From: Barend Köbben <[EMAIL PROTECTED]>
To: Bradley Mclain <[EMAIL PROTECTED]>
Subject: Re: [UMN_MAPSERVER-USERS] Raster Image and Shapefile Alignment
Date: Fri, 02 Feb 2007 09:19:33 +0100
HI,
The shapefile is in an Australian projection, and your raster has been
georeferenced to *something*, but there's no telling to what
projection they
georef'd it, because there's no projection info in the raster file.
In other words: someone told the raster "you fit in this place in the
world,
between XY 1 and XY 2", but they didn't specify in what projection system
those XY's are. You would suppose to the same projection the vector is
in,
and in that case, the fit will be OK as long as the projection of the
shape
remains the same as it was when the raster was georef'd to it. But if one
changes that projection, or maybe only the Datum, as tends to happen
unexpectedly when you transfer files from one GIS to another, things will
misalign...
To make matters worse, it can also just be a case of sloppy
georeferencing...
Without knowing the rasterprojection, there's no solution, except
re-doing
the georeferencing...
On 02-02-2007 07:16, "Bradley Mclain" <[EMAIL PROTECTED]> wrote:
> Umm I know very little about geodata so i'll simply attach the
readouts from
> ogrinfo and gdalinfo so you can see for yourself cause i have no
idea. :)
>
> If it helps any they are only out slightly. (as shown in attached
> screenshot)
>
> Bradley Mclain
>
>
>
>
>> From: "Gregor Mosheh" <[EMAIL PROTECTED]>
>> Reply-To: [EMAIL PROTECTED]
>> To: "Brad_Mclain" <[EMAIL PROTECTED]>
>> CC: [email protected]
>> Subject: Re: [UMN_MAPSERVER-USERS] Raster Image and Shapefile
Alignment
>> Date: Thu, 1 Feb 2007 23:02:05 -0700 (MST)
>>
>>> Ok here is the sitution I have a raster image and shapefile data
but the
>>> two do not line up correctly.
>>
>> Are you positive that they're both in the same projection? Or, do
you know
>> the projection for each one? I've had so many annoyances in the
past where
>> something was in "CA State Plane II" and then had to figure out
which of
>> the five CA State Plane II projections it really was. :)
>>
>> If you know the projection for each, be sure to specify it in your
mapfile
>> using a PROJECTION block in your LAYER block. You can probably get
more
>> help on that once we know a bit more about the matter.
>>
>> Best of luck, Brad.
>>
>> -G
>>
>
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