<div dir="ltr"><br><div>Hi Andre,</div><div><br></div><div>Thank you very much for the reply. I hadn't thought of querying the levels as you suggest but I'll remember next time that it makes a good test.</div><div><br></div><div>However, I'm not sure what I would do with the <TileLevel>7</TileLevel> suggestion</div><div>you make. If I change my WMS control file to use that value, gdal_translate doesn't work at all so there must be something more to it than that. (I've learned the hard way over the years that changing the WMS control file is not for amateurs.)</div><div><br></div><div>If you could explain what you meant, I'd be very grateful. Thanks,</div><div><br></div><div>carl</div><div><br></div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Jul 7, 2015 at 7:22 AM, Andre Vautour <span dir="ltr"><<a href="mailto:andre.vautour@caris.com" target="_blank">andre.vautour@caris.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
Looks like that server only has 7 levels for that satellite layer:<br>
<a href="http://mt.google.com/vt/lyrs=s&x=0&y=0&z=7" target="_blank">http://mt.google.com/vt/lyrs=s&x=0&y=0&z=7</a><br>
<a href="http://mt.google.com/vt/lyrs=s&x=0&y=0&z=8" target="_blank">http://mt.google.com/vt/lyrs=s&x=0&y=0&z=8</a><br>
<br>
The terrain and map layers have 22 levels:<br>
<a href="http://mt.google.com/vt/lyrs=t&x=0&y=0&z=22" target="_blank">http://mt.google.com/vt/lyrs=t&x=0&y=0&z=22</a><br>
<a href="http://mt.google.com/vt/lyrs=t&x=0&y=0&z=23" target="_blank">http://mt.google.com/vt/lyrs=t&x=0&y=0&z=23</a><br>
<a href="http://mt.google.com/vt/lyrs=m&x=0&y=0&z=22" target="_blank">http://mt.google.com/vt/lyrs=m&x=0&y=0&z=22</a><br>
<a href="http://mt.google.com/vt/lyrs=m&x=0&y=0&z=23" target="_blank">http://mt.google.com/vt/lyrs=m&x=0&y=0&z=23</a><br>
<br>
So, you'd have to change the TileLevel element:<br>
<TileLevel>7</TileLevel><br>
<br>
That smaller size probably ended up querying tile levels < 8
which is why it worked.<br>
André<div><div class="h5"><br>
<br>
<br>
<div>On 2015-07-07 11:02, Carl Godkin wrote:<br>
</div>
</div></div><blockquote type="cite"><div><div class="h5">
<div dir="ltr"><br>
<div>Hi,</div>
<div><br>
</div>
<div>I would like to know if there's a way to determine if a
GDAL WMS download</div>
<div>is going to work or not from the information in the local
description file.</div>
<div><br>
</div>
<div>I'm using C++ code to do this, but can illustrate my
question with a gdal_translate</div>
<div>command. This command fails:</div>
<div><br>
</div>
<div>
<div>gdal_translate -outsize 6700 6700 \</div>
<div> -srcwin 144884562 100729336 178000 178687 \</div>
<div> frmt_wms_googlemaps_tms.xml \</div>
<div> out.tif</div>
</div>
<div><br>
</div>
<div>
<div>Input file size is 268435456, 268435456</div>
<div>0...10...20...30...40...50...60...70ERROR 1: GDALWMS:
Unable to download block 35372, 24624.</div>
<div> URL: <a href="http://mt.google.com/vt/lyrs=s&x=35372&y=24624&z=16" target="_blank">http://mt.google.com/vt/lyrs=s&x=35372&y=24624&z=16</a></div>
<div> HTTP status code: 404, error: (null).</div>
<div>ERROR 1: frmt_wms_googlemaps_tms.xml, band 1: IReadBlock
failed at X offset 35372, Y offset 24624</div>
</div>
<div><br>
</div>
<div>but if I change the -outsize arguments to 6500 and 6500, it
works fine. </div>
<div><br>
</div>
<div>I am perfectly willing to accept the limitations of what's
available, but can I tell where that limit will be?</div>
<div><br>
</div>
<div>The service file is from the frmts/wms directory with the
"Satellite" ServerURL line active instead of the "Map" line.</div>
<div><br>
</div>
<div>Notes: </div>
<div>1. Curiously, the default "Map" ServerURL works to much
higher resolution (at least 15000) which makes me</div>
<div>think that the answer to my question will be "no" since the
service description files are otherwise identical!</div>
<div>2. The map area above is Italy, but I see the same sort of
behavior around the world.</div>
<div><br>
</div>
<div>I am using GDAL 1.11.2 on Windows7 x64, but see the same
behavior on Linux RHEL5 64-bit as well.</div>
<div><br>
</div>
<div>Thank you very much for any insight,</div>
<div><br>
</div>
<div>carl</div>
</div>
<br>
<fieldset></fieldset>
<br>
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