This paper develops nonparametric deconvolution density estimation
over $SO(N)$, the group of $N \times N$ orthogonal matrices of determinant 1.
The methodology is to use the group and manifold structures to adapt the
Euclidean deconvolution techniques to this Lie group environment. This is
achieved by employing the theory of group representations explicit to $SO(N)$.
General consistency results are obtained with specific rates of convergence
achieved under sufficient smoothness conditions. Application to empirical Bayes
prior estimation and inference is also discussed.