Study Material on Sensors for CPP by ASIS

1. Sensor

2. Physical Protection System (PPS)

3. Design and Evaluation Process Outline (by Garcia)
Determine PPS
Objectives
Facility
Characterization
Threat Definition
Target
Identification
Design/Characterize
PPS
Physical Protection Systems
Analyze
PPS Design
EASI Model
Adversary Sequence
Diagrams
SAVI Model
Analysis/Evaluation
Risk Analysis
Final
PPS
Design
Redesign
PPS
Delay
Response
Detection
Exterior Sensors
Interior Sensors
Alarm Assessment
Alarm Communication & Display
Access
Delay
Response
Entry Control
Primary Secondary
Deter

4. Physical Protection
Detection
- Intrusion sensors
- Video assessment
- Alarm control and display

5. Types based on Alarm Initiation Conditions
Intrusion
- To detect a potential intrusion
- Presence of any kind of unwanted person in a predefined area
State
- Change in Safety or process
- Rise in temperature, presence of smoke, etc.
Fault Event
- Loss of electric power
- Failure of the sensor itself

6. Types based on Alarm Initiation Conditions
Temper
- Opening, shorting, or grounding of the device circuitry
- Tampering with the sensor’s enclosure or
- Tampering with distributed control panels

7. Sensor Types based on Alarm Initiation Conditions
o Intrusion
o State
o Fault Event
o Temper

8. Performance Characteristics of Sensor
o Probability of detection
o Nuisance Alarm Rate (NAR)
o Vulnerability to defeat

9. Probability of Detection
o Probability of detection =
𝑨
𝑨+𝑩
A = Number of attempts
B = Number of attempts missed
o Expected PD is 1
Confidence Level

10. Nuisance Alarm Rate (NAR)
o any alarm not caused by an intrusion
o nuisance alarms over a given period
o Causes
- Natural Cause (vegetation - trees and weeds)
- wildlife (animals and birds)
- weather conditions (wind, rain, snow, fog, lightning)
- Industrial causes (ground vibration, debris moved by wind)
- electromagnetic interference

11. False Alarms
o One kind of Nuisance Alarm
o generated by the equipment itself
o Causes
- poor design
- inadequate maintenance
- component failure

12. Vulnerability to Defeat
o Bypass
- have a finite detection zone
- can be defeated by going around
- component failure
o Spoof
- pass through the sensor’s normal detection zone without
generating an alarm

13. Design and Evaluation Process Outline (by Garcia)
Determine PPS
Objectives
Facility
Characterization
Threat Definition
Target
Identification
Design/Characterize
PPS
Physical Protection Systems
Analyze
PPS Design
EASI Model
Adversary Sequence
Diagrams
SAVI Model
Analysis/Evaluation
Risk Analysis
Final
PPS
Design
Redesign
PPS
Delay
Response
Detection
Exterior Sensors
Interior Sensors
Alarm Assessment
Alarm Communication & Display
Access
Delay
Response
Entry Control
Primary Secondary
Deter

14. Types of Sensors based on Location of Use
03

15. Classification of Sensors
01
02
03
04
05
06
07
06
Working
Principle
Application
Principle
Application
Principle
Detection
Principle

16. Types of Sensors both Interior and Exteriors
01
02
03
04
05
06
07
06

17. Ported Coaxial Cables
o Characteristics
- active, covert, terrain-following
- buried underground
- Also known as Leaky coax or
radiating cable
- respond to the motion of material with
a high dielectric constant or high
conductivity
- Ex-Human bodies and metal vehicles
Exterior
Intrusion
Sensors

18. Ported Coaxial Cables
o Affected by
- processor settings
- orientation of the
intruder
- soil characteristics
- Presence of metal
or large amounts
of salt in the soil
Exterior
Intrusion
Sensors

19. Fence Disturbance Sensors
o Characteristics
- passive, visible,
terrain-following
sensors.
- can detect motion
or shock
- aiming primarily to
detect an intruder
who climbs on or
cuts through the
fence
Exterior
Intrusion
Sensors

20. Fence Disturbance Sensors
o Affected by
- wind, debris blown by wind, rain driven by
wind, hail, and
- seismic activity from nearby traffic and
machinery
o Ways to Defeat
- tunneling under the fence or crossing above
the fence without touching it
- Presence of metal or large amounts of salt in
the soil
Exterior
Intrusion
Sensors

21. Fence Disturbance Sensors
o Increase Effectiveness
- use of rigid fence posts and
tight fence fabric minimizes
nuisance alarms
- Installing fence sensors on the
inner fence of a two-fence
system can reduce nuisance
alarms
o Ways to Prevent Defeat
- place concrete under the fence
- put the bottom edge of the
fabric in the concrete
Exterior
Intrusion
Sensors

22. Interior Sensors
Application
Boundary-penetration sensors
Interior motion sensors
Proximity sensors

23. Electromechanical Sensor
Magnetic Sensor
Interior
Sensors
Hall effect
switch
Continuity or
Breakwire
Breakwire grids

24. Microwave Sensors (Motion)
o Characteristics
- Active, visible, volumetric
sensors
- establish an energy field
- relies on the Doppler
frequency shift
- Optimum detection for
microwave sensors is achieved
when the target is moving
toward or away from the
sensor, not across the
detection zone
Interior
Sensors

25. Doppler Frequency Shift
o Characteristics
- change in
frequency of a
wave in relation
to an observer
who is moving
relative to the
wave source.
- establish an
energy field
Interior
Sensors

26. Microwave Sensors (Motion)
o Characteristics
- shape of the detection zone is
governed by antenna design
- Usually like an elongated
balloon
- antenna is usually a microwave
horn
Interior
Sensors

27. Microwave Sensors (Motion)
o Limitations
- may be defeated, if the
target to be protected falls
within the concave portion
of the true pattern.
- penetrates most glass,
plaster, gypsum, plywood,
and other materials used in
normal wall construction
- metal objects reflect the
microwave energy
Interior
Sensors

28. Microwave Sensors (Motion)
o Causes of Nuisance Alarms
- include movement of objects
(nonhuman) within and
outside the detection zone,
- movement of small animals
or birds
- vibration allowed by poor
sensor installation and
mounting.
- The ionized gas in
fluorescent lights can reflect
microwave
Interior
Sensors

29. Passive Infrared Sensors (thermopile or pyroelectric)
o Characteristics
- Passive, visible, volumetric
sensors
- respond to changes in the
energy emitted by a human
intruder
- Detection is based on the
difference in temperature
between the intruder and the
background; this difference is
called the minimum resolvable
temperature (MRT)
Interior
Sensors

30. Passive Infrared Sensors (thermopile or pyroelectric)
o Characteristics
- Long, single- segment
sensors are used to protect
corridors
- Multi-segments are used to
protect large open areas.
- detection pattern is not a
perfect shape
Interior
Sensors

31. Passive Infrared Sensors (thermopile or pyroelectric)
o Limitations
- susceptible to nuisance
alarms from birds and flying
insects.
- nuisance alarm can also
result from an insect
crawling on the lens
- Sunlight passing through
windows can heat interior
surfaces
Interior
Sensors

32. Passive Infrared Sensors (thermopile or pyroelectric)
o Cautions
- should be installed
away from heat
sources
- should not be
mounted over or near
radiators, heaters, hot
pipes, or other
heating elements
Interior
Sensors

33. Dual-Technology Sensors
o Probability
- the probability of A and B
(independent events):
- p(A and B) = p(A) X p(B).
Interior
Sensors

34. Proximity Sensors (capacitance)
o Characteristics
- radiates energy and
detects change in the
capacitive coupling
between an antenna
and the ground
Interior
Sensors

35. Q&A Session

36. 1. Which ensor is working on the principal of doppler effect:
A. Microwave sensors
B. Electric Field or Capacitance sensor
C. Electromechanical transducers
D. Passive Infrared Sensors
Sample Questions

37. 1. Which ensor is working on the principal of doppler effect:
A. Microwave sensors
B. Electric Field or Capacitance sensor
C. Electromechanical transducers
D. Passive Infrared Sensors
Sample Questions

38. 2. A room which is exposed to infrared light, which type of
sensor should not be installed?
A. microwave
B. ultrasonic
C. capacitance
D. PIR
Sample Questions

39. 2. A room which is exposed to infrared light, which type of
sensor should not be installed?
A. microwave
B. ultrasonic
C. capacitance
D. PIR
Sample Questions

40. 3. In dual technology sensor settings the resultant probability
of detection of the system will be?
A. More than the probability of detection of the types
of sensor with higher value
B. Less than the probability of detection of the types of
sensor with lower value
C. Equal to the probability of detection of the types of
sensor with higher value
D. Equal to the probability of detection of the types of
sensor with lower value
Sample Questions

41. Sample Questions
3. In dual technology sensor settings the resultant probability
of detection of the system will be?
A. More than the probability of detection of the types
of sensor with higher value
B. Less than the probability of detection of the types
of sensor with lower value
C. Equal to the probability of detection of the types of
sensor with higher value
D. Equal to the probability of detection of the types of
sensor with lower value