Army researchers say they are digging into ways to make radar more efficient and effective on the battlefield. They're looking for techniques to better hone in on information in the midst of a crowded spectrum and in the face of enemy efforts to undermine radar capabilities.
The strategy rests in part on the Advanced Pulse Compression Noise (APCN) technique, a tune-able waveform that could boost effectiveness when the airwaves are crowded or the enemy threatens to backtrack a radar signal to its source.
While the technique is still in its developmental phase, Army researchers report some signs of progress, including the recent execution of a Cooperative Research and Development Agreement with Goleta Star in Torrance, California. The agreement was a significant milestone for the Army project and a sign of support from the commercial radar community, according to Mark Govoni, a scientist with the Army's Communications-Electronics Research, Development and Engineering Center Intelligence and Information Warfare Directorate.
The Army also has undertaken proof-of-concept efforts with the University of Florida researchers.
"We've shown that we can do this," Govoni said. "We are starting to leverage other people's investment to complement what we are already doing on our side."
The Army uses radar to track enemy motion on the ground and for aerial surveillance, among other uses. But the tried-and-true technology still encounters hurdles more than 50 years after its introduction on the battlefield.
Crowded spectrum is a major point of concern, as increasing numbers of users jam the airwaves around the globe.
"It's all about congestion," Govoni said. "If you are a mobile user with a handset, and I am a military system operating in the same frequency band with you, there is a high likelihood for those two systems to interfere, in which case performance will degrade."
Tune-able waveform techniques such as APCN seek to get around increasing congestion and interference.
On the battlefield, commanders may encounter a more critical issue as they attempt to deploy radar assets. The traditional approach — send out a signal and wait to see what comes back — may make troops visible targets in an era of sophisticated radar detection.
When a radar sends a fixed signal on a fixed frequency, "it is a damned easy target for my adversary to go after and kill it. It is like putting up a big sign that says, 'I am here,' " said Doug Carlson, vice president of strategy at MACON, which provides antenna technology to the defense community.
Over the past several years the radar community has struggled to preserve system performance while delivering enhancements to keep radar effective on the modern battlefield. With emerging techniques under development by the Army and industry, it may become possible to modulate radar signals automatically and at random. "Then there is no constant signal for my enemy to lock on, no way for him to know where I am. That's the big trick," Carlson said.
In effect, this is what researchers hope to make possible with APCN. As envisioned, techniques such as this will make it possible to "tune" radar in real time, skipping past congestion while also making the radar and its operator less visible to an adversary.
Right now such adjustments can be made manually, but it's a hit-or-miss affair: Operators send a signal and wait to see where the interference exists, then adjust accordingly. "It goes by trial and error in these scenarios to see whether what is being done is actually optimizing the situation," Govoni said.
Researchers say as their work goes forward, it should become possible for radars to more nimbly tune themselves in response to surrounding conditions.
Govoni describes a needle-and-haystack scenario, with hay the interference and the needle the signal that will give battlefield operators the tactical edge.
"The more interference we remove, the more hay we take away, the better chance we have of finding that signal," he said.
BONUS: Dr. Angelos Keromytis, Program Manager of the Information Innovation Office for DARPA, will speak on a panel about cross-platform and cross-battlefield protection at the C4ISR & Networks Conference on May 26th. He'll participate in a discussion about the connection between cyber and electronic warfare and how military and industry tactics help ensure data protection and integrity across multiple devices and systems. For more information, click here.
