Custom Distance Units in ArcGIS Desktop 10?

Question

Is it possible to add custom distance units (ex. varas) to ArcGIS Desktop so that they can be used when inputting distances in Editor and COGO tools?

I often work with deeds that reference distances in varas. It would be super handy if I could setup the conversion factor and have ArcMap do the math rather than needing to convert all my distances to feet before entering them.

Answer 1

ArcGIS using COGO you can apply 'ground to grid correction'

*ArcEditor or ArcGIS only

Click Ground To Grid Correction on the COGO toolbar.

When you read the COGO descriptions for boundaries on a survey plan or other legal document, the directions and distances are measured on the surface of the earth. These are referred to as ground measurements. However, the directions and distances in your GIS data are based on the spatial data's coordinate system, or the grid measurements. Ground and grid measurements are often different. You may set constants (the ground to grid correction) for directions and distances so that the software can correctly convert between the ground and grid measurements.

http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Applying_a_ground_to_grid_correction/001t000000mz000000/