水下声学 船舶水下声音的描述和测量的量和程序 第3部分:浅水中测量的要求

[中文适用范围]： ISO 17208系列描述了测量被测船舶水下辐射声以及从测量结果计算声源量（如源级和辐射噪声级）的程序。在ISO 17208-1至ISO 17208-3中，假定被测船舶配合测量，以预定速度沿指定航线多次航行经过测量系统，并采用预定的机械配置。对过往船舶辐射声的机会测量不在这三个标准的范围内。ISO 17208-1提供了量化船舶水下声的程序，以辐射噪声级表示，该值根据在船舶远场、横侧方向测量的声压级（SPL）计算，按到CPA的距离缩放，并以十分之一十倍频带报告。辐射噪声级的预期用途是显示符合合同要求或标准，用于比较船舶之间，进行定期特征评估以及研究和开发。ISO 17208-2指定了根据ISO 17208-1获得的辐射噪声级值计算等效单极源在指定标称源深度处的源级的方法。源级及其相关标称源深度的预期用途是进行远场声预测，如环境影响研究或创建水下声等值线图所需。ISO 17208-1和ISO 17208-2适用于深水测量，定义为水深大于150米和1.5倍船舶总长中的较大值。第3部分测量的允许水深和环境条件在4.5节中描述。本文件规定了在浅水中测量被测船舶水下辐射声的程序。它还规定了根据声压测量计算源级及其相关标称源深度的程序，考虑了控制浅水中声音传播的相关现象。这些计算在第7节中描述。一旦计算出源级，其他度量可以从源级和源深度计算。7.3提供了一个程序，用于计算根据ISO 17208-1在深水中对同一船舶在相同操作条件下可能测量的辐射噪声级。 [外文原描述]： ISO 17208 series describe procedures for the measurement of underwater sound radiated by the ship under test, and for calculating sound source quantities such as source level and radiated noise level from the measurement results. In ISO 17208-1 to ISO 17208-3 it is presumed that the ship under test cooperates in the measurements, sailing multiple runs over a specified track past the measurement system at a specified speed with pre-determined machinery configurations. Opportunistic measurements of the radiated sound of passing ships are outside the scope of these three standards. Part 1 of the ISO 17208 standards[ 1 ] provides the procedure to quantify the underwater sound from the ship in terms of its radiated noise level, which is calculated from the sound pressure level (SPL) measured in the far field of the ship, in beam aspect, scaled by the distance to CPA and reported in decidecade bands. The intended use of radiated noise level is to show compliance with contract requirements or criteria, for comparison of one ship to another ship, to enable periodic signature assessments, and for research and development. ISO 17208-2[ 1 ] specifies methods for calculating the source level of an equivalent monopole source at a specified nominal source depth from the radiated noise level values obtained according to ISO 17208-1. The intended use of source level, with associated nominal source depth, is to perform far field sound predictions such as needed for environmental impact studies or for creating underwater sound contour maps. ISO 17208-1 and ISO 17208-2[ 1 ] are applicable for measurements in deep water, defined as water depth greater than the larger of 150 m and 1,5 times overall ship length. The allowable water depths and environmental conditions for part 3 measurements are described in 4.5 . This document specifies procedures for the measurement of underwater sound radiated by the ship under test in shallow water. It also specifies procedures for the calculation of source level, with associated nominal source depth, from the sound pressure measurements, accounting for the relevant phenomena that govern the propagation of sound in shallow water. These calculations are described in Clause 7 . Once the source level has been calculated, other metrics may be calculated from the source level and the source depth. 7.3 provides a procedure for calculating the radiated noise level that would have been measured in deep water according to ISO 17208-1 for the same ship with the same operating condition.