In today’s hyperconnected information environment, in which operators expect connectivity under all conditions, naval forces face a dilemma regarding electronic emissions: to radiate or not to radiate. The force must choose either to take full advantage of the webs of sensors, radars, tactical data links, and command-and-control (C2) networks or to deny itself some or all of its technological advantages and thereby complicate the enemy’s targeting problem.
Emission control (EmCon) is “the selective and controlled use of electromagnetic, acoustic, or other emitters to optimize command-and-control capabilities while minimizing, for operations security: detection by enemy sensors, mutual interference among friendly systems; and/or enemy interference with the ability to execute a military deception plan.”1 In practice, this is less an on/off switch and more a dimmer, with many options between fully on and fully off. The nature of electromagnetic battlespace awareness and exploitation demands flexible options and procedures for employing offensive, defensive, and supporting capabilities.
Further, practicing tailored EmCon responses demands dedicated training opportunities that cut across technical and operational functions. The best plans imperfectly executed are likely to cause greater harm than imperfect plans flawlessly executed, as slipups when setting EmCon may disclose tactics, techniques, or procedures and compromise one’s location to the enemy. Practicing a wide range of EmCon procedures under realistic conditions, and learning to operate without all available emitters, is to today’s information-enabled Navy what gunnery practice was to the ships of the past—the only path to perfection.
Emission Control
When implementing EmCon, the overarching goal is to perform the mission while complicating the enemy’s ability to find, fix, track, and target one’s forces. Depending on the specific tactical goals, operators silence various emitters to alter or eliminate a ship or aircraft’s presence in the electromagnetic spectrum. This comes with a cost. Whether it be lost situational awareness without radar, lost communication channels when limiting radio transmissions, or increased safety risk when shutting down aircraft navigation beacons and implementing strict radio silence between ship and aircraft, tactical advantage often incurs operational disadvantage.
The EmCon process is straightforward for ships operating independently, as risk is controlled and the consequences are borne by a single unit. The process is complex when ships operate in company and planners must take factors such as radar coverage areas and intership communication requirements into account.
Emission Control Strategies
Varying degrees of EmCon employment affect the actions of opposing forces—what one side does to remain undetected (or to attempt to decoy the other), the other may do as well. Therefore, EmCon planners can take one of several approaches in determining the best posture for the force.
At the extreme, they may recommend turning off everything that can transmit a signal on the electromagnetic spectrum. This includes air-search and surface-search radars, commercial navigation radars, bridge-to-bridge radios, aircraft navigation beacons, satellite communication systems, ship-to-ship radios, and the radars, beacons, and radios of embarked aircraft. When both sides are emitting nothing, naval warfare is reduced to the tactics and technologies of the early 20th century: scouting aircraft, ships, and submarines; one-way communication from shore to warn of detected enemy force locations; visual communication between units; and sharp eyesight.
Another option is to allow only commercial emitters, such as Furuno radars that are identical to thousands of similar sets on board civilian ships, and bridge-to-bridge radio for navigational safety. Especially in congested coastal waters, where visual identification is possible, concealing one’s presence in the electromagnetic spectrum is less a matter of “making a duck disappear” than it is helping a “duck blend into a flock of ducks” and thereby complicating the enemy’s targeting solution. Planners may also decide to permit satellite communications that have a low probability of intercept or are commercial in origin.
As opposing forces are likely to scan the skies and the seas with a multitude of sensors from crewed and uncrewed ships and aircraft, Navy EmCon planners may choose to limit the time any single platform is radiating. Specific ships within a strike group would radiate radar and pass track data derived from radar contacts to the other ships of the group via tactical datalinks. By building shared situational awareness through an interlocking web of sensor and communication platforms, the force can attain the advantages of both concealment and awareness.
Only when battle is fully joined do ships and aircraft need all emitters radiating all the time—their location is known and the need to acquire and engage targets and communicate across the force outweighs any advantage of limiting emissions. Yet even this most permissive state presents challenges, as electromagnetic spectrum use must account for all units’ requirements and deconflict frequency assignments across a force of diverse capabilities.
The costs EmCon operations impose on a force are not insignificant, as naval forces have in recent decades adapted to ever-increasing bandwidth availability and good (if not great) communication system reliability. For carrier strike groups and amphibious ready groups, the EmCon problem is both complex and an everyday companion to operations in forward areas. Video teleconferencing, ship-to-shore and intership phone calls, and email as primary forms of communication have resulted in staffs and crews ill-prepared to operate without these user-friendly peacetime communication paths. The Navy must relearn how to operate under self-imposed restrictions while satisfying the information requirements of higher echelons of command.
What Was Old Is New
The Navy can find solutions to today’s problems in the past. Proven techniques, overtaken by technological progress in recent decades, are due for rediscovery and adaptation to modern times. These techniques include:
Flashing light—and beyond. Intragroup communication requires the resurrection of old methods, but with a modern twist. Taking for example the simple matter of passing maneuvering intentions between a carrier and its escorts, the preferred method today is line-of-sight radio. Under EmCon, flashing light is a viable option, but proficiency with flashing light and other means of visual communication has atrophied. This can be mitigated if ships could supplement proven flashing light techniques with technology that converts keystrokes into Morse letters, such as the Flashing Light to Text Converter pioneered by the Office of Naval Research.2 Similarly, continued research into laser communication can further decrease intership communication in the electromagnetic spectrum, where the signals are susceptible to intercept.
Text (only) messages. Writing clear, concise naval messages—a format designed for low-bandwidth media—is an art. These messages offer no space for wordiness or graphics-laden slides. PowerPoint slide decks and email have their purposes, but so do concise messages written in plain, lucid English. Use fewer slides and rediscover the power of crisp, cogent messages.
Discrete communication windows. Similar to the submarine force, establish prearranged communication windows to allow ships to relax their EmCon posture while retaining the discipline of limiting outbound communications to set times. Strict EmCon thus becomes a default operating mode to which the crew becomes accustomed.
Mission command. The art of mission command, defined as “the conduct of military operations through decentralized execution based upon mission-type orders,” requires trust up and down the chain of command.3 Responsibility and the commensurate authority rests with commanding officers at the scene of action. This allows rapid exploitation of opportunities without having to first request permission from higher authority and can alleviate the burden on frail C2 networks.
Uncrewed scouting. Scouting the battlespace with uncrewed surface and aerial systems will gain significant prominence as crewed ships and aircraft spend more time operating under EmCon conditions. Uncrewed ships and aircraft offer commanders options for sensing the battlespace that do not endanger humans. A crewless ship can serve as a radar picket, radiating and transmitting track data while crewed ships maintain electromagnetic silence until the opportunity to fire presents itself.
Practice, Practice, Practice
When gunnery was the sole offensive capability of a ship and the guns were served by human brute strength, skill, and agility, regular practice in firing full charges with live ammunition was the best way to improve the odds of victory in combat. The goal was to develop muscle memory through repetition. Similarly, the goal of setting, checking, and maintaining EmCon often and for extended periods is to keep the enemy from finding the force in the electromagnetic spectrum, or at least make it harder for him to do so. Cruise missiles are smarter than cannon balls, and modern weapons deliver greater destructive effect; avoiding enemy detection is therefore a naval force’s best hope for maneuvering into position and landing the first blows.
The effect of EmCon on naval warfare is as much about process and procedure as it is about technology. The fleet will not return to the days before wireless communication, but the surface fleet will find itself operating more like the submarine force and relearning and reinvigorating time-tested communication methods (see “Run Silent, Not Deep,” pp. 28–32). Learning to live without a full complement of capabilities will force commanders, their staffs, and crews to use disciplined communication methods and find creative ways to acquire battlespace awareness. Frequent EmCon drills are imperative. Crews that practice living, operating, and—to the maximum extent possible—fighting under EmCon will maintain a decisive edge over the nation’s enemies.