SONAR (SOund Navigation And Ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, communicate with or detect objects on or under the surface of the water, such as other vessels and submarines. Two types of technology share the name "sonar": passive sonar is essentially listening for the sound made by vessels; active sonar is emitting pulses of sounds and listening for echoes. The Sensing procedure in Sonar System usually is done by Hydrophones.
A hydrophone is a microphone designed to be used underwater for recording or listening to underwater sounds. Most hydrophones are based on a piezoelectric transducer that generates electricity when subjected to a pressure change. Such piezoelectric materials, or transducers, can convert a sound signal into an electrical signal since sound is a pressure wave. The new Technology of making Hydrophone is Acousto-Optic Transducer that made by Fiber Optic Sensing Technology.
Fiber optic Hydrophones is one major type of hydrophones that are of great importance to underwater and naval acoustics. The chief advantage is that problems related to the integration of traditional underwater acoustic sensing and sonar data transmission can be resolved from an entirely new perspective, thus improving the reliability and possibly decreasing the total cost of manufacture, operation and maintenance of the sonar system.
Because of its inherent directivity and unique phase processing, the Fiber Optic (FO) hydrophone possesses potential advantages in the detection of quiet underwater acoustic targets emitting low frequency and ultra-low frequency noise. Engineering applications for FO hydrophone have gradually emerged from the research laboratory, and will play an active role in the development of future sonar systems. A brief overview of the two technology (Piezoelectric and Fiber Optic) is presented from the viewpoint of sonar design, including the basic physics, principle of operation, key techniques, and applications.
Comparison between Piezo-Electric and Fiber Optic Sensors
Piezoelectric Acoustic Sensor
Fiber Optic Acoustic Sensor
Needing Electrical power at sensor point
Sensors and Pre-amplifier are driven by electric power
Sensors are not driven by electric, It works by laser light
Need post Electronic Processor at Sensor Point
Long Range data transferring method
Convert Electrical Signal to Optical Signal By Optical Modem then transfer on long fiber Optic Cable
transfer on long fiber Optic Cable
Multiplexing Methods for Array
All Hydrophones are independent. So there are many problems in multiplexing
Multiplexing is possible
Maximum Cable length
100~200 Km, with repeater device in fiber cable
25 Km. Repeater device using in this method is impossible
Array weight & size
Big size and heavy weight
Small size and lightweight
Minimum Acoustic Frequency Detection
In our company a sonar array system, based on fiber optic sensors, has been realized to estimate the direction of the underwater acoustic sources. The system is composed of one system with 24 fiber optic sensors.
- Additional Information
SKU RAY-SONAR-01 Part Number RAY-SONAR-01 Applications
Passive & Active Low Frequency SONAR for Underwater Sound Detection
Sonic & Infrasonic Detection
Vehicel & Submarine Detection, Tracking, Localization & Classification
Country of Manufacture Manufacture No Conditions No Lead Time 4-8 Months (Please Call) Export Terms Without Restriction to Export