Error while trying to download image files from sentinel 2

[vsvam45 (sree vamsi)]

# Configure Sentinel Hub with your credentials
config = SHConfig()
config.sh_client_id = 'xxxxx
config.sh_client_secret = 'xxxxxx'



# Evalscript for computing NBR
evalscript = """
// Evaluate pixel function to compute NBR
function evaluatePixel(samples) {
    // Access NIR and SWIR bands
    var nir = samples.B08; // NIR band
    var swir = samples.B11; // SWIR band
    
    // Calculate NBR
    var nbr = (nir - swir) / (nir + swir);

    return {
        default: [nbr] // Return NBR value
    };
}

// Setup for input and output
var setup = {
    input: [{
        bands: ['B08', 'B11'], // Bands required for NBR calculation (NIR and SWIR)
        units: 'DN' // Specify units of input bands
    }],
    output: {
        bands: 1, // Number of output bands (NBR)
        sampleType: 'FLOAT32' // Sample type of output
    }
};
"""
# Function to download satellite imagery from Sentinel Hub
def download_satellite_imagery(bbox, time_interval, output_folder):
    # Define the request
    request = SentinelHubRequest(
        evalscript=evalscript,
        input_data=[
            SentinelHubRequest.input_data(
                data_collection=DataCollection.SENTINEL2_L1C,
                time_interval=time_interval,
                maxcc=0.2,
               
            )
        ],
        bbox=bbox,
        responses=[
            SentinelHubRequest.output_response('default', MimeType.TIFF)
        ],
      #  resolution = (0.0010, 0.0010) ,
        size=(1024,1024),
        data_folder=output_folder,  # Specify the output folder where data should be saved
        config=config
    )
    
    # Execute the request and save the downloaded imagery
    img_paths = request.get_data(save_data=True)
    
    # Return the path of the downloaded imagery
    return img_paths[0]

Error : 400 Client Error: Bad Request for url: https://services.sentinel-hub.com/api/v1/process Server response: "{"status": 400, "reason": "Bad Request", "message": "Script failed to return.", "code": "RENDERER_EXCEPTION"}"

Please , I’m new to this and need some help in figuring out where I went wrong ,I am using sentinel hub python API for this , I have given my evalscript and download function where the error is occurring. I have cross checked my client id and secret details , they seem to be fine , previously I got resolution errors , after reducing resolution , I am getting this specific error. I am trying to compute NBR using 2 bands of sentinel for pre and post fire dates , I have specified the bbox coordinates as well as the download folder path individually for pre and post fire.

[william.ray]

Hi, it was an issue with the evalscript you were using. Do you know where you sourced it from?

If you insert the below evalscript, your request should work:

//VERSION=3

function evaluatePixel(samples) {
    let val = index(samples.B08, samples.B12);
    return [val, samples.dataMask];
}

function setup() {
  return {
    input: [{
      bands: [
        "B12",
        "B08",
        "dataMask"
      ]
    }],
    output: {
      bands: 2
    }
  }
}

[vsvam45 (sree vamsi)]

hello william , thanks for your quick reply , yeah it seems the issue was indeed with the eval script , I have leveraged chat gpt 3.5 for this , as I am still learning things. I am now able to successfully download the required band’s data , thank you.