topic geotiff image displays stretched east -west in Data Management Questions

geotiff image displays stretched east -west

NoelCantwell — Wed, 17 Aug 2011 20:14:15 GMT

New to Arc products,..just tinkering with ArcMap. cannot figure out why geotiff image displays stretched disproportionally in the x (east west). Just thought I'd put it out on this forum while I continue to play with this software.
Thanks in advance.

Re: geotiff image displays stretched east -west

JamieDrisdelle — Wed, 17 Aug 2011 21:14:57 GMT

Hi Noel,

It really depends which projection your imagery is in. Different projections will distort your data in different ways. you can check the projections of a raster by right clicking on it in the table of contents and opening it's properties. Click on the source tab and scroll down to the spatial reference section.

Here is some additional information on projections and how they affect your data:

http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/About_map_projections/003r0000000q000000/

http://support.esri.com/en/knowledgebase/techarticles/detail/23025

I hope this helps.

Jamie

Re: geotiff image displays stretched east -west

NoelCantwell — Thu, 18 Aug 2011 16:47:47 GMT

thanks, I'll look into that,.... but i'm wondering why its not picking the correct projection info from the geotiff header

Re: geotiff image displays stretched east -west

EricRice — Fri, 19 Aug 2011 14:41:38 GMT

Noel,

What is the projection listed in the layer properties? Have you confirmed that the projection listed in the tiff header is different? ArcGIS reads tiff header information. The other thing to consider is the coordinate system of the map's dataframe. If it is different, then ArcMap will project the data on-the-fly to whatever the dataframe is. My guess is your data is either in a geographic coordinate system, or the dataframe is. To check the dataframe, go to ArcMap > View > Dataframe Properties > Coordinate System tab. Perhaps some screen shots would be helpful to show the distortion in the X direction, and of the layer properties (coordinate system info). It would also be helpful to know the location of the data - some projections distort more severely in certain geographic locations.

Best Regards,
Eric