1

Whenever I try to export to the drive the image gives me the following error:

Error: Invalid argument: 'image' must be of type Image.

This is my code:

var mod11 = ee.ImageCollection("MODIS/MOD11A2");

// Specify name of country. 
var country_names = ['Vietnam']; 
// get fusion table with countries
var countries = ee.FeatureCollection('ft:1tdSwUL7MVpOauSgRzqVTOwdfy17KDbw-1d9omPw');
// select the country from the fusion table
var vietnamCountry = countries.filter(ee.Filter.inList('Country', country_names)).geometry();

// set start date
var startdate = ee.Date.fromYMD(2000,1,1);
// set end date
var enddate = ee.Date.fromYMD(2017,12,31);

// filter the data collection
var temp =  mod11.filterDate(startdate, enddate)
  .sort('system:time_start', false)
  .filterBounds(vietnamCountry) 
  .select("LST_Day_1km")

// convert LST to celcius
var toCelsius = function(image){
  var time = image.get('system:time_start')
  var celsius = image.multiply(0.02) // scale factor
                     .subtract(273.15) // from kelvin to C
                     .rename("Celcius")
                     .set('system:time_start',time)
  return celsius;
};

var CollectioninCelsius = temp.map(toCelsius)

var viz = {min:20.0, max:34, palette:"000b5e,96048f,4286f4,e2f442,960424"};
Map.addLayer(CollectioninCelsius.median().clip(table),viz,"temperature map")
Map.centerObject(vietnamCountry,5)

// Predefine the chart titles.
var title = {
  title: 'Temperature over time',
  hAxis: {title: 'Time'},
  vAxis: {title: 'Temperature (C)'},
};

// create the chart
var tempchart = ui.Chart.image.seriesByRegion(CollectioninCelsius, 
                           vietnamCountry, 
                           ee.Reducer.mean(), 
                           'Celcius', 
                            1000, 
                           'system:time_start', 
                           'PROJECT').setOptions(title);

// print the chart
print(tempchart);

Export.image.toDrive({
  image: mod11.select('Temp'),
  description: 'Temperatura',
  scale: 10,
  region: table, 
  crs: 'EPSG:4326',
  folder: 'TCC',
  maxPixels: 10000000
});

https://code.earthengine.google.com/25c00e940fdcd572f8b0524a50b86d94

Table: https://code.earthengine.google.com/?asset=users/eldileoliveira/Novapasta

1 Answer 1

1

You need to use the visualize function. It's hard to tell exactly what you want visualize, but I have a feeling this is what you're going for. I couldn't get the table to load right so I just used the Vietnam geometry for clipping instead. Here, what gets plotted on the map pane is the same image as what exports to drive but at a different resolution. If you want full resolution you can change that under the scale option in Export.image.toDrive() - it's a coarse resolution in this example for download speed/file size.

var mod11 = ee.ImageCollection("MODIS/MOD11A2");

// Specify name of country. 
var country_names = ['Vietnam']; 
// get fusion table with countries
var countries = ee.FeatureCollection('ft:1tdSwUL7MVpOauSgRzqVTOwdfy17KDbw-1d9omPw');
// select the country from the fusion table
var vietnamCountry = countries.filter(ee.Filter.inList('Country', country_names)).geometry();

// set start date
var startdate = ee.Date.fromYMD(2000,1,1);
// set end date
var enddate = ee.Date.fromYMD(2017,12,31);

// filter the data collection
var temp =  mod11.filterDate(startdate, enddate)
  .sort('system:time_start', false)
  .filterBounds(vietnamCountry) 
  .select("LST_Day_1km");

// convert LST to celcius
var toCelsius = function(image){
  var time = image.get('system:time_start');
  var celsius = image.multiply(0.02) // scale factor
                     .subtract(273.15) // from kelvin to C
                     .rename("Celcius")
                     .set('system:time_start',time);
  return celsius;
};

var CollectioninCelsius = temp.map(toCelsius).median();

var viz = {min:20.0, max:34, palette:"000b5e,96048f,4286f4,e2f442,960424"};


Map.addLayer(vietnamCountry,{},"vietnamCountry");

var regionTemp = CollectioninCelsius.clip(vietnamCountry);

Map.centerObject(vietnamCountry,5);
Map.addLayer(regionTemp, viz,"temperature map");

print("region Temp",regionTemp);

var tempExport = regionTemp.visualize({bands:'Celcius', min:20.0, max:34, palette:"000b5e,96048f,4286f4,e2f442,960424"});

Export.image.toDrive({
  image: tempExport,
  description: 'Temperatura',
  scale: 10000,
  region: vietnamCountry, 
  crs: 'EPSG:4326',
  folder: 'TCC',
  maxPixels: 10000000
});
2
  • Thank you very much. Apr 2, 2019 at 23:35
  • 2
    The visualize function is not the one doing the trick here. You tried to export an ImageCollection (mod11), however, you can only export single images. The reducer 'median' makes a single composite of the image collection (var CollectioninCelsius = temp.map(toCelsius).median();). That said, it does not seem reasonable to export an 19-year median landsurface temperature. You might want to make something like seasonal composites, but that depends on your goal.
    – Kuik
    Apr 3, 2019 at 7:19

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