ABQ Times

Dangling from a weather balloon 80,000 feet above New Mexico, antennas attached to a Styrofoam cooler are part of an experiment by researchers from Sandia National Laboratories and Ohio State University. The team is exploring alternative navigation technologies as a backup system for airplanes when GPS signals are unavailable.

The antennas are designed to capture radio frequency waves emitted by cell phone towers and non-GPS communications satellites. "We’re not trying to replace GPS," said Jennifer Sanderson, the lead researcher at Sandia. "We’re just trying to assist it in situations where it’s degraded or compromised."

Sanderson presented preliminary data at the Institute of Navigation GNSS+ conference held in Baltimore. The research is supported by Sandia's Laboratory Directed Research and Development program.

While GPS remains the gold standard for navigation due to its speed and reliability, Sanderson expressed concerns about over-reliance on it without a backup system. "I worry about relying too heavily on it without a backup," she said, highlighting potential risks if GPS connections are disrupted.

GPS disruptions can have widespread impacts, especially for pilots flying near conflict areas who may lose or find unreliable signals. Threats like jamming and spoofing pose significant challenges; jammers can overwhelm receivers with meaningless signals, while spoofing involves misleading receivers with fake signals.

Sanderson's research focuses on using "signals of opportunity" for navigation at high altitudes. These signals could guide vehicles using atmospheric radio frequency waves. Her team collects signal data from stratospheric altitudes using payloads launched via weather balloons.

"So far, the highest altitude we’ve reached is about 80,000 feet," she noted, contrasting this with other studies that focus on lower altitudes.

As they process their initial data batch, researchers aim to develop algorithms for real-time systems capable of matching signals to transmitters and calculating positions relative to those sources. Automation of this process remains a challenge but one that Sanderson believes can be overcome with continued effort.

"The not-sexy but very important side of navigation is understanding all your error sources," she explained. Despite these challenges, Sanderson remains optimistic about future advancements in this field.