Processing of interferometric fringe scanner data for the AXAF/TMA x-ray telescope

An interferometric fringe scanner was used for the Technology Mirror Assembly (TMA) x-ray telescope, built by Perkin-Elmer as a technology demonstration for the Advanced X-Ray Astrophysics Facility (AXAF). We discuss advanced data processing features, implemented during a follow-on project to improve the mirror's midfrequency errors still further. Data processing techniques include interleaving of multiple scans, and optimal smoothing and interpolation of the interleaved data onto a uniform grid. We discuss the underlying mathematics behind the processes, the motivation in terms of recovering the highest possible spatial frequencies from the data, and some sample results.