In-Flight Service: UAV Research at the Top of the World

[My latest field write-up, also online in a slightly different form at http://www.icimod.org/?q=20589 ]

Against the unparalleled backdrop of Everest and Nuptse, the late November sun warms the glaciologist slightly as he prepares for an unmanned aerial vehicle (UAV) survey flight. From his coat pockets he pulls batteries that desperately need to stay warm for full power: batteries for the laptop, camera, and UAV that have been stored in his sleeping bag overnight, when temperatures plummeted below -20 C. He checks the wind. He sets up the flight on his laptop, sends the details to the UAV through a radio transmitter, and heads to the nearby launch location. At 5,350 m above sea level, the air has less than half as much oxygen as at sea level, and it can be difficult to launch the ultralight fixed-wing as the air pressure is so low. He breathes heavily — partly due to the oxygen depletion, and partly due to nerves. With the UAV in his hands, he starts the motor, heart racing as the propeller whine reaches an intense pitch. He steps forward to throw the aircraft and start the flight. He hopes.

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In collaboration with Dr Patrick Wagnon[1] and Dr Dibas Shrestha[2],  I recently joined a field expedition to Sagarmatha National Park (http://www.icimod.org/?q=20187) to conduct UAV surveys of several glaciers in the region. Using the senseFly eBee (www.sensefly.com), we took a total of 730 photos over six successful high-altitude flights. We also collected 56 high-precision ground control points for post-processing. And in very exciting news, our research may have inadvertently set an unofficial eBee altitude record, with a maximum flight elevation of 5,896 m [confirmed!]. However, the flight conditions deteriorated after two great days, and the eBee was damaged after a downdraft pushed it into a large boulder during a launch. [If senseFly wants to work on a high-altitude version, I’ve got some suggestions (and would be happy to test!)]

The project is part of a larger research project that I am working on with Dr. Walter Immerzeel (Utrecht University) and his PhD student Philip Kraaijenbrink. Data collected during the research will be used to construct detailed mosaics and elevation models of the study sites. Comparisons of the UAV datasets with satellite imagery and terrestrial photography will be used to examine rates of glacier change, glacier flow velocities, and the role of ice cliffs and ponds in the melt rates of debris-covered glaciers. The research was funded by the UK Department for International Development (DFID), ICIMOD, and Utrecht University. Special thanks to the Nepal Army, the Civil Aviation Authority of Nepal, and NAST for the UAV flight permissions. The eBee was generously loaned by FutureWater (Netherlands), who have been assured that it will be sent back to the factory for repairs and testing.

[1] Visiting scientist at ICIMOD and researcher at L’Institut du Récherche pour le Développement (IRD, France)

[2] Research Scientist at the Nepal Academy of Science and Technology (NAST)