Arma 3: Sensors

Overview

Vehicle and ammo sensors for target detection and tracking.

User Interface

Action keybinds (default)

R	Select next target (targets are prioritized according to the currently selected weapon and the target threat)
T	Select target under the cursor / center of view
LCTRL + R	Toggle radar on/off

See Custom panels page for more info about controlling the Sensor display.

Mechanics

Active Radar

• only sensor that can be switched ON and OFF.
• only sensor that provides information about a target's speed, altitude, and distance
• to be able to lock on target the radar-guided (ARH) missiles require the radar to be switched ON
• activated radar makes your vehicle detectable by RWR or Passive radars at up to twice the range of your own radar.

RWR and Passive Radar

• detects anyone who has a radar ON at twice the distance of the tracked radar's own range.
• provides unique indication to targets with active radars
• most often the RWR can detect radar threat in 360° field-of-view
• additional passive radar (less common than RWR) allows you to mark the radar threat and use it for targeting your weapons

Infrared

• can only detect 'hot' targets - vehicles that have been heated up by a running engine or fired weapon
• susceptible to environmental conditions (fog)
• often with field-of-view limited to the optics field-of-view
• often coupled with Visual sensor

Visual

• can detect cold targets
• susceptible to environmental conditions (fog, light), useless at night
• often with field-of-view limited to the optics field-of-view
• often coupled with Visual sensor

Laser and Strobe Tracking

• detect a spot lased by a laser designator or an IR grenade (as a homing beacon)
• usually with a 180° front hemisphere field-of-view

Human Tracking

• able to detect and track human targets
• doesn't work with data link

Configuration

The new Sensor system gets enabled by defining a SensorsManagerComponent class inside the vehicle's Components class.

class MyVehicle_F : MyBaseVehicle_F
{
       class Components : Components                   
      {
            class SensorsManagerComponent : SensorTemplatePassiveRadar
            {
            };                                                                                            
      };
};

For simplicity the class can inherit from one of the templates that are available in the configFile root, which allows you to only change the properties you need.

class SensorTemplatePassiveRadar;  
class SensorTemplateActiveRadar;   
class SensorTemplateIR;            
class SensorTemplateVisual;        
class SensorTemplateMan;           
class SensorTemplateLaser;         
class SensorTemplateNV;

Properties

componentType

Mandatory property that defines the type/spectrum and hardcoded behavior of the sensor. Can be one of the following

• IRSensorComponent - detects irTargets according to their irTargetSize and their actual heat signature. Sources of heat are engine, tires or the muzzle. To become a detectable target in IR the engine has to be running at least 6 seconds. To become undetectable the vehicle may need to cool down even as long as 1 hour.
• NVSensorComponent - detects nvTargets.
• LaserSensorComponent - detects laserTargets.
• ActiveRadarSensorComponent - detects radarTargets according to their radarTargetSize. Radar needs to be switched ON via an action (Default Arma 3 and Arma 3 Apex keybind is (Ctrl+R)). Switching the radar on also makes the owner a detectable target for vehicles or ammo with passive radar component (see below). It's also the only sensor that can provide additional information about the target - its distance, speed and altitude.
• PassiveRadarSensorComponent - detects vehicles with active radar switched on at twice their active radar's range.
• VisualSensorComponent - detects visualTargets according to their visualTargetSize.
• ManSensorComponent - detects targets that inherit from Man class.

componentType = "ActiveRadarSensorComponent";

class AirTarget

Defines the sensor detection range in look-up conditions, when the target is positioned against a sky background. It's possible to cap the range by viewDistance (or its portion) for systems that work within visual range. Set the DistanceLimitCoefs to -1 to disable any impact of view distance on the sensor for beyond visual range systems.

The actual sensor's range is the smallest of [maxRange, resulting objectViewDistanceLimit, resulting viewDistanceLimit] but never lower than minRange

In the following case the sensor will be able to detect targets that are within the object view distance as terrain view distance will always be bigger. However if the obj. view distance is set above 5km the sensor won't be able to detect anything above 5km. If it's conversely set below 500m, the sensor will still be able to detect targets at 500m even if they are not visible.

class AirTarget      // ranges for targets with sky background
{                                            
        minRange = 500;         // -1 if undef; in meters 
        maxRange = 5000;       // -1 if undef; in meter                                                        
        viewDistanceLimitCoef = 1;      // -1 if undef; coefficient, multiplies current view distance as set in player's options. -1 means view distance is not used to limit sensor range.
        objectDistanceLimitCoef = 1;    // -1 if undef; coefficient, multiplies current object view distance as set in player's options. -1 means object view distance is not used to limit sensor range.

};

class GroundTarget

Defines the sensor detection range in look-down conditions, when the target is positioned against ground clutter. Properties are the same as in airTarget.

class GroundTarget      // ranges for targets with ground background
{                                            
        minRange = 500;         // -1 if undef; in meters 
        maxRange = 3000;       // -1 if undef; in meters                    
                                                     
        viewDistanceLimitCoef = 1;      // -1 if undef; coefficient, multiplies current view distance as set in player's options. -1 means view distance is not used to limit sensor range.
        objectDistanceLimitCoef = 1;    // -1 if undef; coefficient, multiplies current object view distance as set in player's options. -1 means object view distance is not used to limit sensor range.             
};

typeRecognitionDistance

Distance in meters at which the sensor recognizes the actual target vehicle type (e.g. Mi-48 Kajman)

typeRecognitionDistance = 1000; /// -1 if undef

angleRangeHorizontal

Sensor horizontal (azimuth) coverage (in degrees)

angleRangeHorizontal = 120;
angleRangeHorizontal = 90; // if undef

angleRangeVertical

Sensor vertical (elevation) coverage (in degrees)

angleRangeVertical = 120;    
angleRangeVertical = 90; // if undef

nightRangeCoef

A coefficient of sensor's range during night time (used for visual sensors). Goes linearly between full light conditions (daytime) and poor light conditions (dusk). Overcast weather can sometimes move the range down the scale as well.

nightRangeCoef = 0; // blind at night   
nightRangeCoef = 0.5;  // range halved at night
nightRangeCoef = 1; // full range at night; if undef

maxFogSeeThrough

A fog threshold, sensor won't be able to see through a fog with higher value than this number.

maxFogSeeThrough= 0.1; // sensor blocked by even smallest amount of fog
maxFogSeeThrough= 0.95;  // approx. the normal visibility in fog (vis. sensor)
maxFogSeeThrough= -1; // disable

groundNoiseDistanceCoef

Portion of sensor->target->ground distance. Below this number the targets become invisible to the sensor even if they are still within the GroundTarget range.

 groundNoiseDistanceCoef = 0.1;  // if distance between vehicle and ground in the direction of the target is 1km then the target won't be detected as long as it stays less than 100m close to the ground background
 groundNoiseDistanceCoef = -1 // if undef

maxGroundNoiseDistance

Distance from the ground background in meters, hard cap, above which the target will be visible even if still below groundNoiseDistanceCoef.

maxGroundNoiseDistance = 50; // in the situation from prev. example the target now becomes detectable whenever it is more than 50m from the ground background and still within the sensor GroundTarget range.
maxGroundNoiseDistance = -1; // if undef

minSpeedThreshold

Target speed in m/s above which the target will start to become visible even if below groundNoiseDistanceCoef.

minSpeedThreshold = 27.7; // following the prev. example if target is 20m from the ground background but it's moving more than 100km/h (27.7m/s) it may still be detected by the sensor.
minSpeedThreshold = 0; // if undef

maxSpeedThreshold

target speed above which the target becomes visible even if below groundNoiseDistanceCoef, linearly decreases to minSpeedThreshold.

maxSpeedThreshold = 100; // following the prev. example if target is 20m from the ground background but it's moving more than 360km/h it will be detected by the sensor.
maxSpeedThreshold = 1000; // if undef

minTrackableSpeed

Minimum speed of the target that can be detected.

minTrackableSpeed = -1e10; // if undef; no minimum speed
minTrackableSpeed = 27.7; // targets slower than 100km/h won't be detected at all

maxTrackableSpeed

Maximum speed of the target that can be detected.

maxTrackableSpeed = 1e10; // if undef; no maximum speed
maxTrackableSpeed = 55; // targets faster than 200km/h won't be detected at all

minTrackableATL

Minimum altitude above terrain level that can be detected.

minTrackableATL= -1e10; // if undef; no minimum altitude
minTrackableATL= 50; // targets flying lower than 50m above ground and ground vehicles (unless jumping or dropped from an airplane) won't be detected at all

maxTrackableATL

Maximum altitude above terrain level that can be detected.

maxTrackableATL= 1e10; // if undef; no maximum altitude
maxTrackableATL= 1; // targets higher than 1m above won't be detected

animDirection

Model selection to set the sensor direction.

animDirection = "mainTurret";  // sensor will be aligned with the turret and will rotate together with it
animDirection = "";   // if undef; sensor will be aligned with vehicle body

aimDown

Elevation offset in degrees of the sensor from the animDirection.

aimDown = 35; // sensor will be looking 35° downwards from its original direction given by the animDirection
aimDown = 0; // if undef

allowsMarking

Sets whether targets acquired by the sensor can be "marked", having track visualized in 3D and with possibility to use the info for various aiming aids or weapon guidance. This has specifically been made for RWR simulation via passive radar, so the active radars pop up on Sensor Display but they can't be marked unless also tracked by another sensor (vehicle or weapon).

allowsMarking= 1; // default
allowsMarking= 0; // targets that are tracked by this sensor only won't be target-able

Example Config - full definition

class cfgAmmo
{	
	class MissileCore;
	class MissileBase: MissileCore
	{
		class Components;
	};	
	class My_Missile_Base: MissileBase
	{
		missileLockMaxDistance 	= 3500; 
		missileLockMinDistance 	= 100;
		missileLockMaxSpeed 	= 680;
		missileLockCone			= 50;
		// The properties above limit the locking range, cone and conditions but they are are independent from the sensor. They don't say what the missile can see and track. In this case they are set to similar values as sensor, so what the missile seeker can see and track the missile will also be able to lock onto.

		class Components: Components
		{
			class SensorsManagerComponent
			{
				class Components
				{
					class SomeRadarSensorComponent                   
					{                                                 
						componentType = "ActiveRadarSensorComponent";
						class AirTarget      // ranges for targets with sky background
						{                                            
							minRange  = 5000;         //minimum possible range in meters    
							maxRange = 5000;       //maximum possible range in meters                 
							objectDistanceLimitCoef = -1;    //range not limited by obj. view distance
							viewDistanceLimitCoef 	= -1;      //range not limited by view distance           
						};                                                                                    
						class GroundTarget      // ranges for targets with ground background                           
						{                                            
							minRange  = 3000;                
							maxRange = 3000;                 
							objectDistanceLimitCoef = -1;               
							viewDistanceLimitCoef 	= -1;                 
						}; 
						typeRecognitionDistance = 1000; // distance how far the target type gets recognized                                          
						angleRangeHorizontal 	= 60;     // sensor azimuth coverage in degrees         
						angleRangeVertical 		= 60;       // sensor elevation coverage in degrees       
						groundNoiseDistanceCoef = 0.5;  // portion of sensor-target-ground distance below which the targets become invisible to the sensor
						maxGroundNoiseDistance 	= 250;   // distance from the ground in meters, hard cap, above which the target will be visible even if still below groundNoiseDistanceCoef
						minSpeedThreshold 		= 30;        // target speed in m/s above which the target will start to become visible           
						maxSpeedThreshold 		= 45;       // target speed above which the target becomes visible even if below groundNoiseDistanceCoef, linearly decreases to minSpeedThreshold         
					};
				};
			};
		};
	};
};

Example Config - inheritance from template

class SensorTemplateActiveRadar;   
class SensorTemplateIR;

class cfgVehicles
{	
	class Plane;
	class Plane_Base_F: Plane
	{
		class Components;
	};	
	class My_Plane_Base: Plane_Base_F
	{
		class Components: Components
		{
			class SensorsManagerComponent
			{
				class Components
				{
					class ActiveRadarSensorComponent : SensorTemplateActiveRadar
					{
						class AirTarget      
						{                                            
							minRange = 6000; 
							maxRange = 6000;                                              
							objectDistanceLimitCoef = -1; 
							viewDistanceLimitCoef = -1;             
						};                                                                                                                        
						angleRangeHorizontal = 60;            
						angleRangeVertical = 60;      
					};
					
					class IRSensorComponent : SensorTemplateIR { };
				};	
			};
		};
	};
};

Related

• CfgAmmo
• CfgVehicles
• Arma 3 Custom Info
• Arma 3 Components
• Arma 3 Targeting
• Sensor Overhaul thread