[postgis-users] SRTM Raster Geometry question

yvecai yvecai at gmail.com
Sun Mar 4 05:36:35 PST 2012

Le 04/03/2012 14:14, Ed Linde a écrit :
> Hi All,
> Can someone help me understand a concept with the SRTM raster. My 
> understanding is that the raster can be thought of as a uniform grid 
> with each cell having dimension =  "90m x 90m" (for SRTM-1 dataset). 
> Now I am just wondering if the elevation values are 4 values at each 
> vertex or boundary point of a cell? or is it one elevation value for 
> the 90x90 m^2 area covered by the cell? I ask because if its the first 
> option, then it would mean that every point that falls in the cell has 
> it's elevation calculated using some sort of interpolation between the 
> 4 corner points of the cell to arrive at this point's altitude. Or do 
> several points that fall into this 90x90 cell get assigned the same 
> elevation value?
> Would be great if I could get some help understanding this concept 
> about SRTM rasters.
> Cheers,
> Ed
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Wouldn't that be a grid of 1°/1201 by 1°/1201 with 1201x1201 elevation 
Just a guess.
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