Questions about rtcoef_fy3_5_mwts3_srf.dat

[liu xuan]

Dear James,

I want to simulate the microwave brightness temperature in the 31.4GHz band, under both horizontal and vertical polarization. After checking, I found that the MWTS3 sensor of FY3-E contains a 31.4GHz band. But when I opened its coefficient file to check, I found that his MPOL is not horizontally polarized or vertically polarized in that band. Can this rtcoef_fy3_5_mwts3_strf.dat be regenerated? I know that hydrotable_fy3_mwts3.dat can be regenerated.

Looking forward from you.

Yours sincerely,
LiuXuan

[James Hocking]

Dear LiuXuan,

You can edit the polarisation for each channel in the rtcoef file directly if you want to test V and H pol simulations instead of the QV/QH polarisation. The polarisations do not affect the gas optical depth coefficients. The hydrotables are also independent of the channel polarisation because RTTOV is not a polarised scattering RT model, although you should be aware of the approximate polarisation treatment applied by RTTOV-SCATT in v13. I strongly recommend you consult section 8.7 of the user guide, and particularly page 84 in the v13.2 user guide if you are running RTTOV-SCATT simulations after changing the polarisation to V or H pol for MWTS-3.

Best wishes,
James

[liu xuan]

Dear James,

Thank you for your answer. I directly modified the polarization method in the rtcoef file. In addition, regarding the issue of multithreading, I think it is because the nlevels of each profile are different, and each profile needs to be configured with a corresponding data structure.

Best wishes,
LiuXuan

[James Hocking]

Dear LiuXuan,

Yes, RTTOV requires all profiles to be defined on the same number of levels. It is strongly reommended to input profiles on the native vertical levels of the profile source data. For example, if they come from an NWP model, then you should input the profile data on the NWP model vertical grid. In this case, all your profiles will be on the same number of levels.

Best wishes,
James

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