Projections with Different Units

[Ed McNierney]

Rick -

You have three different entities in play here - the STATES input layer,
the ORTHOS input layer, and the output map image itself.  If you leave
out all PROJECTION blocks, then all entities are presumed to have the
same projection.  If you only specify a PROJECTION for the output map,
then all layers are presumed to use that same projection.  If you
specify two layers with different projections, then you also need to
specify the PROJECTION you want for the output map image.  That
projection can be the same as either of the two input layers, or a
different projection entirely.

        - Ed

Ed McNierney
President and Chief Mapmaker
TopoZone.com / Maps a la carte, Inc.
73 Princeton Street, Suite 305
North Chelmsford, MA  01863
Phone: +1 (978) 251-4242
Fax: +1 (978) 251-1396
ed at topozone.com 

-----Original Message-----
From: UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU] On
Behalf Of Rick Powers
Sent: Monday, April 11, 2005 5:17 PM
To: MAPSERVER-USERS at LISTS.UMN.EDU
Subject: [UMN_MAPSERVER-USERS] Projections with Different Units

I'm trying to display layers with different projections and units. There
was another good post on multiple UTM projections that I will use.

But an example of my case is State Boundaries (LatLong-Decimal Degrees)
and Terra Server WMS DOQs (UTMs-Meters). I can make both work
independently, but each wants the shared map object to provide
appropriate units.  Any suggestions?

NAME MULTI
STATUS ON
SIZE 400 300
SYMBOLSET symbols/symbol.sym
#EXTENT -126 24 -64 50
#UNITS DD
EXTENT 189600 1976600 818200 5478800
UNITS METERS
SHAPEPATH "data"
IMAGETYPE JPEG
IMAGECOLOR 255 255 204
FONTSET etc/fonts.txt

LAYER
  NAME STATES
  METADATA
    WMS_TITLE "Cartgographic Boundaries of United States States"
    WMS_ABSTRACT "US Census"
    WMS_SRS "EPSG:4326"
    "RESULT_FIELDS" "NAME st99_d00"
  END
  GROUP Admin
  STATUS ON
  DATA cont_states
  TYPE POLYGON
  TRANSPARENCY 60
  CLASS
#    COLOR 31 62 21
    OUTLINECOLOR 31 62 21
    TEMPLATE "ttt_query.html"
  END
  PROJECTION
    "init=epsg:4326"
  END
END
 LAYER
  NAME ORTHOS
  GROUP DOQ
  STATUS ON
  TYPE RASTER
  MINSCALE 10000
  MAXSCALE 264000
  CONNECTIONTYPE WMS
  CONNECTION "http://terraservice.net/ogcmap.ashx?"
  METADATA
    "wms_srs" "EPSG:26910"
    "wms_title" "Orthophoto"
    "wms_name" "DOQ"
    "wms_server_version" "1.1.1"
    "wms_format" "image/png"
    "wms_layers" "doq"
    "wms_group_title" "background"
  END
  PROJECTION
    "init=epsg:26910"
  END
 END