<div dir="ltr">James,<div><br></div><div>From the docs:</div><div><br></div><div><p id="index-88"><strong>wms_extent</strong></p>
<ul>
<li><p class=""><em>WMS TAG Name:</em> BoundingBox (WMS1.1.1, sect. 6.5.6)</p>
</li>
<li><p class=""><em>Description:</em> (Optional) Used for the layer’s BoundingBox tag for
cases where it is impossible (or very inefficient) for MapServer to
probe the data source to figure its extents. The value for this
metadata is “minx miny maxx maxy” separated by spaces, with the
values in the layer’s projection units. If wms_extent is provided
then it has priority and MapServer will NOT try to read the source
file’s extents.</p>
<p>For Rasters served through WMS, MapServer can now use the wms_extent
metadata parameter to register the image. If a .wld file cannot be
found, MapServer will then look for the wms_extent metadata
parameter and use the extents of the image and the size of the image
for georegistration.</p>
</li></ul><div><br></div></div><div>So basically the wms_extent is supposed to be in the layer projections coordinate system range. With UTM zones, the x-coordinate for the center of each zone is 500,000m and approximately 180km east and west of the meridian ( varies with latitude) , see <a href="http://geokov.com/education/utm.aspx">http://geokov.com/education/utm.aspx</a> . You should never have a negative number in a UTM zone x coordinate and your minimum x would be around 166,000m and maximum x coordinate is 834,000m ( at the equator). </div>
<div><br></div><div>Not sure where you got your coordinates for all UTM Zones for the Continental US, but I would guess that they are from some continental projection like US Albers Meters CONUS. If you have shapefile indexes of the rasters with projection information, you should not need wms_extent in your mapfile.</div>
<div><br></div><div>Doug</div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div><div><br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Fri, Jan 24, 2014 at 12:31 AM, James_in_Utah <span dir="ltr"><<a href="mailto:James.Evans@hill.af.mil" target="_blank">James.Evans@hill.af.mil</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi,<br>
I'm deploying the USDA NAIP image set on two of our servers on a closed LAN<br>
with about 20 users. About half of the NAIP set on each server. I'm also<br>
running MapCache on one of the servers with the cache being stored on an<br>
empty drive. The NAIP set is divided up by states, and some of the states<br>
have more than one projection, for instance, California is in NAD83 UTM Zone<br>
10 and Zone 11. I've created a layer for each state, and if the state has<br>
more than one UTM Zone, then there is a layer for each of the zones. So,<br>
for California, I have CA_Zone10, and CA_Zone11 layers. So I probably have<br>
close to 100 layers representing all of CONUS. Being lazy, I put the same<br>
"wms_extent" in the METADATA portion of each layer. The extent is large<br>
enough to cover all of CONUS. Will this cause performance issues? All 100<br>
odd USDA_NAIP layers have the same "wms_extent:. Will that cause MapServer<br>
to open each of the shape files looking for the requested bounding box?<br>
<br>
Also, I have all the NAIP layers on one server grouped into "USDA_NAIP", and<br>
all the NAIP layers on the other server grouped into "USDA_NAIP2", and the<br>
MapCache has added each of the these "Groups" as sources. The users will<br>
just have to select both NAIP layers in MapCache. Is there some way to have<br>
both "Groups" appear as one layer in MapCache? Everything seems to be<br>
working, although it does seem slow, with just me hitting it so far.<br>
<br>
I've include my two California layers below as examples. Any suggestions on<br>
optimizing this would be appreciated. I'm using the latest dev release of<br>
MS4W.<br>
Thanks,<br>
James<br>
<br>
<br>
<br>
LAYER<br>
NAME "CA_Zone10"<br>
GROUP "USDA_NAIP"<br>
METADATA<br>
"wms_title" "CA_Zone10"<br>
"wms_name" "CA_Zone10"<br>
#Extent for USA<br>
"wms_extent" "-1154717.71708742, 2635432.86320029,<br>
3632346.10222763, 6578042.27294455"<br>
"wms_srs" "ESPG:26910"<br>
"wms_style" "Default"<br>
"wms_format" "image/png"<br>
END<br>
STATUS ON<br>
TYPE RASTER<br>
TILEINDEX "D:\\MapData\\USDANAIP\\ca\\Zone10.shp"<br>
TILEITEM "Location"<br>
PROJECTION<br>
"init=epsg:26910"<br>
END<br>
MAXSCALEDENOM 1000000<br>
END<br>
<br>
LAYER<br>
NAME "CA_Zone11"<br>
GROUP "USDA_NAIP"<br>
METADATA<br>
"wms_title" "CA_Zone11"<br>
"wms_name" "CA_Zone11"<br>
#Extent for USA<br>
"wms_extent" "-1154717.71708742, 2635432.86320029,<br>
3632346.10222763, 6578042.27294455"<br>
"wms_srs" "ESPG:26911"<br>
"wms_style" "Default"<br>
"wms_format" "image/png"<br>
END<br>
STATUS ON<br>
TYPE RASTER<br>
TILEINDEX "D:\\MapData\\USDANAIP\\ca\\Zone11.shp"<br>
TILEITEM "Location"<br>
PROJECTION<br>
"init=epsg:26911"<br>
END<br>
MAXSCALEDENOM 1000000<br>
END<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
--<br>
View this message in context: <a href="http://osgeo-org.1560.x6.nabble.com/Does-wms-extent-of-a-layer-impact-performance-tp5099776.html" target="_blank">http://osgeo-org.1560.x6.nabble.com/Does-wms-extent-of-a-layer-impact-performance-tp5099776.html</a><br>
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</blockquote></div><br><br clear="all"><div><br></div>-- <br><div>Doug Newcomb</div><div>USFWS</div><div>Raleigh, NC</div><div>919-856-4520 ext. 14 <a href="mailto:doug_newcomb@fws.gov" target="_blank">doug_newcomb@fws.gov</a></div>
<div>---------------------------------------------------------------------------------------------------------</div><div>The opinions I express are my own and are not representative of the official policy of the U.S.Fish and Wildlife Service or Dept. of the Interior. Life is too short for undocumented, proprietary data formats.</div>
</div>