[Mapserver-users] DRGs in MapServer

Thu Jul 1 09:52:10 EDT 2004

Steve -

I've got over 59,000 DRGs loaded and served by MapServer at
www.topozone.com (along with over a quarter of a million aerial photos
and several other data types).  MapServer handles them just fine through
its TILEINDEX mechanism, by which many different raster (or vector)
files can be combined into one single logical layer.

We also provide this data to customers through ArcIMS and OGC WMS
interfaces, so if you're interested in going that route (we host and
serve the images for you), please contact me off-list.

Otherwise, you should have no trouble using MapServer doing what you
want.  There's no "redefinition" of layers involved, beause the one
layer that uses a TILEINDEX tells MapServer to consult the TILEINDEX
file - a table of polygons describing the outlines of each of the
individual raster files - and use that to calculate which raster images
are needed for any image request.

	- Ed

Ed McNierney
President and Chief Mapmaker
TopoZone.com / Maps a la carte, Inc.
73 Princeton Street, Suite 305
North Chelmsford, MA  01863
ed at topozone.com
(978) 251-4242  

-----Original Message-----
From: mapserver-users-admin at lists.gis.umn.edu
[mailto:mapserver-users-admin at lists.gis.umn.edu] On Behalf Of Stephen H.
Savage
Sent: Thursday, July 01, 2004 9:00 AM
To: mapserver-users at lists.gis.umn.edu
Subject: [Mapserver-users] DRGs in MapServer

Greetings,

   In AZ we have nearly 2,000 DRG's at 1:24,000 scale.  We would like to
have these maps displayed as the background for our web site that serves
archaeological sites and projects.  However, in ArcIMS, which we are
currently using, all these image layers would have to be pre-loaded into
the map; this is clearly out of the question.  What we need to do is add
and subtract image layers from the map on-the-fly, as a user pans or
zooms around the map.  Is this something that MapServer can do?
Ideally, at the scale at which we want the DRGs to be displayed,
portions of no more than 4 map tiles would be displayed at any time.

   Basically, ArcIMS defines the map once, with all its layers loaded.
Then, for each user session, the map server sends out session data such
as the view extent, which layers are on, etc.  You can't redefine the
map's layers because it involves a situation where each user would get a
different map definition rather than a different instance of the same
map.  Is the the same way thet MapServer works?

Thanks,

-Steve