The EU-funded 'TeamSurv' system is using satellite navigation technologies to chart the seabed, harnessing the power of numbers by equipping many boats with an inexpensive system to log data as they go about their normal business.
Surveying the sea floor by conventional means is a very specialised and very expensive process involving multi-beam echo-sounding technologies. Because of this, there is still a huge backlog of areas to be surveyed around the world. The problem is not that existing maps are not good; the problem is that the area covered is incomplete, and the mapping of uncharted areas is extremely costly.
"Obviously, up-to-date and detailed charts are crucial for safe navigation, minimising risks and optimising efficient routing," says Tim Thornton of Smartcom Software. "But they are also important for many other activities, such as environmental monitoring or coastal engineering."
Thornton coordinates the EU-funded 'CoSuDEC' project ('Coastal surveying of depths with EGNOS to enhance charts'), which is developing the TeamSurv system. "We are harnessing the power of 'crowd sourcing'," explains Thornton, "gathering small bits of data from large numbers of boats."
Under the TeamSurv scheme, boats are equipped with a simple data logger connected to onboard instruments, including a GPS receiver, ideally assisted by EGNOS, and a depth sounder. If the pilot is using a PC for navigation, then the logger is simply a software package on the PC. Either way, data can be stored on a standard USB memory stick.
"Out at sea, a boat equipped with our system simply goes about its business," says Thornton, "and all the while data is being logged. Once back in harbour, the data is uploaded to the TeamSurv servers via the internet." There, he says, the data is filtered, corrected for tides and other effects, and then merged using sophisticated mathematics. "The result is more accurate than what you can get with just a single boat collecting data on its own," explains Thornton. "And while it may not be as accurate as the latest high-tech survey tools, this method is good enough for many purposes, and it is much more cost effective."
Thornton says the additional accuracy available thanks to EGNOS, the European satellite navigation augmentation system, will help provide crucial horizontal precision, particularly in times of high solar activity.
"The data logging is being done by small boats like pleasure yachts, fishing boats, workboats, coastal ferries and cargo boats. The reason we have not recruited larger vessels is because they spend most of their time crossing oceans, which we aren’t really interested in."
TeamSurv has already developed new data logging hardware and software, a website and new back-end processing procedures. It has also recruited some 40 volunteers to log data in the UK, France and Lithuania, where initial trials are being undertaken.
"In 2011, we are improving the data processing, and we will soon be producing charts," says Thornton, "and we are comparing the accuracy of our results against the best quality surveys in the same areas, so we know what kind of performance we are achieving."
And, Thornton says, you can see the results for yourself. TeamSurv data can be viewed right now by anyone on the project's new website.
A new way of working?
From the introduction of GPS until multi-beam sounders became more common, around the end of the 1990s, GPS systems in combination with depth sounders were used by individual boats for surveying. There are also tools such as the Olex navigation system, which calculates average depths based on readings from a number of boats, but TeamSurv is first in the following areas:
- Using a crowd sourcing approach that is open to all (Olex comprises a closed user community)
- Applying survey-style data processing to crowd sourced data, rather than just averaging results
- A new statistical approach that delivers enhanced accuracy
"The US National Oceanic and Atmospheric Administration (NOAA) and the Canadian Hydrographic Service have also been experimenting with crowd sourcing internally," says Thornton, "but neither has actually brought anything out."
The TeamSurv system is now seen as a way of ensuring that that charts, especially those used by smaller craft, are as detailed and up-to-date as possible, especially off the main shipping lanes where most surveys are concentrated.
Possible commercial applications
"We are now negotiating with a number of chart publishers and chart plotter manufacturers who would like to incorporate TeamSurv data into their products," says Thornton. "Port and harbour authorities have also shown interest in in our system as a cost effective tool for surveying areas that don’t warrant the cost of a multi-beam survey, and also for monitoring changes in the depth of the sea bed that would indicate the need for a full survey.
"We are also getting interest from other areas, such as in helping survey the waters off Antarctica, or in developing countries where they do not have the resources for a multi-beam survey. We are hoping to make some real progress on all of these fronts; we definitely want to keep this working going after the EU-funding period runs out."
For the European GNSS Agency (GSA), which oversees the project on behalf of the European Commission, TeamSurv is a prime example of how innovative ideas and new European satellite navigation resources, such as EGNOS, can be put to good use for the benefit of public authorities, private users, and businesses and service providers.