Simrad EY500, Instruction Manual

Page: 127 / 262

Theory of operation
P3403E/A
7
$ '
2
4
*
(2)
(CD477)
Figure 2 Beam pattern.
3
U
' 3
W
*
10
& U
4
U
2
10
& U
4
U
2
2
4
*
(3)
Gain and effective receiving area are related by reciprocity as shown in equation
2:
where
8
is the wavelength and where A and G are both referred to the same
point on the terminal side of the transducer. Figure 2 shows the gain pattern of
a typical transducer.
The echo from a small object, henceforth the target, is described by equation (3):