Structural Design and Test of a Piezoelectric Flextensional Transducer for Passive Detection of Frogmen

Table 1

Main performance of active sonar for frogman detection in several countries.

No.	Country	Model	Operating frequency range (Hz)	Longest detection distance (m)
1	Britain	Cerberus 360	100 k	800
2	Britain	Cerberus Mod2	70 k–130 k	900
3	Britain	Echoscope-SD	80 k	740
4	Britain	Sentinel IDS	70 k	900
5	Israel	Aqua shield DDS	60 k	1000–1200
6	Israel	Point shield portable DDS	70 k	700
7	Britain	X-type	100 k	1000
8	Canada	CSDS-85	80 k	1500
9	Turkey	—	80 k	1200
10	Russia	PALLADA	100 k	400