igmk / pamtra

Passive and Active Microwave TRAnsfer model
GNU General Public License v3.0
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Wrong cross-pol formula #12

Closed DaveOri closed 4 years ago

DaveOri commented 4 years ago

While investigating issue #10 three additional points became evident: 1) With Tmatrix calculations the polarization state VH is not allowed 2) With Mie-like scattering all the polarization components are treated as the where unpolarized. Even the non valid ones (try to put KK as polarization status) 3) With tmatrix, the cross-pol component HV is equal to the copol component HH

This can be easily investigated using the example script pyPamTest_radarDualPol.py

DaveOri commented 4 years ago

The problem is likely to be linked to the fact that the backscattering matrices are taken from the azimuthally averaged ones which are useful for the passive calculations. The azimuth average will rotate the components of the scattered field such that the cross-pol components will be null. Also there is likely a bug in the formula for the copol and the unpol cross sections; the unpol should be the average of the two (right?)