SAR: Handle correctly GEC data

[remi-braun]

For now, for SAR data, GEC products are not terrain-corrected!
Fix this by applying a terrain correction step tho these images.

Concerned products:

• COSMO GEC
• TSX/TDX/PAZ GEC
• RS2: Potentially SSG and SPG according to user's criteria
• RCM: Potentially GCC and GCD according to user's criteria
• SAOCOM GEC
• Capella GEC
• Umbra GEC Handle Umbra products #114

💡 S1 and ICEYE doesn't have such product type

Example

[remi-braun]

This cannot be done, there is no clean / automatic way to do this.

[remi-braun]

In https://www.asi.it/wp-content/uploads/2019/08/COSMO-SkyMed-Mission-and-Products-Description_rev3-1.pdf

You can't pass from L1C (GEC) to L1D (GTC) easily.