HIGH RESOLUTION BROADBAND ADAPTIVE BEAMFORMING VIA FOCUSING TECHNIQUES

PDF

Authors
  1. Krolik, J.
  2. Swingler, D.N.
  3. Niezgoda, G.
Corporate Authors
Defence Research Establishment Atlantic, Dartmouth NS (CAN);Concordia Univ, Montreal QUE (CAN) Dept of Electrical and Computer Engineering
Abstract
The work investigates focused wideband processing as a means of reducing the threshold observation time required to perform high resolution broadband beamforming and field directionality mapping. As in many other high-resolution methods, the steered covariance matrix approach first forms an estimate of the spatial covariance matrix as a function of frequency. Other high resolution methods would then apply high resolution beamforming at each frequency cell and suffer threshold problems associated with the signal to noise ratio and integration time for each cell. The steered covariance approach applies a steering vector, essentially a conventional beamformer, to focus the covariance matrix to a particular direction and then sums over frequency the covariance matrices focused in the same direction. This summed steered matrix has the stability associated with the full time-bandwidth of the processor. Thus, applying a high-resolution (i.e. minimum variance) beamformer to this matrix yields a lower net threshold than if the beamformer had been applied to a single frequency cell. Through both mathematical analysis and simulation, this report examines the performance of direct steered covariance beamforming as well as two more computationally efficient approximations, doubly steered covariance beamforming and spatial resampling.
Keywords
Steered covariance;High resolution;Adaptive processing
Report Number
DREA-CR-94-404 — Contractor Report
Date of publication
01 Jan 1994
Number of Pages
188
DSTKIM No
96-00603
CANDIS No
154195
Format(s):
Document Image stored on Optical Disk;Hardcopy

Permanent link

Document 1 of 1

Date modified: