Big Island Lasers

Commercial airlines face existential threats to flight safety on a daily basis. Threats from violent weather, volcanic ash and security issues are high on the list of challenges. An ongoing problem is laser beams pointed at aircraft from the ground. Thousands of laser incidents are reported each year — the majority involving individuals pointing small but powerful handheld lasers into the sky, endangering aircraft crew and passengers.

Two of the most powerful telescopes, used for deep space exploration, are operated by the W. M. Keck Observatory — part of a scientific observatories consortium that includes Cal Tech., University of California, University of Hawaii and NASA. The lasers have an innovative aircraft protection system designed to reduce or eliminate any threat to aircraft from their operation. To assist with these efforts, Keck uses Sabre® AirCentre™ Flight Explorer, technology generally used by airlines and airports.

Many airlines worldwide use Flight Explorer as their single-source, graphical decision-support solution for managing irregular operations and rapidly evolving conditions, such as weather events, in real time. Since its introduction in 1996, Flight Explorer has evolved from a flight tracking tool to the foundation that establishes common situational awareness for global airline operations. Flight Explorer has been integrated with Sabre® AirCentre™ Enterprise Operations flight planning solutions to provide seamless planning, dispatch and tracking capabilities. Many features of Flight Explorer provide situational awareness in the planning stage and throughout the entire operation. Flight route impact alerting is among the most powerful tools. The Keck Observatory has harnessed the power of Flight Explorer for a unique yet operationally critical application.

Chilling The Telescopes

The volume of each Keck telescope dome is more than 700,000 cubic feet. Giant air conditioners run constantly during the day, keeping the dome temperature at or below freezing. Chilling the interior of the insulated dome during the day controls temperature variations that could induce deformation of the telescope’s steel and mirrors.

At more than 13,000 feet above sea level, on the Big Island of Hawaii, the Keck Observatory sits on the summit of the dormant volcano Mauna Kea, probing deep space with telescopes using powerful lasers to help sharpen the images captured by astronomers. The Observatory is situated in one of the prime observing locations on earth, near the equator, above the cloud layer and with little light pollution to interfere with its scientific mission.

Despite sitting atop a tropical isle, the environment is harsh and often hostile to human activity. Mauna Kea means “white mountain” in Hawaiian, and the winter months are often snow covered, bitterly cold with high winds. In the best of times, the altitude presents challenges to all human activity, especially aircraft spotters stationed outdoors in the elements.

The Keck Observatory operates two of the world’s largest functional telescopes with mirrors 33 feet across, nearly four times the size of the Hubble Telescope. The telescopes are credited with detecting more planets outside our solar system than any other observation post on Earth. Keck also helped in the discovery of the acceleration of the expanding universe for which a Nobel Prize in Physics was awarded in 2011. The Observatory is also a world-leader in adaptive optics, a technology that, in real time, removes the blurring of cosmic targets caused by the turbulence in Earth’s atmosphere. Observations made using adaptive optics result in image clarity that rivals those made by space-based telescopes.

The use of high-power laser guide star adaptive optics systems carries many operational hazards, including the potential hazard to aviation. To assure that Keck’s lasers do not impact airline operations, the observatory uses human spotters, in conjunction with automated systems, to evaluate the risk and terminate the beams or shutter the system in the event of an aircraft incursion into their operating horizon.

Secondary Mirror On Keck II Telescope

There are two secondary mirrors that can be used on the Keck telescope. One is for optical studies and the other for infrared studies. One of the first telescopes designed for both visible light and infrared viewing, the Keck’s infrared capabilities are far superior to those of any other telescope. It makes infrared measurements 40 times faster (it can see much fainter sources of radiation) and produces infrared photos three times sharper than any telescope before.

Because of potential interference from radio waves associated with surveillance radar, Keck was not able to use radar aircraft detection. It also evaluated different types of camera arrays and a passive radio antenna, a transponder-based aircraft detector, which could detect aircraft approaching the laser beam by listening for the on-board transponders. However, they lacked specific range and location data needed to verify system performance.

Keck’s Adaptive Optics Software Engineer Paul Stomski is part of a team that works on the ongoing effort to automate and improve the aircraft protection system and comply with U.S. FAA regulations as well as develop a potentially U.S. FAA-acceptable aircraft protection system. In early 2010, Stomski contacted Sabre Airline Solutions to learn more about Flight Explorer and evaluate whether its functionalities, used by airlines and airports worldwide, could be useful.

Initially, the Keck team used Flight Explorer’s log file functionality to log the identity of each aircraft passing over Mauna Kea and record its speed and altitude along with its position in latitude and longitude. Analysis of the extended log file demonstrated that there was little traffic at the time the lasers were in operation (nighttime) and that all traffic was commercial aviation. Furthermore, Flight Explorer provided the transponder-based aircraft detector with missing information, such as the precise location of the aircraft at a given point in time.

Flight Explorer allowed Stomski to create a user-defined region of interest, collect aircraft location data and cross reference it with data from the transponder-based aircraft detector to prove that Keck is providing adequate protection to aircraft from the laser operations. After two-and-a-half years of data collection, the team is confident that all air traffic transiting their region of interest are commercial jetliners in very low volume and that the Keck aircraft protection system is effective.

Keck Observatory Headquarters

W.M. Keck Observatory headquarters is located on a 7-acre campus in Kamuela on the Big Island of Hawaii. Approximately 125 full-time employees work at Keck, of which two-thirds were hired from Hawaii. The Observatory is one of Kamuela’s largest employers.

The team at Keck calls the automated system “AIRSAFE” and plans to finalize reporting and data collection with a view to present the evidence of a fully automated aircraft protection system to the U.S. FAA. The final stage of the plan is to invite a team from the U.S. FAA to Hawaii for a practical demonstration during daylight hours to have sufficient air traffic to prove the value of the AIRSAFE system.

“We use Flight Explorer for three purposes: to characterize the air traffic in our environment, help us validate the performance of our automated systems and provide advance notice of possible aircraft over flights,” said Stomski.

“The biggest challenge to validating system performance was knowing exactly where the aircraft was when it was detected by the automated aircraft protection system. We needed to prove that the system could detect aircraft at the farthest distances where there was a risk of laser exposure and that we could shutter the laser before the aircraft could reach the laser beam. Flight Explorer provides the data we needed not just in near real time, but also in a log file that we can use to analyze system performance offline.”