Raytheon Technologies [RTX] said this week that its Germany-based Raytheon Deutschland GmbH subsidiary has developed a passive, digital electronic intelligence (ELINT) system–the Advanced Radar Detection System (ARDS)–that will allow aircraft to escape detection while collecting adversary radar data.

“Like a silent vacuum cleaner, ARDS sweeps up information about a broad range of radar and electromagnetic emitters,” Christian Stenzel, a software engineer at Raytheon Deutschland, said in a statement. “The collected information is analyzed and becomes part of a military’s library of known threats, and it can be used by operators on future missions to counter those threats.”

In 2019, Raytheon tested ARDS on a wing-mounted pod on a General Atomics MQ-9 Reaper drone, but Raytheon said that operators can also configure ARDS inside aircraft–whether commercial or military.

ARDS “works on both manned and unmanned aircraft, as well as ground or sea-based platforms,” the company said. “It can autonomously scan for emitters across the whole electromagnetic spectrum, without operator input, though operators can also control the system if they wish. For ELINT missions, the system can continuously save large amounts of data on a solid-state recorder, then upload it for post-mission analysis. ARDS can also interface with an aircraft’s downlink system to transmit the data to ground control stations in real time.”

The development of ARDS drew upon Raytheon’s work on the Emitter Location System (ELS) for the German and Italian Air Forces’ Tornado electronic warfare aircraft by Panavia Aircraft GmbH–composed of Airbus, BAE Systems, and Leonardo.

“Using the latest digital components, ARDS significantly reduces hardware footprint when compared to the legacy ELS,” per Raytheon. “Additionally, ARDS is what’s known as a ‘software-defined receiver,’ meaning updates can be made through fast and simple software upgrades instead of time-consuming full hardware retrofits.”

Stenzel said that, given current threats, “it’s very important to have the latest ELINT, both for immediate self-protection and for long-term strategic planning against adversaries.”

“To deal with evolving threats, the system’s firmware and software can be easily upgraded to add new detection algorithms and strategies,” he said.

Raytheon said that most of ARDS computer processors are commercial off-the-shelf and readily available and that the company has been sustaining Tornado’s digital ELS “using similar parts for over two decades, so keeping ARDS fine-tuned comes at a low-cost.”