Some integrated sonar also doubles as a reconnaissance function. Hydroacoustic jamming equipment, mainly hydroacoustic jammers, air curtain bombs and so on. Hydroacoustic jammer by launching strong power noise into the water, suppression of enemy sonar work, according to the work of the frequency band, there are high-frequency hydroacoustic jammer and low-frequency hydroacoustic jammer points. Air curtain bombs use the bubble curtain formed in the water to produce a large number of stray echoes, interfering with the work of the enemy's sonar. Hydroacoustic decoys, is a decoy hydroacoustic countermeasures equipment, which emits simulated ship echoes or ship radiation noise into the water, decoying the enemy sonar and acoustic self-guided torpedo tracking, so that the ship from being detected or attacked.
Submarine air curtain bombs appeared during the Second World War, is the earliest passive hydroacoustic countermeasures equipment, has been used to the present. 1960s, ships began to be equipped with special reconnaissance sonar, its frequency range, measurement accuracy, frequency accuracy and so on continue to expand and improve. 70 years since the development of hydroacoustic countermeasures system, and one after another, equipped with the troops.
Modern submarine hydroacoustic countermeasures system usually includes:
1, reconnaissance sonar, there is a set of special multi-mode (low-frequency and high-frequency) hydrophone, can be in a wide frequency range, the number of the target, orientation, frequency, waveform, pulse width, pulse period and so on for detection. The measured parameters are fed directly into the signal analysis and processing system.
2, the basic system, by the detection and identification, display and control, signal processing and analysis, sonar database and its projectors, etc., used to detect and identify hydroacoustic targets, according to the measured parameters, analyze the degree of threat to the boat, control the release of countermeasures against the equipment or to take other countermeasures.
3, suspended bait, when used from the boat thrown into the sea and let it drift, dedicated to confuse or deceive the acoustic self-guided torpedo.
4, self-propelled decoys, that is, submarine simulators, the use of projectors or torpedo tubes into the sea, according to the specified direction of self-propelled, similar to the real movement of the submarine. Some of the equipment in the system can also be used on surface ships or anti-submarine aircraft. Modern naval warfare on the hydroacoustic confrontation equipment put forward higher requirements, is to multi-functional, systematic, generalized and miniaturized direction.