METHOD FOR MEASURING UNDERWATER NOISINESS OF TARGET SHIP Russian patent published in 2007 - IPC G10K11/00 

FIELD: hydro-acoustic measurements, in particular, methods and means for measuring underwater noisiness of ships.

SUBSTANCE: method is based on receiving noise signals via water-water and water-surface beams at depth H₁ in zone of acoustic illumination by means of route of submarine with flexible extensive towed antenna with its horizontal position and orientation of antenna directivity towards water-water beam, electrical filtration of signal with given resolution in given frequency sub-ranges, averaging of signal during depth maneuver of submarine, measurement of distance to target ship, determining of noise emission energy spectrum. Used simultaneously are route of main nose antenna with orientation of its directivity diagram axis along water-water beam. Submarine is submerged to depth H₂ below leap layer. Target ship is tracked automatically. Hydro-acoustic antenna is transferred to vertical position so that its active part with electro-acoustic receivers is located above leap layer. Angle α₀ between water-water and water-surface beams is determined. Receipt is performed by active section of antenna at vertical length d, selected from inequality: 50°·λ/α₀ ≤ d ≤ H₀, where λ - sound wave length in environment, α₀ - angle between beams, H₀ - vertical extent of acoustic illumination zone. Measurements are performed in range of angles α in vertical plane, limited by inequalities: arccosC_B/C₀ ≥ α ≥ arccosC_S/C₀, where C₀,C_S,C_B - speed of sound, respectively, at level of phase center of active part of antenna, near surface and near sea bottom.

EFFECT: ensured concealment of submarine, decreased interference from sea noises.

10 dwg