What Is the Areal Radius in Geography?

[edwiddy]

Homework Statement

My professor mentioned something called "areal radius" briefly in class, but it's I'm unclear as to what it means. It doesn't appear in the index of any textbook I have, and google is pretty unhelpful since it parses it as "area" or "a real" and returns lots of results like that. Can anyone provide some insight?

Homework Equations

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The Attempt at a Solution

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thanks!

 

[grey_earl]

In what context did he mention it?

 

[dextercioby]

I think there might be the case of <areal velocity vector> when speaking about Kepler's laws.

 

[grey_earl]

That could be one. I was more thinking of GR (and curved spaces in general), where areal radius would mean (I think) \sqrt{A/Pi}, which because of the curvature is not the same as coordinate radius, or proper length radius along a geodesic. Maybe too advanced :)