Chapter 6: Intrusion and Contraband Detection Systems

Question 1

Key Point 1

Answer 1

An Intrusion Detection System (IDS) generally includes 1) sensors, 2) annunciators, and a 3) communications or transmission mechanism.

Question 2

Key Point 2

Answer 2

Three main characteristics of intrusion sensor performance are:
Probability of Detection (PD)
Nuisance Alarm Rate (NAR)
Vulnerability to Defeat

Question 3

Key Point 3

Answer 3

NAR is any alarm signal that is not caused by an adversary. Many times, the source of the nuisance alarm condition is known. A False Alarm Rate (FAR) occurs when the source of the alarm is unknown.

Question 4

Key Point 4

Answer 4

There are two ways to defeat a sensor. One was is to bypass, which is where an adversary goes around or beyond a sensor’s capabilities. The second way is to spoof, which is where an adversary goes through the protected zone without an alarm being generated.

Question 5

Key Point 5

Answer 5

At least two continuous lines of protection should be used in high-security applications.

Question 6

Key Point 6

Answer 6

The probability of detection decreases as the time to assess each alarm increases.

Question 7

Key Point 7

Answer 7

Line supervision is the detection communication lines being cut or altered. This is typically accomplished using end-of-line resistors.

Question 8

Key Point 8

Answer 8

PD and Confidence Level (CL) are used to describe the effectiveness of the sensor.

Question 9

Key Point 9

Answer 9

In a dual technology sensor, both sensors have to be activated for the alarm to trip, which reduces the percentage of nuisance alarms, making these sensors a great choice for reliability.

Question 10

Key Point 10

Answer 10

The drawback to dual technology sensors is that the individual technology probability of detection (PD) is reduced because the adversary only needs to defeat one sensor instead of two separate devices.

Question 11

Key Point 11

Answer 11

Microwave sensors use Doppler shift technology. They penetrate most areas and materials and nuisance alarms can be generated from adjacent areas. To limit coverage, use a variable range cut-off circuit.

Question 12

Key Point 12

Answer 12

The higher the resolution of the VMD, the greater the accuracy and performance of the VMD. VMDs typically operate better for interior applications.

Question 13

Key Point 13

Answer 13

nterior sensors may be characterized by three main applications:
Boundary Penetration Sensors
Interior Motion Sensors
Proximity Sensors

Question 14

Key Point 14

Answer 14

In high security applications, a dual technology sensor should not be used in place of two separately mounted sensors due to the reduced PD.

Question 15

Key Point 15

Answer 15

Ultrasonic sensors are susceptible to air movement and should not be installed near stairwells or hallways, but rather into rooms or areas where only infrequent access occurs.

Question 16

Key Point 16

Answer 16

An IDS should have the ability to perform a self-test on a regular basis.

Question 17

Key Point 17

Answer 17

An Alarm Communications & Display (AC&D) system is the part of the electronic security system that transports alarm signals and assessment information to a central point and presents the information to a human operator, typically via a computer monitor display. It collects alarm data, presents the information to a system operator, and enables the operator to enter commands to control the system.

Question 18

Key Point 18

Answer 18

AC&D displays are typically located in the center of the console and should not require much head or eye movement from the operators line-of-sight for the primary interface area (should be within a 30 degree viewing cone).

Question 19

Key Point 19

Answer 19

A magnetometer is often referred to as a “metal detector” but has many differences to the modern-day metal detectors, and should not be used for contraband detection.

Question 20

Key Point 20

Answer 20

Metal detectors are designed to be in close proximity to small amounts of steel and other metals in the surrounding areas; however, a metal detector should not be installed very close or against a steel support beam.

Question 21

Key Point 21

Answer 21

Conventional X-ray detectors may not penetrate heavy metals (like a metal shipping container or some metal compartments in vehicles); however, a high-energy or multiple energy X-ray can be used for such screening.

Question 22

Key Point 22

Answer 22

Quadrupole Resonance (QR) technology uses low radio waves to detect the presence of nitrogen-rich materials, which are found in bulk explosives. QR is compact and has a low cost (about $100,000).

Question 23

Key Point 23

Answer 23

Ramen Analysis uses a spectroscopic technique. It uses laser interrogation, which is followed by a light analysis. It is not suitable for package searches.

Question 24

Key Point 24

Answer 24

Mass Spectrometry (MS) uses magnetic and electrical fields to process ions and determine the mass-to-charge ratio. Considered to be the gold standard.

Question 25

Key Point 25

Answer 25

Canine Olfaction has applications in law enforcement and military for both drugs and explosives and is a good choice when mobility is required. The acquisition costs for the canine are low, but the maintenance, training and handler labor costs are very expensive over time.

Question 26

Intrusion Detection System

Answer 26

A system comprising sensors, controls, and annunciators used to detect an impeding or actual event and alert or notify someone of the detection.

Question 27

Probability of Detection(PD)

Answer 27

PD is always less than 1.0, meaning that no sensor is perfect (1.0 means 100 percent or perfect capabilities). PD often depends on the environmental conditions, system design, target to be detected, installation and the sensitivity setting of sensors, and the weather and condition of the equipment. In addition, a sensor’s PD may vary dependent upon the type of adversary (unsophisticated versus sophisticated).

Question 28

Nuisance Alarm Rate(NAR)

Answer 28

Known as Nuisance Alarm Rate, which is an alarm signal that has a known cause, but that did not detect a specific target or adversary that the system was designed to detect.

Question 29

Transient

Answer 29

A spike in an electrical system. It is often sudden and is caused by lightening.