The Mean Radius of an Ellipse calculator computes Ellipsethe mean radius (rμ) of an ellipse based on the semi-major (a) and semi-minor (b) axes of the ellipse.
INSTRUCTIONS: Choose units and enter the following:
Mean Radius (r): The calculator returns the mean radius (rμ) in meters. However, this can be automatically converted to other length units via the pull-down menu.
In mathematics, an ellipse is a curve in a plane surrounding two focal points such that the sum of the distances to the two focal points is constant for every point on the curve. As such, it is a generalization of a circle, which is a special type of an ellipse having both focal points at the same location. The shape of an ellipse (how "elongated" it is) is represented by its, which for an ellipse can be any number from 0 (the limiting case of a circle to arbitrarily close to but less than 1.
`r_u = (2 a +b)/3`
Since the Earth is an oblate spheroid, closely approximated by an ellipsoid, thedefines the Earth's mean radius using:
This computes and Earth mean radius of 6,371.009 kilometers (3,958.761 mi).
Description of an ellipse is from Wikipedia (en.wikipedia.org/wiki/Ellipse)