58
14. CHARACTERISTICS OF THE
ULTRASONIC WAVE IN WATER
The purpose of this chapter is to provide an overview of the charac-
teristics of the ultrasonic wave in water.
Sound Velocity
It is generally known that an ultrasonic wave travels 1500 meters per
second in sea water, but in practice, some amount of variation arises
depending on the season and area from differences in the following
three factors:
Water temperature ..............................
θ
[ C]
Salinity density ................................... S [%]
Water pressure (water depth) .............. h [m]
Therefore, for propagation in surface water the velocity changes not
only by area but also by direction of the wave propagation. The equa-
tion obtained thru numerous measurements is;
C= 1410 + 4.21
θ
- 0.037
θ
2
+ 1.145S + 0.0168h [m/s]
°
C
°
C
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
1445.4
1450.0
1454.4
1458.8
1463.1
1467.2
1471.3
1475.3
1479.2
1483.0
1486.7
1490.3
1493.8
1497.3
1500.6
1503.8
1507.0
1510.0
1513.0
1515.9
1518.7
Velocity (m/sec)
Depth
(m)
5
10
15
20
25
1.8
3.6
5.4
7.3
9.1
10.9 14.5
1.8
3.6
5.4
7.2
9.0
10.8 14.5
1.8
3.6
5.4
7.2
9.0
10.8 14.4
1.8
3.6
5.4
7.2
9.0
10.8 14.4
1.8
3.6
5.4
7.3
9.1
10.9 14.5
100 200
300
400
500
600
700
Correction value with respect to
Depth and Temperature (m/s.)
Fig.1 Sound Velocity
Содержание CSH-5 MARK-2
Страница 1: ...COLOR SCANNING SONAR CSH 5 MARK 2 ...
Страница 8: ...2 2 SYSTEM CONFIGURATION System Configuration ...
Страница 55: ...49 3 Echo Sounder Combination Mode COMBI 1 Normal Echo Sounder 16 Color Bar Sonar Picture Echo Sounder Picture ...
Страница 56: ...50 4 Sonar Combination COMBI 2 Normal Signal on R B Mark 16 Color Bar Sonar Picture Signal on R B Mark ...