This article will discuss the various types and applications of sensors in military ground vehicles and weapons.
What is a Sensor?
A sensor is any device that detects or measures a physical property, such as light, humidity, heat, and infrared radiation, and transmits the data to a computerised system which performs some specified action, e.g., actuating a switch or triggering an alarm.
Sensors utilised in military ground applications can withstand the harshest operating conditions such as temperature extremes, water and chemical intrusion, mechanical shock, and heavy vibration.
Sensors for Military Applications
Modern military ground vehicles and equipment utilise a broad range of sensory technologies for precise measurement of physical phenomena. The following are some of the most critical:
Active sensors detect and measure physical phenomena by "beaming" generated radiation on objects in the environment and measuring the amount of energy reflected. These sensors contrast with passive sensors that detect physical stimulus from the object. Active sensors and sensor-based technologies include Precise Positioning Service (PPS), ground-based Radar, and LIDAR systems.
Precise Positioning Service (PPS)
Precise Positioning Service is an active sensor-based technology used by the US military and its allies for encrypted and secure communications via Navstar satellites over the GPS L1 and L2 frequency bands.
An example of a ground-based Radar system is Lockheed Martin's AN/TPS-59 and AN/FPS-117 ground-based air surveillance radar systems capable of detecting the position of enemy targets at ultra-low to high altitudes. Radar systems radiate high-frequency pulse signals (produced by a magnetron tube or solid-state amplifier) in the direction of the target, then send the reflected signals to a processing system.
A military tank. Military ground vehicles are replete with electronics systems for a host of functions.
Light Detection and Ranging (LIDAR)
LIDAR is a high-resolution remote sensor technology that measures the distance to a target by illuminating it with light from a laser and analysing the reflected light. Because LIDAR utilises laser pulses with wavelengths up to 100,000 times shorter than radio waves utilised in Radar systems, it has a significantly higher resolution and is more accurate in detecting smaller objects.
Terrestrial LIDAR is used in military applications for 3D terrain mapping (battlefield visualisation), remote target acquisition, and object detection in search and rescue (SAR) missions. LIDAR sensors enable obstacle avoidance and detection in military driverless vehicles for safe navigation by giving a 360-degree map of the vehicle's surroundings.
Smart sensors are devices that continuously detect and monitor input from the environment and carry out a pre-set action when they sense a specific input. In military and defence applications, intelligent sensors are useful for converting large volumes of data generated from continuous monitoring into actionable intelligence.
A good example is the Stinger Intelligent Automatic Number Plate Recognition (ANPR) camera sensor from Appian Technologies which leverages integrated wired or wireless technologies such as GPRS/GSM, IEEE 802.11/IEEE 802.3, and 3G for data transmission. The ANPR camera can recognise license plates of vehicles and send the results to military bases for potential identification.
Infrared (IR) Sensors
Infrared sensors are photo-sensitive instruments that detect infrared radiation or heat emitted by an object in the surrounding. Although invisible to the human eye, living creatures and inanimate objects emit some level of IR. IR are usually of two types; thermal and quantum IR sensors.
Thermal IR sensors detect infrared energy as heat and have a photo-sensitivity independent of the IR wavelength of the detected object. Quantum IR sensors utilise quantum physics principles and have higher photo-sensitivities than thermal IR sensors but are dependent on the IR wavelength of the target.
An essential application of IR sensors is in missile guidance. Also known as "heat-seeking," missile systems utilise thermal IR sensors for tracking infrared radiation emitted by a target. Military ground personnel also use IR sensors in vehicles or weapons for night-vision surveillance, detecting hidden bombs, landmines, and more.
An LMTV military vehicle.
Micro-Electromechanical Systems (MEMS)
MEMS sensors are cost-effective, lightweight sensors that combine electronic and mechanical elements on a single chip to detect physical stimuli such as pressure or temperature. MEMS consist of miniaturised actuators, sensors, and mechanical structures that work together to transform energy from one form to another (e.g., mechanical signals into electrical signals).
Semiconductors, polymers, electroplated metals, and ceramics are the most popular materials used to fabricate MEMS systems. MEMS sensors and MEMS-based systems are suitable for soldier-worn devices, weapons, and ground vehicles.
Detecting a wide range of physical phenomena, including pressure, heat, and infrared radiation, sensors are an integral part of electronic hardware for defence applications.
With technological advancements in artificial intelligence (AI), Internet of Things (IoT), and nanotechnology, sensors will continue to enable a broad range of military applications in the short and long term. A host of electronic sensors are found in military ground systems for surveillance, object detection, location mapping, remote target acquisition, and many more.