Just wanted some clarification regarding the Application LUT Scaling:
From my reading, my understanding is that these are for post processing of Sentinel-1 SLC and GRD images/data to scale the pixel values (DIN, sigma0, Beta0, etc.) to enhance the range of values in a given image, in order to highlight/optimize the range spread for a given application (eg. sea ice classification) for application to Sentinel-1 images.
However, I am uncertain where to find the LUT for ice for a given image/area/sensor, and how to apply it in SNAP.
Unfortunately I didn’t find much else online regarding this. and perhaps I’m reading it completely wrong, but I’m thankful for any help or clarification you can give.
Per https://sentinel.esa.int/web/sentinel/level-1-post-processing-algorithms , Application LUT’s Scaling:
"Application LUT Scaling
Application LUTs are used to apply a range-dependent gain function to the processed data prior to generation of the final image output. The application LUT scaling is used to optimise the radiometric scaling of the main feature of interest, while optimising the available dynamic range in the output product and to compensate for changes in the radar backscatter with changing incidence angles. LUT’s that could be used include:
Point target application LUTs - suited to applications involving scattering from bright points targets. Typically these LUTs provide poor quantisation over areas of very low backscatter. Sea, land, mixed and **ice LUTs - suited to the thematic applications they describe in which low backscatter features are expected. Typically, bright targets will saturate. Values vary with incidence angle.** General application LUT - typically very bright targets will be saturated.
During satellite Commissioning Phase and related calibration activities, a general purpose LUT has been defined for each acquisition mode, allowing to avoid saturation of both brighter and darker targets and at the same time to reduce as much as possible the quantization error.
Level-1 SLC and GRD images are then scaled to 16 bit and saved in GeoTIFF file format."