Metal Gear Wiki
Metal Gear Wiki

Examples of the Soliton Radar in use.

The Soliton Radar System was a type of radar that could detect biological reactions. It was invented by Mei Ling in the 2000s, although the basic technology existed as early as 1974.[1]


The Soliton Radar employed the KdV equation to detect the electromagnetic waves resulting from biological reactions, allowing the user to obtain a variety of information about the immediate area, including the positions of enemies. It could even estimate the interior structure of buildings by bouncing electromagnetic waves from the land structure in question to a satellite. The main difference between the Soliton Radar and the Reactive Radar, used by Solid Snake during the Operation Intrude F014, was that the Soliton Radar could display the direction in which an enemy was facing. Although the radar was completely unaffected by adverse weather, it otherwise had a fragile signal, becoming jammed easily in areas with strong harmonic resonance or in confined spaces such as vents. It could also track the user's movements and relay this to the command center.


During the Peace Walker Incident in 1974, Big Boss's mercenary group, the Militaires Sans Frontières, developed a device similar to the Soliton Radar.

The Soliton Radar was used by Solid Snake during the Shadow Moses Incident, and then again during his mission on the USS Discovery, both times to aid in infiltration. Although during the latter mission Philanthropy was working independently, it is possible that the United Nations granted them access to the required satellite. Raiden also made use of the Soliton Radar during the Big Shell Incident. Naomi Hunter, when sending the SOS signal to Philanthropy at South America, also included a Soliton Radar map data to show where she was located.

Warning: The following information is from outside Hideo Kojima's core "Metal Gear Saga." Its canonicity within the continuity is disputed, therefore reader discretion is advised.[?]

After the fall of the Patriots, classified technology spread all over the world, which included the Soliton Radar. By adding a non-linear Schrodinger equation to the Soliton Solution, jamming during an alert status no longer happened.

Raiden once again made use of the Soliton Radar in his Cyborg Ninja body in 2018.

Non-"Metal Gear Saga" information ends here.

Behind the scenes

Metal Gear SolidMetal Gear Solid 4

The Soliton Radar first appears in Metal Gear Solid, displaying the positions of enemy soldiers around the player's location. Unlike the Reactive Radar from Metal Gear 2: Solid Snake, it also displays the enemy soldiers' fields of vision. The radar reacts actively to the environment, changing color to reflect the mood of the enemies (blue for normal, yellow for suspicious, and red for alerted) as well as getting "knocked offline" when the player is spotted. The radar display is located on the upper right side of the game screen. While the device itself is never actually seen, the IDW comic book adaptation portrays it as a handheld device.

Ripped coding from Metal Gear Solid suggests that, in addition to the Alert, Evasion, Caution, and Normal modes, there would have also been a "Dying" mode. The title implies that it would have appeared if Snake was either killed, prior to the Game Over screen, or close to death.

In Metal Gear Solid 2: Sons of Liberty, the Soliton Radar has additional features such the ability to view pictures or videos sent to the player, and to view the location of bombs when used with various sensors.

The Soliton Radar is not used in Metal Gear Solid 3: Snake Eater or Metal Gear Solid: Portable Ops, due to it not existing in the time that the games are set, its function being replaced by other devices such as sonar and motion detection. Metal Gear Solid 4: Guns of the Patriots replaces the radar with Solid Eye System for the main game, although it is featured in the Shadow Moses dream sequence in Act 4.

Metal Gear Solid: Peace Walker

"High-power sensor that displays surrounding topography and enemy positions. Only functional in Normal Phase. (Ranks 2-4) Modified to extend battery life. (Rank 5) Modified to consume no battery power at all."
―Soliton Radar description in Metal Gear Solid: Peace Walker

A Soliton Radar appears in the Metal Gear Solid: Peace Walker TGS demo while playing as Sneaking Suit Snake, although this version has limited usage due to its reliance on batteries. This would appear to be a retcon of Metal Gear Solid, since Mei Ling had previously been stated as having been its creator. However, the exact words in the game were that she designed Snake's Soliton Radar, which alongside the manual only listing the Codec as being an invention of hers implies that she may have only created the specific Soliton Radar that was used for the mission. In either case, in the full game, the radar's specifications are made available after the first mission in Chapter 5. On a related note, Peace Walker is also the first game to give a visual depiction of the radar itself, as its icon could be seen on the item select screen.

Metal Gear Rising: Revengeance

The Soliton Radar was included in Metal Gear Rising: Revengeance, although it no longer becomes jammed during an alert phase. This was largely due to game's focus being on action gameplay, as opposed to the main series' stealth.

Notes and references

  1. ^ Metal Gear Solid: Peace Walker, Kojima Productions (2010).
    After completing the first Zadornov capture mission, one of the rewards is the blueprints for the Soliton Radar.