The HydroBall – An aquatic GIS adventure.

Madeline Healey (SWEP 2018)

The Queens University Biological Station (QUBS) strives to be one of the best field stations in North America. To enrich the resources available to researchers, QUBS recently sough to apply a new technology to improve the bathymetric maps of our local lakes. A continually evolving technology, the Hydroball® buoy was obtained for data collection at QUBS over a two week period in the summer of 2018 . The Hydroball system integrates three main components: a GNSS L1/L2 receiver, a miniature inertial motion sensor, and a single beam echosounder. The GNSS receiver measures the buoys real time position including latitude, longitude and ‘ellipsoidal height.’ The inertial sensor measures roll, pitch and heading while the echosounder measures the depth under the buoy using SONAR (Sound Navigation and Ranging) properties. The output data of these components is fed into a controller unit inside the buoy that allows up to ten soundings per second to be referenced to the seabed.

Now, you may be asking “What is a Hydroball?” At first glance it looks like something out of a Star Wars movie (BB8’s aquatic cousin?) – the Hydroball concept is actually quite simple. It is a small autonomous bathymetric buoy developed by CIDCO (The Interdisciplinary Centre for Development of Ocean Mapping; Figure 1). It is designed to map non-traditional areas such as rivers, remote locations and ultra-coastal zones. The robustness of the Hydroball instrument supports bathymetric data acquisition in turbulent waters, allowing hydrographers and companies (and field stations!) to map unknown areas with high precision and accuracy.

Figure 1. The Hydroball. A bathymetric instrument used to map and chart bodies of water in high accuracy.

Bathymetry, the study of underwater topography, is fundamental to the studies of oceans, seas and lakes. Bathymetric data, including information about the depths and shapes of underwater terrain have a range of important uses. As of the year 2000, the National Oceanic and Atmospheric Administration estimated that as much as 95% of the world’s oceans and 99% of the ocean floor remained unexplored (NOAA, 2010). The rise of technology including remote sensing and bathymetrical devices such as the Hydroball have opened up opportunities for offshore exploration. By mapping and analyzing the floors of lakes and oceans, scientists can study circulation patterns, marine biology, geophysical properties and sites. In essence, bathymetric data provide valuable information about water depth and topography of lakes and oceans, which are significant for many aspects of marine research, administration, and spatial planning of coastal environments and their resources. Bathymetric maps are increasingly important as scientists learn more about the effects of climate change on our environment.

Figure 2. A previous bathymetric image of Lake Opinicon. Similar to how topographic maps represent three dimensional features of overland terrain, bathymetric maps illustrate the land that lies beneath the water.

The data acquisition was completed during the period of of July 3rd to16th and from July 15th – 22nd thanks to the amazing team efforts of QUBS staff and members from Dr. Stephen Lougheed’s lab (QUBS Director). Many long hours were spent on the water collecting data (Figure 3), as well as in the GIS room ‘cleaning and processing’ the millions of points collected. On the boat, we used ‘Survey’ software to visualize our progress in covering the Lake Opinicon grid that we had created. A Sound Velocity Profiler (SVP) instrument was used to determine the speed sound tab which the boat was moving through the water as we were collecting data. The software, combined with the technology of the Hydroball proved to be a reliable and robust system which yielded high quality of data.

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Once data collection was completed over the time that we had the instrument, the next step was to process and clean the data. A program called ‘Depthstar’ visualized our collected data on a navigation map platform (Figure 4). From here, we scanned through point clouds of data to remove (clean) obvious anomalies in the data set. Post collection cleaning included adding Precise Point Processing (PPP) data to the raw data to georeference the points, and improving the accuracy and reliability of the data. The processed skeletal data was moved into Arc software to create the Digital Terrain Models (DEM). This process required a lot of patience (and coffee) as we collected over 6 million points over the 14 days of data collection!

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The biggest lesson I’ve learned from this project is the importance of quality data for an effective research data management plan. For data to be maximally relevant, it must be current and up to date. With such contemporary data, research organizations like QUBS are better equipped to provide accurate data for research questions. Another significant lesson learned from this project is the importance of strong organizational and communication skills. Effective communication led to a successful execution of data collection and management. Communicating questions and concerns directly with the team members allowed us to foster collaboration and to innovate and problem-solve, ultimately allowing us to attain the goals of this project.

The Hydroball project was a highlight of our summer here at QUBS. Being a part of every step of the process from data acquisition, processing, management and application was incredibly rewarding. We have definitely gained a new appreciation for sunrises above Lake Opinicon, even though it meant waking up at 4:45am to start collecting data! The final product of our work will be a detailed, high accuracy bathymetric map of a significant portion of Lake Opinicon. This information will be further used for multiple research projects at QUBS for many years to come.

Thank you to Kevin J. Wilson from CIDCO for providing us with the training and guidance to use the Hydroball at QUBS. Also thank you to Lougheed lab members and other QUBS SWEP 2018 staff for assisting in the data collection; this project would not have been possible if it wasn’t for your generous help!

Sources:

  1. US Department of Commerce, & National Oceanic and Atmospheric Administration. (2009, January 01). How much of the ocean have we explored? Retrieved from https://oceanservice.noaa.gov/facts/exploration.html
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