Sentinel 1 response = All zeros

Hello!
I’m having some problems to correctly retrieving Sentinel 1 products using the process API
I’ve tried the examples (adapted to my geometry) to no avail… This is my code

  • evalscript is described at the end
  • geometry is the gjson representation of my AOI in the CRS of the crs variable (I’ve tried with CRS 84, EPSG 4326)
  • start_date and end_date are computed from the catalog response to retrieve data from a specific scene (example: [‘S1B_IW_GRDH_1SDV_20200223T091249_20200223T091314_020394_026A2A_3D54’, ‘2020-02-23T09:12:49Z’])

{
“evalscript”: evalscript,
“input”: {
“bounds”: {
“geometry”: geometry,
“properties”: {
“crs”: “http://www.opengis.net/def/crs/EPSG/0/3857
}
},
“data”: [
{
“dataFilter”: {
“timeRange”: {
“from”: start_date,
“to”: end_date
},
“mosaickingOrder”: “mostRecent”,
“resolution”: “FULL”,
“acquisitionMode”: “IW”,
“polarization”: “DV”
},
“processing”: {
“orthorectify”: True,
“demInstance”: “COPERNICUS”,
“speckleFilter”: {
“type”: “LEE”,
“windowSizeX”: 5,
“windowSizeY”: 5
},
“upsampling”: “NEAREST”,
“downsampling”: “NEAREST”,
“atmosphericCorrection”: “NONE”
},
“type”: “sentinel-1-grd”
}
]
},
“output”: {
“resx”: 10,
“resy”: 10,
“responses”: [
{
“format”: {
“type”: “image/tiff”
},
“identifier”: “default”
}
]
}
}

The evalscript is from the custom evalscript repo in Radar Vegetation Index Code for Dual Polarimetric Script | Sentinel-Hub custom scripts
evalscript = “”"
//VERSION=3
function setup() {
return {
input: [{
bands: [“VV”,“VH”],
}],
output: [{
id:“default”,
bands: 1,
sampleType: “AUTO”,
},],
mosaicking: “SIMPLE”,
};
}
function evaluatePixel(sample) {
return {
default: [(4 * sample.VH) / (sample.VV + sample.VH)],
};
}
“”"

Thanks in advance!!
Luc

Hi @lucho ,

Full resolution is not available for IW mode (more info). In this case you may want to set the resolution to “HIGH” as shown below and you will get the data.

{
  "input": {
    "bounds": {
      "bbox": [
        -3741593.977003,
        -2289157.747134,
        -3717741.091949,
        -2280469.678092
      ],
      "properties": {
        "crs": "http://www.opengis.net/def/crs/EPSG/0/3035"
      }
    },
    "data": [
      {
        "dataFilter": {
          "timeRange": {
            "from": "2020-02-23T00:00:00Z",
            "to": "2020-02-23T23:59:59Z"
          },
          "acquisitionMode": "IW",
          "mosaickingOrder": "mostRecent",
          "resolution": "HIGH",
          "polarization": "DV"
        },
        "processing": {
          "orthorectify": true,
          "demInstance": "COPERNICUS",
          "speckleFilter": {
            "type": "LEE",
            "windowSizeX": 5,
            "windowSizeY": 5
          },
          "upsampling": "NEAREST",
          "downsampling": "NEAREST"
        },
        "type": "sentinel-1-grd"
      }
    ]
  },
  "output": {
    "resx": 10,
    "resy": 10,
    "responses": [
      {
        "identifier": "default",
        "format": {
          "type": "image/tiff"
        }
      }
    ]
  },
  "evalscript": "//VERSION=3\nfunction setup() {\nreturn {\ninput: [{\nbands: [\"VV\",\"VH\"],\n}],\noutput: [{\nid:\"default\",\nbands: 1,\nsampleType: \"AUTO\",\n},],\nmosaicking: \"SIMPLE\",\n};\n}\nfunction evaluatePixel(sample) {\nreturn {\ndefault: [(4 * sample.VH) / (sample.VV + sample.VH)],\n};\n}"
}