SEVENTH ANNUAL
ASAP '99 WORKSHOP

Abstract Most existing array processing methods rely on spatial diversity of the sensor array to estimate the direction of arrival. A drawback of this approach is that the accuracy performance becomes highly dependent on the electrical aperture of the array. In many applications, the sensor array is expected to operate over a wide frequency bandwidth. As a result, the physical size of the array is constrained by the highest operating frequency to avoid ambiguities. However this leads to poorer performance at lower frequencies due to their larger wavelength, particularly when a limited number of array channels is available. Increasing the number of array channels to achieve larger aperture is a costly approach. In addition, in many mobile or fast deployment array processing systems, small aperture array is a strongly desired feature. Hence it is important to develop new approaches to DOA estimation using small array aperture while maintaining good performance over a wide frequency bandwidth.

This paper proposes a new approach known as distributed electromagnetic (EM) component sensor array processing to achieve good DOA estimation with small-aperture and parsimonious arrays. The component sensors are distributed as an array of scalar magnetic and electric sensors. This sensor array is able to measure the complete EM information of the source. Together with spatial diversity of the array, the DOA is estimated via the joint exploitation of the Poynting relationship between the electric and magnetic component sensor and the differential time-delay. It is shown in this paper that the proposed approach actually generalizes the vector- and scalar-sensor array processing. Simulation results will be presented to demonstrate the efficacy of this proposed approach.

Presentation (pdf format)