How to change polarization in CRTM?

CRTM
1

Hi,
In CRTM, if the sensor is fixed in the SensorData structure, the polarization of each channel is fixed. For example, the polarization of ATMS channel 1,2, and 16 is QV and the other channels are QH. Is it possible to calculate QH brightness temperature for channel 1, 2, and 16, QV brightness temperature for other channels through CRTM?
Thanks!

Jun

2

@Jun the instrument polarization in the CRTM is supposed to be fixed.
You can try the following workaround:

  1. In your CRTM calculation, load the SC data:
  ! ...Spectral coefficients
  USE CRTM_SpcCoeff          , ONLY: SC
  1. After the call to CRTM_Init(), modify the SC data with the polarization scheme you want:
SC(1)%Polarization(begin_chan : end_chan) = desired_polarization_scheme
  1. Run the CRTM calculation as usual.

This hasn’t been tested though.

3

I’ve tested this in my code:
SC(1)%Polarization(1:2)=10
SC(1)%Polarization(3:15)=9
SC(1)%Polarization(16)=10
SC(1)%Polarization(17:22)=9
The output seems reasonable.
Thanks a lot!

Jun

1 Like
4

Thank you for confirming.