0

I want to map a function over an image collection of Sentinel 1 images. After the calculation, the id and the properties are removed. I tried to maintain the id with .copyProperties in the return line but I got the error

Actual value for parameter 'id' must be a constant.

The function is very long, so I deleted the part between the brackets {...} in the line var calcLee. This link leads to the full script with the complete function: https://code.earthengine.google.com/8ee0437dfc5caedc4b9d284a77ae4282

function dbToPower(img){
      return ee.Image(10).pow(img.divide(10));
    }                                             
function powerToDb(img){
      return ee.Image(10).multiply(img.log10());
    }

function refinedLee(image) {
   
  var bandNames = image.bandNames();

  var image_power = dbToPower(image);
   
  var calcLee= ee.ImageCollection(bandNames.map(function(b){...})).toBands().rename(bandNames);
  
  var result = powerToDb(ee.Image(calcLee));
  return result.copyProperties(ee.Image(image.getString('id')));
 // return result;
}

1 Answer 1

3

You do not need to (and cannot) go through ee.Image lookup by ID to do this. Just copy from the image input:

return result.copyProperties(image);

For copying the asset ID of the image itself, it's a little more work, because “system properties” are not copied by default. The value reported as id in EE JSON outputs is actually the property named "system:id". This can be copied by doing it explicitly in a second step:

return result
    .copyProperties(image)
    .copyProperties(image, ['system:id']);
0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.