[rf] Srf calculation

[Tom Eulenfeld]

Hi Songyun,

welcome to the mailing list!

>  After I running the code and getting Srf in a stream, the component I
> should focus on is L component of Srf based on my understanding, and in the
> documentation, there is no L component mentioned, so I just feel confused
> whether I pay attention to the wrong component of Srf?

Yes, you are correct, you should pay attention to the L component in  
the Srf. The Q component should resemble more or less a peak. In the  
docs only Prfs are described.

> The next question is whether I need to reverse the amplitude polarity of
> Srf? I know the coefficients of Sp and Ps conversions have different signs
> so I think I should reverse Srf polarity to make it comparable with Prf. In
> the documentation, it mentions that Q and T components are multiplied by -1
> to get a positive phase for positive velocity contrast. Does it mean I
> still need to reverse Srf sign again by myself? And all L components are
> not reversed?

Thanks for raising this question. Sorry, I fear the documentation is  
not up to date after I dealt with issue #4  
(https://github.com/trichter/rf/issues/4). At the moment only the Q  
component is polarity reversed *before* the deconvolution for Prf as  
well as Srf. (This is not the case for the R component when using ZRT  
rotation.) I think with this procedure the polarity should be correct  
for Q component in Prf and L component in Srf.
This could be easily checked with synthetic data.

Best regards!
Tom

Zitat von Songyun Huang <songyun at ualberta.ca>:

> Hello sir,
>
> I am Songyun from the University of Alberta, and now I work on S receiver
> function as a graduate student. So sorry to bother you but I have some
> questions about the deconvolution process in rf package.
>
>  After I running the code and getting Srf in a stream, the component I
> should focus on is L component of Srf based on my understanding, and in the
> documentation, there is no L component mentioned, so I just feel confused
> whether I pay attention to the wrong component of Srf?
>
> The next question is whether I need to reverse the amplitude polarity of
> Srf? I know the coefficients of Sp and Ps conversions have different signs
> so I think I should reverse Srf polarity to make it comparable with Prf. In
> the documentation, it mentions that Q and T components are multiplied by -1
> to get a positive phase for positive velocity contrast. Does it mean I
> still need to reverse Srf sign again by myself? And all L components are
> not reversed?
>
> Thank you for your time. Have a nice day.
>
> --
> Sincerely,
> Songyun Huang