Why not RCS_VH ?

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jpadam
2012-08-17
2012-09-11
  • jpadam
    jpadam
    2012-08-17

    I've noticed that the VH cross polarisation is never computed... is there a
    particular reason for that ?

    If I want to add VH, I had to modify the following files (contain occurrences
    of RCS_HV) ?

    code/RCS_MLFMA.py

    code/setup_MLFMA.py

    code/MoM/mpi_mlfma.cpp

    Thanks

     
  • Hi,

    I might be wrong, but I think RCS_HV should be reciprocal to RCS_VH, no? If
    not, I'll implement it...

     
  • jpadam
    jpadam
    2012-08-21

    Hi Ides,

    This might be true in some cases. For example, in radar imaging, both cross
    polarization images are the same. However, I don't think it is true for the
    general bistatic case. Anyway, even in the cases where we expect RCS_HV =
    RCS_VH, it would be good to have both in order to check that the reciprocity
    isn't violated...

     
  • You're right, of course. I'll implement it. It's been a while since my last
    commit, but this one should be relatively easy.

    Cheers

    Ides

     
  • jpadam
    jpadam
    2012-08-21

    Thank you !

    JP

     
  • Hi Jpadam,

    I did it: RCS_VH has been added, and it works: I checked it. It's in the git
    code, not yet in the release. To get the latest code, type in a terminal:

    git clone git://puma-em.git.sourceforge.net/gitroot/puma-em/puma-em

    (you need to install git).

    Cheers

    Ides

     
  • jpadam
    jpadam
    2012-08-29

    Thanks for that, Ides ! I'm testing it right now.

    Thanks also for the little reminder about the reciprocity between RCS_HV and
    RCS_VH. I have to confess I overlooked it a bit too quickly, but It is
    actually useful in many cases.

    JP

     
  • You're welcome...

     
  • jpadam
    jpadam
    2012-09-11

    The files RCS_HH_ASCII.txt, RCS_HV_ASCII.txt, etc... contain the monostatic RCS, right ? The bistatic RCS can be derived from e_theta_far_ASCII.txt and e_phi_far_ASCII.txt, isn't it ?

    I was just wondering what tool you use to handle those files, since Excel and its open source counterparts aren't very good at opening them (complex numbers, not column formatted, etc...).

    JP

     
    • each ascii can be open by scilab or matlab
      On Sep 11, 2012 1:16 PM, "jpadam" jpadam@users.sf.net wrote:

      The files RCS_HH_ASCII.txt, RCS_HV_ASCII.txt, etc... contain the
      monostatic RCS, right ? The bistatic RCS can be derived from
      e_theta_far_ASCII.txt and e_phi_far_ASCII.txt, isn't it ?

      I was just wondering what tool you use to handle those files, since Excel
      and its open source counterparts aren't very good at opening them (complex
      numbers, not column formatted, etc...).

      JP

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  • Yes and I think yes.

    Right now I don't use anything special to handle those files. It would be nice if you could suggest a format that I could implement for maximum portability and ease of use... Could you give me an example of what would be an acceptable format?

    Ides

     
  • jpadam
    jpadam
    2012-09-11

    Thanks for the replies !

    Yehonatan Chattah, can you tell me what command you use to load the ascii files into matlab please ?

    Ides, I don't have any particular format in mind. In my own simulations tools, I usually just use a column format, separated by blanks or tab. For example :

    theta phi RCS ...
    0 90 1.0 ...
    1 90 1.0 ...
    ...

    An alternative would be the CSV format, but there might be a conflict with the complex numbers.

    My suggestions are influenced by the tools I use. Maybe others, using "more scientific" tools want to see something else.

    I think, this is open to discussion...

     
    Last edit: jpadam 2012-09-11