Computing the inertia operator of a rigid body

We prove that the inertia operator A of a rigid body is generically determined, up to a scalar multiple, by the curve Omega in R-3 that describes its angular velocity in the body. The precise condition is that Omega not be contained in a two-dimensional subspace of R-3. We derive two indirect methods to compute A from the values of Omega over an arbitrary interval, and a direct method to compute A from the second- and fourth-order moments of Omega. The direct method utilizes moment identities derived from symmetries in Euler's equation. (C) 2001 American Institute of Physics.