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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.<br>
<a class="moz-txt-link-freetext" href="http://dds.cr.usgs.gov/srtm/version2_1/Documentation/Quickstart.pdf">http://dds.cr.usgs.gov/srtm/version2_1/Documentation/Quickstart.pdf</a><br>
Yves<br>
<br>
Le 04/03/2012 19:36, Ed Linde a écrit :
<blockquote
cite="mid:CAK4dkcV3Rf6szHsCha-DEkHP4wKG9YdL373bW-xWxSw=_6nn=w@mail.gmail.com"
type="cite">Yves, I am not sure I understand what you are
saying..sorry. My question is basically if the points within a
single cell can
<div>potentially have different elevation values because of
interpolation? Or do all the points that lie within a cell get
one elevation</div>
<div>value?<br>
<br>
<div class="gmail_quote">On Sun, Mar 4, 2012 at 2:36 PM, yvecai
<span dir="ltr"><<a moz-do-not-send="true"
href="mailto:yvecai@gmail.com">yvecai@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt
0.8ex; border-left: 1px solid rgb(204, 204, 204);
padding-left: 1ex;">
<div bgcolor="#ffffff" text="#000000"> Le 04/03/2012 14:14,
Ed Linde a écrit :
<blockquote type="cite">
<div>
<div class="h5">Hi All,
<div>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?</div>
<div>Would be great if I could get some help
understanding this concept about SRTM rasters.</div>
<div><br>
</div>
<div>Cheers,</div>
<div>Ed </div>
</div>
</div>
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</blockquote>
Wouldn't that be a grid of 1°/1201 by 1°/1201 with
1201x1201 elevation value?<br>
Just a guess.<br>
Yves<br>
</div>
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