Reply to comment by Z. S. Yao, R. G. Roberts and A. Tryggvason on 'Explicit, approximate expressions for the resolution and a posteriori covariance of massive tomographic systems.'

Comments on the query on the accuracy of the algorithm for the approximate estimation of the resolution matrix of tomographic systems. Suggestion of a Newtonian scheme; Question of the usefulness of the one-step backprojection; Similarity between A[sup T]A and the estimated resolution matrix.