Electronic warfare’s rise and massive Signals Intelligence (SIGINT) investment means near-peer enemy conflicts involve fighting with similar capabilities. Weaponising information and data is more important in tactical warfare than ever before. Obtaining SIGINT early in a conflict without an enemy knowing it is a critical differentiator in deciding future warfare outcomes.

A central challenge in procuring SIGINT data is one reveals one’s own presence. Mathew Willmot, Sales Director for Sirius Compact at Swedish defence company Saab explains it this way: “Anyone who uses radars to detect targets also reveals their own location. On the other hand, passive sensors allow one to observe the enemy’s signals without becoming an emitter. It is precisely this ‘invisibility’ that is increasingly relevant in electronic warfare (EW)”.

Detecting and analysing SIGINT (e.g. radar, data, and communications signals) is perhaps the most mission critical task in multi-domain warfare (MDW).

Here a tripod mounted Sirius Compact stands vigilant and alone, listening carefully for intruders (credit Saab Group)

Situation Invisibility

Gather as much information as possible about enemy activities and potential threats yields a high level of situational awareness and understating of a situation. It is the basis for making the right strategic and tactical decisions. This ultimately protects as many lives and assets as possible.

The fact is: Only those who can quietly collect, analyse, and correctly classify the most data the quickest will have the best chance of defeating an enemy in the MDW space.

Listen to an authoritative podcast with Saab’s Passive Radar expert Mathew Willmot, Sales Director for Sirius Compact at Swedish defence company Saab, and ESD’s Curtis Hand here: Sirius Compact Podcast

According to Willmot, Saab has developed complex systems of passive sensors for ships, vehicles and aircraft for decades. Today, Saab is regarded as a one of the SIGINT and Electronic Support Measures leaders in EW for MDW. Saab’s passive sensors solution – Sirius – has a low Size, Weight, and Power (SWaP) version called Sirius Compact.

This EW sensor has the advantage of being modular and scalable and readily available for just under two years.  Passive sensors like Sirius and Sirius Compact provides at least one solution to increasing surveillance challenges at all levels of tactical operations.

As a stand-alone node in a sensor network Sirius can supplement existing sensors. Compared to larger static solutions, Sirius Compact is adaptable, mobile, and scalable for any situation.

Lowest SWaP

Sirius Compact is available in a number of configurations. Depending on the application, the smallest variant is just 35 cm high with a diameter of 15 cm, and weighs no more than three kilograms – meaning it has low body burden, fitting in any rucksack for easy transport.

“Another plus,” avers Willmot, “is the Sirius has an integrated IMU/GNSS sensor to provide the position data”. Its  needs less than 60 W power – by batteries a host PC platform. Sirius Compact can be positioned virtually anywhere; on a tripod, drone, recon vehicle or manned / unmanned small boat. Being mobile means Sirius Compact provides instant situational awareness where and when required, gaining “invisible” SIGINT in real time.

Here a soldier carries the Sirius Compact with ease, ready to put it into position – (credit Saab Group)

Listen to an authoritative podcast with Saab’s Passive Radar expert Mathew Willmot, Sales Director for Sirius Compact at Swedish defence company Saab, and ESD’s Curtis Hand here: Sirius Compact Podcast

Enabling Precision

As a single sensor improves the situational awareness, three or more sensors allows precise geolocation through triangulation. Saab carried out a large number of tests and demonstrations since it came out two years ago that show the compact sensor’s unique performance.

Situation Management

Detecting signals is the first step in obtaining SIGINT situational awareness. The second step involves identifying, analysing, and classifying signals. Armed forces have threat libraries containing enormous amounts of data. These are continually updated by SIGINT sensors.

Sirius Compact invisibly collects a wealth of protected knowledge kept safe because it does not store sensitive data from the threat library in the sensor.

Rather the sensor forwards the SIGINT directly to the client database. Also, a drone-mounted sensor is operational without a network connection, storing data temporarily in the Sirius Compact for later.   This SIGINT is useless without the software and threat library. Tasking & Reporting System software (TRS Lite) allows sensor control via a tablet to support tactical operability. Up to five sensors can be easily managed per soldier; and, these five sensors can in turn be grouped and controlled as bundles in a more complex system called TRS 9EW. According to Willmot, these associated software systems allow users to automatically generate reports, assign tasks to other sensors, or record new signals to expand a threat library.

Portable Warning

MDW’s increasingly complex threats require efficient and precise early warning systems. Portable passive sensors are suitable for many applications as an ideal electronic support measure asset. Complementing more complex systems they act in particular as an early warning system for ground-based air defence. Sirius Compact’s size enables the sensor’s placement almost anywhere – including civilian infrastructure without disrupting any electronics.

Listen to an authoritative podcast with Saab’s Passive Radar expert Mathew Willmot, Sales Director for Sirius Compact at Swedish defence company Saab, and ESD’s Curtis Hand here: Sirius Compact Podcast

NATO Partners

These sensors also bring advantages for alliance partners such as NATO, as the information obtained can be shared within the framework of Cooperative Electronic Support Measures Operations, benefitting all coalition partners. Saab’s Sirius family’s uniform products DNA ensures high precision and expertise from decades of R&D in this new, compact model and its continual adaptations to new MDW conditions.

A UAV-mounted Sirius Compact scans the horizon and the air above and ground below for dangers, invaders, and predators emitting signals revealing themselves to national defences (credit Saab Group)

Indispensability

While radars are looking, passive sensors are listening as the ears of the modern battlefield.  They provide a detailed understanding of enemy activities and strengths without making themselves evident.

Mobile passive sensor systems are more than just a technological achievement for technologies sake; they are a strategic necessity in modern warfare.

“Sirius Compact is product of ‘our time’,” attests Mathew Willmot. “More than ever before, critical information needs gathering without compromising one’s position. In a world where electronic warfare and SIGINT dominance increasingly determines the outcome of conflicts, these systems are vital.”

Passive sensors such as Sirius Compact enable a new dimension of tactical planning and decision-making based on the speed and accuracy of SIGINT. These sensors become a nation’s silent guardians and protectors of their citizens and armed forces.

Listen to an authoritative podcast with Saab’s Passive Radar expert Mathew Willmot, Sales Director for Sirius Compact at Swedish defence company Saab, and ESD’s Curtis Hand here: Sirius Compact Podcast

Curtis Hand, European Security & Defence special correspondent and AOC member