Navigation and Seamanship (1+1)

6.1.3.1. Transmitter

Transmitter is in the case of echo sounder, the transmitter generates pulses of electrical energy and pass on to the transducer. The pulses of SONAR is meant for long ranges, there are differences in frequency, power and pulse length. For longer range use lower frequencies are prefered because they travel further in water. Common sonar frequency range from 20-40KHz. The power output is increased up to 10 Kw as compared with about 1Kw for an average echosounder. To get such high power into the water the pulse lengths are increased up to 40 milli seconds.