Method for Frequency-Driven Generation of a MultiResolution Decomposition of the Input to Wave-Based Sensing Arrays

• US 20070229353A1
• Filed: 04/02/2006
• Published: 10/04/2007
• Est. Priority Date: 04/02/2006
• Status: Active Grant

• Current Assignee: Rolf Mueller
• Original Assignee: Rolf Mueller
• Inventors: Mueller, Rolf
• Granted Patent: US 7,423,587 B2
• Time in Patent Office: Days
• US Class Current: 342/378
• CPC Class Codes: G01S 3/06 Means for increasing effective directivity, e.g. by combining signals having differently oriented directivity characteristics or by sharpening the envelope waveform of the signal derived from a rotating or oscillating beam antenna comparing amplitude of signals having differently oriented directivity characteristics to determine direction G01S3/16, G01S3/28
• CPC Class Codes: G01S 3/14 Systems for determining direction or deviation from predetermined direction aerial arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00; combinations of different interacting aerial units for giving a desired directional characteristic H01Q21/29; aerials or aerial systems providing at least two radiation patterns H01Q25/00
• CPC Class Codes: G01S 3/801 Details G01S3/82, G01S3/84, G01S3/86 take precedence
• CPC Class Codes: G01S 3/802 Systems for determining direction or deviation from predetermined direction

Abstract

A method for generating a multiresolution decomposition of an array signal by a bank of spatial bandpass filters is disclosed. The signal processing operation is implemented through the use of the directivities of the individual array elements and does not degrade the spatial or temporal resolution of the array.

Claims

1. A method for performing a multiresolution decomposition of an input signal to a wave-based sensing array into a plurality of outputs of spatial bandpass filters comprising the steps of:

a) generating at least two different types of directivity pattern for a plurality of frequency components in the input signal for each array sensor;

at least one of the types being a center-type directivity pattern which concentrates the spatial sensitivity in a central main-lobe and at least one of the types being a surround-type directivity pattern which surrounds the direction of the center-type directivity'"'"'s main-lobe with its most sensitive region;

b) scaling the center-type and surround-type directivity patterns with frequency so that a plurality of different beam-widths are produced;

c) forming center-type and surround-type bandpass channels by isolating frequency components corresponding to the center-type and surround-type directivity patterns via bandpass-filtering performed on the input signal of a single sensor, pairwise combining the outputs the center-type channels with the surround-type channels matching in spatial scale, and determining an amplitude difference between the channels.