400 Client Error :ailed to evaluate script! when trying retrieve sentinel1

Apps / Services Python SDK
1

I’m trying to retrieve sentinel1 images using evalscript.
I have followed the instruction as appear here but I couldn’t understand the reason why I keep getting the 400 client error (bad request).

This is my evalscript:

evalscript = """
function setup() {
  return {
    input: {bands: ["VV","VH"]}
    output:{bands:  2, sampleType:"FLOAT32"}}
      }
      
function evaluatePixel(sample) {
  return [10 * Math.log((sample.VV)+0.0001) / Math.LN10, 10 * Math.log((sample.VH)+0.0001) / Math.LN10]
}
"""

and this is how I have tried to use it,
when dates is list of dates strings (e.g [‘2020-07-01’,‘2020-07-12’]…

or d in dates:
        request = SentinelHubRequest(
            evalscript=evalscript,
            input_data=[
                SentinelHubRequest.input_data(
                    data_collection=DataCollection.SENTINEL1_IW_DES,
                    time_interval=(d,d),
                    other_args = other_args = {"dataFilter":{"resolution":"HIGH","acquisitionMode":"IW"},"processing":{"backCoeff":"GAMMA0_TERRAIN","orthorectify":True,"demInstance":"COPERNICUS"},"id":"S1GRD"}
                )
            ],
            responses=[
                SentinelHubRequest.output_response('default', MimeType.TIFF)
            ],
            bbox=bbox,
            config=config
        )
        
        image = request.get_data()[0]
        
        plt.figure(figsize=(10,8))
        plt.imshow(image)

That returns the error:
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:5: SyntaxError: Unexpected identifier\n output:{bands: 2, sampleType:“FLOAT32”}}\n ^^^^^^\n”,“code”:“RENDERER_EXCEPTION”}}”

I haven’t been able to find the source of this error yet, please help me to understand what am I doing wrong as it seems to me very similar to the evaluate script in the doc.

2

You have a mistake in the definition of the input in the setup function. See evalscripts in examples for S1 e.g. this one

Try this:

function setup() {
  return {
    input: ["VV", "VH"],
    output: { id:"default", 
              bands: 2,
              sampleType: "FLOAT32"
    }
  }
}
1 Like
3

Hi Batic,

I have tried what you suggested (following the example), but I keep getting this error.

evalscript = """
function setup() {
  return {
    input: ["VV", "VH"],
    output: { id:"default", 
              bands: 2,
              sampleType: "FLOAT32"
    }
  }

function evaluatePixel(samples) {
  var vvdB = toDb(samples.VV)
  var vhdB = toDb(samples.VH)
  return [vvdB, vhdB]
}
"""

Server response: “{“error”:{“status”:400,“reason”:“Bad Request”,“message”:“Failed to evaluate script!\nevalscript.js:15: SyntaxError: Unexpected end of input\n}\n^\n”,“code”:“RENDERER_EXCEPTION”}}”

4

Hi Reut,

The first thing that I can see in your code is that you are missing a closing curly bracket in your setup function. The error actually points to this as it mentions SyntaxError: Unexpected end of input.

It can help to have some form of coding editor that helps with syntax errors to write your Evalscripts.

Maxim

5

Hi Maxim

you were right regard the {

but still getting same erro just without the syntax error:

evalscript = """
function setup() {
  return {
    input: ["VV", "VH"],
    output: { id:"default", 
              bands: 2,
              sampleType: "FLOAT32"
    }
  }
 }

function evaluatePixel(samples) {
  var vvdB = toDb(samples.VV)
  var vhdB = toDb(samples.VH)
  return [vvdB, vhdB]
}
"""

Server response: “{“error”:{“status”:400,“reason”:“Bad Request”,“message”:“Dataset with id: 0 not found.”,“code”:“RENDERER_EXCEPTION”}}”

6

You are using the “SIMPLE” mosaicking (which is by default when not explicitly specified), therefore I suggest you try with sample rather than samples in your evaluatePixel function: there is a difference, see here: https://docs.sentinel-hub.com/api/latest/evalscript/v3/#evaluatepixel-function (samples returns an array). erratum: this is just a naming convention: parameters are positional not named, therefore whatever you put with SIMPLE mosaicking will be an object.

If you keep getting an error despite this change, I would check if there is actually data on the dates you are querying.

1 Like
7

just to give some more information-
the flow of the whole script before is that I define date range (in this case lets say from 1/10-10/02), then check if sentinel1 has availabe images with the get_dates() function and then everytime use those dates in order to generate one image per date.

When I use this with another evalscript (one of fusion data for example with sentinel 1) it works no problem (with same dates), so I believe there is still problem with the evalscript (after fixing it to sample as you mentions :slight_smile: )

evalscript = """
function setup() {
  return {
    input: ["VV", "VH"],
    output: { id:"default", 
              bands: 2,
              sampleType: "FLOAT32"
    }
  }
}
  
function evaluatePixel(sample) {

return [10 * Math.log((sample.VV)) / Math.LN10, 10 * Math.log((sample.VH)) / Math.LN10]
  
  }