Drag-type in-situ acoustic measurement system: Design, operation, and experimental results

Abstract

The Drag-type In-Situ Acoustic Measurement System (DISAMS) is a new instrument designed for rapid measurement of seabed sediment acoustic parameters, including the sediment sound velocity and acoustic attenuation coefficient. The DISAMS consists of six independent acoustic probes arranged symmetrically such that each side has one transmitting probe and two receiving probes. The entire operation is controlled and monitored in real time by a deck control unit on board, and the center frequency of the DISAMS is 30 kHz. The DISAMS can record full waveforms to determine the sound velocity and attenuation coefficient in the seabed sediment. In addition to site measurements, the DISAMS can also carry out towing measurements, resulting in improved efficiency compared with existing in-situ acoustic measurement systems. This article presents the configuration, electronics, and tests of the DISAMS in detail. Laboratory tests were conducted in a sediment pool, sea trials were carried out in the Zhoushan Islands, and sound velocity and attenuation coefficient data were obtained. The test results demonstrated that the DISAMS performed well and was able to measure the sound velocity and attenuation coefficient rapidly and accurately in both site measurements and towing measurements.

Keywords:

• Acoustic parameters
• in situ acoustic measurement system
• seabed sediment

Additional information

Funding

This study was funded by the National Natural Science Foundation of China (grant numbers 41706045, 41706062, 41330965), the Key Laboratory of Marine Geology and Environment, Chinese Academy of Sciences (grant number No. MGE2017KG02), the opening foundation of the Key Laboratory of Marine Sedimentology and Environmental Geology, SOA (No. MASEG201707), the Guangdong Natural Science Foundation (grant number 2017A030313237), and Shandong Provincial Natural Science Foundation, China (grant number No. ZR2017BD031).