Sensors

The term sensor, also referred to aboard starships as subspace sensors or sensor probes, is used to refer to any device which is used to scan, record, or otherwise observe any aspect of an environment surrounding a starship, space station, or person. This could be as simple a device as a manual camera or light sensor, or as complicated as the myriad devices designed to scan many aspects of the matter and energies of subspace, space, time and stellar bodies that make up all of existence.

There are two basic types of sensor arrays employed: passive and active. A passive scan is less obtrusive than an active scan, and may not be detected by the subject being sensed. Also, sensors may be divided into short and long range types. (Star Trek: The Motion Picture)

The exact dividing point between short- and long-range sensors has not been clearly established on screen. Long-range sensors have picked up information about targets that were on occasion several hours travel time distant from the sensing ship. Short-range sensors seem to be restricted to a range consistent with the immediate environment of the sensing ship (the term "immediate" being relative), and are most often mentioned being used to scan the surface of planets from orbit or to target weapons fire.

There are many ways to mask a sensor scan, sensor screens are the most commonly used. (TOS: "The Mark of Gideon") One can also mask a sensor scan with certain materials, or radiation. (TNG: "Who Watches The Watchers", "The Pegasus") But to truly hide from a sensor scan one would actually have to change one's molecular structure. (TOS: "Obsession")

Sensors were used by the Vahklas, a Vulcan civilian transport ship, which had left the planet Vulcan in approximately 2143. When Subcommander T'Pol was studying the Arachnid Nebula aboard the Vahklas in 2151, she was temporarily unable to scan the Arachnid Nebula's disodium layer, due to the fact that the transport ship's lateral sensors were out of alignment. (ENT: "Fusion")

The Starfleet vessel Enterprise was equipped with a lateral sensor array. When Captain Jonathan Archer and Commander Charles Tucker III were inspecting the new prototype NX class ship in an orbital inspection pod during 2151, one of the components that Captain Archer wanted to view was the lateral sensor array. (ENT: "Broken Bow")

In early 2368, when investigating the Phoenix Cluster, the lateral sensors of the USS Enterprise-D were booked solid for planetary observation.(TNG: "The Game")

In 2370, the Romulan warbird Terix performed a sensor scan of Asteroid gamma 601 in the Devolin system with its lateral sensor array in hope to locate the USS Pegasus. (TNG: "The Pegasus")

Galaxy-class starships were equipped with high-resolution, multi-spectro sensors. (TNG: "Encounter at Farpoint")

Sensor Systems

There are three primary sensor systems aboard Federation starships/starbases. The first is the long-range sensor array. This package of high-power devices is designed to sweep far ahead of the ship's flight path, or the starbase's orbit, to gather navigational and scientific information.

The second major sensor group is the lateral arrays. These include the forward, port and starboard arrays on the primary hull as well as the port, starboard and aft arrays on the Secondary hull. Additionally, there are smaller upper and lower sensor arrays located around the ship/base to provide coverage in the lateral arrays' blind spots.

The final major group is the navigational sensors. These dedicated sensors are tied directly into the ship's/base's Flight Control systems and are used to determine the ship's location and velocity. On the starbase they are used to control flight operations in much the same way as 20th century air traffic control systems controlled the movement of aircraft.

In addition, there are several packages of special-purpose and engineering sensors such as the subspace flow sensors located at various points on the ship's/base's skin.

Long-Range Sensors

The most powerful scientific instruments aboard Federation vessels are probably those located in the long-range sensor array. This cluster of high-power active and passive subspace frequency sensors is located in the Engineering Hull directly behind the main deflector dish.

The majority of instruments in the long-range array are active scan subspace devices, which permit information gathering at speeds greatly exceeding that of light. Maximum effective range of this array is approximately five light years in high-resolution mode. Operation in medium-to-low resolution mode yields a usable range of approximately 17 light years (depending on instrument type). At this range, a sensor scan pulse transmitted at Warp 9.9997 would take approximately forty-five minutes to reach its destination and another forty-five minutes for the signal to return. Standard scan protocols permit comprehensive study of approximately one adjacent sector per day at this rate. Within the confines of a solar system, the long-range sensor array is capable or providing nearly instantaneous information.

Primary instruments in the long-range array include:

• Wide-angle active EM scanner
• Narrow-angle active EM scanner
• 2 meter diameter gamma ray telescope
• Variable frequency EM flux sensor
• Lifeform analysis instrument cluster
• Parametric subspace field stress sensor
• Gravimetric distortion scanner
• Passive neutrino imaging scanner
• Thermal imaging array

These devices are located in a series of eight instrument bays directly behind the main deflector. Direct power taps from primary electro plasma system (EPS) conduits are available for high-power instruments such as the passive neutrino imaging scanner. The main deflector emitter screen includes perforated zones designed to be transparent for sensor use, although the subspace field stress and gravimetric distortion sensors cannot yield usable data when the deflector is operating at more than 55% of maximum rated power. Within these instrument bays, fifteen mount points are nominally unassigned and are available for mission-specific investigations or future upgrades. All instrument bays share the use of the navigational deflector's three subspace field generators providing the subspace flux potential allowing transmission of sensor impulses at warp speeds.

The long-range sensor array is designed to scan in the direction of flight, and it is routinely used to search for possible flight hazards such as micrometeoroids or other debris. This operation is managed by the Flight Control Officer under automated control. When small particulates or other minor hazards are detected, the main deflector is automatically instructed to sweep the objects from the vessel's flight path. The scan range and degree of deflection vary with the ship's velocity. In the event that larger objects are detected, automatic minor changes in flight path can avoid potentially dangerous collisions. In such cases, the computer will notify the Flight Control Officer of the situation and offer the opportunity for manual intervention if possible.

Navigational Sensors

Federation starship systems constantly process incoming sensor data and routinely perform billions of calculations each second to solve the problem of interstellar navigation.

Sensors provide the input; the navigational processors within the main computers reduce the incessant stream of impulses into useable position and velocity data. The specific navigational sensors being polled at any instant will depend on the current flight situation. If the starship is in orbit about a known celestial object, such as a planet in a charted star system, many long-range sensors will be inhibited, and short-range devices will be favoured. If the ship is cruising in interstellar space, the long-range sensors are selected and a majority of the short-range sensors are powered down. As with an organic system, the computers are not overwhelmed by a barrage of sensory information.

The 350 navigational sensor assemblies are, by design, isolated from extraneous cross-links with other general sensor arrays. This isolation provides more direct impulse pathways to the computers for rapid processing, especially at high warp velocities, where minute directional errors, in hundredths of an arc-second per light year, could result in impact with a star, planet or asteroid. In certain situations. selected cross-links may be created in order to filter out system discrepancies flagged by the main computer.

Each standard suite of navigational sensors includes:

• Quasar Telescope
• Wide-angle IR Source Tracker
• Narrow-angle IR-UV-Gamma Ray Imager
• Passive Subspace Multibeacon Receiver
• Stellar Graviton Detectors
• High-Energy Charged Particle Detectors
• Galactic Plasma Wave Cartographic Processor
• Federation Timebase Beacon Receiver
• Stellar Pair Coordinate Imager

The navigational system within the main computers accepts sensor input at adaptive data rates, mainly tied to the ship's true velocity within the galaxy. The subspace fields within the computers, which maintain faster-than-light (FTL) processing, attempt to provide at least 30% higher proportional energies than those required to drive the spacecraft, in order to maintain a safe collision-avoidance margin. If the FTL processing power drops below 20% over propulsion, general mission rules dictate a commensurate drop in warp motive power to bring the safety level back up. Specific situations and resulting courses of action within the computer will determine the actual procedures, and special navigation operating rules are followed during emergency and combat conditions.

Sensor pallets dedicated to navigation, as with certain tactical and propulsion systems, undergo preventative maintenance and swapout on a more frequent schedule than other science-related equipment, owing to the critical nature of their operation. Healthy components are normally removed after 65-70% of their established lifetimes. This allows additional time for component refurbishment, and a larger performance margin if swapout is delayed by mission conditions or periodic spares unavailability. Rare detector materials, or those hardware components requiring long manufacturing lead times, are found in the quasar telescope (shifted frequency aperture window and beam combiner focus array), wide angle IR source tracker (cryogenic thin-film fluid recirculator), and galactic plasma wave cartographic processor (fast Fourier transform subnet). A 6% spares supply exists for these devices, deemed acceptable for the foreseeable future, compared to a 15% spares supply for other sensors.

Lateral Sensor Arrays

Federation starships/starbases are equipped wit the most extensive array of sensor equipment available. The spacecraft/base exterior incorporates a number of large sensor arrays providing ample instrument positions and optimal three-axis coverage.

Each sensor array is composed of a continuous rack in which are mounted a series of individual sensor instrument pallets. These sensor pallets are modules designed for easy replacement and updating on instrumentation. Approximately two-thirds of all pallet positions are occupied by standard Starfleet science sensor packages, but the remaining positions are available for mission-specific instrumentation. Sensor array pallets provide microwave power feed, optical data net links, cryogenic coolant feeds, and mechanical mounting points. Also provided are four sets of instrumentation steering servo clusters and two data subprocessor computers.

The standard Starfleet science sensor complement consists of a series of six pallets, which include the following devices:

• Pallet #1
  • Wide-angle EM radiation imaging scanner
  • Quark population analysis counter
  • Z-range particulate spectrometry sensor

• Pallet #2
  • High-energy proton spectrometry cluster
  • Gravimetric distortion mapping scanner

• Pallet #3
  • Steerable lifeform analysis instrument cluster

• Pallet #4
  • Active magnetic interferometry scanner
  • Low-frequency EM flux sensor
  • Localized subspace field stress sensor
  • Parametric subspace field stress sensor
  • Hydrogen-filter subspace flux scanner
  • Linear calibration subspace flux sensor

• Pallet #5
  • Variable band optical imaging cluster
  • Virtual aperture graviton flux spectrometer
  • High-resolution graviton flux spectrometer
  • Very low energy graviton spin polarimeter

• Pallet #6
  • Passive imaging gamma interferometry sensor
  • Low-level thermal imaging sensor
  • Fixed angle gamma frequency counter
  • Virtual particle mapping camera

The standard Starfleet sensor complement comprises twenty-four semi-redundant suites of these six standard sensor pallets. These 144 pallets are distributed on the Primary Hull and Secondary Hull lateral arrays. The instrumentation is located to maximize redundant coverage. A total of 284 pallet positions are available on both hulls.

The upper and lower sensor platforms provide coverage in very high and very low vertical elevation zones. These arrays employ a more limited subset of the standard Starfleet instrument package.

In addition to standard Starfleet instruments, mission-specific investigations frequently require nonstandard instruments that can be installed into one or more of the 140 nondedicated sensor pallets. When such devices are relatively small, such installation can be accomplished from service access ports inside the spacecraft.

Installation of larger devices must be accomplished by extravehicular activity. A number of personnel airlocks are located in the sensor strip bays for this purpose. If a device is sufficiently large, or if installation entails replacement of one or more entire sensor pallets, a shuttlepod can be used for extravehicular equipment handling.

Types of Scans

• antiproton beam
• autonomic response analysis
• geological scan
• high-resolution scan
  • passive high-resolution series
• internal scan
• long range sensor scan
• magneton scan
• navigational scan
• multiphasic scan
• subspace differential pulse
• Inverse tachyon pulse
• virtual positron imaging scan