“B03”
- 每個波段的元資料(解析、資料類型、角色)
- 樂隊描述,說明每個樂隊代表的內容(B04 是「紅色」,B08 是「近紅外」)
- 適用於科學應用程式的光譜資訊
轉譯組態會直接參考這些資產索引鍵來建立不同的視覺效果。 例如,當轉譯組態指定 assets=B04&assets=B03&assets=B02時,它會提取item_assets中定義的紅色、綠色和藍色帶,以建立自然色彩影像。
{
"id": "sentinel-2-l2a_Grindavik",
"type": "Collection",
"links": [
{
"rel": "items",
"type": "application/geo+json",
"href": "https://{geocatalog_id}/stac/collections/sentinel-2-l2a_Grindavik/items"
},
{
"rel": "parent",
"type": "application/json",
"href": "https://{geocatalog_id}/stac/"
},
{
"rel": "root",
"type": "application/json",
"href": "https://{geocatalog_id}/stac/"
},
{
"rel": "self",
"type": "application/json",
"href": "https://{geocatalog_id}/stac/collections/sentinel-2-l2a_Grindavik"
},
{
"rel": "license",
"href": "https://scihub.copernicus.eu/twiki/pub/SciHubWebPortal/TermsConditions/Sentinel_Data_Terms_and_Conditions.pdf",
"title": "Copernicus Sentinel data terms"
},
{
"rel": "describedby",
"href": "https://planetarycomputer.microsoft.com/dataset/sentinel-2-l2a",
"type": "text/html",
"title": "Human readable dataset overview and reference"
}
],
"title": "Sentinel-2-l2a",
"assets": {
"thumbnail": {
"href": "https://{storage_account}.blob.core.windows.net/{blob_container}/collection-assets/thumbnail/blob",
"type": "image/png",
"roles": [
"thumbnail"
],
"title": "sentinel-2-l2a_Grindavik thumbnail"
}
},
"extent": {
"spatial": {
"bbox": [
[
-180,
-90,
180,
90
]
]
},
"temporal": {
"interval": [
[
"2015-06-27T10:25:31Z",
null
]
]
}
},
"license": "proprietary",
"keywords": [
"Sentinel",
"Copernicus",
"ESA",
"Satellite",
"Global",
"Imagery",
"Reflectance"
],
"providers": [
{
"url": "https://sentinel.esa.int/web/sentinel/missions/sentinel-2",
"name": "ESA",
"roles": [
"producer",
"licensor"
]
},
{
"url": "https://www.esri.com/",
"name": "Esri",
"roles": [
"processor"
]
},
{
"url": "https://planetarycomputer.microsoft.com",
"name": "Microsoft",
"roles": [
"host",
"processor"
]
}
],
"summaries": {
"gsd": [
10,
20,
60
],
"eo:bands": [
{
"name": "AOT",
"description": "aerosol optical thickness"
},
{
"gsd": 60,
"name": "B01",
"common_name": "coastal",
"description": "coastal aerosol",
"center_wavelength": 0.443,
"full_width_half_max": 0.027
},
{
"gsd": 10,
"name": "B02",
"common_name": "blue",
"description": "visible blue",
"center_wavelength": 0.49,
"full_width_half_max": 0.098
},
{
"gsd": 10,
"name": "B03",
"common_name": "green",
"description": "visible green",
"center_wavelength": 0.56,
"full_width_half_max": 0.045
},
{
"gsd": 10,
"name": "B04",
"common_name": "red",
"description": "visible red",
"center_wavelength": 0.665,
"full_width_half_max": 0.038
},
{
"gsd": 20,
"name": "B05",
"common_name": "rededge",
"description": "vegetation classification red edge",
"center_wavelength": 0.704,
"full_width_half_max": 0.019
},
{
"gsd": 20,
"name": "B06",
"common_name": "rededge",
"description": "vegetation classification red edge",
"center_wavelength": 0.74,
"full_width_half_max": 0.018
},
{
"gsd": 20,
"name": "B07",
"common_name": "rededge",
"description": "vegetation classification red edge",
"center_wavelength": 0.783,
"full_width_half_max": 0.028
},
{
"gsd": 10,
"name": "B08",
"common_name": "nir",
"description": "near infrared",
"center_wavelength": 0.842,
"full_width_half_max": 0.145
},
{
"gsd": 20,
"name": "B8A",
"common_name": "rededge",
"description": "vegetation classification red edge",
"center_wavelength": 0.865,
"full_width_half_max": 0.033
},
{
"gsd": 60,
"name": "B09",
"description": "water vapor",
"center_wavelength": 0.945,
"full_width_half_max": 0.026
},
{
"gsd": 20,
"name": "B11",
"common_name": "swir16",
"description": "short-wave infrared, snow/ice/cloud classification",
"center_wavelength": 1.61,
"full_width_half_max": 0.143
},
{
"gsd": 20,
"name": "B12",
"common_name": "swir22",
"description": "short-wave infrared, snow/ice/cloud classification",
"center_wavelength": 2.19,
"full_width_half_max": 0.242
}
],
"platform": [
"Sentinel-2A",
"Sentinel-2B"
],
"instruments": [
"msi"
],
"constellation": [
"sentinel-2"
],
"view:off_nadir": [
0
]
},
"description": "The [Sentinel-2](https://sentinel.esa.int/web/sentinel/missions/sentinel-2) program provides global imagery in thirteen spectral bands at 10m-60m resolution and a revisit time of approximately five days. This dataset represents the global Sentinel-2 archive, from 2016 to the present, processed to L2A (bottom-of-atmosphere) using [Sen2Cor](https://step.esa.int/main/snap-supported-plugins/sen2cor/) and converted to [cloud-optimized GeoTIFF](https://www.cogeo.org/) format.",
"item_assets": {
"AOT": {
"gsd": 10,
"type": "image/tiff; application=geotiff; profile=cloud-optimized",
"roles": [
"data"
],
"title": "Aerosol optical thickness (AOT)"
},
"B01": {
"gsd": 60,
"type": "image/tiff; application=geotiff; profile=cloud-optimized",
"roles": [
"data"
],
"title": "Band 1 - Coastal aerosol - 60m",
"eo:bands": [
{
"name": "B01",
"common_name": "coastal",
"description": "Band 1 - Coastal aerosol",
"center_wavelength": 0.443,
"full_width_half_max": 0.027
}
]
},
"B02": {
"gsd": 10,
"type": "image/tiff; application=geotiff; profile=cloud-optimized",
"roles": [
"data"
],
"title": "Band 2 - Blue - 10m",
"eo:bands": [
{
"name": "B02",
"common_name": "blue",
"description": "Band 2 - Blue",
"center_wavelength": 0.49,
"full_width_half_max": 0.098
}
]
},
"B03": {
"gsd": 10,
"type": "image/tiff; application=geotiff; profile=cloud-optimized",
"roles": [
"data"
],
"title": "Band 3 - Green - 10m",
"eo:bands": [
{
"name": "B03",
"common_name": "green",
"description": "Band 3 - Green",
"center_wavelength": 0.56,
"full_width_half_max": 0.045
}
]
},
"B04": {
"gsd": 10,
"type": "image/tiff; application=geotiff; profile=cloud-optimized",
"roles": [
"data"
],
"title": "Band 4 - Red - 10m",
"eo:bands": [
{
"name": "B04",
"common_name": "red",
"description": "Band 4 - Red",
"center_wavelength": 0.665,
"full_width_half_max": 0.038
}
]
},
"B05": {
"gsd": 20,
"type": "image/tiff; application=geotiff; profile=cloud-optimized",
"roles": [
"data"
],
"title": "Band 5 - Vegetation red edge 1 - 20m",
"eo:bands": [
{
"name": "B05",
"common_name": "rededge",
"description": "Band 5 - Vegetation red edge 1",
"center_wavelength": 0.704,
"full_width_half_max": 0.019
}
]
},
"B06": {
"gsd": 20,
"type": "image/tiff; application=geotiff; profile=cloud-optimized",
"roles": [
"data"
],
"title": "Band 6 - Vegetation red edge 2 - 20m",
"eo:bands": [
{
"name": "B06",
"common_name": "rededge",
"description": "Band 6 - Vegetation red edge 2",
"center_wavelength": 0.74,
"full_width_half_max": 0.018
}
]
},
"B07": {
"gsd": 20,
"type": "image/tiff; application=geotiff; profile=cloud-optimized",
"roles": [
"data"
],
"title": "Band 7 - Vegetation red edge 3 - 20m",
"eo:bands": [
{
"name": "B07",
"common_name": "rededge",
"description": "Band 7 - Vegetation red edge 3",
"center_wavelength": 0.783,
"full_width_half_max": 0.028
}
]
},
"B08": {
"gsd": 10,
"type": "image/tiff; application=geotiff; profile=cloud-optimized",
"roles": [
"data"
],
"title": "Band 8 - NIR - 10m",
"eo:bands": [
{
"name": "B08",
"common_name": "nir",
"description": "Band 8 - NIR",
"center_wavelength": 0.842,
"full_width_half_max": 0.145
}
]
},
"B09": {
"gsd": 60,
"type": "image/tiff; application=geotiff; profile=cloud-optimized",
"roles": [
"data"
],
"title": "Band 9 - Water vapor - 60m",
"eo:bands": [
{
"name": "B09",
"description": "Band 9 - Water vapor",
"center_wavelength": 0.945,
"full_width_half_max": 0.026
}
]
},
"B11": {
"gsd": 20,
"type": "image/tiff; application=geotiff; profile=cloud-optimized",
"roles": [
"data"
],
"title": "Band 11 - SWIR (1.6) - 20m",
"eo:bands": [
{
"name": "B11",
"common_name": "swir16",
"description": "Band 11 - SWIR (1.6)",
"center_wavelength": 1.61,
"full_width_half_max": 0.143
}
]
},
"B12": {
"gsd": 20,
"type": "image/tiff; application=geotiff; profile=cloud-optimized",
"roles": [
"data"
],
"title": "Band 12 - SWIR (2.2) - 20m",
"eo:bands": [
{
"name": "B12",
"common_name": "swir22",
"description": "Band 12 - SWIR (2.2)",
"center_wavelength": 2.19,
"full_width_half_max": 0.242
}
]
},
"B8A": {
"gsd": 20,
"type": "image/tiff; application=geotiff; profile=cloud-optimized",
"roles": [
"data"
],
"title": "Band 8A - Vegetation red edge 4 - 20m",
"eo:bands": [
{
"name": "B8A",
"common_name": "rededge",
"description": "Band 8A - Vegetation red edge 4",
"center_wavelength": 0.865,
"full_width_half_max": 0.033
}
]
},
"SCL": {
"gsd": 20,
"type": "image/tiff; application=geotiff; profile=cloud-optimized",
"roles": [
"data"
],
"title": "Scene classfication map (SCL)"
},
"WVP": {
"gsd": 10,
"type": "image/tiff; application=geotiff; profile=cloud-optimized",
"roles": [
"data"
],
"title": "Water vapour (WVP)"
},
"visual": {
"gsd": 10,
"type": "image/tiff; application=geotiff; profile=cloud-optimized",
"roles": [
"data"
],
"title": "True color image",
"eo:bands": [
{
"name": "B04",
"common_name": "red",
"description": "Band 4 - Red",
"center_wavelength": 0.665,
"full_width_half_max": 0.038
},
{
"name": "B03",
"common_name": "green",
"description": "Band 3 - Green",
"center_wavelength": 0.56,
"full_width_half_max": 0.045
},
{
"name": "B02",
"common_name": "blue",
"description": "Band 2 - Blue",
"center_wavelength": 0.49,
"full_width_half_max": 0.098
}
]
},
"preview": {
"type": "image/tiff; application=geotiff; profile=cloud-optimized",
"roles": [
"thumbnail"
],
"title": "Thumbnail"
},
"safe-manifest": {
"type": "application/xml",
"roles": [
"metadata"
],
"title": "SAFE manifest"
},
"granule-metadata": {
"type": "application/xml",
"roles": [
"metadata"
],
"title": "Granule metadata"
},
"inspire-metadata": {
"type": "application/xml",
"roles": [
"metadata"
],
"title": "INSPIRE metadata"
},
"product-metadata": {
"type": "application/xml",
"roles": [
"metadata"
],
"title": "Product metadata"
},
"datastrip-metadata": {
"type": "application/xml",
"roles": [
"metadata"
],
"title": "Datastrip metadata"
}
},
"msft:region": "westeurope",
"stac_version": "1.0.0",
"msft:_created": "2024-04-05T19:04:14.168175Z",
"msft:_updated": "2024-08-26T18:24:05.194898Z",
"msft:container": "sentinel2-l2",
"stac_extensions": [
"https://stac-extensions.github.io/item-assets/v1.0.0/schema.json",
"https://stac-extensions.github.io/table/v1.2.0/schema.json"
],
"msft:storage_account": "sentinel2l2a01",
"msft:short_description": "The Sentinel-2 program provides global imagery in thirteen spectral bands at 10m-60m resolution and a revisit time of approximately five days. This dataset contains the global Sentinel-2 archive, from 2016 to the present, processed to L2A (bottom-of-atmosphere)."
}