Title:
PROCESSING SYSTEM OF DIRECTIVITY SYNTHESIS
Document Type and Number:
Japanese Patent JP2710578
Kind Code:
B2
Abstract:
PURPOSE: To obtain a processing system by which an arithmetic processing amount is compressed when the directivity in the near sound field of a vertical wave-receiving array used to detect an underwater sound source is to be synthesized.
CONSTITUTION: When the directivity of a vertical line array 5 in a near sound field is to be synthesized, sound waves are treated as spherical waves, and the directivity is synthesized so as to be directed to a plurality of virtual sound sources. Since the synthesis processing operation is performed over the entire near sound field by successively varying the positions of virtual sound sources, the processing amount becomes enormous. An area computation part 4 finds an area of the near sound field excluding a region which can be handled as plane waves in advance, and the area is supplied to a delay-time computation part 1a. The delay-time computation part 1a computes a time delay for directivity synthesis in the area and a time delay for directivity synthesis with reference to a sound field other than the area, and the time delays are supplied to a delay phasing part 2. Thereby, the directivity is synthesized, and an output is detected by a detection part 3 so as to be output.
Inventors:
Kenji Tsukada
Ebana Kazunori
Hiroyuki Sugiyama
Taku Yamamoto
Ebana Kazunori
Hiroyuki Sugiyama
Taku Yamamoto
Application Number:
JP7012495A
Publication Date:
February 10, 1998
Filing Date:
March 28, 1995
Export Citation:
Assignee:
Director General, Technical Research Division, Defense Agency
NEC
NEC
International Classes:
G01S3/808; G01S7/526; (IPC1-7): G01S3/808; G01S7/526
Domestic Patent References:
| JP5126939A | ||||
| JP5494788A | ||||
| JP54100178A | ||||
| JP123749B2 |
Attorney, Agent or Firm:
Naoki Kyomoto (2 outside)