Sensor Ranges

[wrathgon]

Sensor Ranges

Sensor Range Increments
All sensor systems have range increments based on PL. All systems have a maximum range of 5 increments. Each increment beyond the 1st imposes a -2 penalty to function check made at that distance.

PL 5 range increment: 10 hexes Max 1 system
PL 6 range increment: 20 hexes Max 1 system
PL 7 range increment: 50 hexes Max 2 systems
PL 8 range increment: 200 hexes Max 3 systems
PL 9 range increment: 500 hexes Max 4 systems

Planetary systems or space stations can put much more power behind their systems. Multiply the range increment of a stationary sensor system by 100. This only applies to detailed scan results. Stationary systems can detect object (ships) at a range of 15 systems away if they know where to look (i.e. they receive a transmission from the ship) and the ship is not shadowed by another object.

A ship’s sensors only operate at the range specified unless otherwise noted. By default sensors operate at immediate range, but if manually tuned to work at farther range increments by ship personnel, the sensor now are only focused on the new range increment. This leaves the ship blind at other ranges including immediate range. Secondary sensor arrays can be installed to operate at two ranges simultaneously and some of the higher end sensor systems can operate at multiple ranges.

Proximity alarms
Most starships systems routinely scan the immediate range for objects on a direct collision course with the ship. Alarms will also sound when another identifiable starship (an object with a detectable energy signature) approaches within immediate range. Part of this functionality is the normal operating procedure of ship systems to signal each other via transponders. In order to even attempt to “sneak up” on a target vessel a ship must disable its own transponder. A ship without a transponder signal is generally assumed to be hostile.
You can set the immediate range to anything you want up to first range.

Transponder signals
A normal transponder transmits the following ship information in a radius of 1 system: ship name, port of origin/nationality, current heading and speed, autopilot enable/disabled, voyage priority.

A ship name is assigned when the ship is constructed. Officially changing a ship name takes 48 hours and must be registered with the port of origin. This requires a Knowledge (Civics) check 25 and a purchase DC of 20. This can be combined with a port of origin change at no additional cost.

Port of Origin/Nationality is assigned at ship construction. This designates who owns the ship and what nationality it is for tax/administrative purposes. Changing nationality of ship requires 48 hours, a Knowledge (Civics) 25 check and a purchase DC of 20. This can be combined with a name change at no additional cost.

The current heading and speed of a vessel is broadcast to help facilitate auto-nav systems.

Autopilot status is included so that the ship navigator/pilot or autopilot can make minor course adjustments to maintain a safety buffer of 5000 feet.

A priority is set to indicate the importance of the ship mission. There are a variety of codes ranging from Emergency Vehicle (1) to Garbage Scow (1000). Priority codes 5 and below do not have to respond to distress signals. Other priorities are obligated to respond to distress signals. Ship transponders signals are logged automatically by all vessels that receive it. If a ship fails to respond to a distress and that ship later is rescued by another vessel, then the offending ship will be impounded and the captain banned from piloting another vessel.

Disabling a transponder is a free action requiring a DC 15 Computer Use check. The ability to disable a transponder is a common safety feature in space where even honest ships must “hide” from hostile forces. However, ship caught in major shipping lanes with disabled transponders will always be boarded and may be fired upon.

Forging/altering a transponder signal takes 1d4 minutes. Transponder systems are encrypted and typically installed by transport authorities to be tamper proof. As such modifying one requires a Computer Use check DC 30 for each element forged.

Sensor conditions
There are a variety of conditions that affect sensor performance. Most are caused by close proximity to planets, stars or other massive celestial objects. Here are some suggestions.

Gas Giant: Massive planets like Jupiter have enormous magnetic fields many times more powerful than Earth’s own. Such forces reduce all range increments by half when the ship is within 500 hexes of the planet.
Solar: Stars also produce large magnetic fields and emit masses of particles at their respective “north” and “south” poles. Ships positioned inside this solar wind are invisible to detection from sources outside the effect. Source inside the effect can only operate sensors at 10 hexes with a -5 penalty to checks.
Debris Fields: Sensor systems can be overwhelmed by multitudes of objects. These conditions can be encountered in asteroid fields, large debris fields or any where thousands of huge objects are encountered. Detecting a specific object in this area (like a ship without a transponder) imposes a -10 penalty.
Hard Radiation: Typically encountered inside nebula or at the sight of particularly catastrophic battles, hard radiation imposes a -2 penalty to all sensor checks.
Gas Clouds: Masses of tiny particles impact visual sensors as well as laser based systems. Range increments of ship sensors are halved.


Beating sensors
Skilled pilots and sensor operators can help mask a ship in space. This generally falls in to two categories—becoming invisible and masquerading as something else. Pilots can hide their ship in debris fields, gas clouds and behind other larger objects with a pilot check that is then opposed by any sensor checks. A ship can only hide behind objects larger than itself.

Sensor operators can use their own ship systems to fake readings. The operator uses their Computer Use skill to attempt the masquerade with the following modifiers. Remember to add in range modifiers.

Downgrade/Upgrade the PL of all weapons one step; -4 to the roll.
Fake the top speed of the ship by 500’ (+/-); -2 to the roll.
Increase/Decrease detected lifeforms by 20%; -4 to the roll.
Completely mask lifeforms; -4 to the roll (it is easier to completely hide than fake the number).

Relative sensors
Upgraded systems provide an advantage to detecting tampering and a bonus to masquerading. For each step difference between two ship’s sensors apply a +2 bonus to masquerades to the more advanced ship and a -2 penalty to the roll of a lesser ship. For example the Alpha encounters the Omega within 1000 miles. The Alpha is a smugglers ship and wants to avoid confrontation with the more powerful Omega. The Alpha has altered its transponders (a Computer Use check as above) and is masquerading as an unarmed private yacht. However, the Alpha only has a Class II Sensor array and the Omega has a Class VI. The Alpha will take an additional -4 (two steps difference) to its rolls to masquerade against the Omega. If the situation were reversed, then the Omega would enjoy a +4 advantage to its own masquerading attempts.

Running Silent
Ship sensors can be either “active” or “passive.” Active sensors send out energy looking for the “echoes” of the returning energy to gather data. Passive sensors emit nothing but instead only receive energy and try to interpret it. Any time a ship is actively making a check using its scanners they are considered active. Using active scanners is a dead giveaway of your current position to all ships inside your scanning range increment. Relying only on passive scanners to detect energy signatures is only possible inside 5 hexes and imposes a -15 penalty on analysis checks. Sensors in passive mode can only gather information about powered system in operation (i.e. engines, radio communications, active sensor arrays, charged weapons, weapons fire, energy shields, etc.) Determining the exact location of an object with no energy signatures using only passive sensors requires moving with in 2 hexes of an object.

Navigating a ship without active sensors imposes a -10 penalty to Pilot checks, but also makes a ship undetectable (usually) beyond 10 hexes to passive sensors. A ship using active sensors takes a -10 penalty attempting to detect another ship running silently. A ship running silently moves at only ¼ speed.