Echo sounder on ship

Knowledge points of Echo sounder

1. Requirements: ≥ 300GT ships and passenger ships of any size should be equipped with echo sounder;

2. Acoustic properties:
--Propagation speed influencing factors, temperature, salinity, pressure, proportional to 3 factors;
--Propagation characteristics: propagation attenuation, speed of sound 1500 m/s;

3.Principle of operation:
--Measurement of ultrasonic round-trip time to measure the distance
(1) transducer transmitting surface to the depth of the water bottom
(2) Maximum measurement depth related factors:
Transmit power
Pulse frequency
Minimum measurement depth depends on: pulse width
--Transmitting transducer, transmits ultrasonic pulses, advantages: good resistance to audible sound waves; reflectivity: rock is the strongest, silt is the weakest

4. Composition and timing
-Composition: (1) monitor, send a trigger pulse, control the launch system launch; (2) launch transducer: the launch pulse is converted into acoustic pulse, electrical oscillation signal into a mechanical oscillation signal; (3) receiving transducer: mechanical oscillation signal into an electrical oscillation signal
The three work with the same time reference: zero signal synchronisation;
--Transducer installation: (1) 1/2 to 1/3 of the ship's bow, the surrounding interference with the smallest noise; (2) to avoid the drain and submarine valves; (3) can not reduce the hull structure and the watertight; (4) the working surface and the ship's bottom plane level; (5) the surface can not be painted to absorb the acoustic energy affecting the sound bathymetry;

5. Work indicators: (1) 10 degrees of transverse rocking, longitudinal rocking 5 degrees, normal work; (2) the maximum bathymetry is not less than 200m; (3) the minimum bathymetry is not greater than 2m; (4) a 20m shallow water gear, error control: 0.5m and the range of 2.5%, take the greater; (5) a 200m deep-water gear; (6) the main display must be a graphic display

6. Error control: (1) the actual propagation speed is greater than the design speed of sound, the display of the depth of water becomes smaller (2) the ship's reverse bubble affects the depth of measurement; (3) according to the different substrate to adjust the sensitivity (4) read the water depth of the frontier