UNSUPERVISED BCM PROJECTION PURSUIT ALGORITHMS FOR CLASSIFICATION OF SIMULATED RADAR PRESENTATIONS

A comparison of the unsupervised Projection Pursuit learning algorithm (BCM), with supervised backward propagation (BP) and a laterally inhibited version of BP (LIBP) was performed. Simulated inverse synthetic aperature radar (ISAR) presentations served as a testbed for evaluation. Symmetries of the artificial presentations make the use of localized moments a convenient preprocessing tool for the inputs. Although all three algorithms obtain classification rates comparable to trained human observers for this simulated data base, BCM obtains solutions that classify more effectively inputs that are corrupted by noise or errors in registration; in noise tolerance experiments, the best BCM solution represents a 10 dB improvement over the best BP solution. Recurrent and differential forms of BCM that could be applied to time-dependent classification problems are also developed.