爆炸声源投放间隔对会聚区声传播损失测量的影响

会聚区声传播损失测量是水声调查的重要内容。爆炸声源投放间隔对会聚区声传播损失结构的刻画具有直接影响。基于Argo资料、与距离有关声学模型(Range-dependent Acoustic Model, RAM)和实验数据,对不同投放间隔下获得的会聚区声传播损失进行了比较。结果表明,在不同声源深度和频率下,0.5 km的投放间隔能够很好地刻画出会聚区声场结构的精细特征;1 km的投放间隔基本满足对会聚区结构精细测量的要求;2 km的投放间隔能够测量到会聚区的大致结构,但可能出现对会聚区峰值结构的漏测或欠精确的会聚区增益。考虑到实际条件难以支持全测线0.5 km的投放间隔,建议对会聚区精细测量时,在可知会聚区范围的海域使用在会聚区0.5 km的投放间隔、在影区1 km的投放间隔;在未知海域使用全测线1 km的投放间隔;对了解会聚区大致结构的调查,使用2 km的投放间隔。

Impact of the release interval of explosive sound source on measurements of acoustic transmission loss in convergence zone

Measurements of acoustic transmission loss in convergence zone are an important part of underwater acoustic survey. Among various parameters of the explosive sound source, the release interval has a direct effect on the characterization of the acoustic transmission loss structure in convergence zone. Based on Argo data, RAM acoustic propagation model and experimental data, the structures of acoustic transmission loss in convergence zone for different release intervals are compared. The results indicate that under the conditions of different sound source depths and frequencies, the fine characteristics of the acoustic field structure in convergence zone can be well described at the release interval of 0.5 km, the requirement for fine measurement of the convergence zone structure can be met at the release interval of 1 km, and a release interval of 2 km can be used to measure the general structure of the convergence zone, but the peak structure of the convergence region may be missed or the convergence region gain may not be accurate. In consideration of these results and the fact that 0.5 km release interval is impracticable for the whole survey line under the existing conditions, it is suggested that fine measurement of convergence zone, 0.5-km release interval in the convergence zone and 1-km release interval intervals in the shadow zone should be used in the sea area where the range of convergence zone can be known in advance, 1-km release interval can be used on the whole survey line in the unknown sea area; for a survey which aims at getting the general structure of acoustic transmission loss in convergence zone, 2-km release distance interval can be adopted.