Company LOGO Sound Navigation and Ranging (SONAR) GVHD: PGS.TS Hoàng Đình Chiến Nhóm thực hiện: Nguyễn Hồng Phúc 40801594 Phan Nhật Vũ 50802678
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Company
LOGO
Sound Navigation and Ranging(SONAR)
GVHD: PGS.TS Hoàng Đình ChiếnNhóm thực hiện: Nguyễn Hồng Phúc 40801594
Phan Nhật Vũ 50802678
Phuc - Vu Group
SONAR
Contents
Hardware Design
SONAR Systems
Classifications/Kinds of SONAR
Principles of Sonar
Historical Background of SONAR
Phuc - Vu Group
SONAR
SONAR
Acronym for Sound Navigation and Ranging, a detection system based on the reflection of underwater sound waves, just as radar is based on the reflection of radio waves in the air.
It is a technique based on echolocation used for the detection of objects underwater.
Historical Background of SONAR
1490 – Leonardo Da Vinci first recorded the use by humans of sounds for communication and object detection.
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SONAR
19th century – an underwater bell was used as an ancillary to lighthouses to provide warning of hazards.
1906 – the first sonar device was developed by shipbuilder Lewis Nixon.
Historical Background of SONAR
1912 – the use of sound ‘echo locate’ underwater in the same way as bats use sound for aerial navigation
1920 – they tested their ASDIC on HMS Antrim and started production of units in 1922 .
1923 – the 6th Destroyer Flotilla had ASDIC – equipped vessels.
1924 – an anti-submarine school, HMS Osprey, and a training flotilla of four vessels were established on Portland
Phuc - Vu Group
SONAR
Phuc - Vu Group
Historical Background of SONAR
1931 – the U.S. Sonar QB set arrived.
1939 – the Admiralty made up the story that the letters stood for ASDIC.
1948 – with the formation of NATO, standardization of signals ld to the dropping of ASDIC in favor of sonar
SONAR
Basics of SONAR
SONAR works as follows:• A machine sends out sound waves
(ultrasonic sound)• The sound bounces off the
seafloor; the reflected sound waves are detected by the machine.
• The distance between the machine and the reflecting surface can be calculated from the time the sound takes to travel to the seafloor and back.
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SONAR
• By making measurements in different places, the contours of the seafloor can be plotted. As a general rule, the closer you can get the instrument to the seafloor, the greater the resolution of the contour map.
Basics of SONAR
Sound move quite efficiently through water, far more easily than they do through air.
The ability of sound to travel over great distances allows remote sensing in a water environment.
Sound travels in water in a moving series of pressure fronts known as compressional wave.
The local speed of sound can change depending on the conditions of water such as salinity, pressure, and temperature, but it is independent of the characteristics of sound itself.
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SONAR
Basics of SONAR
Sound waves are useful for remote sensing in a water environment because some of them can travel for hundreds of kilometers without significant attenuation.
The level of attenuation of a sound wave is dependent on its frequency- HF sound is attenuated rapidly, while ELF sound can travel virtually unimpeded throughout the ocean.
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SONAR
BLOCK DIAGRAM OF SONAR
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SONAR
Simple block diagram.
Block diagram using waves.
DIGITAL CIRCUIT
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SONAR
TRANSMITTER CIRCUIT
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SONAR
The Transmitter circuit emitts sound waves in the water.The transmitter consists of a ultrasonic transducer which emits ultrasonic waves in water.this transducer is controlled by a digital circuit consisting of IC’s & other electronic components.
RECEIVER CIRCUIT
Phuc - Vu Group
SONAR
The receiver circuit receives sound waves in the water which are reflected from the obstacle. The receiver consists of a ultrasonic transducer ,this transducer is driven by a digital circuit consisting of IC LM567 which acts as a Tone decoder
Active Sonar: emitting pulses of sounds and listening for echoes.
MAINLY TWO TYPES
Passive Sonar: is essential only listening for the sound made by vessels.
ACTIVE SONAR
Active sonar uses a sound transmitter and a receiver. When the two are in the same place it is monostatic
operation. When the transmitter and receiver are separated it is
bistatic operation. When more transmitters (or more receivers) are
used, again spatially separated, it is multistatic operation.
Most sonars are used monostatically with the same array often being used for transmission and reception.
Active sonar creates a pulse of sound, often called a "ping", and then listens for reflections (echo) of the pulse.
This pulse of sound is generally created electronically using a sonar Projector consisting of a signal generator, power amplifier and electro-acoustic transducer/array.
ACTIVE SONAR
PASSIVE SONAR
Passive sonar listens without transmitting.
It is often employed in military settings, although it is also used in science applications, e.g., detecting fish for presence/absence studies in various aquatic environment.
Passive sonar detects the target's radiated noise characteristics.
The radiated spectrum comprises a continuous spectrum of noise with peaks at certain frequencies which can be used for classification.
PASSIVE SONAR
SOUND PROPAGATION
Sonar operation is affected by variations in sound speed, particularly in the vertical plane. Sound travels more slowly in fresh water than in sea water, though the difference is small. The speed is determined by the water's bulk modulus and mass density.
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SONAR
Ambien Noise
Ambien noise is the signals that are left all identifiable signals have been removed (accounted for).
Some important sources that increase the noise level:
a) Coast sounds (water breaking over rocks)b) Marine life (shrimp can be especially
loud)c) Water flow (over the hydrophone)d) Noise floor of electronic equipment
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SONAR
Hardware Design
1. CIRCUITRY COMMON TO BOTH CIRCUITS
2. TRANSMITTER DESIGN
3. RECEIVER DESIGN
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SONAR
CIRCUITRY COMMON TO BOTH CIRCUITS
a) MICROCONTROLLER
b) PROGRAMMING INTERFACE (BDM)
c) USER INTERFACE
d) POWER
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SONAR
Phuc - Vu Group
MICROCONTROLLER
Chip Motorola MB68 H12
i. Serial Communication Interface: easy connect to computer running HyperTerminal
ii. PWM
iii. A/D 10-bit Analog to Digital Converter: detect incoming signal
iv. Cheap, powerful
SONAR
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SONAR
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PROGRAMMING INTERFACE (BDM)SONAR
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USER INTERFACESONAR
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POWERSONAR
TRANSMITTER DESIGN
a) POSSIBLE TRANSDUCER EXCITATION CIRCUITS
b) FINAL TRANSFORMER CIRCUIT TOPOLOGY
c) EMI
d) TRANSMITTER SCHEMATIC
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SONAR
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POSSIBLE TRANSDUCER EXCITATION CIRCUITSSONAR
Buck regulator
Initial power circuit design
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POSSIBLE TRANSDUCER EXCITATION CIRCUITS
Push-pull converter
SONAR
Phuc - Vu Group
FINAL TRANSFORMER CIRCUIT TOPOLOGY
2 transistor forward converter
SONAR
Phuc - Vu Group
FINAL TRANSFORMER CIRCUIT TOPOLOGY
Alternate power circuit
SONAR
Phuc - Vu Group
EMI
Good and bad circuit design
SONAR
Phuc - Vu Group
TRANSMITTER SCHEMATICSONAR
RECEIVER DESIGN
a) INITIAL CONSIDERATIONS
b) RECEIVER SCHEMATIC
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SONAR
Phuc - Vu Group
INITIAL CONSIDERATIONSSONAR
Phuc - Vu Group
SONAR
Company
LOGO
SONAR
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