Davis Aerodrome Project (DAP) - Acoustic Mooring recordings

The Davis Aerodrome Project (DAP) collected a range of environmental survey data over several field seasons to support a comprehensive environmental assessment of the proposed aerodrome. This data includes flora, fauna, soils, lake ecosystem, nearshore, marine, air quality and meteorological information which has been collected by a number of different methods, and extends across the current Davis Station, proposed aerodrome and supporting infrastructure footprint (Ridge Site), previous sites considered for the aerodrome (Heidemann Valley, Adams Flat), as well as locations across the Vestfold Hills away from any of the proposed developments. This dataset contains long-term underwater acoustic recordings made for the Australian Antarctic Division’s Davis Aerodrome Project 5097 environmental assessments. Calibrated measurements of sound pressure were made at two sites in the vicinity of Davis Research station (approx. 5km west of the station and one in Long Fjord to the north of station). The attached data was downloaded from the instrument deployed west of Davis Station. Data was recorded over 7 months using a custom moored Autonomous Multichannel Acoustic Recorder (AMAR G4) designed and manufactured by JASCO Applied Science following specifications provided by the Australian Antarctic Division. These moored acoustic recorders were designed to operate for year-long, near shore, Antarctic deployments. The moorings were deployed through the ice during the 2021 winter and one retrieved during the 2021/22 summer when the sea ice was clear of the surface. The Autonomous Multichannel Acoustic Recorder is a fully autonomous underwater sound and data recorder. The acoustic recorder included a factory calibrated M36-100 hydrophone, data acquisition electronics and solid state digital storage (SDHC) to reduce power consumption and mechanical self-noise (e.g. from hard-drives with motors and rotating disks). Batteries, SDHC cards and electronics were placed in watertight pressure sealed PVC housing rated to a depth of 250 m. The moorings were secured to the seafloor by weights and suspended up into the water column by a string of floats attached to the top of the structure to separate the recorder and hydrophone from sea-bed. The hydrophone was securely mounted to the base of the AMAR housing. All connections between mooring components where taped with protective coverings to reduce mechanical self-noise from movement of the structure. The target noise floor of each recorder was below that expected for a quiet ocean at sea state zero. The data for each recording site comprise folders of 24-bit WAV audio files recorded on a duty cycle with two different sample rates. The duty cycle recorded for 60 s at a sample-rate of 512 kHz, followed immediately by a 580 s at a sample-rate of 32 kHz, and then 280 s off before repeating. The names of each WAV file correspond to instrument serial number followed by the start time (in UTC) of the file as determined by the AMAR’s real-time clock e.g. AMAR897.20210722T061621Z.wav would correspond to a wav from AMAR serial number 897 that starts at 06:16:21 on 22 July 2021 (UTC).戴维斯机场项目（Davis Aerodrome Project, DAP）在多个野外考察季中收集了多类环境调查数据，以支撑拟建机场的全面环境评估工作。本次采集的数据涵盖植物区系、动物区系、土壤、湖泊生态系统、近岸海域、海洋环境、空气质量及气象信息，采集手段多样，覆盖范围包括当前戴维斯站、拟建机场及配套基础设施占地范围（里奇场址，Ridge Site）、此前拟用于机场建设的场址（海德曼谷、亚当斯平原），以及维斯弗德丘陵（Vestfold Hills）内远离所有拟建开发项目的区域。 本数据集包含为澳大利亚南极局（Australian Antarctic Division）戴维斯机场项目5097号环境评估所录制的长期水下声学录音。研究人员在戴维斯研究站附近的两个点位开展了经校准的声压测量：一处位于站西约5公里处，另一处位于站北的长峡湾（Long Fjord）内。附件数据源自部署在戴维斯站西侧的采集仪器。 该数据由一台定制系泊式多通道自主声学记录仪（Autonomous Multichannel Acoustic Recorder, AMAR G4）录制，总时长7个月。该设备由JASCO应用科学公司（JASCO Applied Science）根据澳大利亚南极局提供的技术规格设计制造，专为南极近岸的长期部署场景设计，可连续运行一年。系泊装置于2021年冬季通过海冰完成布放，其中一套于2021/2022年夏季海冰消融后回收。 多通道自主声学记录仪为完全自主的水下声学数据采集设备，内置经工厂校准的M36-100型水听器、数据采集电子元件及固态数字存储（SDHC）模块，旨在降低功耗与机械自噪声（例如搭载电机和旋转盘的硬盘所产生的噪声）。电池、SDHC存储卡及电子元件均封装于额定耐压250米的防水密封聚氯乙烯（PVC）外壳中。系泊装置通过重物固定于海底，再通过一串浮子将设备悬吊于水柱中，使记录仪与水听器脱离海床。水听器牢固安装于AMAR外壳底部。系泊组件间的所有连接处均缠绕防护包覆物，以降低设备移动产生的机械自噪声。每台记录仪的目标本底噪声低于海况0级下的安静海洋本底噪声。 每个录制点位的数据均以文件夹形式存储，包含24位WAV音频文件，采用两种采样率的占空比录制模式：以512 kHz采样率录制60秒，随后以32 kHz采样率录制580秒，接着停止录制280秒，之后重复该循环。每个WAV文件的文件名由仪器序列号及以协调世界时（UTC）表示的文件开始时刻组成，示例如下：AMAR897.20210722T061621Z.wav 对应序列号为897的AMAR设备于2021年7月22日06:16:21（UTC）开始录制的音频文件。