How do you convert from USA Contiguous Albers Equal Area Conic to meters? Or, to latitude and longitude?
I am using ArcGIS 10.1, and within it, ArcMap. The shapefile I have reports the coordinates as USA Contiguous Albers Equal Area Conic. I want to take areas and distances of the polygons and they are very large due to the units. I am wondering how to convert to meters.
In particular, I want to do distance calculations, and I worry that Albers distorts the distances. How can get the most precise and meaningful distances when the shapefile orginated as Albers Equal Conic?
The shapefile is of United States counties. I would like to compute its distances within it.
Best Answer
The coordinate system, USA Contiguous Albers equal area conic, by default is in meters, so any calculations you do should be in meters or square meters. Depending on how large the polygons are, the values could be very large. Did you want to have the values reported in kilometers instead? The Calculate Geometry tool lets you choose a different unit value.
In the ArcGIS for Desktop 10.1 help, the help topic is in Geodata, Data types, Tables, Calculating field values, Calculating area, length, and other geometric properties.
There's a small chance that someone modified the USA Contiguous Albers definition and changed the units. You can check this by looking at the coordinate system of the layer in ArcMap or ArcCatalog.