Heartbeat Sensor



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 similarly 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 is not a separate piece of equipment). It displays the positions of people who are fairly close to and in front of the player. In 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 level Just Like Old Times if the player as Soap swap 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. The new version of UAV jammer, Cold-Blooded, cannot block the sensor; only the perk Ninja can. 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.



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 is coming from behind.
 * The Heartbeat Sensor helps its user locate enemies through any obstructions, such as walls and smoke screens.
 * When used by one member in team death match who has a mic, it can be useful when going into buildings after campers. The person with the HB sensor can pinpoint and announce the location of the camper to his team.

Disadvantages

 * There is a somewhat 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.
 * The sensor is almost useless in third-person multiplayer for obvious reasons, although the beep is still audible.
 * 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.
 * In two-player offline multiplayer, the heart beat sensor is off the bottom of the screen on some guns ( E.g LMG), making it almost useless, and a waste of an attachement. In three-player, only the bottom player experiences this.
 * When using the Heartbeat Sensor some people rely heavily on it, allowing people using the Ninja perk to surprise attack them.
 * The sensor can be very confusing in multi-story buildings as it will beep even if the opponent is on a different floor.
 * Even though most people use Ninja on Search and Destroy, somewhat don't. If useing a HB sensor, try to also be aware like you didn't have it!

Trivia

 * The Heartbeat Sensor cannot be folded back towards the gun in multiplayer.
 * The Heartbeat Sensor seems to have a smaller area of effect in multiplayer. This was done for balancing purposes.
 * The Heartbeat Sensor has a range of approximately 30 meters in singleplayer.
 * The player will get a fuzzy screen when the enemy team uses an EMP.
 * There is a known glitch where if a player who is using the Ninja perk is killed by a player using a Heartbeat Sensor, the former player will show up on the killer's Heartbeat Sensor when watching the KillCam.
 * It is strange how the heartbeat sensor can detect which people are enemies and which ones are allies, just by their heartbeat. Of course, this is obviously just for gameplay purposes. It has been suggested that perhaps allies have been injected with some kind of tracker, allowing their heartbeat to be differenitiated from that of enemies.
 * In campaign, an AA-12 with a heartbeat sensor can be used. The heartbeat sensor is not available in multiplayer on the AA-12 or any other secondary weapon.
 * In real life, there are actually devices that sense heartbeats, but they are larger than the one in MW2, about the size of a radar gun. As the game takes place in 2016, new advances to reduce size may have been made.
 * 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 50. Cal or M4A1 while other guns like the SCAR-H or FAMAS don't show the screen at all.
 * When aiming down the sights with the TAR-21 with a Red Dot Sight, almost the entire heartbeat sensor screen is still visible.
 * Many players say they often end up watching the Heartbeat Sensor more than they actually look in front of themselves. This is counteracted by playing as though you don't have the Sensor until it detects an enemy and makes a ping, the pitch of which ascending as the enemy draws closer.
 * Some players choose not to use the Heartbeat Sensor due to the fact that it can be distracting at times, often leading to easily preventable deaths.
 * 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.
 * Due to the Heartbeat Sensor's loud beep when it detects enemies, players can still sprint or aim down the sights just as often as they normally would and only stop when a beep is heard.
 * The beep is a lot more audible on the console versions than the PC version.
 * In campaign, the enemies pop up as white, as in multiplayer the enemies are red.
 * Some weapons (SCAR-H, TAR-21) and many more weapons' reload animations differ with the heartbeat sensor attached probably because the heartbeat sensor obstructs the charging handle (noticeable on SCAR.)
 * On Offline Split-Screen Multiplayer, the Heartbeat Sensor is nearly useless because of the screen being cut and the only way to know if someone is there or near you is if you listen carefully or he/she appears on the top of the sensor.