APPLICATION OF OPTICAL SIGNAL PROCESSING TO ADAPTIVE PHASED ARRAY RADAR

The application of optical systems to Adaptive Phased Array Radar (APAR) data processing is described. The contributions of this dissertation include items from several related topics, each addressing a different aspect of the role of optical data processing in APAR. The proposal and analysis of a new iterative technique for the generation of a weight vector which matches a set of constraints on the placement of nulls in the farfield pattern is provided along with numerical evaluations for specific test cases. The proposed algorithm makes excellent use of the optical Fourier transform property. The equation of the optimal Wiener weight vector is solved by both iterative and direct techniques on two laboratory Optical Linear Algebra Processing (OLAP) systems. Iterative techniques are implemented on a low accuracy analog system, while direct techniques are used with high accuracy, encoded systems. Solutions obtained on the encoded optical system are shown to be essentially identical to those obtained using commercially available software routines and floating point arithmetic on a minicomputer. Investigations concerning the effect of the errors present in OLAP systems on the solution vector are presented through a classical analysis and simulations. Effects of processor errors on iterative algorithms are used to explore the benefits of adaptively switching processor accuracy. It is demonstrated through laboratory experiments, theoretical analysis, and computer simulation, that there are several potential niches where optical signal processing provides useful results for the APAR problem.