Conclusion
Introduction to passive underwater detection

In addition to the numerical results presented for the three examples discussed, the reader is given an insight into the intellectual mechanism used by a sound engineer, enabling him to determine the factors he can play on to improve performance. Two key points are source levels (linked to discretion) and the most suitable frequency bands according to the environment, the carrier, etc. The use of the sonar equation for performance comparisons and equipment selection guidance is usually legitimate. However, the actual value of the range obtained can sometimes be highly uncertain.

Each term in the sonar equation (with the possible exception of the low end (§