Design of a multiple-zone aperture and application to a Fabry-Perot interferometer

A design for a multiple-zone aperture (MZA), which is applied to a Fabry-Perot interferometer for gaining greater throughput, is described. It is shown that there exists a definite value for the width of the aperture that gives, the minimum error in Doppler temperature measurements when instrumental parameters and the width of the source profiles are given. The effects caused by the imperfections of the MZA are analyzed. The successful use of an MZA with a 15-cm (6-in.) Fabry-Perot interferometer for measurement of an airglow emission line is described.