Error exporting GeoTIFF to Google Drive - Google Earth Engine

Question

I am trying to export a GeoTIFF to my Google Drive, but this error occurs -

Error: Image.clipToBoundsAndScale, argument 'input': Invalid type. Expected type: Image. Actual type: ImageCollection. (Error code: 3).-

This is the code I use:

Map.centerObject(geometry);

// Apply Cloud mask
function maskL8sr(col) {

  // Bits 3 and 5 are cloud shadow and cloud, respectively.

  var cloudShadowBitMask = (1 << 3);

  var cloudsBitMask = (1 << 5);

  // Get the pixel QA band.

  var qa = col.select('pixel_qa');

  // Both flags should be set to zero, indicating clear conditions.

  var mask = qa.bitwiseAnd(cloudShadowBitMask).eq(0)

                 .and(qa.bitwiseAnd(cloudsBitMask).eq(0));

  return col.updateMask(mask);
}


// Declare visualization parameters (2 sets)

var vizParams = {

  bands: ['B5', 'B6', 'B4'],

  min: 642,

  max: 3307,

  gamma: [1, 0.9, 1.1]

};


var vizParams2 = {

  bands: ['B4', 'B3', 'B2'],

  min: 0,

  max: 3000,

  gamma: 1.4,

};



// Load Landsat Data collection for the data span declared

var col = ee.ImageCollection('LANDSAT/LC08/C01/T1_SR')

    .map(maskL8sr)

    .filterDate('2018-03-01','2023-10-1')

   .filterBounds(geometry)

    .map(function(image){return image.clip(geometry)});

print('collection', col);

 

// Image Reduction & Visualization - Product was named Median

var image = col.median();

Map.addLayer(image, vizParams2,'median');

// NDVI Calculation

var ndvi1 = image.normalizedDifference(['B5', 'B4']).rename('NDVI');

var ndviParams = {min: 0.10554729676864096, max: 0.41295681063122924, palette: ['blue', 'white', 'green']};

//individual LST images

var col_list = col.toList(col.size());

var LST_col = col_list.map(function (ele) {

var date = ee.Image(ele).get('system:time_start');

var ndvi = ee.Image(ele).normalizedDifference(['B5', 'B4']).rename('NDVI');


// find the min and max of NDVI

  var min = ee.Number(ndvi.reduceRegion({

    reducer: ee.Reducer.min(),

    geometry: geometry,

    scale: 30,

    maxPixels: 1e9

  }).values().get(0));

 

  var max = ee.Number(ndvi.reduceRegion({

    reducer: ee.Reducer.max(),

    geometry: geometry,

    scale: 30,

    maxPixels: 1e9

  }).values().get(0));

 

  var fv = (ndvi.subtract(min).divide(max.subtract(min))).pow(ee.Number(2)).rename('FV');

 

  var a= ee.Number(0.004);

  var b= ee.Number(0.986);

 

  var EM = fv.multiply(a).add(b).rename('EMM');

 

  var image = ee.Image(ele);

 

  var LST = image.expression(

    '(Tb/(1 + (0.00115* (Tb / 1.438))*log(Ep)))-273.15', {

      'Tb': image.select('B10').multiply(0.1),

      'Ep': fv.multiply(a).add(b)

  });

return ee.Algorithms.If(min, LST.set('system:time_start', date).float().rename('LST'), 0);

}).removeAll([0]);

// Create an Image Collection
LST_col = ee.ImageCollection(LST_col);

print("LST_collection", LST_col);

Map.addLayer(ndvi1, ndviParams, 'ndvi');

// Select Thermal Band 10(with brightness temperature), no calculation

var thermal= image.select('B10').multiply(0.1);

var b10Params = {min: 306.4, max: 322.8, palette: ['blue', 'white', 'green']};

Map.addLayer(thermal, b10Params, 'thermal');

// find the min and max of NDVI

var min = ee.Number(ndvi1.reduceRegion({

  reducer: ee.Reducer.min(),

  geometry: geometry,

  scale: 30,

  maxPixels: 1e9

}).values().get(0));


//print('min', min );

var max = ee.Number(ndvi1.reduceRegion({

  reducer: ee.Reducer.max(),

  geometry: geometry,

  scale: 30,

  maxPixels: 1e9

}).values().get(0));

 

//print('max', max);

 

// Fractional Vegetation Equation

var fv = (ndvi1.subtract(min).divide(max.subtract(min))).pow(ee.Number(2)).rename('FV');

 

//print('fv', fv);

 

//Map.addLayer(fv);

 

//Declare Emissivity coefficients as variables

var a= ee.Number(0.004);

var b= ee.Number(0.986);

var EM = fv.multiply(a).add(b).rename('EMM');

 

var imageVisParam3 = {min: 0.9865619146722164, max:0.989699971371314};

 

//Map.addLayer(EM, imageVisParam3,'EMM');

 

//LST in Celsius Degree bring -273.15

//NB: In Kelvin don't bring -273.15

var LST = col.map(function (image){
var date = image.get('system:time_start');
var LST = image.expression(

    '(Tb/(1 + (0.00115* (Tb / 1.438))*log(Ep)))-273.15', {

    'Tb': thermal.select('B10'),

    'Ep':EM.select('EMM')

  }).float().rename('LST');

   return LST.set('system:time_start', date);
});

//print(LST);

Map.addLayer(LST, {min: 34.22748947143555, max: 50.7606086730957, palette: [

'040274', '040281', '0502a3', '0502b8', '0502ce', '0502e6',

'0602ff', '235cb1', '307ef3', '269db1', '30c8e2', '32d3ef',

'3be285', '3ff38f', '86e26f', '3ae237', 'b5e22e', 'd6e21f',

'fff705', 'ffd611', 'ffb613', 'ff8b13', 'ff6e08', 'ff500d',

'ff0000', 'de0101', 'c21301', 'a71001', '911003'

]},'LST');


print(

      ui.Chart.image.series({

        imageCollection: LST_col,

        region: geometry,

        scale: 20, // nominal scale Landsat imagery

        xProperty: 'system:time_start' // default

      }));

//export 
 var LST_map = LST_col.select (['LST']);
 print(LST_map);

 Export.image.toDrive ({image: LST_map, description: 'LST', scale: 20,
  fileFormat: 'GeoTIFF',
});

Answer 1

The error is that you are giving LST_map as an input to Export.image.toDrive, but LST_map is ee.ImageCollection. You can only export one image per Export task.

Image export tasks are created with a call to a client-side function Export.Image.toX where X is toDrive, toAsset, or toCloudStorage (e.g. Export.Image.toDrive).

You can make your image collection into a list and then use ee.List.get:

var n = myCollection.size().getInfo()  
var imgList = myCollection.tolist(n)
var img = imgList.get(0) 

You can wrap the imgList.get(X) and subsequent call to Export.image.toDrive in a loop or in a function, and create all the export tasks that you need. Note that this process requires the use of .getInfo() because Export.image.toX is a client-side function. Take a look at the full example given in this answer

There are also some third-party modules you can use to handle this process for you, both for javascript and python, some of which are listed below:

• https://github.com/fitoprincipe/geetools-code-editor/wiki/Batch
• https://github.com/gee-community/gee_tools
• https://github.com/gee-community/geemap/blob/master/geemap/common.py#L581