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Re: optimization; which point falls into a polygon [message #68033 is a reply to message #68032]

Wed, 23 September 2009 04:38

Maarten[1]
Messages: 176
Registered: November 2005

Senior Member

On Sep 22, 11:57 pm, Klemen <klemen.zak...@gmail.com> wrote:

> I am working with geostationary satellite data and some GIS rasters.
> The satellite data do not have a regular sampling (pixel has a form of
> a parallelogram) but I know corner coordinates of each pixels.
>
> I would like to do some kind of spatial join - I would like to know
> which of my pixels in GIS rasters (regularly sampled) fall into each
> satellite pixel – I would like to create a raster where each GIS pixel
> contains an index of the corresponding satellite index.

[snip]

> Does anybody have a suggestion?

Approach from the other direction.

The IDLanROI class can do this for you. Loop over all Satellite
pixels, and create an IDLanROI object for it, using the corner
coordinates. Use the ContainsPoints method to figure out which GIS
raster point fall in this Satellite grid cell. ContainsPoints is array
aware. Use where on the result, and set the result in your destination
array to the intended value.

Caveats: Since you are geostationary, you won't have to deal with the
poles, but the dateline might be an issue. The correct way is to do
everything in Cartesian coordinates, but I never bothered.

Maarten

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[Message index]

		Re: optimization; which point falls into a polygon By: penteado on Wed, 23 September 2009 08:56
		Re: optimization; which point falls into a polygon By: hethomas on Wed, 23 September 2009 08:08
		Re: optimization; which point falls into a polygon By: Klemen on Wed, 23 September 2009 05:11
		Re: optimization; which point falls into a polygon By: Jeremy Bailin on Wed, 23 September 2009 04:46
		Re: optimization; which point falls into a polygon By: Maarten[1] on Wed, 23 September 2009 04:38
		Re: optimization; which point falls into a polygon By: Klemen on Fri, 25 September 2009 02:13

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