Publication Title

Journal of Guidance, Control, and Dynamics

Document Type


Department or Program


Publication Date



An analytical method is presented for determining if two ellipsoids share the same volume. The formulation involves adding an extra dimension to the solutions space and examining eignevalues that are associated with degenerate quadric surfaces. The eigenvalue behavior is characterized and then demonstrated with an example. The same method is also used to determine if two ellipsoids appear to share the same projected area based on an observer's viewing angle. The following approach yields direct results without approximation, iteration, or any form of numerical search. It is computationally efficient in the sense that no dimensional distortions, coordinate rotations, transformations, or eigenvector computations are needed.


Original version is available from the publisher at:

Copyright Note

This is the author's version of the work. This publication appears in Bates College's institutional repository by permission of the copyright owner for personal use, not for redistribution.