Ask A Cartographer

Projections and data migration

May 18 2011 | 0 comments
Categories: ArcGIS Methods, Map Data

Hi. I have a feature class (a) with a GCS_North_American_1983 XY Coordinate System. I have another, empty, feature class (b) that has a NAD_1983_UTM_Zone_12N XY Coordinate System. I want to append data from (a) to (b). Can I append data directly from (a) to (b) and maintain the original data's (a) spatial accuracy?

Thanks!

Mapping Center Answer:

The UTM coordinate system (in meters) will actually have higher precision (think of this as more decimal places) than the geographic coordinate system (in decimal degrees), so in converting the GCS data to the UTM projected coordinate system you will not lose any "accuracy". When you do this, choose the NAD_1983_To_WGS_1984_5 geographic transformation for the 48 contiguous United States.

And one last thing -- check the units of measure for the UTM projection -- normally they are meters but some folks in Arizona use U.S. survey feet. Just make sure you are using the right ones for what you need.

If you would like to post a comment, please login.

Contact Us | Legal | Privacy |