Wrong Projection of map after georeferencing

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07-11-2013 02:43 AM
joda
by
New Contributor
Hello all,

I have a little problem with the map Projection after georeferencing.

Tried to georeference a map of Antarctica.

Before doing this i set the projection of the layer, the shapefile i want the tiff map to be georeferenced to and the tiffmap itself to the projection: Southpole Stereographic with WGS1984 coordinate system.

After having perfect overly with georeferencing i pushed: "rectify" and saved the georeferenced map as a new tiff.

But when i check properties of this new tiff in ArcCatalog it has always: Nortpole stereographic projection.
How can that be? what am I doing wrong?

Can anybody help me with this issue?
thanks a lot.
joe
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2 Replies
WilliamMortimer
New Contributor III
Hello all,

I have a little problem with the map Projection after georeferencing.

Tried to georeference a map of Antarctica.

Before doing this i set the projection of the layer, the shapefile i want the tiff map to be georeferenced to and the tiffmap itself to the projection: Southpole Stereographic with WGS1984 coordinate system.

After having perfect overly with georeferencing i pushed: "rectify" and saved the georeferenced map as a new tiff.

But when i check properties of this new tiff in ArcCatalog it has always: Nortpole stereographic projection.
How can that be? what am I doing wrong?

Can anybody help me with this issue?
thanks a lot.
joe


Hi Joe,
Try this sequence:
1. Project your shapefile to UPS etc.
This is now your known projection & coord system.
(So you now have a shape file in Universal Polar Stereographic)

2. Open up a new arc-map session:
Add your shape file. _ check your co-ord system. It should be UPS and have units that make sense.
Now drop in your Tiff file and start Geo-referencing... (This will be done in your 'known co-ord system & projection).
Save a text file with your GCP's created during Geo-referencing.
Now rectify..and save as a different image file-name.
If you get asked to create a world file with your tiff/jpeg etc you should say - yes.

If you have a problem with the rectify - you can go back and load your GCP's again.. etc.

Often you get data that says its one system, but the units don't look right, when you drop it into arc etc.
You may have also been working with a tiff file that was already in a projected system. (ie it had a world file and was a geo-tiff).
If this was the case then you could have just reprojected/transform the raster (arctoolbox -... projections & transformations...raster....)

Hope this helps in some way,
William.
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joda
by
New Contributor
Hi Joe,
Try this sequence:
1. Project your shapefile to UPS etc.
This is now your known projection & coord system.
(So you now have a shape file in Universal Polar Stereographic)

2. Open up a new arc-map session:
Add your shape file. _ check your co-ord system. It should be UPS and have units that make sense.
Now drop in your Tiff file and start Geo-referencing... (This will be done in your 'known co-ord system & projection).
Save a text file with your GCP's created during Geo-referencing.
Now rectify..and save as a different image file-name.
If you get asked to create a world file with your tiff/jpeg etc you should say - yes.

If you have a problem with the rectify - you can go back and load your GCP's again.. etc.

Often you get data that says its one system, but the units don't look right, when you drop it into arc etc.
You may have also been working with a tiff file that was already in a projected system. (ie it had a world file and was a geo-tiff).
If this was the case then you could have just reprojected/transform the raster (arctoolbox -... projections & transformations...raster....)

Hope this helps in some way,
William.





Hi William,

thank you it worked now with this way and a new shapefile.
The one i used first seems to be somehow erroneous although arcgis prperties are the same.

thanks :)

joe
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