Space, as the famous voiceover goes, is the final frontier. Full of strange new worlds where no one has gone before, space seems like the ultimate challenge when it comes to exploration.
Yet we’re actually doing quite well at mapping space. The Hubble telescope sits outside our atmosphere, quietly taking impressive photographs of stars light years away from us. Hubble also joins the list of gamma ray, x-ray, ultraviolet, infrared, microwave and radio telescopes that are watching the invisible light in our skies. We even have neutrino and now gravitational wave telescopes for seeing the unseeable.
Meanwhile, the oceans around us have been getting overlooked.
Space, of course, is big. Really big. You just won’t believe how vastly, hugely, mind-bogglingly big it is, as another famous voiceover once pointed out. But so are the oceans and they’re much harder to see into that space – light can travel many millions of miles unfettered in space, but water bends it in different directions as soon as it makes contact, and it all but disappears a mere 100m below the surface, refracted and absorbed by the water and the material suspended within it.
All of which means that surveyors have their work cut out for them. However, this issue we look at how a different kind of explorer is helping surveyors to see further and in more detail than ever before. We start with a look at underwater photogrammetry. Photogrammetry above the surface has many challenges already but add in the distortions caused by waves, currents that speed up or hinder the progress of moving cameras, and the loss of light and colour, and you get a near-impossible situation.
However, Lisa Chen and Romain Pinel describe on page 18 a project in the Indian Ocean that’s developing a methodology to take account of all these factors. While still in early stages, it’s already capable of producing of 3D digital elevation models of the ocean floor.
The methodology is restricted to small areas, since it requires divers to take photographs. But since oceans cover roughly 361.9 million square kilometres of the Earth’s surface, it’s not something that can scale up easily. Few techniques do – many bathymetric charts still rely on soundings taken more than a century ago, because no one’s passed by to take any since. If only there were a way to exploit the navigation equipment of the innumerable vessels sailing the oceans to improve those charts. They could pass back bathymetric and other data automatically so that charts could be updated for both them and anyone else in the area.
On page 24, Tim Thornton and Duncan Kent report back on a crowdsourcing project designed to do just that. In particular, they’ve been working on a way to incentivise boat owners to install a small device on their vessels that would automate the procedure using WiFi – a smartphone app that allows them to access their vessels’ data.
Earth observation is another way to monitor the oceans on a far larger scale than other surveying techniques can consider. Careful analysis of the spectra enable organisations to not only observe and preserve marine life, but to also create industries and revenues around the world. Katherine Anderson reveals how this new ‘Ocean Enterprise’ is being achieved, on page 26.
But this brings us full circle back to space. We’re now living in an age of unprecedented positioning accuracy, thanks to the likes of the GPS and GLONASS satellite constellations. But more and more satellites are coming online in more and more constellations each year, potentially improving accuracy and availability even further, with Europe’s Copernicus being just the latest system to go live. On page 32, Nick Lenske looks at what Copernicus offers and what you should be looking for in surveying equipment to be able to use it. But before you rush out to buy the next tool in your toolkit, read Bernhard Ricther on page 35. He considers how to future-proof your purchase, so that you don’t have to worry about the constellation after Copernicus.
I hope you enjoy the issue and that it inspires you in your own work.
If you have a comment or wish to express your views on anything in this issue or in the world of geospatial information, then please email me at [email protected] with Letter to the Editor in the Subject line. Please start your email with Dear Editor and the chances are your letter will appear in the Letters to the Editor page