First developed over 100 years ago by the Romulan Empire, the cloaking technology from that era is paled in comparison by today's cloaking technology. Although the principles and results are the same, to be rendered 'invisible' to visual (i.e. electro-magnetic spectrum) and various sensor systems. The methods and hardware used today by various cultures is far superior to the first Romulan units.  All cloaking technology utilizes the same basic principle, the distortion of energy around an object. The effect is to make the object appear to not 'exist' at its location since it cannot be detected by normal means. If not operating at 100%, or even slightly out of phase, cloaked objects can be detected either by sensor or even by 'sight' as they may be detected as a 'distortion' of background star fields or planetary bodies. This gives the cloaked object the ability to move about without concern of being observed by its enemies. Cloaking a ship requires precisely balancing the radiative emissions from the warp drive nacelles, dissipating all electromagnetic radiation, gravitational fields and other energy emissions emanating from the ship, and distorting space in such a way that electromagnetic radiation and energy emissions are directed around the ship through subspace at velocities faster than light. Most large scale cloaking technology in space requires the expenditure of immense amounts of energy. For effective cloaking, the device must be able to distort (or curve) not only visible spectra, but background radiation's and energies such as gamma rays, x-rays, delta radiation, tachyons, etc.

All of these energies can be scanned for and if they are not distorted  precisely, they can effective give away the position of the cloaked vessel. It is because of all these types of energies that exist in free space that cloaking energy consumption is so dramatic. The cloaking device must also be able to effectively dampen ship emissions as well. Every space going  vessels emits any number of detectable energies. Warp fields, Impulse drive plasma, communication signals, containment fields, gravity displacement, etc. All these must be neutralized. When a starship's cloaking device is active, several ships' systems operate under special protocols to minimize the interference of the cloaking device. The ability to emit inversely tuned energy fields that 'cancel out' these emissions as well as themselves is all part of the cloaking devices function. Off-axis warp field controllers balance the radiative emissions from the warp drive nacelles. This is necessary because the power source must be in phase with the cloaking device. These devices are used on warp-capable ships without cloaking devices, as well as warp-capable ships with cloaking devices, because they increase the engine operating efficiency. If any one of these controllers are misaligned or in some way damaged it would produce a polarized, magnetic distortion, detectable by other ship's sensors. When a cloaked ship is travelling faster than light in warp, the fact that the ship is moving so quickly makes it difficult to pin-point the location of a ship even if one of the controllers are in some way damaged or misaligned. Because the cloaking device exists as a conformal field surrounding the ship, it is usually tied directly into the ships Deflector Shield system. By using the common Deflector grids connected around the hull of the ship, a cloak can be maintained even if some damage has occurred to the Deflector grid. This would not be the case if the Cloaking Device were to rely on one (or a few) cloaking emitters, so all known races seem to have adopted the use of tying in the Cloaking Device to the Deflector grid.  By selective manipulation, it is possible for cloaked ships to take some actions. Transporter beams, low frequency scans, even shuttle or probe launches are all possible, but each use presents the enemy the ability to pinpoint the cloaked ships location. If his can be determined, even cloaked ships can be hit by random fire or scattered fire. Cloaked ships are not invulnerable. They are, in fact, more vulnerable to damage if hit without their protective shields, but the cloak does effectively prevent pinpoint or accurate firing against them.

This also presents the Cloaking Devices greatest drawback. Since it is tied into the Deflector grid, the shielding system cannot be used. Since shields operate out away from the ship (usually in a form of a elliptical 'bubble') and not within the conformal Deflector Screen, the shields would be readily detectable. In addition, the emission of the energy to erect the Shields would destabilize the Cloaking Devices output, either significantly negating its effectiveness or rendering it inoperable. Thus, while in operation, no ship can raise shields.  Since the cloaking device energy output must generate sufficient levels of energy to operate, there is a noticeable time lag between the time the cloaking field is activated to the time it is 100%. The same is true in 'dropping cloak', the time lag between deactivating the cloaking device and the time the cloaking field disperses. These time lags lead to the appearance of the ship 'fading' in and out as the device activates or deactivates. During these brief moments, (and scientists continue to research ways to reduce this lag) that the device is not 100% and shields are not operating, that create a 'open window'. It is within this window, that ships are vulnerable. Without shields and without 100% cloaking capability, opponents can attempt to fire and score a hit. Such shots are extremely inaccurate, since most fire control units need time to 'lock-on' before firing, and the window is open for only a few brief seconds. If a lucky shot (either by automatic or by manual fire control) where to strike, the cloaking ship would be extremely vulnerable to critical damage since such shots would strike without the shields to absorb the incoming energy.

Another disadvantage of the Cloaking Device is the inability to fire weapons while under cloak. There are several reasons. In most cases, ships cannot generate enough power to cloak, move, and energize weapons all at the same time. Many ships have limited energy output that several limit  their movement capabilities while under cloak, much less being able to channel energy to weapons. Another problem is the weapons themselves. The ability to dampen Warp signatures is difficult enough, the precision andenergy expended by the Cloaking Device in negating these emissions alone can account for up to 70% of the cloaking energy cost. Energy weapons emissions are not nearly as stable as the artificially created warp fields, they suffer from fluctuations that are more random, and the ability to mask these emissions would be extremely difficult. In addition, fire control is another factor. When using an active fire control, ships must emit a traceable energy to 'lock on' to enemy ships. This energy is detectable. There has been only one example of a semi-successful ship being able to fire under cloak. A Klingon Bird of Prey was built to test this ability. It was successful in testing the 'fire while cloaked' concept. The ship was able to mask its energy weapons build up prior to firing and was able to utilize a unique form of fire control that was undetectable. This ship did have a fatal flaw. In sacrificing the energy to render its energy weapons charging undetectable, the ability to dampen the Impulse Drive plasma emissions was compromised. This compromise would be its Achilles heel, which rendered it vulnerable to detection by a modified photon torpedo that could trace plasma gases.

With the continued advances in cloaking technology, and anti-cloaking technology, standards and methods are continuously being created and counter-measures developed. It is, for the most part, a continual arms race. Newer detection methods, including tachyon detection grids, will some be outdated as increases in cloaking technology continue. Even newer cloaking technologies, like the Federations phasing cloak (developed by renegade Starfleet officers) allows starships to not only be undetectable,  but can actually move through solid matter because the matter within the cloaking field has be 'phased' into a sub-space realm which allows it to 'co-exist' within the same location a 'un-phased' matter.  Although personnel cloaking fields operate under different principle,  examples being used by Jem 'Hadar soldiers are worthy of mention. The 'miniature' cloaking devices are limited to visual and background radiation's found in habitable environments. They have limited capabilities and lack the power for long term use. For the Jem 'Hadar, they are effective as they are only used for the soldier to close to within striking range of the enemy and possibly for reconnaissance.  

Date - Sept. 27, 1998