The tactical deflector system is the primary defence of any starship. It is a series of powerful deflector shields that protect it and the crew aboard from the effects of hazards both natural and artificial.

Like most force fields the deflectors use a zone of highly focus spacial distortion within which an energetic graviton field is maintained. Deflectors fields them selves are emitted from a series of conformal transmission grids that cover the surface of a ships hull (can be noticed on Star Fleet ships as small raised lines covering the surface of the ships). This causes the field to follow a form close to that of the ship itself. This field is highly resistant to impact due to mechanical incursions ranging from extreme subatomic particles to larger objects at a lesser velocity. When such an intrusion occurs the field energy is concentrated to the point of impact creating an intense, localized spatial distortion. To the observer it appears that the intruding object has "bounced off" the shields. To an observer from a zero dimension it would look like their trajectory is unchanged and the location of the ship has suddenly changed. This is some what similar to the spatial distortion created by a natural gravity well. The moment of impact is usually accompanied by a momentary discharge of Cerenkov radiation often perceived as a brief blue flash. Deflector shields can also protect from a wide range of electromagnetic, nuclear and other radiated energies, by a similar process of deflection and distribution.

Operating procedures.

Providing shielding against the full electromagnetic spectrum would be far too energy costly during normal operations. However the crew requires protection from various sources of radiation and micro meteorites etc.. To protect the crew most starships (all Starfleet vessels), maintain a low level out put of around 5% at the appropriate frequencies and bandwidths for common space hazards.

During alert situations shields are raised to a defensive level by increasing generator output to around 85%. Frequencies and bandwidths are randomly modulated to prevent a threat source from adjusting the frequency and phase of the energy weapon to match that of the shields as so bypassing there effect completely. The effect can be used to shielding advantage if the exact frequency of the attacking weapon can be determined by modulating the shield frequencies to that frequency causing repulsion. Similar techniques are used to protect from natural hazards such as when shields are increased into the 10 to the power -10 bandwidth to protect against X rays.

Deflector Side Effects.

Besides the drain on ships power deflectors also have several other side effects. Sensor frequency and phase has to be matched to that of the shields drastically reducing their bandwidth and so data collection capacity. Also sensor operation has to be restricted to passive scans as active scans would reveal shield phase and frequency.

By far the most well know side effect is the disruption of transporter beams. The annular confiment beam that serves as the transmission medium for the transporter beam requires such a wide subspace bandwidth that it is normally impossible to pass transport through the shields. Additionally the spatial distortion caused by the shields is severely disruptive of the transporter beam's pattern integrity.

Shield operation also has a significant effect on warp drive operation due to all the subspace distortion. This distortion has adverse effects on warp field geometry causing 32% degradation in force coupling energy transfer (see warp drive theory). Starfleet vessels have computer algorithms that upshift deflector output to 147 kilohertz to compensate for translational field interaction thus overcoming this effect.