Authors: Beaman, R.J.
Publication: Crowdsourced bathymetry on the Great Barrier Reef. In: Maschke, J. (Editor), Hydrospatial 2021 Conference, 16-18 Feb 2022. Australasian Hydrographic Society, Cairns, Australia.
Crowdsourced bathymetry (CSB) is the collection of depth measurements from vessels using standard navigation instruments. Many vessels on the Great Barrier Reef – from dive boats to fishing boats – use some type of echo sounder to measure the depth of water. Combined with GPS satellite navigation, these instruments are used for safe navigation and guiding the activities permitted within the zoning maps for the Great Barrier Reef Marine Park.
In 2018 we started the ‘Crowdsourced bathymetry on the Great Barrier Reef’ project to collect bathymetry and navigation data from volunteer vessels using their own echo sounder and GPS sensors. We initially partnered with Biopixel, a documentary film company, using their expedition vessel Argo, to install the SmartLog data logger developed by TeamSurv in the UK. Raw NMEA0183 data are stored onto a USB flash drive inserted into the data logger.
Once copied off the USB stick, the raw NMEA data files are parsed using a python script into ‘clean’ tables of latitude/longitude/date/time/speed/course/depth. Data can be further analysed in 3D point clouds for any noise, or imported into hydrographic software for more rigorous depth and position adjustment, such as applying sensor offsets to a reference point at the waterline, correction for sound velocity, and the application of predicted tides in relation to nearest tidal ports.
The success of the CSB data collected by the Argo has led to an expansion of the project across Queensland. In 2019 we were funded by the Great Barrier Reef Foundation to establish a pool of SmartLog USB data loggers for volunteer vessels to collect CSB data. This project also became an activity of the Citizens of the Great Barrier Reef, which gives people an increasing role in contributing valuable citizen science data to improve a fundamental dataset that helps the Reef.
Our overall strategy is to develop comprehensive, high-resolution bathymetry maps for the Reef, with outputs being accurate 3D depth models at mixed 100/30 m-resolutions, for use by the general public, scientists and managers. Such 3D depth models require digital source data for which this crowdsourced bathymetry project is contributing valuable coverage, with multiple vessel tracks that reach into remote parts of the Reef – far away from the well-mapped shipping channels.
The many lessons from this project feed into the IHO Crowdsourced Bathymetry Working Group meetings by providing contributions on installation, calibration, processing, errors, costs and time involved, and the importance of feedback to volunteer vessels to ensure the project is sustainable. The talk concludes with future work planned for this project, including being considered a ‘Trusted Node’ for provision of CSB data into the IHO Data Centre for Digital Bathymetry and for the global Seabed 2030 Project.