UTD Space Scientist Wins $1.4-Million NASA Grant

Team Led by Dr. Gregory Earle to Study ‘Scintillation’ of Ionosphere

RICHARDSON, Texas (June 28, 2004) – Dr. Gregory D. Earle, a space scientist at The University of Texas at Dallas (UTD), has won a $1.43-million grant from the National Aeronautics and Space Administration (NASA) to conduct research of the Earth’s ionosphere that could help explain conditions that impair satellite and radio communications around the globe.

The ionosphere is a portion of the planet’s upper atmosphere that is ionized, or electrified, by solar radiation and plays an important practical role by serving as a “mirror” that reflects some radio waves, allowing communication over long distances.

Specifically, Earle and fellow researchers from four other universities and research institutes and the United States Air Force plan to study a phenomenon that occurs at temperate latitudes called “scintillation” – where density irregularities in the ionosphere may interfere with radio signals. Scintillation of radio signals is analogous to the process that occurs as light from distant stars comes through the Earth’s atmosphere; it’s the effect that causes stars to “twinkle.”

“The experiment is designed to probe the upper atmosphere with a rocket-borne instrument payload and ground-based radars to identify when scintillation is occurring and what is driving it,” said Earle, an associate professor of physics and member of UTD’s William B. Hanson Center for Space Sciences. “We expect the occurrence may be linked with nearby thunderstorm activity or other large-scale low-pressure events.”

The project will involve building an instrument package which will be launched from NASA’s Wallops Flight Facility on the Eastern Shore of Virginia – probably sometime in 2006, according to Earle. The mission will be a suborbital flight aboard a sounding rocket – a small, low-cost rocket used extensively by the space agency for scientific research. The flight time will be approximately 15 minutes.

“The rocket will carry instruments designed to measure key variables in the perturbed atmosphere, as we simultaneously use three radars on the ground to measure the oscillations that are thought to be linked – in poorly understood ways – to the perturbations,” Earle said. “We expect that these observations will provide the most complete and comprehensive data set ever gathered on the causes of scintillations at these latitudes.”

In addition to disrupting radio communications, scintillation can lead to errors in the interpretation of signals received from global positioning satellites, potentially affecting aircraft navigation and other important systems.

The scintillation study is a collaborative project involving researchers from UTD, the U.S. Air Force Research Laboratory, Utah State University, the Aerospace Corporation, the Southwest Research Institute in San Antonio and the Applied Research Laboratory at The University of Texas at Austin.

Earle has been involved in more than 15 sounding rocket investigations, five in the role of principal investigator. He holds a Ph.D. degree in space plasma physics from Cornell University and an M.S. degree in engineering physics and a B.S. degree in electrical engineering from Purdue University.

About UTD

The University of Texas at Dallas, located at the convergence of Richardson, Plano and Dallas in the heart of the complex of major multinational technology corporations known as the Telecom Corridor®, enrolls more than 13,700 students. The school’s freshman class traditionally stands at the forefront of Texas state universities in terms of average SAT scores. The university offers a broad assortment of bachelor’s, master’s and doctoral degree programs. For additional information about UTD, please visit the university’s web site at www.utdallas.edu.