Potential applications include optical communications, target tracking, and image processing.

Progress has been made on several fronts in a continuing program of research oriented toward the development of real-time algorithms, and computer and control systems that utilize the algorithms, for adaptive filtering, prediction, and system identification with improved efficiency and numerical stability in applications that involve large numbers of channels and high filter orders. Potential applications include adaptive optics, optical communications, target tracking, image processing, blind identification and deconvolution in wireless communications, and active control of noise and vibration.

The program has included three main subprograms supporting different aspects of research and development at the Air Force Research Laboratory on directed-energy weapons and laser communications:

• Control (more precisely, suppression) of laser-beam jitter.

These Scoring-Camera Images, acquired in experiments in an adaptive-optics laboratory testbed, show that the laser beam was more tightly focused when adaptive control was used.

In this subprogram, lattice-filter- based subspace system- identification and adaptive control algorithms were applied in laser- beam-steering experiments. It was shown that enhanced rejection of disturbances is achievable in laser-beam steering by use of modern optimal feedback controllers augmented with adaptive control loops that determine control gains that are optimal for the current disturbance acting on the laser beam. In each adaptive control loop, an adaptive lattice filter implicitly identifies disturbance statistics from real-time data on the relative orientation of the laser beam as measured by use of a quad cell.