Abstract: Techniques are disclosed for using a genetic algorithm to identify a processing pipeline that transforms spectra into a form usable to generate predicted characteristics of corresponding samples. The genetic algorithm is used to generate and evaluate multiple candidate solutions specifying various pre-processing and machine-learning-processing configurations. The processing pipeline is defined based on the candidate solutions.

Abstract: An antenna and system for determining two-dimensional angle-of-arrival includes circular array interferometers for azimuth, linear interferometers for elevation, and a mast for positioning the interferometers in a vertically stacked orientation. The circular array interferometers exhibit azimuth constant-phase-difference contours orthogonal to elevation constant-phase-difference contours exhibited by the linear interferometers. An antenna and system for determining azimuth of input signals includes ambiguous and non-ambiguous circular array interferometers. The non-ambiguous circular array interferometer resolves ambiguities introduced by the ambiguous circular array interferometer, the at least one ambiguous circular array interferometer operatively coupled to a low-order Butler matrix and power divider/combiner such that a high order Butler matrix is not required to generate omnidirectional phase modes from the ambiguous circular array interferometer.