This keeps user anonymous, and has use in police and military setting

The secure waveform changes continually and is difficult to intercept

A new secure waveform developed by the US Army can change continually, masking its identity to allow military and police officials to become entirely anonymous to radar detectors.

The encrypted system allows radar transmissions to look like noise, making it difficult to intercept and exploit.

Researchers say this design aims to meet the challenges of the evolving battlefield, and is programmable in real-time to optimize performance.

A new secure waveform developed by the US Army can change continually, masking its identity to allow military and police officials to become entirely anonymous to radar detectors. The encrypted system allows radar transmissions to look like noise, making it difficult to intercept and exploit

NOISE-ENCRYPTED RADAR The US Army is developing a noise-encrypted radar waveform called Advanced Pulse Compression Noise, or APCN. The ‘continually changing’ secure waveform uses both traditional and non-traditional radar waveforms. It can be programmed in real-time to optimize performance for a given situation. APCN looks like noise and can be tuned in real time, so it never repeats itself. This makes it difficult to intercept, and keeps the user anonymous. This has applications in both a military and police setting. Researchers also say the APCN waveform can help fight the challenge of frequency congestion, or high traffic. Advertisement

The encrypted radar system designed by the US Army Materiel Command's Communications-Electronics Research, Development and Engineering Center (CERDEC) is being called Advanced Pulse Compression Noise, or APCN.

Its applications range from the homefront to the battlefield.

The availability of radar detectors has allowed speeding motorists to locate police presence before coming in the line of sight.

This type of secure waveform, the researchers say, would keep police anonymous even in the face of such technology.

And, soldiers face the challenges of adversarial attack to radar systems, and high traffic in the radio frequency environment, which the system aims to tackle.

'The battlespace is continually evolving, and with that, comes the need to change the way we think about radar design,' said Dr. Paul Zablocky, director of Cerdec's Intelligence and Information Warfare Directorate.

'Techniques such as real-time re-programmable waveform synthesis and low probability of intercept/low probability of detection (LPI/LPD) provide added capability that will address the emerging electromagnetic spectrum challenges our soldiers are likely to face in the future.'

This technology combines traditional and non-traditional radar waveforms, and real-time programming capabilities allow the user to optimize its performance to match the particular situation.

'Encrypting our radar waveforms limits the likelihood for adversaries to intercept and exploit our emissions,' said Dr. Mark Govoni, a research scientist in Cerdec I2WD's Radar Division who established the theory and patented the design for the APCN waveform.

'Having the ability to transmit a radar waveform that's continually changing, one that never repeats itself, and looks like noise, is extremely difficult to intercept and becomes advantageous for police because they can now remain anonymous to radar detectors,' Govoni said.

'Given the prevalence of software-define capabilities, it's totally conceivable to consider this type of technology as an alternative to what's currently used with some of the more critical communication networks like GPS and emergency broadcasting,' he said.

The US Army is developing a noise-encrypted radar waveform called Advanced Pulse Compression Noise, or APCN. APCN looks like noise and can be tuned in real time, so it never repeats itself. This makes it difficult to intercept, and keeps the user anonymous

The APCN secure waveform also has potential to stand tough against frequency congestion, and researchers plan to develop 'cognitive radar waveform diversity' to further reduce challenges.

'Autonomy can relieve the soldier of unnecessary burden, which then affords more attention for his or her primary tasks,' Govoni said.

'Technologies like waveform diversity and cognition provide exactly that, and are where we're headed with future radar capability.'

In a scenario in which frequency congestion is heavy, the researchers explain the programmable waveform could adapt to diversify its emissions, and work around the challenge.

Right now, this can be done manually, but future development hopes to see this become autonomous.

'There's a growing desire to consolidate systems operating in the electromagnetic spectrum,' said Govoni.

'As a (large) tenant of this spectrum, radar is an attractive candidate. The kind of technology we're researching here at Cerdec gets us one step closer to real-time coordinated and cooperative operation with other systems,' Govoni said.

'It's a great example of where Army technologists are pushing the state-of-the-art.'

So far, an experimental version of the system was demonstrated in 2012, using modifications to an existing waveform.