Flash light detection and ranging range accuracy limits for returns from single opaque surfaces via Cramer-Rao bounds

A Cramer-Rao lower bound on the range accuracy obtainable by a Flash light detection and ranging (LADAR) system receiving a return from a single surface in the instantaneous field of view of each detector is developed and verified with experimental data. The bound is compared to the performance of a new algorithm and that of a matched filter receiver by using both simulated and measured LADAR data. The simulated data are used to show that the estimator is nearly unbiased and efficient for systems that match the negative paraboloid model used in its derivation. It is found that the achievable range accuracy for the LADAR system and for the target geometry used to collect the measured data is of the order of 2.5 in. while the bound predicts a range accuracy limit of approximately 0.6 in.