Design of a diluted aperture by use of the practical cutoff frequency

We analyze the imaging performance of a number of diluted-aperture configur ations, using the modulation transfer function. We select a single figure o f merit, the practical cutoff frequency, rather than the traditional cutoff frequency, as the more useful frequency for the detection of details. Usin g this new parameter, we compare the performance of a number of published a perture configurations. On the basis of this analysis a new configuration i s proposed for the Polar Stratospheric Telescope primary. (C) 1999 Optical Society of America.