Mozaika obrazów Landsat Antarktydy (LIMA) to spójna mozaika praktycznie bez chmur, utworzona z przetworzonych scen Landsat 7 ETM+.
Przetworzone sceny Landsat (16-bitowe) to sceny poziomu 1Gt NLAPS przekonwertowane na 16-bitowe, przetworzone z korekcją kąta padania promieni słonecznych i przekonwertowane na wartości odbicia (Bindschadler 2008).
Każda scena Landsat jest przetwarzana z użyciem danych o wysokości i korekty kąta padania promieni słonecznych, aby zapewnić dokładne odwzorowanie elementów powierzchni. Kąt padania promieni słonecznych na Antarktydzie sprawia, że słońce wygląda jak zachodzące. Ze względu na niski kąt padania promieni słonecznych, gdy Landsat przelatuje nad Antarktydą, zewnętrzne krawędzie kontynentu wydają się jaśniejsze niż obszary bliżej bieguna południowego, więc sceny mają jasne i ciemne obszary.
Niespójne kąty padania promieni słonecznych i cienie, które zostały skorygowane w tych scenach. Bez tego procesu mozaikowanie dałoby efekt patchworku scen, ponieważ każda scena miałaby jaśniejszą i ciemniejszą stronę.
Jest to tabela zawierająca metadane kolekcji obrazów USGS/LIMA/SR.
Schemat tabeli
Schemat tabeli
Nazwa
Typ
Opis
ACQ_DATE
CIĄG ZNAKÓW
Data zakupu w formacie RRRR-MM-DD
PATH
PRZ
Ścieżka WRS
POLY_ID
PRZ
Unikalny identyfikator przypisany do wielokąta
Pozostałe kraje
PRZ
Wiersz WRS
SCENE_ID
CIĄG ZNAKÓW
Identyfikator sceny
SENSOR
CIĄG ZNAKÓW
Czujnik
SPACJA
CIĄG ZNAKÓW
Nazwa satelity użytego do zbierania danych
Warunki korzystania z usługi
Warunki korzystania z usługi
Te obrazy należą do domeny publicznej i można ich używać bezpłatnie i bez podawania źródła. Jednak doceniamy podanie informacji o projekcie Landsat Image Mosaic of Antarctica (LIMA).
Cytaty
Cytowania:
Bindschadler, R., Vornberger, P., Fleming, A., Fox, A., Mullins, J.,
Binnie, D., Paulson, S., Granneman, B., and Gorodetzky, D., 2008,
The Landsat Image Mosaic of Antarctica, Remote Sensing of
Environment, 112, pp. 4214-4226.
PDF
Mozaika obrazów Antarktydy z satelity Landsat (LIMA) to spójna i praktycznie bezchmurna mozaika utworzona z przetworzonych zdjęć z satelity Landsat 7 ETM+. Przetworzone sceny Landsat (16-bitowe) to sceny NLAPS na poziomie 1Gt przekonwertowane na 16-bitowe, przetworzone z korekcją kąta padania promieni słonecznych i przekonwertowane na wartości odbicia (Bindschadler 2008). Każda scena Landsat to…
[null,null,[],[[["\u003cp\u003eUSGS LIMA is a cloud-free Landsat 7 ETM+ mosaic of Antarctica, created from scenes processed to reflectance values with sun-angle correction.\u003c/p\u003e\n"],["\u003cp\u003eThis dataset provides a table containing metadata for the USGS/LIMA/SR Image Collection, including acquisition date, sensor, and scene ID.\u003c/p\u003e\n"],["\u003cp\u003eLIMA data covers the period from June 30, 1999, to September 4, 2002, and is freely available for use without acknowledgment.\u003c/p\u003e\n"],["\u003cp\u003eEach Landsat scene in the mosaic was individually processed using elevation data and sun-angle correction to ensure accurate representation of surface features.\u003c/p\u003e\n"],["\u003cp\u003eThe metadata table schema includes fields such as acquisition date, WRS path/row, polygon ID, scene ID, sensor, and satellite name.\u003c/p\u003e\n"]]],["The Landsat Image Mosaic of Antarctica (LIMA), provided by USGS, is a cloudless mosaic from processed Landsat 7 ETM+ scenes. Data, available from 1999-06-30 to 2002-09-04, are level 1Gt NLAPS scenes converted to 16-bit reflectance values with sun-angle correction. Metadata for the collection can be accessed via `ee.FeatureCollection(\"USGS/LIMA/SR_METADATA\")` in Earth Engine, providing acquisition date, path, row, scene ID, sensor, and satellite information. These images are public domain.\n"],null,["# Landsat Image Mosaic of Antarctica (LIMA) - Processed Landsat Scenes (16 bit) Metadata\n\nDataset Availability\n: 1999-06-30T00:00:00Z--2002-09-04T00:00:00Z\n\nDataset Provider\n:\n\n\n [USGS](https://lima.usgs.gov/index.php)\n\nTags\n:\n[antarctica](/earth-engine/datasets/tags/antarctica) [ice](/earth-engine/datasets/tags/ice) [landsat-derived](/earth-engine/datasets/tags/landsat-derived) [lima](/earth-engine/datasets/tags/lima) [mosaic](/earth-engine/datasets/tags/mosaic) [satellite-imagery](/earth-engine/datasets/tags/satellite-imagery) [sr](/earth-engine/datasets/tags/sr) [table](/earth-engine/datasets/tags/table) [usgs](/earth-engine/datasets/tags/usgs) \n\n#### Description\n\nThe Landsat Image Mosaic of Antarctica (LIMA) is a seamless\nand virtually cloudless mosaic created from processed\nLandsat 7 ETM+ scenes.\n\nProcessed Landsat Scenes (16 bit) are Level 1Gt NLAPS\nscenes converted to 16 bit, processed with sun-angle\ncorrection, and converted to reflectance values\n([Bindschadler 2008](https://lima.usgs.gov/LIMA_paper.pdf)).\n\nEach Landsat scene is processed with elevation\ndata and sun-angle correction to ensure surface features\nwere accurately represented. The sun's angle in Antarctica\ngives the appearance of a setting sun. Because of the low\nsun angle, as Landsat passes over Antarctica, the outer\nedges of the continent appear brighter than areas closer\nto the South Pole, so scenes have bright and dark areas.\nInconsistent sun angles and shadows where corrected for\nthese scenes. Without this process, mosaicking would produce\na patchwork of scenes since each scene would have a brighter\nand a darker side.\n\nThis is a table which contains metadata for the Image Collection\n[USGS/LIMA/SR](/earth-engine/datasets/catalog/USGS_LIMA_SR)\n\n### Table Schema\n\n**Table Schema**\n\n| Name | Type | Description |\n|----------|--------|-------------------------------------------|\n| ACQ_DATE | STRING | Acquisition date in YYYY-MM-DD format |\n| PATH | INT | WRS path |\n| POLY_ID | INT | Unique ID assigned to a polygon |\n| ROW | INT | WRS row |\n| SCENE_ID | STRING | Scene ID |\n| SENSOR | STRING | Sensor |\n| SPACE | STRING | Name of the satellite used to gather data |\n\n### Terms of Use\n\n**Terms of Use**\n\nThese images are in the public domain and can be used freely\nand without acknowledgement. However, credit to the Landsat\nImage Mosaic of Antarctica (LIMA) Project is greatly appreciated.\n\n### Citations\n\nCitations:\n\n- Bindschadler, R., Vornberger, P., Fleming, A., Fox, A., Mullins, J.,\n Binnie, D., Paulson, S., Granneman, B., and Gorodetzky, D., 2008,\n The Landsat Image Mosaic of Antarctica, Remote Sensing of\n Environment, 112, pp. 4214-4226.\n [PDF](https://lima.usgs.gov/LIMA_paper.pdf)\n\n### Explore with Earth Engine\n\n| **Important:** Earth Engine is a platform for petabyte-scale scientific analysis and visualization of geospatial datasets, both for public benefit and for business and government users. Earth Engine is free to use for research, education, and nonprofit use. To get started, please [register for Earth Engine access.](https://console.cloud.google.com/earth-engine)\n\n### Code Editor (JavaScript)\n\n```javascript\nvar dataset = ee.FeatureCollection('USGS/LIMA/SR_METADATA');\n\n// Calculate the age of each feature by subtracting\n// the acquisition date from \"today\".\nvar feature_ages = dataset.map(\n function(feature) {\n var today = ee.Date.fromYMD(2024, 1, 12);\n var acq_date = ee.Date.parse(\n 'yyyy-MM-dd', feature.get('ACQ_DATE'));\n var diff = today.difference(acq_date, 'day');\n return feature.set({'ACQ_AGE': diff});\n }\n);\n\n// Reduce by calculating the smallest ACQ_AGE,\n// which gives the most recent acquisition date for\n// that area.\nvar reduced_ages = feature_ages.reduceToImage({\n properties: ['ACQ_AGE'],\n reducer: ee.Reducer.min()\n});\n\nvar reduced_ages_vis = {\n min: 6000,\n max: 9000,\n palette: ['00ff00', 'ff0000'],\n};\n\nvar lon = -43.6;\nvar lat = -74.2;\nvar gray = 150;\nvar background = ee.Image.rgb(gray, gray, gray).visualize({min: 0, max: 255});\n\nMap.setCenter(lon, lat, 2);\nMap.addLayer(\n reduced_ages,\n reduced_ages_vis,\n 'Acquisition Age');\n```\n[Open in Code Editor](https://code.earthengine.google.com/?scriptPath=Examples:Datasets/USGS/USGS_LIMA_SR_METADATA) \n[Landsat Image Mosaic of Antarctica (LIMA) - Processed Landsat Scenes (16 bit) Metadata](/earth-engine/datasets/catalog/USGS_LIMA_SR_METADATA) \nThe Landsat Image Mosaic of Antarctica (LIMA) is a seamless and virtually cloudless mosaic created from processed Landsat 7 ETM+ scenes. Processed Landsat Scenes (16 bit) are Level 1Gt NLAPS scenes converted to 16 bit, processed with sun-angle correction, and converted to reflectance values (Bindschadler 2008). Each Landsat scene is ... \nUSGS/LIMA/SR_METADATA, antarctica,ice,landsat-derived,lima,mosaic,satellite-imagery,sr,table,usgs \n1999-06-30T00:00:00Z/2002-09-04T00:00:00Z \n-90 -180 -55 180 \nGoogle Earth Engine \nhttps://developers.google.com/earth-engine/datasets\n\n- [](https://doi.org/https://lima.usgs.gov/index.php)\n- [](https://doi.org/https://developers.google.com/earth-engine/datasets/catalog/USGS_LIMA_SR_METADATA)"]]
