While piloting a ship, being aware of nearby objects is vastly important. Almost every ship is equipped with a basic sensor suite, which is composed of three different subsystems: a set of visual sensors, a RADAR array, and a tachyonic sensor.
A basic sensor suite is broken down into three subsystems. Visual sensors are arrays of different cameras that are capable of picking out objects at close range. RADAR still functions by sending out radio waves and waiting to receive them again. Tachyonic uses an array of specialized receivers that are tuned to pick out bursts of tachyons most commonly produced by hyperdrives or warp drives. When all of these are used in tandem, a ship’s sensor suite can track a target across a system. However, individually, tachyonic sensors are used for long range detection, RADAR is used to detect targets at medium range, and visual sensors are used for short range detection.
Structural Stealth Modifications & Effect on Detectability | |||||
---|---|---|---|---|---|
Structural Stealth Modifications | |||||
Detectability [Sensor Type Used] |
No Modifications Made |
Anti-Radar Structure(s) |
Laser Absorbing Structure(s) |
AR/LA (BOTH) | |
At Close Range [Visual] (1 Ls) |
Detectable | Detectable | Inconsistent Lock | Inconsistent Lock | |
At Medium Range [RADAR] (1 AU) |
Detectable | Undetectable | Detectable | Undetectable | |
At Long Range [Tachyonic] (11 AU) |
Detectable (Only when exiting Hyperlanes) |
Detectable (Only when exiting Hyperlanes) |
Detectable (Only when exiting Hyperlanes) |
Detectable (Only when exiting Hyperlanes) |
In space, ranges are quite literally astronomical. Combat generally takes place in extremely short range (“combat range” is generally what it's called), or, about a dozen kilometers to a few dozen kilometers because shots become extremely hard to land past that. Short range is within 1 lightsecond, and that’s where passive visual sensors work best. Medium range is generally within 1 AU (About 8 light minutes) and is generally where most active RADAR reaches its limit. Long range is anywhere between 1 AU and 11 light days, however because only the tachyonic sensor array is able to detect things passively at this range, only a general location of a few hundred miles around the emission source can be acquired, making it still rather inaccurate.
All sensors, with the exception of tachyonic, have two modes, passive and active. Sensors in passive mode do not create any kind of detectable emissions meaning they don’t set off a ship’s warning systems, however, are not as long ranged or reliable as they are in active mode. Once turned to active mode, the sensors will begin to actively emit detectable energy, such as radio waves with RADAR and low-powered lasers with the visual sensors. Active mode boosts their range and accuracy greatly, however this also makes your ship visible to every other ship in the area.
All ships are also equipped with a Sensor Warning System or SWS that warns the pilot or crew that they’re either being detected, locked, or being fired at by a piece of tracking ordnance. An SWS is generally a lot more sensitive than a ships’ sensor systems, capable of picking up faint energy from very low-powered lasers at long-range.
A visual sensor array is composed of hundreds if not thousands of small cameras and low-powered lasers placed around a ship that’re both fixed and turret-mounted capable of picking up various wavelengths of light from ultraviolet to infrared. The fixed sensors constantly passively scan the area surrounding a ship and when it finds an object’s parallax moving faster than the background of space, it knows it’s found something. The limit of visual sensors is because it quite literally becomes exponentially harder to find something the farther away it is, and even with modern technologies seeing ship-sized objects past or around 1 lightsecond when you don’t even know if something is there is extremely hard.
On the other hand, visual sensors are designed to work in tandem with the other two systems and are actually what normally maintains a lock on an object. The visual sensors that’re mounted on small turrets across a ship, when paired with either the RADAR system or the Tachyonic sensors, will point to where the other subsystem is showing where an object is. Because the other two subsystems aren’t as accurate, these “active” visual sensors are only given a ballpark of a few dozen miles (in the case of RADAR) to hundreds of miles (in the case of tachyonic) of where to look. However, when (or if) the visual sensors find the object, the sensors will then use a system of very low-powered lasers to keep a track on it until the system confirms what the object is. At this point, if the object is a ship, then it knows that it’s being detected. This is only accurate at medium range because the RADAR subsystem can actively continue to tell the visual subsystem where an object is while the tachyonic subsystem only has one burst of information to give. In order to track an object at long range a ship must maintain an active lock on the object.
Visual sensors are the ones generally maintaining an active lock on an object. They do this in a similar way to their active scanning mode. By pointing several of the small sensor turrets towards a target- and therefore more tracking lasers -the system can paint a more accurate image of an object and give more reliable information about its position, trajectory, and acceleration. At the same time, if the object is a ship the increase in tracking lasers will alert it that it’s being locked.
A RADAR subsystem consists of dozens of small RADAR bulbs scattered across a ship. An array in active mode functions by broadcasting radio waves that bounce off an object and return to the various receivers within the bulbs across the ship which then use those returning waves to calculate distance, trajectory, acceleration, etc.
While the RADAR subsystem is set to passive mode, the arrays do not broadcast any signal. Instead, they sit and listen for other radio waves within the wavelengths that are used by RADAR. When the subsystem picks these up, they trace them back to their origin point and proceed to calculate the information needed to track the source. Some of the sensors used during passive mode are also used in a ships’ SWS to tell a ship when they’re being hit by someone else’s RADAR.
The tachyonic subsystem is made up of only a handful of sensors and is normally a large chunk of the price when buying a sensor suite. Unlike the previous two kinds of sensors, the tachyonic system only has a passive listening mode since tachyons do not interact with much matter and as such cannot bounce back to the ship like RADAR does. Instead, the tachyonic system “listens” for high-energy tachyonic bursts caused by ships entering and exiting hyperlanes. While ships at warp still produce tachyons, warp drives produce a much lower amount of tachyons compared to hyperdrives and because of that are harder to detect. Higher-end systems are capable of picking out ships at warp, however these systems are too large to be fitted onto anything smaller than a Frigate.
Gravimetric or simply “gravity” sensors are part of a ships’ basic sensor suite and are generally the first subsystem to identify planets. Outside of that, they’re normally not that useful. Extremely expensive gravimetric sensors are used on advanced sensor crafts to detect much smaller objects such as ships and asteroids. Once again, like a tachyonic system, the gravimetric suite is only a passive sensor system.
Magnetic sensors, or “mag-sensors,” are a niche subsystem, generally only functioning at combat range, mag-sensors use an array of sensors containing a combination of magnellium and other materials to detect the EM field of all but the most expensive and/or specialized of stealth ships.
Stealth ships come in two completely different philosophies, one associated with Fringe smugglers and one associated with Civ Space smugglers.
Generally associated with Fringe smugglers, the “rock” philosophy is very self-explanatory. Since the best way to fool visual sensors is to blend in with the surroundings, many die-hard Fringe smugglers will simply hollow out and reinforce an asteroid, and then build a ship inside of it. While it’s more conspicuous from the get-go, as it doesn’t have radar absorbing surfaces, not only is this cheap, if the pilot is smart, they can avoid even the most scrutinous of sensor stations by turning off all systems and hoping they glance over their ship as a simple asteroid. The problems arise when the asteroid is big enough that it sets off a station’s or planet's point-defense against large asteroids.
The much more expensive, and more inconspicuous philosophy is that of “the chip.” These stealth ships gained their names because of their normally flat and wide build. They’re covered in aegisalt structures designed to absorb not only radar but also the lasers that visual suites rely on to keep a lock on targets. When caught, they generally go into a “silent running” mode, disabling anything that gives off a heat signature and wait. At this point, these ships can easily be mistaken as cosmic background radiation to the untrained eye. The problem with the chip, is that at a certain point the visual suites don’t need their lasers to continuously track it meaning that once in-range of railguns or laser cannons they can easily be shot down. Missiles, despite their range advantage over railguns, would have a hard time tracking even at combat distances.
Most systems owned by developed nations will have a few sensor stations within their system. Sensor stations are generally installed with advanced sensor suites with high-end tachyonic and visual sensors; they're capable of accurately tracking most traffic within close range. When paired with other sensor stations, they can more accurately track traffic at medium range. Many standalone sensor stations are also autonomous, automatically sending information to a Space Traffic Control station or a military outpost.
Nations in both the Fringe and CivSpace generally link up their sensor stations and their ships together into a network, giving ships and space stations within their jurisdiction access to a real time map of systems around them. Sensor networks do not need to be on a nation-wide scale; however, if a handful of ships are working together at different areas, they can create a comprehensive map of a system and track ships not in their group more accurately than if they were alone.