Fetch and resample bands for eo-learn

evalscript_batch_eolearn.js

// Evaluate pixels in the bands
function evaluatePixel(samples, scenes) {
  
  // Initialise arrays
  var valid_samples = {'B02':[], 'B03':[], 'B04':[], 'B08':[], 'B11':[], 'B12':[]}; 
  
  var valid_dates = []
  // Loop over samples. 
  for (var i = samples.length-1; i >= 0; i--){
      if (is_valid(samples[i])) {
        valid_dates.push(withoutTime(new Date(scenes[i].date)));
        valid_samples['B02'].push(samples[i].B02);
        valid_samples['B03'].push(samples[i].B03);
        valid_samples['B04'].push(samples[i].B04);
        valid_samples['B08'].push(samples[i].B08);
        valid_samples['B11'].push(samples[i].B11);
        valid_samples['B12'].push(samples[i].B12);
      }
  }
  
  var [b02_interpolated, b02_dm] = lininterp(sampled_dates, valid_dates, valid_samples['B02'], 0);
  var [b03_interpolated, b03_dm] = lininterp(sampled_dates, valid_dates, valid_samples['B03'], 0);
  var [b04_interpolated, b04_dm] = lininterp(sampled_dates, valid_dates, valid_samples['B04'], 0);
  var [b08_interpolated, b08_dm] = lininterp(sampled_dates, valid_dates, valid_samples['B08'], 0);
  var [b11_interpolated, b11_dm] = lininterp(sampled_dates, valid_dates, valid_samples['B11'], 0);
  var [b12_interpolated, b12_dm] = lininterp(sampled_dates, valid_dates, valid_samples['B12'], 0);

  // Calculate indices and return optimised for UINT16 format (will need unpacking)
  var ndvi = interpolated_index(b08_interpolated, b04_interpolated);
  var ndwi = interpolated_index(b03_interpolated, b08_interpolated);
  var ndbi = interpolated_index(b11_interpolated, b08_interpolated);
  
  // Return all arrays
  return {
            B02: b02_interpolated,
            B03: b03_interpolated,
            B04: b04_interpolated,
            B08: b08_interpolated,
            B11: b11_interpolated,
            B12: b12_interpolated,
            NDVI: ndvi,
            NDWI: ndwi,
            NDBI: ndbi,
            data_mask: b02_dm
  }
}