Creating just one image with time intervals

[mcihadarslanoglu]

When we set time intervals like ["2022-04-01", "2022-04-15"], it returns a lot of scene images. However, I just want to have one image which includes the all bounding box.

As you can see there are many images, can we merge them and get just one image ? Maybe we can do it when mergin the patches as well ?

Here code I used

import earthspy.earthspy as es
import cv2

script = """

  //VERSION=3 (auto-converted from 1)

//Basic initialization setup function
function setup() {
  return {
	//List of all bands, that will be used in the script, either for visualization or for choosing best pixel
    input: [{
      bands: [
         "B04",
         "B08",
         "SCL"
      ]
    }],
	//This can always be the same if one is doing RGB images
    output: { bands: 1 },
    mosaicking: "ORBIT"
  }
}

/*
In this function we limit the scenes, which are used for processing. 
These are based also on input variables, coming from Playground. 
E.g. if one sets date "2017-03-01" ("TO date") and cloud coverage filter 30%, 
all scenes older than 2017-03-01 with cloud coverage 30% will be checked against
further conditions in this function.
The more scenes there are, longer it will take to process the data.
After 60 seconds of processing, there will be a timeout.
*/

function filterScenes (scenes, inputMetadata) {
    return scenes.filter(function (scene) {
//Here we limit data between "(TO date - 1 month) to (TO date)
	  return scene.date.getTime()>=(inputMetadata.to.getTime()-1*31*24*3600*1000) ;
    });
}

function calcNDVI(sample) {
  var denom = sample.B04+sample.B08;
  switch(sample.SCL){
      
      // Unclassified (dark grey)
    case 7: return [0];
    
    // Cloud medium probability (grey)
    case 8: return [0];
        
    // Cloud high probability (white)
    case 9: return [0];
      }
  return ((denom!=0) ? (sample.B08-sample.B04) / denom : 0.0);
}
function evaluatePixel(samples) {  
  var max = 0;
  for (var i=0;i<samples.length;i++) {
      var ndvi = calcNDVI(samples[i]);
    max = ndvi > max ? ndvi:max;
  }



if (max>0.53) return [1];
else return [0]

}

"""

job = es.EarthSpy("auth.txt")

job.set_query_parameters(
    bounding_box=[
  37.836908,
  36.527295,
  43.626709,
  38.718198
],
    time_interval=["2022-04-01", "2022-04-15"],
    evaluation_script=script,
    data_collection="SENTINEL2_L2A",
    download_mode = 'SM',
    store_folder = 'images',
    save_name = 'test'
    
)
image = job.send_sentinelhub_requests()

[AdrienWehrle]

Hi @mcihadarslanoglu !

Thank you a lot for your message! Passing a date range (here, ["2022-04-01", "2022-04-15"]) indeed tells earthspy to download all available days over the bounding box you prescribe.

I think I understand you would like one image only for the whole period. However, many pixels appear several times at different dates and would need to be somehow combined. What criterion/method would you like to use? Would you like to sum them up? Average them?

One item that is on my TODO list of new features is a (potentially per-pixel) mosaicing based on the solar zenith angle to choose a given pixel when several ones are available over the same period (mainly over the same day).

[mcihadarslanoglu]

maybe flexible structrue can be insterted. If I give parameter as sum, then it should sum. If I give avg, it should apply avg operator on the pixels.

[AdrienWehrle]

Thank you a lot for your input @mcihadarslanoglu ! To keep earthspy flexible and easy to maintain I think it would be better to let the user take care of the post processing. You could create the averaged or summed raster using the rasterio library!