Measure type: Sensors

Sensors could be used for detection, identification, localisation or tracking.

The following chart includes various Sensor solutions that can be implemented as event driven-measures to mediate the risk of a high-impact crime (such as a terrorist attack) at an event in a designated area. These are examples derived from the PRoTECT project.

Tech description	Threat type	Threat phase	Tech use	Tech criteria
Weapon detector (DEXTER)	Fire arms attack	Pre-attack	Surveil / detect / protect	Performance (detection rate)
Explosive detector (DEXTER)	PBIED	Pre-attack	Surveil / detect / protect	Performance (detection rate)
Automatic vehicle behaviour and threat detection (SASSSISLAN)	Vehicle Attack	Pre-attack	Surveil / protect	Performance (detection rate)
Automatic person behaviour and threat detection (SASSSISLAN)	Sharp object attack / PBIED	Pre-attack	Surveil / protect	Performance (detection rate)
Automatic aggression detection	Sharp object attack	Pre-attack / execution	Surveil / protect	Performance (detection rate)
Person re-identification to avoid next attack (DEXTER)	PBIED	Post-attack / Pre-attack (next)	Surveil / detect / protect	Performance (detection rate)
Automatic crowd behaviour and threat detection (SASSSISLAN)	Sharp object attack	Pre-attack / execution	Surveil / protect	Performance (detection rate)
mmw-portals (≈30-300 GHz)	Fire arms, sharp object, PBIED, chemical, biological & radiological attack	Execution	Detect	anomaly detection, slow (person by person)
mmw walk-through (≈30-300 GHz)	Fire arms, sharp object, PBIED, chemical, biological & radiological attack	Execution	Detect	anomaly detection (several 100 persons/h)
radar/microwave (≈3-30 GHz)	Fire arms, sharp object, PBIED, chemical, biological & radiological attack	Execution	Detect	anomaly detection large distance
THz/IR cameras	Fire arms, sharp object, PBIED, chemical, biological & radiological attack	Execution	Detect	anomaly detection difficult image interpretation
X-ray backscatter persons	Fire arms, sharp object, PBIED, chemical, biological & radiological attack	Execution	Detect	forbidden for use in public in Europe – ionising radiation
X-ray transmission persons	Fire arms, sharp object, PBIED, chemical, biological & radiological attack	Execution	Detect	forbidden for use in public in Europe – ionising radiation
X-ray transmission belt systems	Fire arms, sharp object, IED, chemical, biological & radiological attack	Execution	Detect	checkpoint necessary, slow (bag by bag), ATR possible for explosives, guns and knives
X-ray backscatter for cars	Fire arms & VBIED attack	Execution	Detect	covert: needs close proximity to car (drive by), image difficult to interpret, Mobile Portal solution possible, checkpoint situation, driver has to leave the car
Explosive vapour Detection – High Volume Sampling (HVS)	IED, PBIED & VBIED attack (potentially chemical attack)	Execution	Detect	not all explosives can be detected, detection rate depends on circumstances (eg temperature), needs time (1-30 minutes), sampling device is portable, detection device is large and expensive, detector usually mass spectrometer based technology
Explosive vapour Detection – Direct Sampling	IED, PBIED & VBIED attack (potentially chemical attack)	Execution	Detect	Less sensitive than HVS, lower DR, handheld, limited use, many technology sub categories
Explosive Trace Particle detection – contact	IED, PBIED & VBIED attack (potentially chemical attack)	Execution	Detect	contact with object necessary (swab), very sensitive equipment mostly Ion Mobility Spectrometry (IMS) based, but also other technologies success depends on skill operator
Explosive Trace Particle detection – non-contact	IED, PBIED & VBIED attack (potentially chemical attack)	Execution	Detect	Mostly Raman-effect based technology, use of laser, eye-safety is an issue when use in public. Proximity measurements (<2 cm) are mature, longer distance (up to several meters) less mature, also bulk detection possible up to 40 m for some explosives (low TRL), line of sight necessary
Walk Through Metal Detection	Fire arms, sharp object & vehicle attack	Execution	Detect	checkpoint necessary, only works if threat contains metal
Hand held Metal Detector	Fire arms, sharp object & vehicle attack	Execution	Detect	depends on skill operator, only works if threat contains metal
Explosive Detection Dogs	IED, PBIED & VBIED attack (potentially chemical attack)	Execution	Detect	versatile use, performance varies from dog to dog and in time, expensive
Pat down	Fire arms, sharp object, PBIED, chemical, biological & radiological attack	Execution	Detect	often used as alarm resolution, invasive, time consuming, depends on skill of the screener and cooperation of the subject
Visual inspection of bags, cars, etc.	Fire arms, sharp object, PBIED, chemical, biological & radiological attack	Execution	Detect	often used as alarm resolution, invasive, time consuming, depends on skill of the screener and cooperation of the subject
Detection of deviant behaviour offline (for example, security questioning, distinguishing psychiatric patient from terrorist (Rapid Observation of Psychological Disorders (ROPD) tool))	all	Execution	Surveil	Performance (detection rate)
Use of animals as sensor (for example, emotions, stress level, use of substances, presence of explosives, and establishing identity)	all	Execution	Surveil / respond / detect / restrict	Readiness /  Performance
Risk assessment of individuals on the spot (i.e., stress assessment)	all	Execution	Respond / detect	Performance (accuracy)
Vulnerability assessment of individuals before the fact (for example, Multi-Agency Vulnerability Assessment Support Tool (MAVAST))	all	Initial target identification	Surveil	Performance (accuracy, at face value as data are largely absent)
Automatic sprinkler system	IED, PBIED, UAVIED & VBIED attack	Execution	Respond / protect / overcome	Performance
Drones with sensor	all	Initial target identification / execution / post-attack/escape	Surveil / respond / detect	Performance (detection rate, accuracy)

In the first column, under 'Tech description', technological solutions are listed.

The next column indicates which 'Threat types' can be mitigated with these technological solutions:

1. Fire arms attack - small calibre pistol or semi/full-automatic rifle;
2. Sharp object attack - knifes, machete, other sharp and blunt objects;
3. Vehicle attack - use of vehicle as a weapon by ramming large crowds;
4. Improvised Explosive Device (IED) - left/concealed in objects or goods (based on home-made or commercial explosives);
5. Person-Born Improvised Explosive Device (PBIED) - explosives concealed on a person (suicide or carrier);
6. Unmanned Aerial Vehicle Improvised Explosive Device (UAVIED) - explosives delivered by a remote-controlled airborne device;
7. Vehicle-Borne Improvised Explosive Devise (VBIED) - explosives concealed inside a vehicle (or its cargo);
8. Chemical attack - threat object concealed in goods or carried items (e.g. canister or UAV dispensed);
9. Biological attack - threat object concealed in goods or carried items (e.g. canister or UAV dispensed);
10. Radiological attack - threat object concealed in goods or carried items (e.g. canister or UAV dispensed).

The 'Threat phase' column states in which phase of the attack the technological solution has the most effect:

1. Initial Target Identification (before the attack);
2. Operational Planning (before the attack);
3. Pre-Attack Preparation (before the attack);
4. Execution (during the attack);
5. Post-Attack/Escape (after the attack).

Finally, the 'Tech use' column states the appertaining security function of the technological solution:

1. Alert - used for alerting public (e.g. sirens, texting service);
2. Surveil - used for situational awareness (e.g. cameras, social media tools);
3. Respond - used for responding to an attack (e.g. security personnel, non-lethal weapons);
4. Protect - used to protect assets (people, buildings, infrastructure);
5. Detect - used for detecting a weapon or weapon use (e.g. entry scanning equipment);
6. Overcome - used for overcoming a sudden vulnerability (e.g. extra concertina wire);
7. Improvise - created on the spot from available means (e.g. use police vehicle as a road block);
8. Restrict - used for restricting public access (e.g. safety barriers);
9. Adapt - used for changing circumstances (e.g. moving assets to a safer location);
10. Other.

Other measure types are:

• ICT
• Actuators
• Physical measures
• Methods