Heartbeat Sensor

File:Cliffhanger.jpg

The Heartbeat Sensor from Cliffhanger equipped on an ACR.

The Heartbeat Sensor is an attachment used in Call of Duty: Modern Warfare 2. The attachment allows the user to track multiple targets, somewhat like UAV and similar to the motion trackers in the Halo games (though the latter is a 360 degrees detector with immediate update, built into the armor) and notably, to the motion tracker in the Aliens movie (despite it not being a separate piece of equipment). It displays the positions of people who are fairly close to and in front of the player.

In the campaign, the display screen can be folded out from the side of the weapon and folded back in again. The first time it is used is in the level Cliffhanger, where Roach finds himself in near white-out conditions. It is used also in the levels Contingency mounted on two M240s and in Just Like Old Times if the player, as Soap, swaps his weapon to the Silenced ACR. The sensor uses some kind of IFF system to tell the difference between friendlies and enemies. Friendlies are blue dots and enemies are white. In multiplayer games, friendlies appear as green dots instead of blue and enemies appear as red dots instead of white.

Cold-Blooded cannot bypass the sensor; only the perk Ninja can. The EMP killstreak will render it inoperative for the duration of the killstreak so that only static can be seen on the screen. This attachment is compatible with Assault Rifles, Light Machine Guns, and Sniper Rifles. It is also seen on the AA-12 in a few Special Ops missions such as Acceptable Losses. To unlock the Heartbeat Sensor the player must get 15 suppressed kills with the weapon.

It was planned to be an attachment for Submachine Guns, but the plan was canceled. The UMP45 and the P90 both have the side rail to which a heartbeat sensor could be attached.

File:Heartbeatsensor modernwarfare2.png

A close-up of the Heartbeat Sensor from Cliffhanger. The blue dot is Soap.

File:Heartbeat.png

Heartbeat Sensor in Modern Warfare 2's Multiplayer

File:Heartbeat sensor.JPG

Heartbeat Sensor in Multiplayer (note the red dots that denote the enemy)

Advantages

• The Heartbeat Sensor allows the user to locate non-firing enemies without the use of a UAV. This makes it useful in Hardcore or when a Counter-UAV is airborne.

• Unlike the UAV, the Heartbeat Sensor can detect players using the Cold-Blooded perk.

• It is especially effective for snipers to have this equipped as it can alert them of an approaching enemy, unless said enemy is using Ninja or/and is coming from behind.
• Consider using Scrambler and Heartbeat Sensor, the enemy will have a jammed radar and come searching for you, but your sensor will find out where they are.

• The Heartbeat Sensor helps its user locate enemies through any obstructions, such as walls and smoke screens.

• When used by one member in Team Deathmatch who has a microphone, it can be useful when going into buildings after players hiding. The person with the Heartbeat Sensor can pinpoint and call out their position of the player(s) to his/her team.

• A player can use the Heartbeat Sensor effectively even without looking at it, as the Heartbeat Sensor beeps when it detects enemies.

• The Heartbeat Sensor can be used while utilizing a grenade launcher or shotgun attachment.

• While using the FMJ attachment, the Heartbeat Sensor makes the perfect assistant in performing unexpected penetration kills. Be aware that in modes that do not feature kill-cam, it is fairly likely you will be accused of hacking. Nonetheless it is a simple strategy for unlocking extended magazines on assault rifles and light machine guns.

Disadvantages

• There is a fairly long period of time (slightly longer than a UAV) between sweeps.
• When reloading a Grenade Launcher, the Sensor will obstruct the middle of the screen.
• Enemies with Ninja will be able to easily surprise someone using the Heartbeat Sensor. This makes the Heartbeat Sensor inadvisable for Search and Destroy.
• This attachment is almost useless in third-person, because the player cannot see the sensor.
• Players using a heartbeat sensor can inadvertently give away the positions of their teammates, if the victim watches the shooter's Kill-Cam.
• In single player, the display cannot be seen while using night vision goggles. The sensor will glow brightly making it impossible to see.
• The sensor only scans the area in front of and to the sides of the player. Enemies behind the player cannot be detected if they are directly behind the player.
• In two-player splitscreen, the Heartbeat Sensor is off the bottom of the screen on some guns (E.g LMG), making it almost useless, and a waste of an attachment. In three-player splitscreen, only the last player will experience this.
• When using the Heartbeat Sensor many people tend to stare down at the sensor, allowing players using the Ninja perk to surprise attack them. Some say the Heartbeat Sensor can be a distraction at times.
• The sensor can be very confusing in multi-story buildings as it will beep even if the opponent is on a different floor.
• Sprinting will obscure the player's view of the Heartbeat Sensor.
• If the player is using the Masterkey shotgun attachment, the Heartbeat Sensor is not visible while the shotgun is readied on any AR other than the M4A1, M16A4, and F2000
• The Heartbeat Sensor is more useful against low-level players who do not have the ninja perk unlocked.
• Heartbeat Sensors can pick up enemies through surfaces and may misguide the player as to the enemy's actual location.

Trivia

• Originally the Heartbeat Sensor may have been meant for some submachine guns.

• The Heartbeat Sensor is one of the most frowned upon features of the game due to its ability to detect most average players (the exception being those using Ninja), regardless of UAV status or the use of Cold-Blooded.

• The Heartbeat Sensor does not pick up the heartbeat of chickens or civilians. This was likely done so as not to confuse the player.

• The Heartbeat Sensor has a smaller range of detection in multiplayer. This was done for balancing purposes.

• In Just Like Old Times, the player can pillage weapons from Shadow Company equipped with Heartbeat Sensors that, strangely, display SC soldiers as unidentified (hostile) contacts. This is strange, since their own weapons should light them as allied contacts.

• The Heartbeat Sensor is very hard to use in split-screen mode because the screen is smaller. Only a few weapons will show the whole screen, such as a Barrett .50cal or M4A1 while other weapons such as the SCAR-H or FAMAS don't show the screen at all.

• When aiming down the sights with the TAR-21 with a MARS Sight, the Heartbeat Sensor remains almost entirely visible.

• The Heartbeat Sensor is nearly identical to the motion trackers used in the movie Aliens, down to using the same blips for moving objects, and the same static beep when no movement is detected.

• If the player never folds out the Heartbeat Sensor at the beginning of "Cliffhanger," Soap will never explain what the blue and white dots mean.
• In Battlefield: Bad Company 2, one of the characters, Sweetwater, makes a remark about how General Braidwood will send "some Special Ops douchebags with pussy-ass Heartbeat Monitors on their guns instead of us." He says this during a mission that takes place on snowy mountains while recovering a piece of a crashed satellite, which is extremely similar to the scenario in Cliffhanger.

• The Heartbeat Sensor on the M240 in Contingency can't be folded unlike the ACR in Cliffhanger.
• When viewed in 3rd person with a sniper scope, one can clearly see up and down arrow buttons, as well as "Menu" and "Power" buttons. There are also small speakers and writing that says "Motion Tracker MT-33".