Geoscience Reference
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2
p
t
s
Z
b
¼
r
0
cos
ð
1
Þ
The equation: of ship vertical velocity while swimming on wave (
2
):
2
p
s
2
p
t
s
v
z
¼
r
0
sin
ð
2
Þ
here, v
z
—
speed, m/s,
s
—
the wave length, m, r
0
—
wave radius, m, The radius r
0
is
equal to the half of the wave height (
3
):
h
2
¼
r
0
¼
1m
ð
3
Þ
Here h
b
—
the wave height, m, then:
¼
2
p
s
t
max
¼
r
0
1
:
52 m
=
s
ð
4
Þ
maximum velocity on vertical axis, m/s.
Real waves can mismatch the waves being described with the equations of the
motion. That is why we will use the maximum speed
t
max
¼
v
max
—
is which is higher
than counted value. The maintenance of height above the seabed that is required by
the side view sonar is also a very important aspect to be addressed. If sonar is towed
not in optimal depth, image quality drops drastically. It is complicated to reach the
necessary depth. The scientists of CORPI cope with this issue by running the ship
slower than is required by the manufacturer. Decreasing the speed means that the
quality of the images would be worse. Avoiding sonar hitting the seabed is also
very important, as sonar can be damaged. Several scientists like Teixeira et al. [
8
]
proposed a standard system of seabed scanning. This system includes a ship and a
side scan sonar with the stabilizer of weight. Their system is used to explore the
seabed of the deep ocean. The length of the cable used in the system reached 900 m.
The mass of the stabilizing weight reached 200 kg and the weight of the sonar was
113 kg. To implement this method the following components are proposed to be
used: ship
2m
=
s motion sensors, data processing system and the weight of the stabil-
ization of the sonar. Similar system was used by Teixeira et al. [
8
].
The purpose of weight is the stabilisation of sonar depth and steady movement of
the sonar. In our system case we are planning to use gravitic depressor that will be
scaled down to 50 kg weight, but system will operate on same basic method. The
total weight of modi
'
ed sonar system with gravitic depressor is 90 kg, it consists of
the sonar, 50 kg of stabilization weight and connecting cables. This does not
include cable drum motor and its controllers weight, because they are considered as
a part of ship, not sonar, weight. For modifying our system we will leave same basic
sonar lifting mechanism, only motor and its controller will be changed. Cable
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