Christian Froeschlin <chr### [at] chrfrde> wrote:
> Mahadeesh wrote:
>
> > I mean reflectivity pattern here as BACK SCATTERING effect of the objects in the
> > scene. Like calculation of single, double and triple bounce effect from the
> > ray.. When all these effects are summed together we get, back scattering effect
> > of the object.I need reflectivity map of any 3D modeled object. I may not
> > require to consider the effects of interference. Just a simple creation of
> > reflectivity map of any object/ scene. Thank you.
>
> It sounds like what you want to achieve could be approximated by
> a light source (possibly a spot light if you have a confined beam),
> diffuse textures for the back scattering, and radiosity for the
> bounces. With the caveat that the light model for diffuse reflection
> probably does not accurately reflect microwave backscattering.
>
> I'm still not quite sure what the end result should be. A normal
> render (camera image) would give you an image of the scene indicating
> how much light is reflected into the direction of the camera for each
> point of the object. If the camera and the light source are in the
> same location that is probably an approximation of an "echo".
>
> If you are more interested in the effect of the  object on the
> surrounding you can put a sphere around the object and see how this is
> illuminated through radiosity. If you want some total measure of light
> scattered from each position of the object regardless of direction,
> things are likely to get tricky although the mesh camera might help.


Hello,

You are exactly right. What you have mentioned in the paragragh one is what im
looking for.

SAR image comes under microwave imaging technology. The SAR image simulation for
an scene is my final output. The input here has to be an image from which i have
to extract the backscattering values for each position in the image/for an
object. Finally using this back scattering values in the any of the pre-existing
SAR algorithm to form SAR equivalent image.

I agree that we cant simulate microwave backscattering effect, but instead of
that an light model is considered here. Can you throw some light on the line
"diffuse texture for the back scattering" as mentioned in your post ? Similarily
on the "radiosity for the bounces" ?

It would be very much useful if POV ray can calculate these values for me ? So
that i can extract those values and use it in my algorithm.

Sample SAR image for your reference.

https://www.google.co.in/search?q=SAR+image&hl=en&client=ubuntu&hs=bEM&channel=fs&tbm=isch&tbo=u&source=univ&sa=X&ei=Us
xaUZHQMcSIrQebm4GgDA&ved=0CDAQsAQ&biw=1067&bih=713#hl=en&client=ubuntu&hs=cZ1&channel=fs&tbm=isch&sa=1&q=synethetic+ape
rture+radar+image+&oq=synethetic+aperture+radar+image+&gs_l=img.3...14733.26980.4.27340.34.31.3.0.0.0.154.2713.29j2.31.
0...0.0...1c.1.8.img.j2PiLVDb-G4&bav=on.2,or.r_qf.&bvm=bv.44697112,d.bmk&fp=9cd1c99b78ac4f1a&biw=1067&bih=713&imgrc=kuh
ug3D1KiKnvM%3A%3BhL2JrnPfbrQReM%3Bhttp%253A%252F%252Fwww.sandia.gov%252FRADAR%252Fimages%252Fcapitol.jpg%3Bhttp%253A%25
2F%252Fwww.sandia.gov%252FRADAR%252Fimageryku.html%3B1200%3B800


PLease let me know if you need more details. Awaiting for your response.

Regards,
M

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