SOF (Special Operations Forces) must act with the highest levels of discretion in hostile and often unfamiliar environments. In these scenarios, real-time RF situational awareness is vital for ensuring friendly forces remain undetected and detecting enemy activity. However, this vital capability must be weighed (literally) against the need for forces to be able to carry the equipment and remain agile.

So what levels of situational awareness can be gained from RF signals, even using exclusively man-portable equipment?

For SOF, freedom of maneuver in the Electromagnetic Environment (EME) is a must. The important question is not, “How advanced can my SIGINT capability be?” or, “How much SIGINT can my personnel carry?” The former risks overloading SOF operators and support personnel with unnecessary equipment. The second risks missing out on vital intelligence that can make or break a mission. Often, leaders ask, “How much SIGINT do we need?” instead.

SIGINT collection, like any capability, has to justify the weight it adds, and where exactly that tradeoff lands is determined on a mission-by-mission basis. CRFS understands that SWaP (Size, Weight and Power) is a crucial element in these decisions. Our RFeye systems allow SOF teams to maintain spectrum intelligence and situational awareness of the EME because we put SWaP at the center of our design philosophy.

Real-time RF situational awareness up to 18 GHz

SOF teams can gain greater situational awareness by incorporating knowledge of the EME in their overall operational picture. In practical terms, being able to see signals from 9 kHz all the way up to 18 GHz gives operators the versatility to gather intelligence on everything from enemy radio, aircraft and radar, to military and commercial satellite communications systems. Equally importantly, the system can be carried comfortably.

Unfortunately, many high-performance radio receivers available today were not designed to be SWaP-optimized from the outset – they were intended to be deployed in vehicles or at fixed locations. As man-pack equivalents have been developed, this has caused significant compromises in performance, including frequency range and sensitivity. However, receivers designed with low SWaP as a guiding principle, like the RFeye Node, have created more portable packages such as the RFeye Stormcase or Backpack, which are inherently optimized for performance-weight.

Exceptional receiver sensitivity also lets your forces detect any signal of interest at a much longer range. Early detection of signals can provide tactical advantages on the battlefield, enabling plans to evolve rapidly via greater understanding of the operational environment, including the EME.

It is equally important to avoid enemy detection by the same means. EMCON (Emissions Control) can usually be assured by having the correct procedures in place to avoid devices being left on or switched on during periods of radio silence. However, spectral awareness can provide an extra layer of protection against human error or even equipment malfunctions.

Direction Finding (DF) and geolocation

To safely navigate in hostile environments, just knowing a signal is present is not helpful – you also need to know where exactly it is coming from. Locating signal sources can help you avoid potential threats and target enemy forces, insurgents or infrastructure. However, DF is one of the hardest capabilities to make portable, as low frequencies always require large antenna arrays. Vehicle-portable DF can go as low as VHF frequencies, but not man-portable DF.

Our lightweight and tripod-mountable RFeye Arrays can be readily packed away into a carrying case, while Backpacks with DF wands can provide DF down into the UHF band. With just one of these devices, your forces are then able to tell where enemy transmissions are coming from and take appropriate action. Portable DF with a single array can help build a geolocation over time. By taking multiple measurements from different locations, it can also help pinpoint the exact origin of enemy signals. Alternatively, if foes are on the move, you can track their movements based on the changing LOBs over time.

Alternative geolocation methods and 3D geolocation

One alternative approach to DF geolocation is TDOA, which uses multiple fixed or semi-fixed receivers deployed in the field. These receivers can easily be installed on Forward Operating Bases, Combat Outposts or vehicles, or by using the man-portable RFeye Stormcase. TDOA requires a minimum of 3 receivers to determine the enemy lat/long to within a few 10’s of meters. 3D geolocation (ideal for aircraft & drone tracking) simply requires the addition of one more receiver, which itself does not have to be at any specific altitude.

Another alternative is a pop-up or fly-up network using receivers mounted on small drones or aerial persistent threat detection systems (PTDS). This drone-fitting capability lets you rapidly deploy receivers over remote and/or especially hazardous terrain to minimize threats to personnel.

Creating a distributed network on the fly (pun intended) might not always be feasible, but where it is the benefits can be significant. You can locate a greater frequency range of signals. The systems are man-portable, and the weight burden becomes non-existent when the receivers are deployed as a distributed network on the ground or in the air.

3D geolocation has never been more important than it is today given the significant threats posed by insurgent use of drones to attack friendly forces. Drones are cheap; insurgents can easily obtain commercial versions and use them for surveillance or even weaponize them. A 3D geolocation solution provides front-line forces with capabilities and information previously only accessible to headquarters staff.

SIGINT recording and post-analysis

Gathering information prior to, during, and post-operation is key to providing intelligence for future operations. SIGINT can provide significant insight into enemy tactics, techniques and procedures (TTPs) via lightweight RF recording systems. These can be used alongside a laptop to record signal information in high fidelity. This information can be classified, exploited and even geolocated in post-mission debriefings to add real operational advantage to the planning phase of the next operation.

When choosing the right RF monitoring, geolocation and recording systems for SOF operations, equipment capabilities and equipment load have to be balanced for an optimal mission outcome. Effectively balancing this capability-to-weight ratio is key to enabling mission success and maximizing actionable intelligence gathering to provide the clearest intelligence and operational picture moving forward.

Get in touch and find out how you can better optimize your systems with CRFS.