Why today’s C-UAS systems must be built to defend against tomorrow’s USVs and UGVs is an article from Zac George of CRFS. This article was republished with the permission of CRFS.

An arms race is unfolding within the realm of Robotics and Automated Systems (RAS). While unmanned aerial vehicles (UAVs) dominate, there is a notable upsurge in the development and operational deployment of unmanned surface vessels (USVs) in the maritime domain and unmanned ground vehicles (UGVs) in the land domain.

Militaries across the globe are investing in these technologies and investigating how to employ them tactically. For example, the US Navy’s Task Force 59 is experimenting with various contractor-owned and operated USVs. However, most counter-RAS (C-RAS) systems and plans focus solely on countering the air threat. The outlier is the Australian MoD, the first defense organization to publicly publish a strategy to address all robotic and autonomous systems.

Given the communications and spectrum usage vulnerabilities, now is the time to develop C-RAS systems. RF detection and geolocation offer key capabilities to exploit communication backhaul vulnerabilities.

What are Counter Robotics and Automated Systems (C-RAS)?

Operators are starting to use unmanned platforms together, such as a UAV delivering a UGV or a USV launching UAVs. Therefore, countering unmanned platforms is no longer a domain-specific problem (air, land, sea). Multi-domain unmanned threats must be addressed together.

C-RAS technologies are designed to counter various robotic systems, including drones, autonomous vehicles, robotic weapons, and other automated platforms. They aim to develop methods to identify, track, and potentially disable or neutralize these systems.

Recent uses of RAS systems in combat and against illegal smuggling

There have been many documented UAV operations in Ukraine, the 2020 Nagorno-Karabakh War, and US operations in Iraq and Afghanistan. However, there have also been many other RAS-assisted military operations across the globe. While combat platforms receive the most media attention, countries also invest in unmanned platforms for logistical and medical tasks, such as resupply and MEDAVC.

Below are some recent examples of USV and UGV usage.


Cartels are incorporating USVs into their operations. In July 2022, Spanish Police recovered semi-submersible unmanned vessels capable of carrying up to 200kg (441 lbs) of drugs or contraband from Morocco. The systems likely operate with reach-back communications.

USVs with explosives

Taking lessons from historic attacks and maritime terrorism (such as the USS COLE attack in 2000), forces across the globe are experimenting with low-profile USVs laden with explosives to degrade enemy combat and logistical capabilities. They are likely using commercial SATCOM to control the vessel; however, terrestrial communications may also be employed.


China developed a machine gun “robot dog” UGV, that can be airlifted by a heavy-lift UAV into a combat zone to support infantry units and provide covering fire on an enemy’s flank. Various RF transmitters sit on top of the dog, likely in the VHF/UHF range.mar

In the maritime domain, a Chinese defense company has developed a USV with autonomous, obstacle avoidance, and swarm capabilities with reported stealth-like capabilities. Reportedly, it has remote control of 2km, private network control of 20km (line of sight), and SATCOM control. (See Post Image video above)

What do RAS systems mean for force protection?

Despite the increased focus on creating RAS systems, there has been a shortage of developments to combat ever-increasing threats from USVs and UGVs. Militaries need to start asking hard questions—for example, how to protect a naval base against a low-profile USV laden with explosives that enters at night. This USV scenario is a force protection nightmare.

USV and UGV spectrum vulnerabilities

USVs and UGVs are highly dependent on communications backhaul, as no human operator is physically on the platform to take over if communications are denied. Therefore, it is very difficult for a USV or UGV to go into total Emissions Control (EMCON)—while possible, there are high risks of collision or faults. Although SATCOM is harder to jam, it can still be targeted with malware.

For USVs, the open ocean provides limited physical barriers, but it is harder to use terrain to hide a signal transmission. Also, more considerable distances require higher signal power unless a mothership is employed, but EW systems more easily detect higher power.

Conversely, for UGVs, physical barriers exist due to the greater need for relay stations and transmitters to communicate over hills, buildings, and other terrain. Also, battlefields congested with artillery may inhibit UGVs from navigating. Therefore, with more replay stations and mesh networks, signal transmissions are louder, EMCON is more complex, and UGV communications become more vulnerable to geolocation.

RF detection and geolocation solutions

By overlaying military and civilian spectrum plans, detecting the non-allocated (enemy) USV and UGV signals is easier. Once these possible signals are identified, the enemy USV/UGV PACE plan could be mapped, and electronic attack herding techniques employed to push them to a more jammable frequency. Also, signal detectors (instead of masks) could be used to alert to the presence of an unmanned communication network.

To counter multi-domain unmanned platforms, detector-based 3D TDOA could potentially distinguish the drone’s signals from the weapon’s signals. As such, C-UAS sensors, jammers, or gun systems can be employed to engage the UAV, while ground sensors and weapons can detect and track the UGV.

AIS spoofing detection is also helpful in the C-USV toolkit, as USV motherships might go “dark” and turn off—or spoof—their AIS before deploying lethal USVs. Being able to detect AIS spoofing is vital for coastal defense applications.

Lastly, as the world enters a blue vs. red “drone wars” battlespace, being able to protect friendly spectrum from jamming and interference and ensure that USV, UGV, and UAVs can operate freely is vital. Many lessons can be learned from developments within unmanned traffic management and advanced air mobility space and applied to naval and ground operations. Friendly unmanned operators of USVs and UGVs should also be trained on EMCON techniques to minimize detection from enemy EW forces.


Robots in war are becoming more prevalent, and unmanned platforms are already being employed. Western militaries have long focused on the tactical use of this technology from a friendly point of view. However, C-UAS systems can be copied and pasted for counter-USV and UGV missions. Custom RF detection is vital to any C-RAS system.

See Also- The magic of RF demodulation: From RF signals to usable data