Improved and quantified accuracy for linear spectral estimates

In the context of spectral estimation, this paper examines the use of an `orthonormal basis´ wherein prior knowledge (in the form of fixed poles) may be incorporated in the solution and FIR structures are then seen as a special case of implicitly involving prior knowledge of all poles at the origin. The main technical results are ones that quantify the accuracy of the resulting spectral estimates in a way that clearly exposes how it is affected by the fixed pole choice