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NAD27 to NAD83

Question asked by geonetadmin on Aug 30, 2011
Latest reply on Aug 31, 2011 by MKennedy-esristaff
Original User: CJHatTRWD

Hi all-

I have a few questions to ask about a project I am working on. I have scanned maps from the 70's into .jp2s, and am having a hard time converting the coordinates from NAD_1927_StatePlane_Texas_North_Central_FIPS_4202 to NAD_1983_StatePlane_Texas_North_Central_FIPS_4202. The coordinates given on the maps are in NAD27, so I used the Georeferencing toolbar and control points to place the points on the image in a workspace defined in NAD83 (images at this stage are NAD27 because of the coordinates on the map). So, when the maps are in NAD27, they are in the correct place in my workspace, but, when I right click a layer and go Data -> Export Data to change the projection, or use Define Projection, or Project Raster, ArcMap takes my NAD27 image and throws it way south of where it needs to be. So, I have two main questions: 1) Why is my image being placed south of where I need it to be and 2) when I use Data ->Export Data (which is what I've had the most luck working... sometimes) the image that is exported is nowhere near the quality of the original, and there are little black dots all around the image that end up looking somewhat like a blackline border. Anyone know anything about how to fix?? Thanks!

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