Low-Frequency Airborne Sonar Systems.

Abstract

The LOMASS project is a high-performance low-frequency sonar system to be carried by a helicopter. Such an ASW combination offers great potential for obtaining high area coverage. The program is divided into three phases. LOMASS I is a simplified echo-ranging system which serves as a basis for the other two phases. LOMASS II uses the basic LOMASS I system with the addition of a high- power driver and transducer. LOMASS III is a new system which uses an acoustic Luneberg lens to obtain preformed beams for scanning operation rather than the searchlight operation used in the first two phases. Each phase uses new and improved signal-processing techniques. Tests were performed to determine the spectral level and radiation pattern of noise radiated into the water by a Sikorsky HR2S helicopter. These tests, though incomplete, do indicate a high noise operating background which places a severe restriction on expected sonar range. More tests need to be performed to gain a better picture of the radiated, helicopter noise.

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Document Details

Document Type
Technical Report
Publication Date
Oct 31, 1958
Accession Number
AD0303629

Entities

People

  • C .l. Maskaleris
  • J. J. Yagelowich

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Air Platforms
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Airborne
  • Aircrafts
  • Detection
  • Diameters
  • Directional
  • Echo Ranging
  • Engineering
  • Frequency
  • Helicopters
  • Hydrophones
  • Junction Boxes
  • Long Island Sound
  • Measurement
  • Noise
  • Noise Reduction
  • Test Facilities
  • Transducers

Fields of Study

  • Physics

Readers

  • Acoustical Oceanography.
  • Acoustics.
  • Phased Array Antenna Design.