GEE：Landsat-T1级别影像去云和辐射校正

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这几天在做指数运算的时候，发现landsatT1级别数据是需要做辐射校正的，看到很多人使用LandsatT1数据，所以记录一下T1数据做辐射校正的方法和使用的波段。使用的数据集和波段如下表所示，

Landsat-9

// 未辐射校正数据
var L5 = ee.ImageCollection("LANDSAT/LC09/C02/T1")
           .filterBounds(roi)
           .filterDate('2022-1-1','2022-10-30')
           .filterMetadata('CLOUD_COVER',"less_than",15)
           .map(radiance)
           .max()
           .clip(roi);
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8

Landsat-9 去云和云阴影

function remove_cloud(image){
	  //去云和云阴影
	  var cloudShadowBitMask = (1 << 3);  
	  var cloudsBitMask = (1 << 5);  
	  var qa = image.select("QA_PIXEL");  
	  var mask = qa.bitwiseAnd(cloudShadowBitMask).eq(0).and(qa.bitwiseAnd(cloudsBitMask).eq(0));  
	  return image.updateMask(mask);  
}
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8

Landsat-9 辐射校正

function radiance(image){
    var ThermalRadiance=ee.Algorithms.Landsat.calibratedRadiance(image.select('B10')).rename('B10_radiance');
    return image.addBands(ThermalRadiance)
}
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Landsat-8

var L8 = ee.ImageCollection("LANDSAT/LC08/C01/T1")
                   .filterBounds(roi)
                   .filterDate('2020-1-1','2020-12-31')
                   .filterMetadata('CLOUD_COVER',"less_than",15)
                   .map(remove_cloud) 
                   .map(radiance)
                   .max()
                   .clip(roi)
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8

Landsat-8 去云

function remove_cloud(image){
   var image_qa = image.select('BQA');
   var maskComposite = image_qa.bitwiseAnd(1 << 4).eq(0)
   return image.updateMask(maskComposite) 
}
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5

Landsat-8 辐射校正

function radiance(image){
    var ThermalRadiance=ee.Algorithms.Landsat.calibratedRadiance(image.select('B10')).rename('B10_radiance');
    return image.addBands(ThermalRadiance)
}
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Landsat-7

// 未辐射校正数据
var L7 = ee.ImageCollection("LANDSAT/LE07/C02/T1")
           .filterBounds(roi)
           .filterDate('2013-1-1','2013-12-31')
           .filterMetadata('CLOUD_COVER',"less_than",15)
           .map(radiance)
           .max()
           .clip(roi);
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8

Landsat-7 去云和云阴影

function remove_cloud(image){
	  //去云和云阴影
	  var cloudShadowBitMask = (1 << 4);  
	  var cloudsBitMask = (1 << 3);  
	  var qa = image.select("QA_PIXEL");  
	  var mask = qa.bitwiseAnd(cloudShadowBitMask).eq(0).and(qa.bitwiseAnd(cloudsBitMask).eq(0));  
	  return image.updateMask(mask);  
}
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8

Landsat-7 辐射校正

function radiance(image){
    var ThermalRadiance=ee.Algorithms.Landsat.calibratedRadiance(image.select('B6_VCID_1')).rename('B6_radiance');
    return image.addBands(ThermalRadiance)
}
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Landsat-5

// 未辐射校正数据
var L5 = ee.ImageCollection("LANDSAT/LT05/C01/T1")
           .filterBounds(roi)
           .filterDate('2005-1-1','2005-12-31')
           .filterMetadata('CLOUD_COVER',"less_than",15)
           .map(radiance)
           .max()
           .clip(roi);
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8

Landsat-5 去云

function remove_cloud(image){
		 var image_qa = image.select('BQA');
	     var maskComposite = image_qa.bitwiseAnd(1 << 4).eq(0)
	     return image.updateMask(maskComposite)
}
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5

Landsat-5 辐射校正

function radiance(image){
    var ThermalRadiance=ee.Algorithms.Landsat.calibratedRadiance(image.select('B6')).rename('B6_radiance');
    return image.addBands(ThermalRadiance)
}
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