We study Cramér-Rao bounds (CRB's) for estimation problems on Riemannian manifolds. In [S. T. Smith, “Covariance, Subspace, and Intrinsic Cramér-Rao bounds,” IEEE Trans. Signal Process., vol. 53, no. 5, 1610-1630, 2005]
Boumal, N. (2013). On intrinsic Cramér-Rao bounds for Riemannian submanifolds and quotient manifolds. IEEE Transactions on Signal Processing, 61(7), 1809-1821. https://doi.org/10.1109/TSP.2013.2242068 (Original work published 2013)