Motion Tracker

From Star Frontiers Network

by Madin Jackson

A sonar unit combined with passive, air-density sensors, the Motion Tracker is a hand-held motion sensor, which provides the user with information about unseen opponents. A Character must have the Computer skill to operate a Motion Tracker and requires a Displaying Information skill check. The device is operated by a trigger mounted in the handgrip; thus, when not in active use the Motion Tracker cannot be left on, conserving battery power and decreasing the possibility that the Motion Tracker, itself, is detected.

The location of detected movement is displayed on an LCD screen mounted on the top of the device as a set of probability contours ranging from black to white; black indicating no movement and white indicating a high probability of the location of movement. An auditory cue is also provided in the form of a reverberating tone that changes in pitch and reverb speed, based on the size and proximity. A Motion Tracker will indicate the position, size and speed of any object within its range.

In ideal conditions (i.e., open terrain with no wind), the Motion Tracker can scan accurately up to a kilometer, however in buildings (such as the average, Frontier building with metal and synthesized walls which to a great extent, absorb the sonar bursts and returns), the effect range drops to 30 meters. The size of object the Motion Tracker is scanning for is determined by the user, down to a minimum diameter of about 60cm. The frequency and settings must be adjusted repeatedly to filter interference and operating the Motion Tracker in cluttered terrain is difficult without a good Computer skill. The Motion Tracker will not work in a vacuum.

The Motion Tracker can register movement on the far side of a solid obstacle, but the air flow between the two locations must be unblocked and the operator’s task is made more difficult. For each corner or intervening obstacle, reduce the operator’s Displaying Information skill check by minus 10; one corner is minus 10, two corners is minus 20 and so on.

If the operator uses a Motion Tracker successfully, then he or she receives accurate information regarding the number, position speed and size of all moving objects within the Tracker’s range; if the roll is failed, then the information will be inaccurate to some degree. If the roll is failed by 10 or less, the Tracker will show the range and speed to all nearby targets, but the number and size of the targets will be unknown. If the result is failed by 20 or less, only the range will be known. If the roll fails by 30 or less, the operator receives no significant information. If the operator fails by more than half, the Referee should give the operator significantly incorrect information.

The device does have problems, however:

• First, because the tracker emits high-frequency, sonar bursts it can be easily detected by passive listening stations as a target for enemy fire or by cybernetic, sound enhancers.
• Second the Motion Tracker is designed to filter out slight, “natural” movement, such as insects or flags blowing, so a very slow target may be able to infiltrate a Motion Tracker’s scan area.
• Third, because the Tracker uses air-density sensors (Doppler radar) to discriminate between immobile objects and targets, a target moving across the Tracker’s scanning cone may be effectively invisible. Finally, the unit is vulnerable to ultrasound jamming.

The Motion Tracker uses a standard, power clip and provides the device power, for up to 48 hours of continuous use. The clip can be replaced in one turn. The device is available at many high tech worlds without a license (it could be used for hunting). It costs 500Cr and weighs 1kg.