Passive ranging through wave-front coding: information and application

Passive-ranging systems based on wave-front coding are introduced; These si ngle-aperture hybrid optical-digital systems are analyzed by use of linear models and the Fisher information matrix. Two schemes for passive ranging b y use of a single aperture and a single? image are investigated: (i) estima ting the range to an object and (ii) detecting objects over a set of ranges . Theoretical limitations on estimator-error variances are given by use of the Cramer-Rao bounds. Evaluations show that range estimates with less than 0.1% error can be obtained from a single wave-front coded image. An experi mental system was also built, and example results are given. (C) 2000 Optic al Society of America OCIS codes: 150.0150. 150.5670, 150.6910, 150.3040.