Sentinel 1 GRD localIncidenceAngle


I am sending a request to receive Sentinel1 data from the process API, and I am having difficulty bringing back the localIncidenceAngle.

Below is my request:

This request works, but the localIncidenceAngle has always returned 255 for every pixel. I don’t think this is valid, and I am guessing that I’m doing something wrong. Can you take a look at my evalscript and request and see if anything is wrong?

Hi @sentinel_hub_user ,

The default SampleType of your output in the Evalscript is AUTO, which takes values from 0 to 1 and automatically stretches the values from the interval [0, 1] to [0, 255] (more details). Please try to modify the output as below:

{id: "default", bands: 4, sampleType: "FLOAT32"}

I’d also recommend going through this blog post which provides a comprehensive explanation about SampleType.

This makes sense for the localIncidenceAngle, but for the VV, VH, and dataMask values, I want UINT16 values. Is there a way to specify different sampleType values for different bands?

In this case, you could define 2 outputs, one for the VV, VH, and dataMask which contains 3 bands and the other for the localIncidenceAngle.

I’m having trouble finding documentation on how to do define 2 outputs. Can you point me in the right direction? Or do you have an example on how to do this?

Here’s an example request of multiple outputs in curl.

You could copy it, paste it to the Requests Builder, and parse the request using the Request Preview window. Then, you can select sh-py from the drop-down list to convert the request to python.