Researchers from Japan and the United States have used two digital single-lens reflex cameras set 5 miles apart to capture 3D images of Aurora Borealis (Northern Lights). They have also determined the altitude where electrons in the atmosphere emit the light that produces aurora.

“We had initial success when we projected the digital SLR images at a planetarium and showed that the aurora could be seen in 3D. It was very beautiful, and I became confident that it should be possible to calculate the emission altitude using these images,” explained Dr Ryuho Kataoka of the National Institute of Polar Research, Japan, who is a lead author of the study published in the Annales Geophysicae.

Dr Kataoka with colleagues used two single-lens reflex (SLR) cameras, mimicking the left and right eyes, separated by 5 miles across the Chatanika area in Alaska.

The cameras, equipped with fisheye lenses and GPS units, captured two simultaneous all-sky images that the team combined to create a 3D photograph of the aurora and measure the emission altitude.

“Using the parallax of the left-eye and the right-eye images, we can calculate the distance to the aurora using a triangulation method that is similar to the way the human brain comprehends the distance to an object,” Dr Kataoka said.

The technique is low cost and allows researchers to measure the altitude of small-scale features in the aurora.

“Commercially available GPS units for digital SLR cameras have become popular and relatively inexpensive, and it is easy and very useful for photographers to record the accurate time and position in photographic files,” Dr Kataoka said.

“I am thinking of developing a website with a submission system to collect many interesting photographs from night-sky photographers over the world via the Internet.”

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Bibliographic information: R. Kataoka et al. 2013. Stereoscopic determination of all-sky altitude map of aurora using two ground-based Nikon DSLR cameras. Ann. Geophys., 31, 1543-1548; doi: 10.5194/angeo-31-1543-2013