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Modified central meridian and UTM grid with 'standard' central meridian

April 26 2011 | 0 comments
Categories: ArcGIS Methods, Map Elements, Page Layout

Hello- I've recently created a map with an SRS of UTM 12N NAD83 and a modified central meridian of 114°. (111° being the standard CM for zone 12N) I did this simply because it 'straightened' out the study area and made it fit on the paper better.

However, now i'm attempting to place a UTM grid on the map that users will be able to use in conjunction with GPS units, and the output UTM grid is also in UTM 12N NAD83 with a central meridian of 114°. This doesn't affect the UTM northing values, but the easting values are shifted considerably due to the modified CM.

So, is it possible for me to add a UTM grid with UTM values based on the 'standard' central meridian of 111° without modifying the whole map's central meridian and having to lay the whole map out again?


Mapping Center Answer:

To modify the grid on the map, you need to change the coordinate system properties for that measured grid.  You can either do this when you create the new grid (it will be on the second page of the dialog -- click the Properties button next to Coordinate System to change the central meridian back to 111) or you can do it after you have added the grid (right click the data frame name in the table of contents, click Properties, on the Grids tab click the measured grid you added, then click Properties, and on the System tab, select the option to "Use another coordinate system" and set the parameters to be what you want).

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