TechMemo:ECM

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Star Fleet Engineering
Bureau of Starship and Starcraft Technology

Star Fleet Engineering
Technical Memorandum
Stardate: 170318 (18 March 2005)

RE: Electronic Countermeasure (ECM) Systems


The tactical equation in space is a balance between being seen and remaining unseen. This discussion often brings thoughts of one particular electronic warfare technology, the cloaking device, which attempts to completely avoid detection by all sensors. However, this is far from the only available electronic warfare system aboard a modern starship.

Electronic countermeasure systems operate on two general principles. Either they attempt to prevent a starship from being observed or they prevent it from being observed accurately. There is a subtle, but important, difference between the two. Effective ECM involves a combination of jamming, energy and gravitic emission masking, generating false emission signatures, and the deployment of decoys (see EW drones).

The detailed functioning of electronic warfare systems is complicated, but the results are not. Using electronic warfare systems, a starship is capable of vanishing from a target ship's sensors entirely at long range by reducing emission levels and keeping drive power down. This means that a ship willing to use passive sensors (which means no targeting sensors), low accelerations, and keep its shields down become a virtual hole in space. In the large volume of a system, a starship that does not advertise its presence is very difficult to localize unless it comes very close to a sensor platform. But it also means that a warship can pretend to be something that it is not. A destroyer could pretend to be a battlecruiser in order to dissuade a hostile pirate cruiser from intercepting it and the merchant ship it is escorting. Alternatively, the battlecruiser hunting the same pirate might pretend to be the destroyer or even an unescorted merchant to invite attack and draw an enemy ship in closer to its own optimal attack range.

The key difficulty to electronic warfare systems comes at close range. The shorter the range, the more sensor information available to the other vessel. This makes it more likely that any deception is detected. That is why subterfuge comes into play with the employment of electronic warfare systems. If you convince another vessel at long range that they know what they are looking at, then they are less likely to look too closely as they close. More importantly, at close range visual sensor become more practical. Moreover, it is much more difficult to fool visual sensors than other sensors since the living observer is fundamentally more difficult to predict than a computer algorithms than sort the input from most other sensors. Visual deceptions fall into the basic categories of cloaking systems and holographic projectors. Gravitic cloaking devices bend light around an object to make visual sensors believe that they are seeing the space behind an object as expected and that no object is between the observer and the distant field of view. Holographic projectors create an image which substitute one set of visual emissions for the true emissions of the ship in the visual range of the electromagnetic spectrum. When these emissions match emissions in other ranges created by the rest of the electronic warfare suit, very convincing illusions are possible.

After a ship is actually engaged in combat, the primary concern of ECM is degrading the opposing ship's targeting solution though the use of signal ghosts and jamming rather than actually deceiving the enemy ship about what sort of vessel they are fighting. It should be noted since tactical sensors are short-range, light-speed sensors that ECM systems are unaware of incoming light speed (beam) weapons until they actually strike the outer shield layer. For this reason, ECM systems are incapable of actively reacting to light-speed incoming fire. The ECM solution is continually updated throughout a battle as new information, but cannot actually proactively change to adjust to incoming beam weapons fire.