ISO DIS 17208-2

Description / Abstract: This document specifies methods for calculating source levels by converting radiated noise level values obtained in ISO 17208-1 for deep water, or directly from measurements made in shallow water. For measurements made in deep water according to ISO 17208-1, formulae are provided to correct the radiated noise level values obtained in Part 1 to convert source level. The measurement procedures and geometry for shallow water are illustrated in detail.

In this document, shallow water is defined as water depth less than 150 m or 1,5 times of the ship overall length which is under test, whichever is smaller. The minimum water depth for measurements depends on a number of factors.

For deep water, two alternative algebraic expressions are stated to correct the influence of pressure release surface. For measurement of source level from ships in shallow water, the procedure illustrated in this document accounts for the reflection from the pressure release sea surface as well as the reflection from the sea bottom.