IMOS - National Mooring Network - Passive Acoustic Observatory at Perth Canyon, WA (PAPCA)

The Perth Canyon Passive Acoustic Observatory consists of two to four moorings fitted with hydrophones set on the seabed at 400-490 m depth that record noise in the ocean. This system can be used to monitor whale and fish migrations, seismic activity and other natural and man-made noise sources. If four moorings are set they are configured with a mooring at each apex of an approximate equilateral triangle of 5 km side with the fourth mooring in the triangle centre. Temperature loggers are set on each mooring at the seabed.Each logger records at a sampling rate of 6 kHz for between 3-8 min of every 15 min. If four loggers are set a 22 kHz recording is also made once a day to allow accurate synchronisation of the instrument clocks. This is required for locating the source of a sound based on its time of arrival at each hydrophone in the array. A 7 kHz pinger set on the central mooring pings for 35 minutes at a 20 s interval once per day to overlap the 22 kHz sample.Raw data from each logger is in the form of mixed binary/text files comprised of: 1) text header and footer containing recording start and end date/time, quality control and sampling configuration; and 2) sea noise data of 16 bit unsigned integer, binary values (IEEE, little endian). Instruments are calibrated for system gain with white noise of known level input with the hydrophone in series, before and after deployments. System calibrations are made over 2 Hz to the Nyquist frequency. The instrument clock drift is checked against GPS transmitted UTC time before and after deployment.The raw data can be obtained on portable disk from the Australian Ocean Data Network (AODN).The Centre for Marine Science and Technology (CMST) at Curtin University has developed Matlab software to process and analyse these data.This observatory was decommissioned in October 2017.

珀斯峡谷被动声学观测站(Perth Canyon Passive Acoustic Observatory)由2至4套锚系设备组成，每套锚系搭载水听器(hydrophone)布设于400~490米深的海底，用于记录海洋环境噪声。该系统可用于监测鲸类与鱼类洄游、地震活动，以及其他自然和人为噪声源。
当布设4套锚系设备时，它们会被配置为以边长约5公里的近似等边三角形的三个顶点各部署一套锚系，第四套锚系布设于三角形中心。每套锚系的海底位置均安装温度记录仪。
每台记录仪每15分钟内采集3~8分钟的声学数据，采样率为6千赫兹(kHz)。若部署4台记录仪，则每日额外开展一次22千赫兹的采集，以实现各仪器时钟的精准同步——这一操作是基于阵列中各水听器接收声音的到达时间来定位声源的必要前提。
布设于中心锚系上的7千赫兹脉冲信号发射器(pinger)每日会以20秒的间隔持续发射35分钟，以与22千赫兹的采样时段重叠。
每台记录仪的原始数据为混合二进制/文本文件，包含两部分内容：1) 文本形式的文件头与文件尾，内含记录的起止日期/时间、质量控制信息以及采样配置参数；2) 16位无符号整数格式的海洋噪声数据，二进制值采用IEEE标准小端序(little endian)编码。
在部署前后，均会通过串联水听器并输入已知强度的白噪声的方式，对系统增益进行校准。系统校准的频率覆盖范围为2赫兹(Hz)至奈奎斯特频率(Nyquist frequency)。仪器时钟漂移量会通过比对部署前后GPS传输的协调世界时(UTC)进行校验。
原始数据可通过便携式磁盘从澳大利亚海洋数据网络(Australian Ocean Data Network, AODN)获取。科廷大学(Curtin University)海洋科学与技术中心(Centre for Marine Science and Technology, CMST)开发了用于处理与分析此类数据的Matlab软件。
该观测站已于2017年10月退役。