Hello! when I imported ALOS PALSAR quad-polarization data, the screen showed that “PolSARpro will take into account the ALOS-PALSAR engineer convention for the definition of the polarimetric channels with: s12 = VH and s21 = HV”. What does this mean?
This is most probably not an error but an informative/clarifying message from the app. It informs the construction of the full-polarimetric scattering matrix (S) used for further processing, pointing out that it takes into account the ALOS-PALSAR engineering convention.
By matrix row-column definition, elements of S are : [s11, s12; s21, s22] and the usually followed PolSAR convention for indices is: polarization received polarization transmitted (RT). Check the info below from [1]
From ALOS-PALSAR definition in [2], it seems that their naming of PolSAR indices is reversed (TR). But this only impacts the cross-pol channels, and PolSARpro seems to handle it internally.
[1] Polarimetric Synthetic Aperture Radar: Principles and Application | SpringerLink
Got it, thanks for explaining! Good to know PolSARpro handles that automatically — saves some confusion with the channel naming.
I got it. Thank you very much for your detailed reply. Does this mean that in the .bin files output by PolSARpro, s12 = svh and s21 = shv? However, when I calculated the Faraday rotation angle (FRA) according to the convention s12 = svh and s21 = shv, there is a problem with the sign of the FRA estimates obtained.