[Mapserver-users] EXTENT and PROJECTION
Ed McNierney
ed at topozone.com
Mon Apr 26 14:21:06 EDT 2004
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Ethan -
=20
I think there have actually been quite a few answers - but there are a
lot of different versions of the question!
=20
The very first thing you should do is remove the PROJECTION block from
your MAP file. You are taking the right approach in trying to get just
this image to appear in a single-layer MAP file. If all your layers and
output map are the same projection, you don't need any PROJECTION blocks
at all. If you add one, you create one more thing you have to get
exactly right.
=20
Your EXTENT seems fine based on the listgeo output.
=20
Is your image actually BLANK or is there a broken-link icon (i.e. the
image is missing entirely)? You might try adding the statement
=20
IMAGECOLOR 128 0 0
=20
to the top of the MAP file - this will set the map background to a
distinctive red color (pick any color) to help you confirm that
MapServer's really generating the image.
=20
- Ed
=20
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=20
_____ =20
From: Ethan Alpert [mailto:ealpert at digitalglobe.com]=20
Sent: Monday, April 26, 2004 1:27 PM
To: mapserver-users at lists.gis.umn.edu
Subject: [Mapserver-users] EXTENT and PROJECTION
=20
=20
Hello!
=20
=20
I spent yesterday scouring the archives of this email list trying to
find some info that would help me get a handle on displaying geotiff's
from my mapserver. I found plenty of posts that ask the same questions
but no responses. :/
=20
I promise to write up a summary if someone can point me in the right
direction.
=20
I've learned that if you bork the projection and extents in your mapfile
you end up with a nice blank image and no error message. I'm somewhat at
a loss as to how to go about debugging. So my question is given the
following info about a geotiff how do you experts go about setting up
PROJECTION and EXTENT?
=20
Here's the output of listgeo on my image:
=20
Geotiff_Information:
Version: 1
Key_Revision: 1.0
Tagged_Information:
ModelTiepointTag (2,3):
0 0 0
-5760628 4488331 0
ModelPixelScaleTag (1,3):
1001.042 1001.042 0
End_Of_Tags.
Keyed_Information:
GTModelTypeGeoKey (Short,1): ModelTypeProjected
GTRasterTypeGeoKey (Short,1): RasterPixelIsArea
GTCitationGeoKey (Ascii,31): "TIFF 6.0, GeoTIFF Revision 1.0"
GeographicTypeGeoKey (Short,1): GCS_WGS_84
GeogCitationGeoKey (Ascii,157): "Actual datum is nonstandard,
based on sphere with radius 6370997 meters. Coded in GeoTIFF as WGS84
datum. The difference is not significant at this scale."
ProjectedCSTypeGeoKey (Short,1): User-Defined
PCSCitationGeoKey (Ascii,117): "Lambert Azimuthal Equal Area
projection with arbitrary plane grid; projection center 100.0 degrees W,
45.0 degrees N"
ProjCoordTransGeoKey (Short,1): CT_LambertAzimEqualArea
ProjLinearUnitsGeoKey (Short,1): Linear_Meter
ProjCenterLongGeoKey (Double,1): -100
ProjCenterLatGeoKey (Double,1): 45
End_Of_Keys.
End_Of_Geotiff.
=20
Projection Method: CT_LambertAzimEqualArea
ProjCenterLatGeoKey: 45.000000 ( 45d 0' 0.00"N)
ProjCenterLongGeoKey: -100.000000 (100d 0' 0.00"W)
ProjFalseEastingGeoKey: 0.000000 m
ProjFalseNorthingGeoKey: 0.000000 m
GCS: 4326/WGS 84
Datum: 6326/World Geodetic System 1984
Ellipsoid: 7030/WGS 84 (6378137.00,6356752.31)
Prime Meridian: 8901/Greenwich (0.000000/ 0d 0' 0.00"E)
Projection Linear Units: 9001/metre (1.000000m)
=20
PROJ.4 Definition: +proj=3Dlaea +lat_0=3D45.000000000 =
+lon_0=3D-100.000000000
+x_0=3D0.000 +y_0=3D0.000 +ellps=3DWGS84 +units=3Dm
=20
Corner Coordinates:
Upper Left (-5760628.000,4488331.000) (157d29'26.96"E, 40d47'
8.71"N)
Lower Left (-5760628.000,-2784239.130) (151d38'58.71"W,
4d43'23.63"N)
Upper Right (4279823.260,4488331.000) ( 4d 0'39.82"W, 53d59' 8.05"N)
Lower Right (4279823.260,-2784239.130) ( 61d 9'17.99"W, 11d18'
6.31"N)
Center (-740402.370, 852045.935) (110d51' 5.84"W, 52d12'27.42"N)
=20
Here's the borked map file I wrote:
=20
MAP
IMAGETYPE PNG
SIZE 600 600
SHAPEPATH "data"
EXTENT -5760628.000 -2784239.130 4279823.260 4488331.000
=20
PROJECTION
"proj=3Dlaea"
"lat_0=3D45.000000000"
"lon_0=3D-100.000000000"
"x_0=3D0.000"
"y_0=3D0.000"
"ellps=3DWGS84"
"units=3Dm"
END
=20
=20
=20
WEB
LOG "/var/www/ms.log"
END
=20
LAYER
NAME land
DATA landcvi0201.tif
STATUS DEFAULT
TYPE RASTER
=20
END
END=20
=20
I've tried all kinds of permutations. I'm assuming the extents should be
something other than the extents provided by listgeo but I haven't any
idea what they should be and would like to know what others do when the
get a new image to come up with appropriate extents.
=20
Thanks!
=20
-ethan
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD><TITLE>Message</TITLE>
<META http-equiv=3DContent-Type content=3D"text/html; =
charset=3Dus-ascii">
<META content=3D"MSHTML 6.00.2800.1400" name=3DGENERATOR></HEAD>
<BODY>
<DIV dir=3Dltr align=3Dleft><SPAN class=3D220051618-26042004><FONT =
face=3DArial=20
color=3D#0000ff size=3D2>Ethan -</FONT></SPAN></DIV>
<DIV dir=3Dltr align=3Dleft><SPAN class=3D220051618-26042004><FONT =
face=3DArial=20
color=3D#0000ff size=3D2></FONT></SPAN> </DIV>
<DIV dir=3Dltr align=3Dleft><SPAN class=3D220051618-26042004><FONT =
face=3DArial=20
color=3D#0000ff size=3D2>I think there have actually been quite a few =
answers - but=20
there are a lot of different versions of the =
question!</FONT></SPAN></DIV>
<DIV dir=3Dltr align=3Dleft><SPAN class=3D220051618-26042004><FONT =
face=3DArial=20
color=3D#0000ff size=3D2></FONT></SPAN> </DIV>
<DIV dir=3Dltr align=3Dleft><SPAN class=3D220051618-26042004><FONT =
face=3DArial=20
color=3D#0000ff size=3D2>The very first thing you should do is remove =
the PROJECTION=20
block from your MAP file. You are taking the right approach in =
trying to=20
get just this image to appear in a single-layer MAP file. If all =
your=20
layers and output map are the same projection, you don't need any =
PROJECTION=20
blocks at all. If you add one, you create one more thing you have =
to get=20
exactly right.</FONT></SPAN></DIV>
<DIV dir=3Dltr align=3Dleft><SPAN class=3D220051618-26042004><FONT =
face=3DArial=20
color=3D#0000ff size=3D2></FONT></SPAN> </DIV>
<DIV dir=3Dltr align=3Dleft><SPAN class=3D220051618-26042004><FONT =
face=3DArial=20
color=3D#0000ff size=3D2>Your EXTENT seems fine based on the listgeo=20
output.</FONT></SPAN></DIV>
<DIV dir=3Dltr align=3Dleft><SPAN class=3D220051618-26042004><FONT =
face=3DArial=20
color=3D#0000ff size=3D2></FONT></SPAN> </DIV>
<DIV dir=3Dltr align=3Dleft><SPAN class=3D220051618-26042004><FONT =
face=3DArial=20
color=3D#0000ff size=3D2>Is your image actually BLANK or is there a =
broken-link icon=20
(i.e. the image is missing entirely)? You might try adding the=20
statement</FONT></SPAN></DIV>
<DIV dir=3Dltr align=3Dleft><SPAN class=3D220051618-26042004><FONT =
face=3DArial=20
color=3D#0000ff size=3D2></FONT></SPAN> </DIV>
<DIV dir=3Dltr align=3Dleft><SPAN class=3D220051618-26042004><FONT =
face=3DArial=20
color=3D#0000ff size=3D2>IMAGECOLOR 128 0 0</FONT></SPAN></DIV>
<DIV dir=3Dltr align=3Dleft><SPAN class=3D220051618-26042004><FONT =
face=3DArial=20
color=3D#0000ff size=3D2></FONT></SPAN> </DIV>
<DIV dir=3Dltr align=3Dleft><SPAN class=3D220051618-26042004><FONT =
face=3DArial=20
color=3D#0000ff size=3D2>to the top of the MAP file - this will set the =
map=20
background to a distinctive red color (pick any color) to help you =
confirm that=20
MapServer's really generating the image.</FONT></SPAN></DIV>
<DIV dir=3Dltr align=3Dleft><SPAN class=3D220051618-26042004><FONT =
face=3DArial=20
color=3D#0000ff size=3D2></FONT></SPAN> </DIV>
<DIV dir=3Dltr align=3Dleft><SPAN =
class=3D220051618-26042004> <FONT=20
face=3DArial color=3D#0000ff size=3D2>- Ed</FONT></SPAN></DIV>
<DIV dir=3Dltr align=3Dleft><SPAN class=3D220051618-26042004><FONT =
face=3DArial=20
color=3D#0000ff size=3D2></FONT></SPAN> </DIV>
<DIV dir=3Dltr align=3Dleft><SPAN class=3D220051618-26042004>
<P><FONT size=3D2>Ed McNierney<BR>President and Chief =
Mapmaker<BR>TopoZone.com /=20
Maps a la carte, Inc.<BR>73 Princeton Street, Suite 305<BR>North =
Chelmsford,=20
MA 01863<BR>ed at topozone.com<BR>(978) 251-4242 =
</FONT></P></SPAN></DIV><BR>
<DIV class=3DOutlookMessageHeader lang=3Den-us dir=3Dltr align=3Dleft>
<HR tabIndex=3D-1>
<FONT face=3DTahoma size=3D2><B>From:</B> Ethan Alpert=20
[mailto:ealpert at digitalglobe.com] <BR><B>Sent:</B> Monday, April 26, =
2004 1:27=20
PM<BR><B>To:</B> mapserver-users at lists.gis.umn.edu<BR><B>Subject:</B>=20
[Mapserver-users] EXTENT and PROJECTION<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial=20
size=3D2>Hello!</FONT></SPAN></DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial size=3D2>I =
spent yesterday=20
scouring the archives of this email list trying to find some info that =
would=20
help me get a handle on displaying geotiff's from my mapserver. I found =
plenty=20
of posts that ask the same questions but no responses. =20
:/</FONT></SPAN></DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial size=3D2>I =
promise to write=20
up a summary if someone can point me in the right =
direction.</FONT></SPAN></DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial size=3D2>I've =
learned that if=20
you bork the projection and extents in your mapfile you end up with a =
nice blank=20
image and no error message. I'm somewhat at a loss as to how to go about =
debugging. So my question is given the following info about a geotiff =
how do you=20
experts go about setting up PROJECTION and EXTENT?</FONT></SPAN></DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial size=3D2>Here's =
the output of=20
listgeo on my image:</FONT></SPAN></DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial=20
size=3D2>Geotiff_Information:<BR> Version: 1<BR> =
Key_Revision: 1.0<BR> =20
Tagged_Information:<BR> ModelTiepointTag=20
(2,3):<BR> =20
0 =
=20
0 =
=20
0<BR> =20
-5760628 =20
4488331 =20
0<BR> ModelPixelScaleTag=20
(1,3):<BR> =20
1001.042 =20
1001.042 =20
0<BR> End_Of_Tags.<BR> =20
Keyed_Information:<BR> GTModelTypeGeoKey=20
(Short,1): ModelTypeProjected<BR> =20
GTRasterTypeGeoKey (Short,1):=20
RasterPixelIsArea<BR> GTCitationGeoKey =
(Ascii,31):=20
"TIFF 6.0, GeoTIFF Revision 1.0"<BR> =20
GeographicTypeGeoKey (Short,1): =
GCS_WGS_84<BR> =20
GeogCitationGeoKey (Ascii,157): "Actual datum is nonstandard, based on =
sphere=20
with radius 6370997 meters. Coded in GeoTIFF as WGS84 datum. =
The=20
difference is not significant at this =
scale."<BR> =20
ProjectedCSTypeGeoKey (Short,1): =
User-Defined<BR> =20
PCSCitationGeoKey (Ascii,117): "Lambert Azimuthal Equal Area projection =
with=20
arbitrary plane grid; projection center 100.0 degrees W, 45.0 degrees=20
N"<BR> ProjCoordTransGeoKey (Short,1):=20
CT_LambertAzimEqualArea<BR> =
ProjLinearUnitsGeoKey=20
(Short,1): Linear_Meter<BR> =
ProjCenterLongGeoKey=20
(Double,1): -100<BR> ProjCenterLatGeoKey=20
(Double,1): 45<BR> =
End_Of_Keys.<BR> =20
End_Of_Geotiff.</FONT></SPAN></DIV>
<DIV> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial =
size=3D2>Projection Method:=20
CT_LambertAzimEqualArea<BR> ProjCenterLatGeoKey: 45.000000 ( =
45d 0'=20
0.00"N)<BR> ProjCenterLongGeoKey: -100.000000 (100d 0'=20
0.00"W)<BR> ProjFalseEastingGeoKey: 0.000000 =
m<BR> =20
ProjFalseNorthingGeoKey: 0.000000 m<BR>GCS: 4326/WGS 84<BR>Datum: =
6326/World=20
Geodetic System 1984<BR>Ellipsoid: 7030/WGS 84 =
(6378137.00,6356752.31)<BR>Prime=20
Meridian: 8901/Greenwich (0.000000/ 0d 0' 0.00"E)<BR>Projection =
Linear=20
Units: 9001/metre (1.000000m)</FONT></SPAN></DIV>
<DIV> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial size=3D2>PROJ.4 =
Definition:=20
+proj=3Dlaea +lat_0=3D45.000000000 +lon_0=3D-100.000000000 +x_0=3D0.000 =
+y_0=3D0.000=20
+ellps=3DWGS84 +units=3Dm</FONT></SPAN></DIV>
<DIV> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial size=3D2>Corner =
Coordinates:<BR>Upper Left =
(-5760628.000,4488331.000) =20
(157d29'26.96"E, 40d47' 8.71"N)<BR>Lower Left =20
(-5760628.000,-2784239.130) (151d38'58.71"W, =
4d43'23.63"N)<BR>Upper=20
Right (4279823.260,4488331.000) ( 4d 0'39.82"W, =
53d59'=20
8.05"N)<BR>Lower Right (4279823.260,-2784239.130) ( =
61d=20
9'17.99"W, 11d18' =
6.31"N)<BR>Center =20
(-740402.370, 852045.935) (110d51' 5.84"W,=20
52d12'27.42"N)<BR></FONT></SPAN></DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial size=3D2>Here's =
the borked=20
map file I wrote:</FONT></SPAN></DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial =
size=3D2></FONT></SPAN><SPAN=20
class=3D727181517-26042004><FONT face=3DArial size=3D2>MAP<BR> =
IMAGETYPE=20
PNG<BR> SIZE 600 600<BR> SHAPEPATH "data"<BR> EXTENT=20
-5760628.000 -2784239.130 4279823.260 4488331.000</FONT></SPAN></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial size=3D2> =
PROJECTION<BR> =20
"proj=3Dlaea"<BR> =20
"lat_0=3D45.000000000"<BR> =20
"lon_0=3D-100.000000000"<BR> =20
"x_0=3D0.000"<BR> =20
"y_0=3D0.000"<BR> =20
"ellps=3DWGS84"<BR> "units=3Dm"<BR> =20
END</FONT></SPAN></DIV>
<DIV> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial=20
size=3D2></FONT></SPAN> </DIV>
<DIV> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial size=3D2> =
WEB<BR> LOG "/var/www/ms.log"<BR> =20
END</FONT></SPAN></DIV>
<DIV> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial size=3D2> =
LAYER<BR> NAME land<BR> DATA=20
landcvi0201.tif<BR> STATUS =
DEFAULT<BR> TYPE=20
RASTER</FONT></SPAN></DIV>
<DIV> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial size=3D2> =
END<BR>END=20
<BR></FONT></SPAN></DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial size=3D2>I've =
tried all kinds=20
of permutations. I'm assuming the extents should be something other than =
the=20
extents provided by listgeo but I haven't any idea what they should be =
and would=20
like to know what others do when the get a new image to come up with =
appropriate=20
extents.</FONT></SPAN></DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial=20
size=3D2>Thanks!</FONT></SPAN></DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D727181517-26042004><FONT face=3DArial=20
size=3D2>-ethan</DIV></FONT></SPAN></BODY></HTML>
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