Kite Assist Project
Kites Provide a Cost-Efficient Aerial Photography
and Remote Sensing Alternative
A rokkaku is a classic kite design that allows researchers to efficiently take aerial photograp ...
Custom-made camera mounts allow researchers to collect stable and accurate images while at sea. ...
Using kites as information gathering tools is an ancient tradition that began out of strategic military necessity. Kites used as eyes in the sky have become a valued part of many researchers’ toolboxes, both on land and at sea. For over 125 years, kites have been used as platforms for aerial photography. The demand for kites capable of carrying cameras and other devices into the air prompted organizations like the California-based Kite Assist Institute (KAI) to develop increasingly sophisticated products for a wide range of uses, including aerial photography, mapping and topography, meteorology, and climate research.
Don Montague, head of research and development at KAI and a former professional windsurfer and sail designer, said technological advances, including lighter materials and better designs have opened up new possibilities in the realm of kite assisted devices over the years, increasing their value to both research professionals and avid amateur aerial photographers. “It’s possible for much smaller, lighter kites to lift camera gear into the air than when I began my design career over 25 years ago,” Montague said.
In essence, a kite is simply an wind-powered aircraft tethered to the ground, a boat, or a person. Its surface area acts as a wing that lifts its frame into the air. The ability to send high resolution cameras into the air above research vessels at sea via kites is particularly valuable to some researchers, because it offers a much more efficient way of obtaining real-time aerial photography than airplanes, helicopters, and satellites. Satellite images of the same quality as those taken from any kite or aircraft flying below 1000 meters are especially expensive, according to the KAI.
High resolution images taken from cameras mounted to kites could be used to assess a variety of phenomena such as the extent of an oil spill, progression of an algal bloom, and whale migration patterns.
In turn-of-the-19th-century military applications, some of the largest “kites” were actually balloons that resembled blimps and had the ability to carry human observers into the sky so they could keep watchful eyes on the enemy. They were also used to erect temporary communication antennas.
The KAI, in a partnership with the Marine Science and Technology Foundation (MSTF) developed a much smaller, sleeker version of the kite balloon. KAI designers made their version of a kite balloon, which the industry now widely calls a “Kytoon.” It is a balloon that has many of the aerodynamic properties of a kite, allowing it greater stability in the wind. “The big trick about aerial photography, especially aerial video, is you need the kite to be extremely still,” Montague said. KAI personnel field tested a version of the Kytoon during an oceanographic research expedition aboard the Schmidt Ocean Institute ship Lone Ranger in February of 2012 in the Sargasso Sea.
As in any form of aviation, kite balloons must strike a delicate balance between the weight of their cargo and the lift they generate.“Launching our Kytoon in the Sargasso Sea gave us several advantages from a testing standpoint,” Montague said. “In the Bay area, there are restrictions on altitude and other air traffic that can get in the way. Out there, we were able to experiment with much longer tether lengths.”
Montague and his team from the KAI attached a GoPro camera to the Kytoon. A GoPro is a high-resolution camera that weighs only 98 grams – about the same as a small bag of chips or 40 pennies. With a waterproof case and hardware to mount the camera to the balloon, the total camera assembly added 351 grams to the Kytoon’s payload, or about three quarters of a pound. When filled with helium gas, the balloon generated 760 grams of lift above and beyond its own weight. Over the course of five days at sea, that lift decreased to 535 grams – still enough to fly the camera assembly without any wind. The Kytoon generates substantially more lift when there is a wind source, Montague said.
Montague and his team continue to refine a camera mount stabilized by servos attached to motion sensors so they can obtain sharper images. “Each time we test our equipment, it’s a learning experience,” Montague said. “We take that experience and data and use it to refine our kites and kite balloons to maximize their effectiveness in research applications.”
Another new kite developed by the KAI based on a Rokkaku design has an airframe that is inflated, but it has the appearance of a traditional kite. When launched from the stern of a moving ship, it can stay in the air almost indefinitely, allowing researchers to collected images transmitted wirelessly from a camera suspended from its frame.
The ability to communicate wirelessly with a digital camera mounted on a flying kite further increases the potential value of the kite platform for researchers. A new technology called the Eye-Fi card – a small memory card capable of transmitting images wirelessly it receives them from the camera – was used by Montague and his team during a research cruise in early 2012. He said his team also experimented with a high-frequency transmitter with a much longer range, similar to those used in high-end amateur remote control airplanes. Those devices, Montague said, are lightweight and are capable of transmitting images over several kilometers.
Montague anticipates that the use of kites and kite-assisted devices will continue to remain a valuable asset to ocean researchers as the technology continues to improve and the cost of traditional aerial photography from airplanes, helicopters, and satellites increases.
For more information:
On the history of kites: The Drachen Foundation