SYSTEM DESCRIPTION 



The basic underwater sound measuring system is 

 shown in the block diagram of figure I, and figure 2 is a 

 photograph of the system. Each of the elements will be 

 described in detail. Some auxiliary equipment to determine 

 the depth of the hydrophone can be used and such a system 

 is discussed in Appendix A. 



HYDROPHONE 



AND 

 PREAMPLIFIER 



SHIP EQUIPMENT 



I 



Figure 1. Block diagram of the Basic Underwater Sound-Measuring System. 



