The M336 targeting computer is the core of what sets the M45/M56 Smartgun family apart from all other machine guns. Mounted on the top of the barrel shroud and protected by a prominent cage of bars surrounding it, the M336 works in conjunction with the M76 combat helmet to recognize, prioritize, and aid in targeting of hostile contacts.
M76 Combat Helmet:
The M76 is the smartgun operator’s primary means of interface with the M336. Closely related to the design of the SPH-4C helicopter helmet, the M76 offers ballistic protection similar to the M10 helmet, along with the same personal data transmitter and camera systems. However, in addition to this, it features an SPH-4-derived faceplate which can be slid down over the gunner’s face for use in combat. This clear faceplate, which has a slight tint applied, is where the information from the M336 is projected in the form of a heads-up display. Another feature carried over from the SPH-4 is the integrated ear covers, complete with headphones that not only function as radio receivers but also help protect the gunner’s hearing, while small external microphones transmit sounds to the headphone speakers, allowing the gunner to clearly hear sounds at voice level and quieter just as if they were not wearing the helmet at all. The SPH-4’s left-mounted boom microphone is also present on the M76. The M76 was not the helmet originally designed for use with the M45/M56. The original helmet was developed by Rheinmetall for use by the German Heer with the MG45 and MG56. The design, which was adopted as the M103, added the computer systems and sliding faceplate to the Bundeswehr’s standard M92 helmet. This design was rejected by the United States, which developed the M76 instead.
The gunner’s main form of control over the helmet’s computer, and consequently the M336 targeting computer, is a basic neural control interface. Although NCIs were still in fairly primitive experimental and developmental stages at the time of the smartgun system’s creation, they were advanced enough to provide sufficient functionality, and more capable NCIs were integrated into the helmet as they became available, resulting in the M76A1, M76A2, and finally, the M76A3.
M336 Smart-Targeting Computer:
The M336 is capable of functioning in the infrared and visible light spectrums, allowing different methods of acquiring targets. The neural control interface allows the computer to recognize hostile targets by means of the operator’s own ability to understand what consists of a hostile target; that is, when the operator sees an enemy soldier, their recognition of the object and the threat it poses makes the computer recognize the soldier as a threat compared to nonthreatening stationary and/or moving objects in the environment. The computer is capable of highlighting targets with an outline, so that if the operator takes their eyes off of it and then wants to reacquire the target if it moves slightly, it will still be easily visible on the heads-up display. In addition to targets acquired from the gunner through the neural interface, the M336 has its own target recognition software, allowing it to identify targets without the gunner’s input, provided they meet certain criteria.
The M336 also projects an infrared laser dot sight which helps it determine exactly where the weapon is pointed and project a set of crosshairs on the gunner’s HUD. This laser sight is effective up to 1,000 meters, and in addition to determining where the weapon is pointing, also calculates the range to the target. The M336 is then capable of telling the operator when the gun is aimed correctly to strike the target, as well as offering input suggestions if the gun is not aimed correctly. The computer also tracks the exact position of its own laser dot at all times, preventing confusion with any other laser dots (such as from other smartguns) that cross the receiver’s field of view. Although the M336 cannot account for effects such as downrange crosswinds on its own even with the laser sight, it can interface with other sensor systems in use by friendly units and incorporate such data if available, providing a more precise firing solution.
The M336 is capable of analyzing multiple targets and determining which a greater immediate threat is. For example, if it detects a nearby enemy soldier who is not aiming a weapon at the gunner, and another enemy soldier farther away who is aiming in the gunner’s direction, it will establish priority towards eliminating the farther soldier, and will provide an alert on the gunner’s HUD. The neural interface also makes the computer able to understand the gunner’s goals to a limited degree, so if, for example, the gunner’s intent is protection of a friendly vehicle, the computer can recognize this and determine that an enemy soldier with a rocket launcher is a greater threat than one with a rifle.
Interfacing with other systems and computers being used by friendly forces is another key part of the M76/M336 system’s functionality. The smartgun operator is meant to be accompanied by a spotter, who is equipped with AN/TS-7 (Army-Navy/Targeting Sight) binoculars. These binoculars have the same targeting systems as the M336, and can transmit their data to the smartgun, allowing a target found and selected by the spotter to appear on the gunner’s HUD. The operator’s direct commanders can also select and transmit target data to an individual smartgun operator. For example, in a normal heavy weapons company, the machine gun platoon is broken down into three twelve-Marine squads, themselves separated into three four-Marine fireteams. Each fireteam is commanded by a corporal and each squad is commanded by a sergeant, and so an individual smartgun operator can be sent target data by his spotter, his fireteam leader, or his squad leader.
Additionally, the M336 can also accept information from the AN/TTS-13 (Army-Navy Telescopic-Targeting Sight) rifle scope used on the M656P marksman rifle and the AN/TTS-17 used on the M42 sniper rifle. The gunner can also request targeting data from automated weapon systems such as the UA 571 series of sentry guns, as well as other sources such as friendly vehicles. The M577 APC used by Reconnaissance In Force Teams is also able to send target data from the command center to the team’s smartgunners.
If targeting data sent to a smartgun operator is out of the computer’s field of vision, a colored bar will be displayed on the side of the HUD closest to the target.
In addition to receiving target information, the smartgun operator can also send it, in several ways. Data can be sent to other smartgun operators, or to other weapon systems. If the operator is unable to eliminate a long-range target, the data can be sent to a marksman with the M656P rifle or a sniper with the M42 rifle so that they can eliminate the target. If the operator detects a hostile armored vehicle, the data can be sent to a friendly soldier armed with an M5 rocket launcher or even to vehicles.
In a further step, the gunner is also able to request manual override of nearby UA 571-series sentry guns and provide targeting data to them; target data transmitted by a smartgun operator to a sentry gun takes priority over the sentry gun’s own targeting systems. However, the gunner cannot directly control the weapon via remote link, as is the case with the UA 571-E sentry gun, only send target information.
One final option that the M336 provides its operator is quaternary priority to direct the launch of certain vehicle-based missile systems, specifically the surface-to-surface MGM-220C Hellhound launched by the M574 Guided Missile Carrier and the FIM-218 Hornet, the secondary weapon of the M579 Mobile Aircraft Defense System. Quaternary priority means that if the gunner (primary priority) of a nearby M574 or M579 has opened up their vehicle for remote weapon launches and command of that vehicle’s launch systems has not been preempted by a fire support controller (secondary priority) or unit commander (sergeant, lieutenant, captain, etc, tertiary priority), the gunner can connect to the vehicle’s computer and instead of merely sending target data, manually direct a missile launch against an enemy target, such as a bunker, tank, or aircraft, even if the target is out of the vehicle’s line of sight. This not only increases the usefulness of these missile launch platforms, but gives the smartgun operator a significant increase in available firepower, making them able to engage and destroy virtually any target on the battlefield.