Sentinel-1 incidence angles

Hi,
I was wondering, if I can somehow obtain the incidence angles when using Sentinel-1 scenes via WCS or eo-learn.
That information would be extremely helpful when using the SAR data!

Kind regards,
Johannes

This is for the moment not possible, but certainly a useful feature to be added in the future!

+1 for this feature request!

2 Likes

Hi,

I would like to ask if there has been an update regarding this matter (incidence angles). Or if at least it is possible to get the satellite’s coordinates (lat/long/altitude) when an acquisition has been made. This may help computing the corresponding incidence angle (using the incidence range, the pixels’ coordinates and the Earth’s curvature).

Thanks,
Best regards,
Arlen

We are actuallt considering adding this option at the moment. Significant chance it will be added in the next 2-3 months.
Stay tuned.

1 Like

Hello,
I was wondering if you eventually consider to include information about incidence angles.
Kind Regards,
Christoph

Working on them at the moment.
They are actually already supported, but not yet documented as validation process is in place.
Feel free to give it a try and provide your feedback.

input: [{bands:["VV", "VH", "ILLUMINATED_AREA", "INCIDENCE_ANGLE", "dataMask"], metadata: ["bounds"]}],

Orthorectification needs to be enabled.

Thanks for the quick response.

Are incidence angles also available for EW acquisition mode?
My aim is to download HH maps (gamma0 in decibel) and the corresponding local incidence angle. When I download maps via python API (WMS request) I am using the following simple evalscript:

//VERSION=3
return [Math.max(0, Math.log(HH) * 0.21714724095 + 1), dataMask, INCIDENCE_ANGLE];

Unfortunately, I receive either 0 or 225 for the INCIDENCE_ANGLE and no range of values. Did I make a mistake? If yes, do you have an example evalscript, which can be used to obtain the local incidence angles?

Thanks a lot!
Kind regards,
Christoph

I was not able to try as I do not know, where you are trying to get some reasonable result, nor how result should look like, but perhaps worth trying the following Evalscript.
If it does not work, please send us the examplary WMS request (mask part of the instance ID), so that we give it a try.

//VERSION=3
function setup() {
  return {
    input: ["HH","INCIDENCE_ANGLE", "dataMask"],
    output: { 
	bands: 3,
	sampleType: "FLOAT32" 
    }
  };
}
function evaluatePixel(sample) {
  var val = Math.max(0, Math.log(sample.HH) * 0.21714724095 + 1);
  var angle = 255;
  if ( samples.dataMask != 0) angle = samples.INCIDENCE_ANGLE / 360 * 254;
  return [val,sample.dataMask,angle];
}
1 Like

Hello,

+1 interested in incidence angles from S1.

I was able to get them through Mundi. They were written as UINT8 [0-255] in degrees; however I was wondering if it’s possible to get in FLOAT. I have an area of 25x25km and only 3 data points in integers. It’s for a model input so the more granular the better. If we change the data type to FLOAT32 can I get the data in degrees with decimal places (not only integers)? Is that what the above formula answering to cherbert90 is trying to do?

Thanks,
Tatiana

I think the angle is in UINT8 in the source data, so we cannot provide anything more detailed.

1 Like

Hello,

I get Sentinel 1 images through Mundi, I have a code to download images including the incidence angle which was working on December 10. I tried downloading data last week again on Thursday 17 but I was getting an error message.

Francois-Xavier from Mundi told me that the problem was on Sinergise’s side. He’s on holidays now. I attach a screen shot of the error message I get. Is this something that you recognise?

Thanks!
Tatiana

It’s quite a bit difficult to assist without proper information, e.g. example of the WCS request (part of the instance ID should be masked).

That being said, the band name is “ANGLE”, I believe, not "INCIDENCE_ANGLE.

S1GRD has no band ANGLE

Any idea?

Angle band (I believe it is called localIncidenceAngle) is generated by Sentinel Hub in the process of CARD4L processing, see: