It seems to me that the SRTM dataset is available in tiles of 1°x1°,
with a 3 arc second resolution, which gives a raster of 1200x 1200
pixels. 3 arc second is ~90 meter, but *exactly* 3 arc second in WGS84.
http://dds.cr.usgs.gov/srtm/version2_1/Documentation/Quickstart.pdf
Yves
Le 04/03/2012 19:36, Ed Linde a écrit :
Yves, I am not sure I understand what you are saying..sorry. My
question is basically if the points within a single cell can
potentially have different elevation values because of interpolation?
Or do all the points that lie within a cell get one elevation
value?
On Sun, Mar 4, 2012 at 2:36 PM, yvecai <yve...@gmail.com
<mailto:yve...@gmail.com>> wrote:
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 value?
Just a guess.
Yves
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