Kaveh This research builds on experience that has been gained during the construction and calibration of a laboratory ultrasound-in-air array, in order to establish a systematic approach for experimentation and theoretical analysis. Optimizing functionals are being developed for a general class of estimators with similar computational burden as the well-known method of MUSIC. These estimators are expected to significantly reduce the threshold signal to noise ratio, for a general calibrated array, over a method such as MUSIC. Analysis techniques are being established within a probabilistic framework for comparing the resolution thresholds of estimators in this class. Detection methods are also being developed in conjunction with experimental measurements that make optimum use of the array calibration data. The new algorithms are being generalized to cases involving wideband signals and signals possessing special characteristics such as cyclostationarity. The ongoing experimental work, which includes the implementation of subspace estimation algorithms on DSP processors, is intended to establish the level of practicality of many proposed methods.
