MODE OF DETECTION OF NOISY OBJECTS IN THE SEA Russian patent published in 2007 - IPC G01S3/80 G01S15/04 

FIELD: the invention refers to the field of hydro acoustics and may be used in the systems of direct listening.

SUBSTANCE: the mode includes reception of the primary field of noise radiation in a horizontal plane, at that frequency-time processing of received noisy signals for each spatial channel of observation in the horizontal plane is executed, squared, averaged over the time, centered and normalized towards the interference, accumulation of signals is executed and the decision about detection is taken by way of comparison the reception of the noise with the threshold meaning of the ratio signal-interference. At that the reception of the noise is executed by a static vertical fan simultaneously in several directions of the vertical plane of each spatial channel of observation in the composition of the static fan in the horizontal plane, the reception by each horizon spatial channel by way of choosing the outmost probable angles of reception in the vertical plane for existing hydro acoustic conditions of underwater observation. For these purposes the sea surface is measured, the speed of the signal is measured in the water in dependence of the depth, the level of the noisy signal in the point of reception with given levels of primary field of noise radiation on different distances and horizon according to measured data and known characteristics of the bottom is calculated in each vertical spatial channel deciding the hydro acoustics equitation in passive regime for each object taking into consideration the characteristics of the receiving system, the level of the sea noises are calculated in each vertical spatial channel taking into consideration the characteristics of the receiving system according to measured data and the known characteristics of the bottom, calculated levels of noise in each spatial channel received for given distances to calculated noisy object and horizon are normalized relatively to calculated noise of the sea in vertical spatial channels, the ratio signal-interference is calculated for each distance and horizon of the noisy object in vertical spatial channels, processing of receiving noises with weights, before route accumulation, is executed and summed up with calculated weights.

EFFECT: increases reliability of detection and prolonged maintenance of the contact.

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