The paper will describe the use of a TV based system to measure the position of fringes in the interferograms of OTF standard lenses, as formed in a Twyman-Green interferometer. The core of the system is the transfer, under computer control, of sampled image signals from the TV to the buffer store of a desktop computer. Data recovered from this memory is then analysed to determine the exact position of fringes within the interferogram pupil. Details of the computer subroutines used to evaluate fringe positions and to automatically renumber the fringes will be followed by a brief description of data fitting routines used to derive aberration polynomials and thence the lens Optical Transfer Function.
K. G. Birch,
D. J. Pugh,
P. D. West,
"TV Based System For Interferogram Analysis", Proc. SPIE 0369, Max Born Centenary Conf, (16 June 1983); doi: 10.1117/12.934367; https://doi.org/10.1117/12.934367