海洋工程物探勘察中的几种声学假象

Several Acoustic Artifacts in Marine Engineering Geophysical Survey

海洋工程物探勘察主要基于各种声学调查设备,通过换能器发射和接收不同频率的声波来获取地层声学反射信息,在实际工程应用中,技术人员会面临多种复杂的作业环境以及各类声学假象,需要技术人员熟知声学假象的产生原理和特征。本文研究了多波束测深资料中圆弧状地形反射、浅地层剖面绕射、电火花剖面三类调查资料中存在的声学假象,分析了波束频率、发射和接收角度、接收范围等因素的影响和限制,及造成声学假象的原因。研究显示,对海底管道、海底沙丘、已建平台等环境均会造成不同影响的声学假象,包括多波束的绕射波、浅地层剖面的绕射波,以及电火花水听器接收到的环境反射。技术人员应提高对海洋工程物探资料声学假象的认识,作业前期应做好工区环境、海底设施、背景资料等研究,在海洋工程勘察的处理和解释过程中综合利用水深地形、海底地貌、地层剖面的相互印证解释,注意辨识绕射、已建设施反射等造成的声学假象。

Marine engineering geophysical survey much relying on various acoustic survey equipment,the acoustic reflection information of the formation is obtained by transmitting and receiving sound waves of different frequencies through transducers.In practical engineering applications,technicians are troubled by a variety of complex operating environments and various acoustic artifacts.It is necessary for technicians to be familiar with the generation principle and characteristics of acoustic artifacts.Firtly,this paper studies the acoustic artifacts existing in the three types of survey data of arc terrain reflection,sub-bottom profile diffraction and sparker profile in the multi-beam bathymetric data.Then analyzes the influence and limitation of beam frequency,transmitting and receiving angle,receiving range and other factors,and the causes of acoustic artifacts.Results show that acoustic artifacts can have different impacts on environments such as submarine pipelines,submarine sand dunes,and built platforms,including multiple beam diffraction waves,sub-bottom profile diffraction waves,and environmental reflections received by sparker hydrophones.The paper concludes that technicians should improve their understanding of acoustic artifacts in marine engineering geophysical data.In the initial stages of operations,desktop research should be done on the environment of the work area,submarine facilities,background and other aspects.In the processing and interpretation process of marine engineering surveys,mutual confirmation and interpretation of water depth,topography,and stratigraphic profiles should be comprehensively utilized,and attention should be paid to identifying acoustic artifacts caused by diffraction,reflection and other constructed objects.