Shot with 26,000 Feet Interaxial 3D Rig
Ryuko Kataoka from the National Institute of Polar Research (Tokyo, Japan) is using a stereoscopic pair of Nikon DSLR cameras to determine the altitute of northern lights in the scope of the Aurora research project. The unusual setup requires a very large interaxial distance between both cameras: 8 km (26,200 feet). Ryuho Kataoka got the idea for this innovative method to measure the height of sky features such as northern lights after working on a 3D movie for a planetarium.
Since aurora borealis extend between 90 and 400 km in altitude, a very large interaxial distance is needed to see them in 3D, so Mr. Kataoka used two SDSLR cameras with fisheye lenses and GPS locators,separated by 8 km across the Chatanika area in Alaska. Simultaneous capture was ensuring through remote control and GPS clock. Triangulation methods were then used to compute the distance to the various objects in the picture. The altitude maps obtained by stereoscopic photography proved to be consistent with previous observations done by other methods.
All-sky images of aurora borealis obtained from (left) Poker Flat and from (right) Aurora Borealis Lodge on March 17, 2013. Camera settings are ISO6400 and 2 s exposure time. The center of images is the zenith, geographic north is to the top, and west is to the right.
Timelapse Video from the Aurora Project
Visit the Aurora project web site.
Stereoscopic determination of all-sky altitude map of aurora using two ground-based Nikon DSLR cameras
This scientific paper was written by Ryuho Kataoka from the National Institute of Polar Research (Tokyo, Japan) with other researchers.
Abstract: A new stereoscopic measurement technique is developed to obtain an all-sky altitude map of aurora using two ground-based digital single-lens reflex (DSLR) cameras.
Two identical full-color all-sky cameras were set with an 8 km separation across the Chatanika area in Alaska (Poker Flat Research Range and Aurora Borealis Lodge) to find localized emission height with the maximum correlation of the apparent patterns in the localized pixels applying a method of the geographical coordinate transform.
It is found that a typical ray structure of discrete aurora shows the broad altitude distribution above 100 km, while a typical patchy structure of pulsating aurora shows the narrow altitude distribution of less than 100 km.
Because of its portability and low cost of the DSLR camera systems, the new technique may open a unique opportunity not only for scientists but also for night-sky photographers to complementarily attend the aurora science to potentially form a dense observation network.
Access the full paper in Annales Geophysicae.