[postgis-users] SRTM Raster Geometry question

[Ed Linde]

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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