Target detection system

• US 5,309,409 A
• Filed: 10/28/1982
• Issued: 05/03/1994
• Est. Priority Date: 10/28/1982
• Status: Expired due to Term

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Westinghouse Electric Company LLC (Brookfield Asset Management Incorporated)
• Inventors: Jones, Charles H., Thompson, John H., Kesner, John W.
• Primary Examiner(s): Pihulic, Daniel T.
• Application Number:
  US06/437,372
• Time in Patent Office: 4,205 Days
• Field of Search: 367/103, 367/118, 367/123, 367/126, 367/905, 343/16 R, 343/380, 343/383, 342/368
• US Class Current: 367/103
• CPC Class Codes: G01S 13/426 Scanning radar, e.g. 3D radar G01S13/66 takes precedence
• CPC Class Codes: G01S 3/46 using antennas spaced apart and measuring phase or time difference between signals therefrom, i.e. path-difference systems
• CPC Class Codes: G01S 3/808 using transducers spaced apart and measuring phase or time difference between signals therefrom, i.e. path-difference systems
• CPC Class Codes: G10K 11/348 using amplitude variation
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence

Abstract

An array of transducer elements receives energy from a target or targets in a field of view and operates on the transducer outputs to provide a plurality of different levels of shading. The most useful portion of the field pattern is selected and combined with other most useful portions of other field patterns into a single composite display which results in one or more relatively narrow lobes, indicating targets, and without the presentation of side lobes which may be masking targets.

Claims

1. A detection system, comprising:

A) an array of transducer elements, each operable to provide an output signal in response to energy received from a target area under observation;

B) means including beamformer means operable in response to all of said output signals of said transducer elements to apply different levels of shading function thereto to derive a plurality of different field pattern signals; and

C) means for selecting different predetermined portions from said plurality of field pattern signals and combining said predetermined portions into a single unitary composite field pattern signal.

2. Apparatus according to claim 1 wherein:

A) said array is a line array.

3. Apparatus according to claim 1 wherein:

A) said array is a multi-dimensional array.

4. Apparatus according to claim 1 wherein:

A) said transducer elements are sonar transducer elements each operable to provide an output signal in response to received acoustic energy.

5. Apparatus according to claim 4 which includes:

A) acoustic projector means for transmitting acoustic energy toward said target area under investigation.

6. Apparatus according to claim 1 wherein:

A) said beamformer means is comprised of a plurality of individual beamformer sections simultaneously operable to apply said different levels of shading function.

7. Apparatus according to claim 1 wherein:

A) said beamformer means is a digital beamformer means; and

which includes

B) analog-to-digital converter means coupled to said transducer elements to convert the analog signals therefrom into respective digital signals.

8. Apparatus according to claim 1 wherein:

A) different levels of the same shading function are applied to said output signals.

9. Apparatus according to claim 1 which includes:

A) means for displaying said unitary composite field pattern signal.

10. Apparatus according to claim 9 wherein:

A) said array is a line array; and

B) said display presents signal intensity on one axis and azimuth angle on a second axis perpendicular to said one axis.

11. Apparatus according to claim 9 wherein:

A) said array is a multi-dimensional array; and

B) said display respectively presents on three mutually perpendicular axes, signal intensity, a first direction and a second direction.

12. Apparatus according to claim 9 which includes:

A) signal processor means responsive to said means for selecting and operable to join lines of adjacent selected portions to provide a continuous curve presentation on said means for displaying.