Radiometric processing of RCM compact pol not supported

s1tbx
#1

I succeeded in opening a MLC compact pol RCM product in SNAP
(I posted a solution for this and for some reason it is variable: you have to open the product.xml file of the /metadata/ subdir, but sometimes opening the manifest.safe file works instead).
However, radiometric operations such as Calibrate or Radiometric Terrain Flattening fail with the following message: “Not handled polarization”.
Of course, RCM’s compact pol, specifically hybrid compact polarization (HCP), is something quite different from the usual dual cross-pol.
I am wandering if there is a temporary workaround for this, or if there are any plans for including RCM HCP in radiometric processing (or polarimetric processing for that matter).

Thanks

#2

My experience is that I have been able to apply Calibrate operator to RCM compact pol data before, although it was SLC (complex format) compact-pol data that I used. I have not attempted the Calibrate operator on an MLC format RCM product. If the data are not in SLC format the Calibrate operator may not work.

Something else I found, sometimes RCM data does not open properly unless I unzip the data myself (before opening manifest.SAFE)

Hope to hear back on what you discover! cheers

#3

Thanks Ashlin. The problem is that over the Canadian territory, the RCM compact pol (CH CV) 30 m resolution MLC product is the one with the largest coverage. Although I can open the MLC files (after unzipping), the radiometric operations fail with the “Not handled polarization” message. Calibration or Radiometric terrain flattening fail.

1 Like
#4

Hi Benoit,
Thank you for the information. My guess would be the calibration method depends on the “actual” complex numbers, so the calibration or terrain flattening can’t be applied in that format. However, with any luck, the product is actually radiometrically calibrated already (might want to check the metadata or even get in touch with the NRCAN ground segment group if there aren’t any clues or documentation online)

(Big coverage is great! Admittedly I’m a bit of a quad-pol die-hard. Different applications can benefit from different processing or channels, a lot more corrections and quality control are possible with the full quad-pol in SLC format haha!)
cheers
Ashlin

#5

That is, if you have a Compact-pol RCM dataset which is in SLC which is also not the scan-sar SC30CMCPB, my guess is the calibration operator would run for you. Just now I tried running the “Calibrate” operator on such a dataset and it did run without errors : )