topic Re: Projecting point shapefile between northern and southern hemispheres in ArcMap9.3 in Data Management Questions

Projecting point shapefile between northern and southern hemispheres in ArcMap9.3

seanblake — Thu, 08 Sep 2011 06:06:58 GMT

Hi all
I have a point shapefile in WGS84 UTM Zone 55S. I am trying to project it to WGS UTM Zone 55N so I can calculate the corresponding E/N values. For some reason when I go through the process of projecting the view to WGS84 UTM Zone 55N my eastings look fine (ie the same as for the S) but my northings are negative values. As all the literature states there should be no -ve values in UTM. I'm not sure what is happening?
I'm also trying to project a .tiff from the N to the S hemisphere and can't do that either.
Anyone had experience of this??
Cheers

Re: Projecting point shapefile between northern and southern hemispheres in ArcMap9.3

MelitaKennedy — Thu, 08 Sep 2011 18:11:08 GMT

Hi,

You're getting the right coordinates. Northern hemisphere UTM zones have a Y/northing origin at the equator so any data below there will have negative Y values. Southern hemisphere UTM zones have a Y origin at the equator too, but add a false northing of 10000000 m. That means all Y coordinates in the southern hemisphere will be positive. Points above the equator will have Y values larger than 10 million meters.

Melita

Re: Projecting point shapefile between northern and southern hemispheres in ArcMap9.3

seanblake — Fri, 09 Sep 2011 03:38:27 GMT

Thanks for that Melita!