What is "Projected Local Incidence Angle"?

I use SNAP for the radarsat2. During the Doppler Range Terrain Correction, we are able to get some outputs such as Projected Local Incidence Angle (PLIA) and Local Incidence Angle (LIA) and also Incidence Angle from Ellipsoid (IAE).

But I didn’t get exactly what is the main “difference” and “advantages” of exporting any of these three? The most confusing one is PLIA! And the most common one is LIA I guess.

The input to produce this could be “calibrated Sigma naught” in addition to DEM. Am I right?

Is there anyone to clarify these terms?

Hello, have you received any answer from someone? I have the same question, I do not see the difference between the Projected Local Incidence Angle and the Local Incidence Angle…