Resampling rasters from unprojected WMS sources ?

[Lars V. Nielsen (HVM)]

Hi Ed,

Posting the complete MAP file would be too much, and I thought the general
issue whether MS can reproject wms/rasters or not wouldn't need specific
examples.

But in any case, here is a relevant excerpt:

MAP myMAP
RESOLUTION 96
STATUS ON
UNITS METERS
SIZE 600 480
EXTENT 363842 6027893 863744 6427815
PROJECTION
    "init=EPSG:25832"
END
# the lat-long WGS84 only WMS service
LAYER
    NAME GoogleMaps
    TYPE RASTER
    STATUS ON
    CONNECTIONTYPE WMS
    CONNECTION
"http://www.gispro.dk/googlemaps_wms.php?service=wms&version=1.1.1&request=g
etmap&layers=sat_auto&format=image/jpeg"
    PROJECTION
        "init=EPSG:4326"
    END
END
# other vector layers natively in EPSG:25832, e.g.:
LAYER
    NAME "myVectorLayer"
    PROJECTION
        "init=EPSG:25832"
    END
    Type LINE
    CONNECTIONTYPE OGR
    CONNECTION ".../myTable.TAB"
    STATUS ON
    CLASS
        COLOR 0 0 255
        TEMPLATE void
    END
    TOLERANCE 10
END
END

I've uploaded the experienced visual appearence of the same front vector
layer with each background layer :

- with satellite imagery: http://www.gis.hvm.dk/test/ms_sat_back.jpg (with
the flattened appearence)

- with grey backdrop: http://www.gis.hvm.dk/test/ms_grey_back.png

- as seen in MapInfo Pro (distorts the vector to fit the raster):
http://www.gis.hvm.dk/test/mi_sat_back.jpg

- - - - - - - -

I'm using MapScript 4.5 ($Revision: 1.223 $ $Date: 2005/01/04 22:55:27 $) in
Php 4.3.7 on W2K.

Best regards / Med venlig hilsen
Lars V. Nielsen
--------------------------------------------------------
Hvenegaard & Meklenborg
Rugaardsvej 55, DK-5000 Odense C
Denmark
http://www.hvm.dk
----- Original Message -----
From: "Ed McNierney" <ed at topozone.com>
To: "Lars V. Nielsen (HVM)" <LVN at HVM.DK>; <MAPSERVER-USERS at LISTS.UMN.EDU>
Sent: Friday, May 27, 2005 8:36 PM
Subject: RE: [UMN_MAPSERVER-USERS] Resampling rasters from unprojected WMS
sources ?


Lars -

It sounds like the right approach; could you post the MAP file if
possible?  Thanks.

- 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 Lars V. Nielsen (HVM)
Sent: Friday, May 27, 2005 9:14 AM
To: MAPSERVER-USERS at LISTS.UMN.EDU
Subject: [UMN_MAPSERVER-USERS] Resampling rasters from unprojected WMS
sources ?

I'm rendering a map in a UTM projection, but want to add a satellite
image wms service that only delivers images in lat/long wgs84.

No problem, I set the wms layer projection to epsg:4326, while my map
(and other layers) use projection epsg:25832. And it works, or almost
...

The sat image is distorted - "flattened" - so the vector line work
layers on top of it exceeds the country coast line north and south. And
quite significantly so.

Shouldn't the raster re-projection algoritms in Mapserver take care of
such distortions, or is mixing projected and unprojected coordinate
systems
(still) a no-no ?

Best regards / Med venlig hilsen
Lars V. Nielsen
--------------------------------------------------------
Hvenegaard & Meklenborg
Rugaardsvej 55, DK-5000 Odense C
Denmark
http://www.hvm.dk