How to get statistical info about ndvi from sentinel-3-OLCI

1

for sentinel-3-OLCI, i am using the below posted evalscript to have statistical information using statistical-api.
please let me know why the app crashes when attempts to process the evalscript?

evalscript:

const evalscript = 
`
//VERSION=3

function setup() {
    return {
      input: [{
        bands: ["B08", "B17", "dataMask"],
        units: "DN"
      }],
      output: [
        {
          id: "ndvi", 
          bands: 1,
        },
        {
          id: "dataMask", 
          bands: 1,
        }
      ]
    }

  }

  function evaluatePixel(samples) {
    // Precompute an array to contain NDVI observations

    if (!samples) {
      return {
        ndvi: [NaN], 
        dataMask: [NaN]
      };
    }
    if (samples.length < 1) {
      return {
        ndvi: [NaN], 
        dataMask: [NaN]
      };
    }

    let index = null;
    if (samples.B17 + samples.B08 === 0) {
      index = 0; // to avoid division by zero
      return {
        ndvi: [index],
        dataMask: [samples.dataMask]
      };
    }
    index = (samples.B17 - samples.B08) / (samples.B17 + samples.B08);

    return {
      ndvi: [index],
      dataMask: [samples.dataMask],
    };
}`
2

Hi,

For the data collection you are using, checking the docs, Digital Numbers: DN are not available as an input parameter. In future, as I am sure you know, you can test your scripts in Request Builder (which is where I found the error message pointing me to this.

3

thank you
your help is appreciated