Re: [arts-users] Polarized brightness temperature
Hi Patrick， Thank you for your quick reply, the advice you provided is very helpful, thank you again very much! Best wishes, Jiaan He At 2023-10-18 01:11:31, "Patrick Eriksson" wrote: >Hi, > >The only way to get ARTS to do QV and QH automatically, is to use a >"system" denoted as metmm. You find it in folder > >arts/controlfiles/instruments/metmm > >It is not totally straightforward to use and the documentation is not >extensive. As far as I know, the documentation is basically the file >TestMetMM.arts. > >The sensor definitions are found in sub-folder sensor_descriptions. >Inside these QV and QH are denoted AMSU-V and AMSU-H. This assumes that >QH and Qv work in the same way for all cross-track microwave radiometer. >I assume this is true, but I am not 100% sure. > >Bye, > >Patrick > > > >On 2023-10-17 14:15, suifengbenpao2023 wrote: >> Dear ARTS community, >> >> >> ARTS provides calculation methods for vertical polarization and >> horizontal polarization. However, many sensors are now set up with QH >> and QV polarization. I simulated the brightness temperature of a >> satellite borne microwave radiometer channel at 23.8GHz (QH >> polarization) over the ocean using a one-dimensional atmosphere, and the >> first Stokes vector I obtained was close to the observed QH polarization >> brightness temperature. However, the simulated brightness temperature of >> H polarization （instrument_pol, [6] ) was significantly different from >> the observed QH brightness temperature, May I ask if it is possible to >> simulate the QH polarization of spaceborne radiometers through the H >> polarization of ARTS? Is it still possible that I input other variables >> incorrectly? >> >> >> Looking forward to your reply！Thank you! >> >> Best wishes, >> >> Jiaan He
Re: [arts-users] Polarized brightness temperature
Hi, The only way to get ARTS to do QV and QH automatically, is to use a "system" denoted as metmm. You find it in folder arts/controlfiles/instruments/metmm It is not totally straightforward to use and the documentation is not extensive. As far as I know, the documentation is basically the file TestMetMM.arts. The sensor definitions are found in sub-folder sensor_descriptions. Inside these QV and QH are denoted AMSU-V and AMSU-H. This assumes that QH and Qv work in the same way for all cross-track microwave radiometer. I assume this is true, but I am not 100% sure. Bye, Patrick On 2023-10-17 14:15, suifengbenpao2023 wrote: Dear ARTS community, ARTS provides calculation methods for vertical polarization and horizontal polarization. However, many sensors are now set up with QH and QV polarization. I simulated the brightness temperature of a satellite borne microwave radiometer channel at 23.8GHz (QH polarization) over the ocean using a one-dimensional atmosphere, and the first Stokes vector I obtained was close to the observed QH polarization brightness temperature. However, the simulated brightness temperature of H polarization （instrument_pol, [6] ) was significantly different from the observed QH brightness temperature, May I ask if it is possible to simulate the QH polarization of spaceborne radiometers through the H polarization of ARTS? Is it still possible that I input other variables incorrectly? Looking forward to your reply！Thank you! Best wishes, Jiaan He
Re: [arts-users] Polarized brightness temperature
Hi Patrick,Thank you for your help! I tried the method you provided and it shows that TBv=TB(I)+TB(Q),TBh=TB(I)-TB(Q). So does that mean TB(Q)=(TBv-TBh)/2. Not sure if I have to understand correctly? Note: TB stands for brightness temperature. Looking forward to your reply again, thanks! Sincerely， Jiaan He. At 2023-10-10 18:50:31, "Patrick Eriksson" wrote: >Hi, > >For theory, see Sec 5.7 of doi:10.1016/j.jqsrt.2011.03.001 >Note especially Eq 19. > >To automatically extract V and/or H inside ARTS, you need to use >sensor_responsePolarisation, with polarisations measured/wanted >specified by instrument_pol. > >Bye, > >Patrick > >On 2023-10-09 09:32, suifengbenpao2023 wrote: >> Dear ARTS community, >> >> >> Currently I am simulating H and V polarization brightness temperatures, >> but I found that the polarization calculation in the description is not >> the same as the traditional radiation calculation (Q=Iv-Ih), so how >> should I calculate the brightness temperatures of H and V polarization >> from the stokes vector of brightness temperatures? How is it derived? >> >> >> Looking forward to your reply！Thank you! >> >> Best wishes, >> >> Jiaan He
Re: [arts-users] Polarized brightness temperature
Hi, For theory, see Sec 5.7 of doi:10.1016/j.jqsrt.2011.03.001 Note especially Eq 19. To automatically extract V and/or H inside ARTS, you need to use sensor_responsePolarisation, with polarisations measured/wanted specified by instrument_pol. Bye, Patrick On 2023-10-09 09:32, suifengbenpao2023 wrote: Dear ARTS community, Currently I am simulating H and V polarization brightness temperatures, but I found that the polarization calculation in the description is not the same as the traditional radiation calculation (Q=Iv-Ih), so how should I calculate the brightness temperatures of H and V polarization from the stokes vector of brightness temperatures? How is it derived? Looking forward to your reply！Thank you! Best wishes, Jiaan He
