Seeing beneath the vast Antarctic and Greenland ice sheets–and, in particular, seeing whether any water sits between ice and ground–is critical to understanding how fast ice might slide into the sea in the future. But many areas are still uncharted territory. Now, engineers at the University of Kansas, in Lawrence, are in the final stages of constructing, from scratch, an unmanned aircraft that will carry ground-penetrating radar and other sensors.
The project should greatly accelerate the pace of mapping without risking the lives of human pilots who now fly limited missions across parts of the ice sheets. “We can cut costs for large-scale mapping projects, increase the range, and reduce dangers,” says Rick Hale, an associate professor of aerospace engineering and leader of the effort.
The plane will fly in conditions that would be too risky for humans, and it will fly lower than would be safe for human pilots, enabling sensors to bring back sharper pictures. The aircraft’s key instrument, a 125-pound radar unit, will fire signals through kilometers of ice at several frequencies. Software will then analyze the timing of returning signals to create a clear picture of subsurface ice layers, water pockets, and the contours of the underlying bedrock or soil.
To be sure, there’s plenty of unmanned aircraft already out there, such as the Predator, made by General Atomics. But while a Predator might cost around $30 million, Hale’s team is working with a National Science Foundation budget of around $2 million. And not just any old plane will do: this aircraft needs to work in bitterly cold and extremely remote polar locations, function far from communications centers, and carry specific kinds of gear.
Hale’s team is giving the aircraft three means of communication. The first will allow humans to remotely control takeoff and landing. The second will allow radio-frequency communications when the aircraft is near a base camp. The third means enables satellite communications when the aircraft might be as far as 600 kilometers away from the nearest camp. The plane’s wings–which have a span of about 26 feet–are being designed to have de-icing capability, and heaters will prevent the electronics from failing in the extreme cold.
The aircraft, called Meridian, is part of a larger effort at the University of Kansas’s Center for the Remote Sensing of Ice Sheets. Together with groups at other institutions, the Kansas team is pushing technology advancements to get a better fix on ice melt rates, ice thicknesses, and the accelerating rate at which glaciers are moving toward the ocean, which could accelerate the rate of sea-level rise.
The aircraft will leverage a powerful radar technology honed at the university. The radar, developed jointly with other institutions, is unique in its ability to provide a detailed picture of ice layers and, in particular, the boundary between ice and ground, which is helpful in efforts to understand how fast ice sheets might slide into the ocean. “Basically, our radar can see deeper, and with better resolution, than any of the other competitors out there at the moment,” says Claude Laird, a research scientist at the University of Kansas who used the system on an expedition in Greenland this summer. The radar was used on an overland expedition and to help choose the site for an ice-core drilling expedition next year.
If all goes well, Meridian will make its maiden flight on Greenland next summer, followed by a tour of duty later in the year, during the Antarctic summer, says Hale.