A Remote Sensor is a sensing device that allows the user to detect targets outside their line-of-sight without revealing themselves. They can range from simple trip-wire to advanced electromagnetic scanners and are deployed by a variety of means, from 'Mechs and other vehicles to Battle Armor and specialized sensor engineers. Remote sensors are commonly used to establish a defensive perimeter or aid in the assistance of scouting and reconnaissance missions.
While the use of remote sensors goes back for many centuries, modern remote sensors were first introduced by the Terran Hegemony in 2590. However, because they were easy to destroy and expensive to replace, the use of remote sensors declined during the Succession Wars. The rediscovery of many lost Star League technologies allowed for their revival following the Clan Invasion.
Remote sensors can be monitored using equipment that is properly tuned to the correct frequencies; while basic communications equipment can accomplish this task, more specialized equipment is necessary to take full advantage of the technology. Infantry, especially when using portable remote sensors, can also compare multiple sensors at once, though only through special monitors tied to each type of sensor. Hostile ECM can disrupt the link between sensor and monitor, while certain stealth systems can render the target harder to detect. As well, while remote sensors can detect targets that enter their sensing range, they are unable to positively identify the target. Doing so requires a skilled operator that can tell the difference between a harmless animal or an infiltrating enemy soldier.
Vehicles and battle armor equipped with remote sensor dispensers, along with infantry designated as Sensor Engineers, may deploy a Remote Sensor at any point during the Movement Phase at a cost of 1MP. Aerospace units deploy sensors via the traditional Bombing rules. Once deployed, any unit within 67 hexes (2 kilometers) with the following equipment may monitor as many Remote Sensors as allowed: Light Active Probe (1), Active Probe (2), C3 Master Computer (4), Improved C3 Computer (3), Cockpit Command Console (4), and Communications Equipment (1 per ton). Sensor Engineers may monitor 2 Remote Sensors per 7-man squad. While being monitored, Remote Sensors can spot any hidden unit unless they are using Stealth Armor, Null Signature System, Void Signature System, or ECM. They may also be used to spot for indirect LRM and artillery attacks, though these attacks gain a negative to-hit modifier. Remote Sensors may not be a part of a C3 Network, and may be destroyed with shooting attacks or by a unit moving through its hex at a cost of 1MP.
- LosTech: The Mechwarrior Equipment Guide, p. 107, "Remote Sensors"
- Tactical Operations, p. 375, "Remote Sensors"