Detecting improvised explosive devices in Afghanistan requires constant, intensive monitoring using rugged equipment. When Sandia researchers first demonstrated a modified miniature synthetic aperture radar  (MiniSAR) system to do just that, some experts didn’t believe it.

But those early doubts are long gone. Sandia’s Copperhead — a highly modified MiniSAR system mounted on unmanned aerial vehicles (UAVs) — has been uncovering IEDs in Afghanistan and Iraq since 2009. Now, Sandia is transferring the technology to the US Army to support combat military personnel, says Sandia senior manager Jim Hudgens (5340).

The technology was developed with the Defense Department’s Joint Improvised Explosive Device Defeat Organization (JIEDDO), the US Army Engineer Research and Development Center/Cold Regions Research and Engineering Laboratory (CRREL), the Naval Air Systems Command (NAVAIR), Johns Hopkins University’s Applied Physics Laboratory, the Naval Research Laboratory, and Florida-based force protection company AIRSCAN.

“JIEDDO tested a number of technologies and ours emerged as one that was viable,” Jim says. “Today, we’re acknowledged as the most successful airborne IED detection capability out there.”

Department of Energy Secretary Ernest Moniz honored the team that developed Copperhead with an Achievement Award at a ceremony in Washington, D.C., this spring.

Copperhead detects disturbances in the earth, for example, those made when IEDs are buried. It can find them day or night and in many weather conditions, including fog and dust storms. Extremely fine-resolution images are processed onboard UAVs and transmitted in real-time to analysts on the ground. Those analysts pass the information to soldiers charged with destroying IEDs.

Though fewer IED have detonated in Afghanistan since a peak of more than 2,000 in June 2012, IEDs account for 60 percent of US casualties, according to Department of Defense reports.

MiniSAR legacy enables Copperhead’s rapid development

Sandia is a world leader in the development of SAR systems, a history that grew out of Sandia’s mission to develop radars for nuclear weapons. Recent SAR systems have vastly improved radar images from aircraft flying at great heights.

SAR and its descendent MiniSAR, the first system of its size to successfully transmit real-time images from UAVs in 2006, use small antennae that capture reflections of microwaves returned from objects on the ground, transmitting and receiving many radar pulses as the aircraft flies. The received pulses are integrated by signal processing techniques to synthesize a fine-resolution image, hence the name “synthetic aperture.”

Jim and Sandia manager Bill Hensley say had it not been for Sandia’s research and development process to reduce the size of the SAR that led to MiniSAR, Copperhead might never have been ready in time to help the Army.

“If we wouldn’t have made that investment, we wouldn’t have been in position to be ready. Otherwise it would have taken us years,” Jim says. “So what we were able to focus on were the radar modes and the enhanced processing that we needed to do.”

But MiniSAR was still limited when it came to the real-world problem of IEDs. As Americans heard more reports of soldiers killed or maimed by IEDs in Afghanistan and Iraq, Sandia researcher Bryan Burns (5300) wanted to help.

“People were getting blown up driving along the road and I said, ‘We can help solve this problem,’” Bryan says.

A few different demonstrations and tests were conducted to demonstrate the fundamental capability. Though some experts expressed doubt that any coherent change-detection system could detect IEDs, in 2007, the Sandia team connected with Mark Moran, director of the special projects office at CRREL. Moran’s team was running a series of scientific investigations to predict the operational ability of various technologies for JIEDDO. During one of those tests, the team showed the value of the MiniSAR technology.

JIEDDO then became interested in the technology and assigned Moran’s team at CRREL as the developing and fielding program office. JIEDDO needed Copperhead developed in nine months, about half Sandia’s normal development period, Bill says.

“Sandia does this advance research and development because there’s a significant number of customers who come to us, they’ve exhausted their other possibilities, they need something and they need it now,” he says. “If we haven’t gotten out ahead of that with the technology, if we’ve got an 18-month technology development cycle out ahead of us, we can’t help them.”

Focusing on mountaintops, valley floors simultaneously is solved

Just as cameras are limited by depth of field — where a near object is in focus but the background is blurry or vice versa — MiniSAR needed a way to keep the entire height of the terrain in an image in focus, for example, the top of a mountain and the valley floor.

So Bryan created advanced image-processing algorithms that focused the high and low terrain simultaneously while continuing to provide fine-resolution imagery. The new capability, which has been proven effective on slopes of more than 40 degrees, made Copperhead useful in the wide variety of terrain present in places like Afghanistan.

To make Copperhead a reality, more than 300 people each spent at least three months on the project during development, including researchers with diverse areas of expertise and Labs staff who helped with logistics, foreign travel, and contracting, Bill says.

“The team is awesome,” he says.

Sandia and its partners had to quickly adapt and enhance the 30-pound MiniSAR so it could fly on NAVAIR’s 17-foot Tiger Shark UAV and accomplish the mission JIEDDO had set.

Completing the modifications and getting them mature enough for operational use in nine months stressed Sandia’s capabilities and the Copperhead team gave their best to meet an urgent mission need, Bill says.

“There were many late nights and long weekends. Key individuals spent months at Yuma Proving Ground,” Bill says.

 In the ensuing years, an additional 200 Sandians have applied their talents to make the program successful. “I wish we had room to list all their names,” Bill says.

When the modifications were made Copperhead’s MiniSAR technology weighed about 65 pounds and was about 1 foot wide, it could do all its image processing on board, and it was rugged enough for the environments it would face, Jim says.

Then the modified MiniSAR was integrated into the operational system known as Copperhead, which includes hardware and software tools to help radar analysts on the ground understand the data coming from the aircraft and a training program for them.

“We developed a flight planner and an exploitation tool that the analysts use in the ground station, and we had to develop all the concepts of operations to make it work and tactics, techniques, and protocols for utilizing the system,” Jim says. “While MiniSAR was a radar that we flew and used to collect data, Copperhead is an entire system, everything from communications to analyzing imagery to providing information useful to people who defeat IEDs.”

Wartime conditions test a success

In 2009, JIEDDO sponsored a 30-day evaluation of the technology in wartime conditions and — despite doubts raised that all the images could have such fine resolution — Copperhead has been fielded in Afghanistan ever since, Bill says.

Copperhead uses a technology called coherent change detection, which compares a pair of extremely detailed SAR images taken of the same scene but at different times. The process allows analysts to detect minute physical changes on the surface.

“There are other approaches to change detection out there, but this is the only one that’s all-weather,” Jim says.

An earlier version of coherent change detection developed at Sandia showed images of a lawn taken 20 minutes apart from an aircraft flying 10,000 feet up and three miles away. The images revealed the path of a lawn mower due to the bending of the blades of grass.

Bryan and the team are working with the Army to ensure that Copperhead continues to solve current problems. “We’re helping them to use it in better and more effective ways, even when things change,” he says. “The system is continuously adapting.”

Sandia’s transfer of the technology to the Army will take years to complete, but the Sandia team members say they are happy that they’ve provided the Army with a needed tool to detect IEDs.

Of the transfer to the Army, Bill says, “We’re making a positive, measureable impact right now on the security of US people. This acknowledgement that it needs to be kept in the Army is very satisfying.”