Until recently, this test would have required numerous runs and off-site analysis, but the U.S. Department of Defense has awarded Brigham Young University researchers nearly $1 million in grant money to develop technology that streamlines the testing communications process and saves money.
"When the government wants to buy an airplane, it has to be fully tested—the more expensive it is to test an airplane, the more expensive the plane is,” says Michael Rice (left), the Jim Abrams professor in the department of electrical and computer engineering. “You don’t want to cut corners on reliability or safety, but if you could reduce expenses in testing, the airplane would be cheaper and everyone would be safe.”
Previously, airplanes used only one antenna to send data to ground crews, but the signal dropped whenever the plane banked and obscured the antenna from the ground. The jet had to be refueled, the equipment and personnel reassembled, and the mission re-flown to acquire the missing data. To solve that problem, two antennas were mounted to transmit signals from the top and bottom of the plane. A new problem emerged, however: when jets with two antennas flew parallel to the ground, both antennas transmitted signals simultaneously, interfering with each other and masking important data about the jet’s performance.
The solution came in the form of theoretical analysis by Rice and Michael Jensen, an associate professor of electrical and computer engineering, and two graduate students, who demonstrated the viability of the multi-antenna solution in a series of papers published at the International Telemetering Conference in October. The researchers received Air Force grants administered out of Edwards Air Force Base in California in the last two years to complete further analysis and build a prototype transmitter that was mounted on a small plane. The BYU researchers will use the DOD grant to develop and test a prototype receiver that interprets the relationship between the two antennas’ signals and translates them into separate streams as the plane flies, allowing data analysis to occur on-site.
“The technology gets rid of those data drop outs so we don’t have to refuel and retest,” said Saul Ortigoza, executing agent for spectrum efficient technologies at Edwards Air Force Base. “That’s a big plus from a test-range perspective. It saves us a lot of money, and it’s pretty exciting.”
The technology solves the antenna dilemma in commercial jets as well, Rice said, referring to another possible application of his work.
“When they are testing a new prototype commercial jet, they put the whole notion of ‘the tray table in its upright and locked position’ in a new perspective,” Rice said, explaining that airlines gather data about their new planes just like the military. “They do hard turns, landings with one engine off—things they’d never do with passengers to ensure the plane is safe.”
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