I am new to this software and trying to generate the incidence angle band after terrain correction, but there are some options: incidence angle from ellipsoid, local incidence angle, and projected local incidence angle.
I think “incidence angle from ellipsoid” is the angle between radar beam and the normal to the surface of the ellipsoid, and “local incidence angle” is the angle between radar beam and the normal to the earth surface.
But what about “projected local incidence angle”? What is its definition?

The projected local incidence angle is basically the local incidence angle projected into the range plane. It is defined as the angle between the incoming radiation and the projected surface normal into the range plane.

@jun_lu Thanks for your explanation!!!
The figure below is what I understood, alpha is the “local incidence angle”, and beta is the “projected local incidence angle”. Is my understanding correct?

To define the projected local incidence angle, we project the local surface norm n1 to the range plane first. Let’s denote it as n1’. Then the projected local incidence angle is defined as the angle between the radiation S and n1’

Hello @jun_lu
I ask if there are papers about the application of Incidence Angle change detection and its role in archaeological buried/hidden features.

I am sorry that I don’t have papers in the area that you wanted. Generally, before we use the SAR images for change detection, we apply the radiometric calibration to the images to eliminate radiometric effects introduced by the incidence angle, the antenna pattern etc. Then the calibrated SAR images can be used in change detection.