Replicating Request Builder query in SH-PY

EO Products / Scripts
1

So I’m trying to use the scripts provided by the request builder to retrieve data with sentinelhub python. For some reason it keeps throwing Error 400, though.

config = SHConfig()

config.sh_client_id = xx
config.sh_client_secret = xx

evalscript = """

//VERSION=3

function setup() {

  return {

    input: [

      {

        bands: ["B01","B02","B03","B04","B05","B06","B07","B08","B8A","B09","B11","B12"],      

        units: "REFLECTANCE",            

      }

    ],

    output: [

      {

        id: "default",

        bands: 12,

        sampleType: "AUTO",        

      },    

    ],

    mosaicking: "SIMPLE",

  };

}

function evaluatePixel(samples) {

    return {

      default: [sample.B01,sample.B02,sample.B03,sample.B04,sample.B05,sample.B06,sample.B07,sample.B08,sample.B8A,sample.B09,sample.B11,sample.B12],

    };

  }

"""

bbox = BBox(bbox=[15.62174, 46.6803, 15.63014, 46.68603], crs=CRS.WGS84)

geometry = Geometry(geometry={"type":"Polygon","coordinates":[[[15.62339,46.68603],[15.62273,46.68505],[15.623,46.68499],[15.62216,46.68236],[15.62174,46.68205],[15.62268,46.68217],[15.62289,46.68263],[15.62344,46.68258],[15.62356,46.68244],[15.62337,46.68205],[15.62331,46.68128],[15.62423,46.68115],[15.62425,46.68112],[15.62476,46.68152],[15.62475,46.68225],[15.62597,46.68208],[15.62633,46.68159],[15.62701,46.68125],[15.62842,46.68039],[15.6284,46.6804],[15.62914,46.6803],[15.62971,46.68069],[15.62969,46.68098],[15.63014,46.68218],[15.63011,46.68252],[15.628,46.68341],[15.62764,46.68306],[15.62694,46.6836],[15.62544,46.68399],[15.62371,46.68391],[15.62341,46.68402],[15.62358,46.68461],[15.62405,46.68499],[15.62339,46.68603]]]}, crs=CRS.WGS84)

request = SentinelHubRequest(

    evalscript=evalscript,

    input_data=[

        SentinelHubRequest.input_data(

            data_collection=DataCollection.SENTINEL2_L2A,          

            time_interval=('2021-01-05', '2021-01-05'),          

            other_args={"dataFilter": {"mosaickingOrder": "leastRecent"}}

        ),
    ],
    responses=[
        SentinelHubRequest.output_response('default', MimeType.TIFF),
    ],
    bbox=bbox,
    geometry=geometry,
    size=[512, 509.07],
    config=config
)
response = request.get_data()

Interestingly, the following evalscript actually works, but I don’t understand why, exactly:

evalscript = """
//VERSION=3

function setup() {
  return {
    input: ["B01","B02","B03","B04","B05","B06","B07","B08","B8A","B09","B11","B12"],
    output: { bands: 12 }
  };
}

function evaluatePixel(sample) {
  return [sample.B01,sample.B02,sample.B03,sample.B04,sample.B05,sample.B06,sample.B07,sample.B08,sample.B8A,sample.B09,sample.B11,sample.B12];
}
"""
2

Hi!

The issue is that you are requesting B10 band, which is not present in Sentinel-L2A data. If you change the data_collection to DataCollection.SENTINEL2_L1C it will work (or if you remove the B10 from the evalscript).

3

Please correct me, if there is a misunderstanding, but I request B10 in neither input:bands, nor the return function. In fact even if I change my evalscript to request just one band, it still throws an error:

evalscript = """
//VERSION=3

function setup() {
  return {
    input: [
      {
        bands: ["B03"],      
        units: "REFLECTANCE",            
      }
    ],
    output: [
      {
        id: "default",
        bands: 12,
        sampleType: "AUTO",        
      },    
    ],
    mosaicking: "SIMPLE",
  };
}


function evaluatePixel(samples) {
    return {
      default: [sample.B03],
    };
  }


"""


DownloadFailedException: Failed to download from:
https://services.sentinel-hub.com/api/v1/process
with HTTPError:
400 Client Error: Bad Request for url: https://services.sentinel-hub.com/api/v1/process
Server response: "{"error":{"status":400,"reason":"Bad Request","message":"Failed to evaluate script!\nevalscript.js:26: ReferenceError: sample is not defined\n      default: [sample.B03],\n                ^\nReferenceError: sample is not defined\n    at evaluatePixel (evalscript.js:26:17)\n    at executeForSingleScene (<anonymous>:1119:17)\n","code":"RENDERER_EXCEPTION"}}"
4

Indeed you are not requesting B10, but now your output states that you are requesting 12 bands, while you are in fact only requesting one.

5

I’m sorry, definitely an oversight on my part. Changing output:bands to 1 doesn’t change the result, however. Here again, the script I’m using:

evalscript = """
//VERSION=3

function setup() {
  return {
    input: [
      {
        bands: ["B03"],      
        units: "REFLECTANCE",            
      }
    ],
    output: [
      {
        id: "default",
        bands: 1,
        sampleType: "AUTO",        
      },    
    ],
    mosaicking: "SIMPLE",
  };
}


function evaluatePixel(samples) {
    return {
      default: [sample.B03],
    };
  }


"""
bbox = BBox(bbox=[15.62174, 46.6803, 15.63014, 46.68603], crs=CRS.WGS84)
geometry = Geometry(geometry={"type":"Polygon","coordinates":[[[15.62339,46.68603],[15.62273,46.68505],[15.623,46.68499],[15.62216,46.68236],[15.62174,46.68205],[15.62268,46.68217],[15.62289,46.68263],[15.62344,46.68258],[15.62356,46.68244],[15.62337,46.68205],[15.62331,46.68128],[15.62423,46.68115],[15.62425,46.68112],[15.62476,46.68152],[15.62475,46.68225],[15.62597,46.68208],[15.62633,46.68159],[15.62701,46.68125],[15.62842,46.68039],[15.6284,46.6804],[15.62914,46.6803],[15.62971,46.68069],[15.62969,46.68098],[15.63014,46.68218],[15.63011,46.68252],[15.628,46.68341],[15.62764,46.68306],[15.62694,46.6836],[15.62544,46.68399],[15.62371,46.68391],[15.62341,46.68402],[15.62358,46.68461],[15.62405,46.68499],[15.62339,46.68603]]]}, crs=CRS.WGS84)

request = SentinelHubRequest(
    evalscript=evalscript,
    input_data=[
        SentinelHubRequest.input_data(
            data_collection=DataCollection.SENTINEL2_L2A,          
            time_interval=('2021-01-05', '2021-01-05'),          
            other_args={"dataFilter": {"mosaickingOrder": "leastRecent"}}
        ),
    ],
    responses=[
        SentinelHubRequest.output_response('default', MimeType.TIFF),
    ],
    bbox=bbox,
    geometry=geometry,
    size=[512, 509.07],
    config=config
)

response = request.get_data()

And the error:

DownloadFailedException: Failed to download from:
https://services.sentinel-hub.com/api/v1/process
with HTTPError:
400 Client Error: Bad Request for url: https://services.sentinel-hub.com/api/v1/process
Server response: "{"error":{"status":400,"reason":"Bad Request","message":"Failed to evaluate script!\nevalscript.js:26: ReferenceError: sample is not defined\n      default: [sample.B03],\n                ^\nReferenceError: sample is not defined\n    at evaluatePixel (evalscript.js:26:17)\n    at executeForSingleScene (<anonymous>:1119:17)\n","code":"RENDERER_EXCEPTION"}}"
6

The error description from the server is rather clear: there is no variable “sample” (it also points to the line number!).

function evaluatePixel(samples) { // <- the parameter here is samples (plural)
    return {
      default: [sample.B03],      // <- the parameter here is sample (singular)
    };
  }

In your case (simple mosacking), the appropriate way is to have function evaluatePixel(sample).

7

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