[GRASSLIST:5128] Re: Sound reflection and refraction

Crudeli crudeli at mail.nauta.it
Mon Dec 2 02:33:33 EST 2002

>Hi all,
>Has anybody ever tried to interpolate sound (==> noise) in a general 
>GIS? I only mean 2D interpolation. I know 2D is a big compromise but 
>it has to be done for my school assignment and at this level I do 
>not intend to use a 3D technique.
>How would you treat the spread of a signal from a source r.cost is 
>not a very good solution because of the refraction (picture the 
>emission and imission points on the opposite sides of a building).
>What about the reflection from objects?

you could use an aspect map in conjunction with a slope map, so that 
you know the normal 3D-versor to the surface, and hence calculate the 
main reflection path (beware the 0° orienation of the aspect map).
Since you are working in 2D, I assume that you have a raster map 
defining the edges of buildings.
BTW, how do you want it to work? raster maps based or vector-like?


RafDouglas CTC

RafDouglas Candidi Tommasi Crudeli

ct at ehleng.com

"To know, to will, to dare, to be silent."

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