CCTV-Tech-HBK_0713-508.pdf

System Assessment and Validation for Emergency Responders (SAVER)

CCTV Technology Handbook

July 2013

Prepared by Space and Naval Warfare Systems Center Atlantic

Approved for public release, distribution is unlimited.

The CCTV Technology Handbook was funded under Interagency Agreement No.

HSHQDC-07-X-00467 from the U.S. Department of Homeland Security, Science and Technology Directorate.

The views and opinions of authors expressed herein do not necessarily reflect those of the U.S. Government.

Reference herein to any specific commercial products, processes, or services by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the U.S. Government.

The information and statements contained herein shall not be used for the purposes of advertising, nor to imply the endorsement or recommendation of the U.S. Government.

With respect to documentation contained herein, neither the U.S. Government nor any of its employees make any warranty, express or implied, including but not limited to the warranties of merchantability and fitness for a particular purpose. Further, neither the U.S. Government nor any of its employees assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product or process disclosed; nor do they represent that its use would not infringe privately owned rights.

Approved for public release, distribution is unlimited.

i

FOREWORD

The U.S. Department of Homeland Security (DHS) established the System Assessment and Validation for Emergency Responders (SAVER) Program to assist emergency responders making procurement decisions. Located within the Science and Technology Directorate (S&T) of DHS, the SAVER Program conducts objective assessments and validations on commercial equipment and systems and provides those results along with other relevant equipment information to the emergency response community in an operationally useful form. SAVER provides information on equipment that falls within the categories listed in the DHS Authorized Equipment List (AEL). The SAVER Program mission includes:

• Conducting impartial, practitioner-relevant, operationally oriented assessments and validations of emergency responder equipment; and

• Providing information, in the form of knowledge products, that enables decision-makers and responders to better select, procure, use, and maintain emergency responder equipment.

Information provided by the SAVER Program will be shared nationally with the responder community, providing a life- and cost-saving asset to DHS, as well as to Federal, state, and local responders.

The SAVER Program is supported by a network of Technical Agents who perform assessment and validation activities. Further, SAVER focuses primarily on two main questions for the emergency responder community: “What equipment is available?” and “How does it perform?”

As a SAVER Program Technical Agent, the Space and Naval Warfare Systems Center (SPAWARSYSCEN) Atlantic has been tasked to provide expertise and analysis on key subject areas, including communications, sensors, security, weapon detection, and surveillance, among others. In support of this tasking, SPAWARSYSCEN Atlantic prepared the CCTV Technology Handbook. CCTV Technologies fall under AEL reference number 14SW-01-VIDA: Systems, Video Assessment, Security.

Visit the SAVER section of the DHS S&T website for more information on the SAVER Program or to view additional reports on CCTV or other technologies.

https://www.dhs.gov/science-and-technology/saver ii

POINTS OF CONTACT

National Urban Security Technology Laboratory U.S. Department of Homeland Security Science and Technology Directorate 201 Varick Street New York, NY 10014

E-mail the National Security Technology Laboratory National Urban Security Technology Laboratory SAVER Website

Space and Naval Warfare Systems Center Atlantic Advanced Technology and Assessments Branch P.O. Box 190022 North Charleston, SC 29419-9022

E-mail the Advanced Technology Assessments Branch mailto:saver@hq.dhs.gov mailto:ssc_lant_saver_program.fcm@navy.mil iii

TABLE OF CONTENTS

Foreword i

Points of Contact ii

Preface vi

1. Introduction 1

2. CCTV System Design 1

2.1 Defining System Requirements 1

2.2 CCTV System Design Considerations 3

3. Components of CCTV Systems 9

3.1 Cameras 9

3.2 Lenses 15

3.3 Housing and Mounts 22

3.4 Video Monitors 25

3.5 Switchers and Multiplexers 30

3.6 Video Recorders 32

4. Transmission 36

4.1 Wired Transmission 36

4.2 Wireless Transmission 39

4.3 IP Network Transmission 42

5. Video Storage 44

5.1 Media Storage 44

5.2 Scalable Network Storage 45

6. Video Analytics 46

7. System Integration 46

7.1 Systems Approach 47

7.2 Integrating CCTV Components 47

7.3 Other Considerations 48

8. Emerging Technology 49

8.1 Digital Technologies 49

8.2 Improvements to Existing Technology 50

8.3 Major IT Trends 50

9. Vendor Selection Considerations 50 iv

9.1 Selection Criteria 50

9.2 Vendor Resources 51

Appendix A. Glossary A-1

LIST OF TABLES

Table 2-1. CCTV System Design Worksheet 7

Table 2-2. Sample Site Survey Checklist 8

Table 3-1. Standard Lenses for Image Sensor Size 17

Table 3-2. Calculating the Horizontal and Vertical FOV 18

Table 3-3. CCTV Monitor Technology Comparisons 27

Table 3-4. Video Transmission Signal Display Types 28

Table 3-5. Rear-Projection Monitor Comparisons 29

LIST OF FIGURES

Figure 3-1. CCTV Component Diagram Example 9

Figure 3-2. Color Reference Chart 12

Figure 3-3. Image from Thermal Camera 12

Figure 3-4. Representative CCTV Lens 15

Figure 3-5. Calculating FOV 17 Figure 3-6. Focus Chart Example 19

Figure 3-7. Distortion Comparison 20

Figure 3-8. Approximately 500 Lines of Horizontal Resolution 20

Figure 3-9. Sealed Camera Housing 23

Figure 3-10. Impact-Resistant Housing 23

Figure 3-11. Tamper-Resistant Housing 23

Figure 3-12. Bullet-Resistant Housing 23

Figure 3-13. Camera on Pan-Tilt Head with a Pole Mount 25

Figure 3-14. CRT Monitor 26

Figure 3-15. LED Tiles 30

Figure 3-16. Microprocessor-Based Switcher 31

Figure 3-17. Monitoring Station with Matrix Switcher 31 v

Figure 3-18. Multiplexers 32

Figure 3-19. Hard Drive Recorder for 19-inch Rack 35

Figure 4-1. Coaxial Cable Construction 37

Figure 4-2. Telephone Network Example 38

Figure 4-3. Types of Antennas for RF Transmission 41

Figure 4-4. Typical Microwave Installation 42

Figure 4-5. IP-Based CCTV System 42

Figure 5-1. Storage Area Network 45

Figure 5-2. Network Attached Storage 46

Figure 7-1. Integrated Security System 47 vi

PREFACE

PURPOSE

This CCTV Technology Handbook provides emergency responders, law enforcement security managers, and other security specialists with a reference to aid in planning, designing, and purchasing a CCTV system. This handbook includes a description of the capabilities and limitations of CCTV components used in security applications.

SCOPE

The CCTV technologies described in this handbook include cameras, lenses, monitors, multiplexers, recorders, transmission systems, and Internet protocol (IP)-based systems. This handbook also provides considerations for implementing a CCTV system. An overview of video analytics and programmatic considerations such as design, data storage and retention, cyber security strategies, and system integration is also included. The outlook for new or improved CCTV capabilities is briefly discussed. Information provided in this handbook was gathered from Internet research and consultations with subject matter experts. No assertion is made that this handbook is comprehensive in its breadth or depth. It is introductory-level information and should not be considered a definitive reference for planning or implementing a CCTV system.

Such efforts should be undertaken only in consultation with organizations experienced in the various phases of planning, constructing, testing, operating, and maintaining comprehensive CCTV systems for access control, surveillance, or forensic applications.

The U.S. Government did not conduct independent tests of any CCTV products or systems and does not warrant, guarantee, or endorse any specific products. CCTV technologies under development or restricted to military use are not included in this handbook.

1. INTRODUCTION

CCTV systems provide surveillance capabilities used in the protection of people, assets, and systems. A CCTV system serves mainly as a security force multiplier, providing surveillance for a larger area, more of the time, than would be feasible with security personnel alone. CCTV systems are often used to support comprehensive security systems by incorporating video coverage and security alarms for barriers, intrusion detection, and access control. For example, a CCTV system can provide the means to assess an alarm generated by an intrusion detection system and record the event.

A CCTV system links a camera to a video monitor using a direct transmission system. This differs from broadcast television where the signal is transmitted over the air and viewed with a television. New approaches within the CCTV industry are moving towards more open architecture and transmission methods versus the closed circuit, hard-wired connection systems of the past.

CCTV systems have many components with a variety of functions, features, and specifications.

Key components include cameras, lenses, data distribution, power, and lighting, among others.

CCTV technologies continuously undergo feature refinements to improve performance in areas such as digital equipment options, data storage, component miniaturization, wireless communications, and automated image analysis.

The components, configuration options, and features available in today’s CCTV market create a complex set of purchasing options. It is the intent of this handbook to provide information on the capabilities and limitations of CCTV components that will aid an agency procuring a new CCTV system or upgrading an existing one.

2. CCTV SYSTEM DESIGN

Following a sound design process enables organizations to make purchasing decisions that result in the procurement and installation of a CCTV system that meets functional and operational requirements. As CCTV is part of a multi-layered security approach, a system design should begin with a comprehensive needs assessment to ensure security risks and mitigation plans are identified. Clear requirements, a comprehensive site survey, and proper equipment selection and installation must all be considered when designing a CCTV system.

2.1 Defining System Requirements

In order for an organization to properly implement a CCTV system, site-specific characteristics need to be assessed by a knowledgeable multidisciplinary team of personnel. This team is critical to identifying key functional and operational requirements. Functional requirements consist of determining the area of surveillance, such as a perimeter area or an access point.

Operational requirements define what information a CCTV system will be expected to provide given the existing operating conditions.

2.1.1 Multidisciplinary System Design Team

Organizations should begin by establishing a team of people with relevant knowledge to help guide the CCTV system design process. The system design team should be involved in all phases of the project to include: needs assessment, requirements development, system design and layout, procurement, installation, and final check-out of the system. Personnel should be included from varied internal disciplines such as security, facility maintenance and management, and those who work directly with assets on-site or in controlled monitoring environments. The team may opt to consult with external subject matter experts, such as electricians, systems engineers, and information technology (IT) professionals.

2.1.2 Needs Assessment

A thorough risk and needs assessment should be conducted to identify locations or assets that will benefit from CCTV surveillance as part of an overall security approach. Organizations can enhance the security of facilities and critical infrastructure most effectively by defining their overall goals and objectives for CCTV systems in terms of the requirements within their operational environment.

A needs assessment gathers and analyzes four sets of requirements: functional, operational, infrastructure, and video retention.

• Functional requirements–Define camera coverage needs such as surveillance of perimeters, parking lots, and storage areas; surveillance of approaches to, and spaces within, buildings or other structures; and surveillance of waterfronts;

• Operational requirements–Define the capabilities of the CCTV system components that will enable it to provide the expected information under all operating conditions.

Conditions to consider in the operational environments include day and night operations, lighting, weather conditions, and temperature changes. It is important that operational requirements are detailed and testable. For example, waterfront surveillance may demand that the CCTV system provide a recognizable image, during day or night, of any type of surface watercraft operating at speeds between 0 and 60 knots in wave heights of up to 6 feet while within 500 yards of a pier;

• Infrastructure requirements–Define needs for installing or accessing fiber or hard-wire cables, wireless networks, and power sources, to name a few, necessary to successfully implement an integrated CCTV system; and

• Video retention requirements–Define the organization’s video retention and storage needs.

2.1.3 CCTV Site Survey

A CCTV system’s effectiveness can be enhanced when integrated with access control, intrusion detection, or duress systems. Successful integration requires a comprehensive site survey which supports the development of detailed equipment specifications, installation design, and ultimately a thorough system test.

A site survey should address all aspects of specifying and building a CCTV system and it is an integral part of defining the requirements for discrete tasks and the role of each piece of equipment. Whenever possible, CCTV systems should be included in the planning and design stage of any new asset to ensure all necessary infrastructure requirements are adequately incorporated into the overall facility or asset design.

The result of a comprehensive survey of the area in which a CCTV system is to be installed or upgraded provides input to the requirements and design process. Considerations inherent in a site survey include the number of operators, local and remote operator consoles, layout, light levels, camera and lens selection and location, and power and data transmission.

2.1.4 System Layout Considerations

A key input to the design and specification of the layout of an outdoor CCTV system is the site survey team’s collection and analysis of aerial photographs. Images can be obtained from a wide variety of sources such as satellite photographs, local government files, privately contracted aerial photography services, and a host of free web-based mapping applications. Aerial photographs can provide information regarding on-site distances and blind areas where outdoor video coverage may be needed. Additionally, aerial photographs and detailed maps can be used during the design of the system to overlay alarm and video information useful for planning the dispatch routes of response personnel.

Interior surveys are similar to exterior surveys. Aerial photographs can be replaced with scaled computer aided drawings or blueprints of the facility being surveyed. These can be used to mark potential camera site locations to identify the necessary coverage of access points, critical assets, and desired fields of view. A camcorder is often used to determine camera positions and evaluate video images from proposed camera locations.

An important factor in the design and layout of a CCTV system is the location of its transmission hubs. Transmission routes channeled through a primary transmission hub could lead to a single point of failure in which an outage of one transmitter could disable the transmission of data from other camera sites.

2.2 CCTV System Design Considerations

System design considerations include factors such as lighting, power, transmission, and cost.

These factors are important in the design and layout of a CCTV system. In addition to these factors, camera types, lenses, monitors, multiplexers, and other components are also important considerations, and are discussed in Section 3.

Selection of the CCTV components is an iterative process that takes place in conjunction with the design phase. Section 3 contains more details on common component features and specifications that should be considered when selecting equipment for a CCTV system.

2.2.1 Lighting

Lighting strategies, camera selection, and camera location should be considered together in the design of a CCTV system to ensure optimum performance and to prevent operational environment conflicts. Light (or illumination) levels, both natural and artificial, affect system requirements at different times of the day for exterior systems. Exterior cameras often require lenses with automatic apertures to compensate for changes in light levels. Interior cameras may require internal software to compensate for backlight, which is the contrast between low interior light levels and high exterior daytime light levels. For example, backlight compensation allows security personnel to see details of a person moving in front of a brightly lit window. Artificial lighting can affect the appearance of the image as well as the operation of the CCTV system.

Types of artificial lights include:

• Fluorescent–Primarily used for indoor areas in the United States, these lights produce a 60-hertz (Hz) flicker that can interfere with image quality;

• Incandescent–Include halogen bulbs and are used to illuminate large outdoor areas.

Incandescent lights consume more power than other lighting types and are generally the most expensive to operate;

• High-intensity discharge (HID)–Include high- and low-pressure sodium and metal-halide lighting and are the least expensive to operate. Low-pressure sodium lights produce a yellow light that may distort true color reproduction on video.

Metal-halide lights provide the best color resolution. These types of lights require a few minutes to reach their full luminance once turned on;

• Infrared (IR)–Emit light at a much longer wavelength than white lights, and are faintly visible to the human eye as a red glow or they are not visible at all. IR lighting provides a longer illumination range than white light and can be used for discrete or covert CCTV system illumination. IR light can be provided by light emitting diodes (LEDs) and lasers as well as filters on incandescent bulbs; and

• LED–Provide high levels of brightness and intensity. These lights are highly efficient, and generate low levels of radiated heat. As such, they are increasingly used in CCTV systems.

It is important to verify that the selected lighting technology sufficiently illuminates the area of interest to meet the operational requirements. An overview of CCTV illumination is provided in the Illumination for Closed Circuit Television Surveillance Systems TechNote. Detailed information concerning lighting as it applies to security systems is available in the Security Lighting Guide. Both of these documents can be found in the the SAVER section of the DHS S&T website.

2.2.2 Power Distribution

A number of considerations must be taken into account when designing the power distribution system. Therefore, it is prudent to consult licensed engineers and electricians in the design and installation of a CCTV power distribution system.

Inadequate power is one of the most common problems with CCTV equipment and can often be the cause of erratic or sporadic equipment behavior. Proper system performance requires a clean, adequate power source. For example, it is possible for power to fluctuate considerably on hot days when air conditioning units overload power grids. Therefore, agencies should plan accordingly and specify power conditioning or backups as needed. The stability of the input power to CCTV equipment can be determined by taking several readings of the voltage and current levels over a short time period, or by using a voltage recorder for long-term monitoring.

An inadequate power system can affect the quality of the video across the entire system.

Placement of power components is an important design consideration. Placing low-voltage power components near high-voltage lines can induce currents in the low-voltage system, presenting a hazard to personnel and equipment. Alternatively, placing a power source too far away can cause power fluctuations and also drive the installation costs up due to the larger conductor sizes needed to reduce voltage drop over long distances. Therefore, it is advisable to locate power sources close to CCTV equipment. In addition, uninterruptible power supplies (UPSs) are beneficial in protecting equipment and conditioning the power. Since there are many types of UPS products on the market, it is important to find models appropriate to the application. Determinations about backup power requirements during a power interruption are also important. For example, some CCTV systems may have designated primary cameras focused on critical access points with a need for longer term backup power than secondary cameras such as those within internal corridors.

Voltage spikes and lightning are common phenomena affecting CCTV systems. Lightning, a common cause of voltage spikes, may cause failures and disable major pieces of equipment in buildings. When designing a system, all pieces of electronic equipment should have sufficient lightning suppression to help reduce damage and failures. Ground loop correctors help prevent voltage differentials between two or more installations or pieces of equipment powered by separate power sources (i.e., the ground loop corrector puts the separate pieces of equipment at the same ground potential).

Components of a CCTV system should ideally have an internal regulated power supply;

however, this feature is often eliminated to reduce cost. This is particularly likely with low cost cameras. There are power supplies available that distribute individually fused and regulated feeds for each camera from a central location.

2.2.3 Video Transmission

Selecting the appropriate video transmission media, such as coaxial cable or unshielded twisted pair (UTP), is one of the most important aspects of designing a quality CCTV system. A system may include the highest quality hardware components available, but if the video signal is not transmitted by the proper media, overall performance could be degraded. Many common problems with video image quality can be avoided by selecting the appropriate transmission media and following proper installation techniques and procedures.

As CCTV technology has evolved, video transmission has progressed from analog to digital transmission. New cameras with Internet protocol (IP) capability transmit compressed video as digital data. A drawback of IP transmissions is that video places a high demand on a network’s bandwidth, and the tradeoff may be image quality. One potential solution for this issue is to separate the video stream from the primary network. Section 4 provides a more detailed discussion on video transmission and IP-based CCTV systems.

2.2.4 Scalability

Scalability of CCTV systems refers to the ability of the system to accommodate additional components such as cameras, increased video storage, and additional monitors. Large facilities often implement CCTV systems in stages due to budget limitations or in order to verify system performance. The ability to easily incorporate hardware and software updates should be a consideration of a CCTV system design.

2.2.5 Cost

Cost estimates for a CCTV system should cover all aspects of the system’s life cycle including planning, design, installation, operation, maintenance, and personnel costs. In addition, long-term personnel costs, such as initial and refresher training programs should be included.

Hardware and software upgrades should also be a cost consideration.

Using existing CCTV infrastructure such as cameras, camera mounts, and cable runs may reduce costs. However, as the capabilities of cameras and information handling components of CCTV advance, replacing old equipment and infrastructure may improve system performance and be a more cost-effective solution.

2.2.6 Infrastructure

Each camera deployed in a CCTV system requires power and the means to transmit video data to monitoring and storage systems. These requirements can necessitate modifications to a facility’s infrastructure, such as installing new poles for mounting cameras. When planning a CCTV installation, there are four important considerations:

1) To what extent can the system use existing infrastructure?

2) To what extent can the new CCTV system integrate with existing enterprise systems?

3) To what extent can the new CCTV system integrate with or complement other existing or planned intrusion detection and access control systems?

4) To what extent can the new system operate in parallel with existing systems and which system will influence operational procedures and response?

Employing existing infrastructure is an important factor in controlling equipment and installation costs. For example, old coaxial cable systems can be converted to IP systems by running Ethernet over coaxial cable with a converter module. Analog video and Ethernet can also be run over telephone lines.

The extent to which a CCTV system integrates with the overall security program will be a major factor in its effectiveness. Any new installation should operate in parallel with existing systems until the new system is accepted and the old system upgraded or phased out. See Section 7 for more details on system integration.

2.2.7 Reliability and Maintainability

Predicting the reliability and maintainability of a new CCTV system is difficult without a demonstration period. Primary reliability and maintainability considerations include whether the new system will be able to perform the required functions over time and to what degree personnel can operate, maintain, and upgrade the system. Several techniques may be used to improve user confidence in a new installation, including:

• Conferring with security and management personnel at other facilities that have implemented similar systems or used the same vendor;

• Requesting competing vendors to run trial programs on-site or bench test equipment prior to installation; and

• Installing new equipment on a small scale in order to verify that performance meets the organization’s needs.

Vendor warranty terms may require that all technicians working on equipment be certified.

Some vendors may require a maintenance contract to ensure they have staff available to respond within a specific period of time. The support requirements should be understood prior to purchase and installation of equipment. See Section 9 for more details on vendor selection considerations.

2.2.8 Annunciation, Assessment, and Response

The role of many CCTV systems in a comprehensive security program is to aid security personnel. For instance, when a security alarm occurs at a location not currently displayed on a monitor; the system can alert the operator by automatically switching the display to the location of the security alarm. The operator can then assess the security alarm visually and dispatch appropriate response forces.

2.2.9 Requirements and Design Worksheets

Table 2-1 lists basic questions to determine high level CCTV system requirements and to influence the system design.

Table 2-1. CCTV System Design Worksheet

Basic Questions for Addressing CCTV System Requirements

1) What areas require coverage by the CCTV system?

2) What are the highest value assets that need to be protected? For example:

• High-value material property;

• Critical infrastructure;

• Intellectual property; and/or

• Classified material or intelligence information.

3) Where are the sites of greatest vulnerability?

4) Does the information technology infrastructure adequately support the number of cameras?

5) Will the system integrate with an existing physical security system?

6) Will the system integrate with an existing electronic access control system?

7) Does the security budget cover regular maintenance, training, and upgrades to the system?

8) Does the system’s installer/vendor provide adequate training to operate the system?

A sample checklist containing some of the factors to consider during a site survey is provided in Table 2-2. This checklist can be used by the design team to record the number and type of cameras, monitors, and housings as well as address connectivity requirements.

Table 2-2. Sample Site Survey Checklist

Operational Environment Indoor Outdoor

Exposure to:

Water Corrosives Explosives Fire Extreme Temperatures

Location of Cameras Access Points: Doors/Gates Building Exterior High-Security Interior Areas High-Security Exterior Zones Hallways/Corridors Parking Lot Perimeter Other

Light Levels Day Night

Lens Wide Angle Normal Telephoto Zoom

Camera Power 12 Volts Direct Current (DC) 24 Volts DC 120 Volts Alternating Current (AC)

Cameras Indoor

Fixed Pan-Tilt-Zoom Outdoor

Fixed Pan-Tilt-Zoom *Total Number of Cameras

Housings Dome Weather-Resistant Tamper-Resistant Other (e.g., Specialized Housings)

Mounts Wall Ceiling Pole Corner Fences Building Exterior

Display/Monitors Size _______ Split-Screen Displays Multi-Screen Displays Video Walls

Recorders Digital Video Recorders (DVRs) Network Video Recorders (NVRs) Hybrid DVRs

Transmission Wired

Coaxial Twisted Pair Fiber Optics Telephone Category 5

Wireless Laser Infrared Radio Frequency Microwave

IP-Based Internet Protocol (IP)-Based

Network Storage Direct Attached Storage (DAS) Storage Area Network (SAN) Network Attached Storage (NAS) Other

3. COMPONENTS OF CCTV SYSTEMS

CCTV uses components that are directly connected to generate, transmit, display, and store video data. A CCTV system can be as simple as a camera purchased from a retail electronics store connected to a video monitor. However, larger systems operated by professional security personnel are comprised of a number of components falling into several basic categories:

• Cameras;

• Lenses;

• Housings and mounts;

• Monitors;

• Switchers and multiplexers; and

• Video recorders.

Many features exist within each of these categories that can satisfy an agency’s operational requirements in the most challenging environments. The most complex CCTV systems may incorporate hundreds of cameras and sensors integrated into one overall security network.

Figure 3-1 provides a CCTV component diagram example.

Figure 3-1. CCTV Component Diagram Example

Most new CCTV systems maximize the advantages of digital technologies by utilizing electronic databases, compact components, and wireless transmission techniques. With larger quantities of data being collected, it is essential that the system be capable of retaining data in accordance with the organization’s policies and procedures.

3.1 Cameras

Cameras are an essential component of any CCTV system. Matching the right CCTV camera to a particular application is increasingly complex due to rapid technological developments and a greater range of applications. A system’s performance is affected by many factors beyond those listed in the vendor data sheets. Effective camera selection requires detailed knowledge of the camera, application, supporting architecture, and host environment.

All CCTV cameras include three basic elements:

• Image sensor–Converts light (photons) into electronic signals;

• Lens–Gathers light reflected from a subject and focuses the light on the image sensor;

and

• Image processing circuitry–Organizes, optimizes, and transmits video signals.

The type of camera best suited for a CCTV system depends on the operational environment and how it will integrate into the system. The answers to the following questions may help determine the best camera type:

• What is the desired image quality?

• What size is the desired field of view (FOV)?

• How much lighting is available?

• Will the camera be installed indoors or outdoors?

• Will the video be monitored on a full time basis?

• How will the video be transmitted?

• Will the camera be exposed to extreme conditions?

There are many types of cameras designed to perform under specific environmental conditions but cameras can be grouped into two primary categories: fixed and pan-tilt-zoom (PTZ). Fixed cameras are intended to constantly view a single scene, while PTZ cameras are motor driven and can pan left or right, tilt up or down, and zoom in or out to instantly customize the view as needed. A combination of fixed and PTZ cameras are often used to provide the required surveillance coverage.

3.1.1 Fixed Cameras

Fixed cameras are mounted in a stationary position and are focused on a single FOV, typically one particular area of interest. These cameras can be used indoors or outdoors and can be installed overtly or covertly. Fixed cameras vary in size and can be mounted in a wide range of locations (e.g., inside cabinets or control panels, or on poles, fence lines, or roofs).

Fixed cameras can be integrated with an electronic security system (ESS) and used to assess ESS alarms. For example, a fixed camera can surveil a secured gate but only record data when the gate opens, triggering an alarm. Fixed cameras are usually less expensive than PTZ cameras and require less maintenance as they have fewer moving parts.

3.1.2 PTZ Cameras

PTZ cameras come in a variety of sizes and shapes for interior and exterior uses. Typically, a PTZ camera can be turned and tilted on two axes to provide pan and tilt capabilities and the focal length of the lens can be varied to change the FOV. This enables PTZ cameras to offer more flexibility for viewing and capturing images in real time than fixed cameras. PTZ cameras can be operated manually or in an automatic scan mode, thus capturing the most relevant video possible.

In manual mode, the operator can control the direction of the camera depending on situational needs and zoom in on an object (e.g., a suspicious bag, a person’s facial features, or a license plate) to capture specific details of interest.

PTZ cameras can also be configured to automatically scan back and forth over a wide area that cannot be covered by a single fixed camera. Preset positions can be programmed to switch views based upon specified time segments. For example, a PTZ camera could be programmed to change its view every 10 seconds to capture different areas of interest within the camera’s overall surveillance area.

3.1.3 Connectivity Type

CCTV cameras may employ one of two types of data transmission:

Network Cameras–Network cameras connect to IP-based networks, including the Internet, and provide remote viewing and recording. Network cameras are also available in high definition (HD) which can provide greater image detail.

Analog Cameras–Despite increasing use of digital network cameras, a market for analog cameras still exists. This may be due to the cost involved in upgrading and converting to a new transmission process. Analog cameras have options for high resolution, making them applicable for various surveillance needs. These cameras also have some cyber security advantages because the coaxial cable they are connected with would require physical access to breach.

3.1.4 Day/Night Cameras

Day/night cameras offer flexibility by automatically adjusting to current lighting conditions.

These cameras capture color images in daylight and switch to black-and-white to improve image quality at night. The camera relies on an analysis of the current image or a photoelectric sensor to determine when to automatically remove the infrared-cut filter and switch to monochrome settings.

3.1.5 Low-Light or Night Vision Cameras

Cameras used to capture images in dark environments are either low-light or night vision cameras.

Low-light cameras are designed to perform in some level of ambient lighting, such as indoor restaurant lighting, street lamps, or a full moon; they are not intended for use in complete darkness.

Night vision cameras used in CCTV systems typically consist of near-infrared (NIR) and IR cameras with built-in IR illuminators. They are designed to allow the operator to view night scenes. The distance from which a CCTV camera can detect objects at night depends on the capability of the camera components, such as the lens and sensor, as well as on the intensity of the IR illuminator used. The IR light emitted from these illuminators can be at wavelengths that are invisible to the human eye.

The primary determinant for whether a camera transmits an image in color or monochrome (varying tones of a single color) is the camera’s image sensor. Monochrome cameras record images using light in NIR wavelengths outside the range of human perception (i.e., spectroscopic) while the image sensor of a color camera uses filters on the individual light sensitive elements of the image sensor to limit that element to specific color wavelengths. These filters allow the sensor to detect and transmit color in addition to light intensity, which is what an unfiltered, monochrome sensor would detect.

Color cameras are used in daylight and well-lit night situations.

There are many applications in which accurate reproduction of color is important. Color reference charts like that shown in Figure 3-2 provide an accurate color source for the selection/evaluation of cameras and optics. CCTV installers and technicians often use a color reference chart to assess the colors in an image. In addition, waveform generators and vector scopes are also used to measure system performance. It is important to remember that video monitor color reproduction is also critical.

Figure 3-2.

Color Reference Chart

Monochrome cameras can capture images at night or in near-dark conditions that have more detail than the human eye can perceive. However, images captured with a monochrome camera during the day may lack some contrast and detail because the image is formed from visible and infrared light, which have different planes of focus. Monochrome image sensors are made mostly of silicon and germanium material and have two different spectral responses. This allows the image sensors to perform well in the infrared light region.

3.1.6 Thermal Imaging Cameras

Some operational environments may require a thermal imaging camera to detect through obstructions such as fog or smoke. Thermal imaging cameras detect infrared or heat radiation that is invisible to the human eye. Currently these cameras are sensitive to a temperature difference of one tenth of a degree Fahrenheit. Thermal imagers cannot detect through glass or water, but can provide an image through limited density fog or smoke.

Many thermal imaging cameras have built-in image processing to create images with improved contrast, like that shown in Figure 3-3. This provides better feature definition and sharper, clearer images. Thermal cameras are often mounted in gyro-stabilized, pan-and-tilt devices as well as on boats and helicopters for night surveillance in poorly lit areas. They are also available as small handheld units with built-in displays, which can be used in safety, security, and emergency responder applications.

The image sensors in thermal cameras can degrade, so it is important to consult with the camera manufacturer to determine performance characteristics over time and to budget for the cost of periodic maintenance and replacement. Figure 3-3. Image from

Thermal Camera 3.1.7 Miniature or Covert Cameras Special applications may exist that require the installation of small, hidden cameras as part of a CCTV system. These cameras are not usually weather resistant, so they may require an external housing if they are to be used outdoors. These cameras are typically battery operated and may use built-in transmitters to provide a compact wireless solution. Organizations can choose from many types of miniature and covert cameras depending on their requirements.

3.1.8 Optional Camera Features

CCTV cameras can include a variety of optional features to meet the specific needs of the operational environment. Some of these common features are described below.

Auto Scan–Some PTZ cameras can be programmed to perform automated functions. Auto scan is the term used to describe a constant cycle of sweeping through the surveillance area.

Preset–A preset is a programmed orientation and lens setting, which a PTZ camera moves to either periodically or when a certain type of event occurs. For example, during an intrusion alarm, a camera can be preset to display the high-value assets in the surveillance area or to focus on the access point where the alarm was triggered.

Privacy Masking–A camera with privacy masking capability can selectively block portions of the video image for the purpose of protecting privacy. For example, PTZ cameras may be used to monitor a parking lot adjacent to an apartment building with the images of the windows in the building masked. This is a feature of the system configuration (software or hardware) and can be complex and costly.

Slip Ring–A slip ring is an electrical connection that allows a PTZ camera to turn without twisting the signal/control cable. Slip rings can use light beams to optically transmit the image, or use a sliding brush contact on a base ring to create an electrical path. Slip rings tend to be sensitive to contamination and temperature changes.

Motion Detection–Cameras can be equipped with built-in motion detection features, which can be programmed to trigger an alarm if motion occurs within the FOV. The alarm can be programmed to trigger recording, alert an operator, or both. Motion detection features can also result in nuisance alarms if the environment has natural movement.

Backlight Compensation (BLC)–Some cameras have built-in BLC settings. BLC can compensate for the high contrast of images with a bright background and enhance the image detail accordingly. For example, BLC allows security personnel to see details of a person moving in front of a brightly lit window.

Digital Noise Reduction (DNR)–This feature is common for cameras intended to capture images in low-light or dark environments. DNR removes the noise (grainy appearance displayed as spots known as “raster”) from the video image. This makes the image clearer, brighter, and easier to interpret. Less digital noise can also reduce storage space requirements since there is less extraneous information in the video.

Mobile Compatibility–This application enables remote viewing of video on mobile devices such as smartphones, tablets, and laptops. Some remote viewing methods require special camera software or hardware while other methods and applications can be configured to connect directly with a camera and do not require a personal computer (PC).

3.1.9 Types of Image Sensors

CCTV cameras commonly use charge-coupled device (CCD) or complementary metal oxide semiconductor (CMOS) image sensor technology. The smallest part of an image produced on a solid-state chip is the picture element, or pixel. Regardless of the sensor type, pixels are engineered in number, size, and filtration to provide different resolutions, light sensitivity, and spectral responses.

3.1.9.1 Charge-Coupled Device Sensors

Cameras that use CCD image sensors entered the CCTV industry in the mid-1980s and now dominate the market for daylight and low-light, or NIR cameras. CCD technology has many advantages over the tubes used in the earliest video cameras. CCD image sensors are smaller, generate less heat, and their captured images are less susceptible to “blooming.” Blooming occurs when the image sensor is overwhelmed by a high-intensity light source in the FOV and eliminates details in other parts of the image. The life expectancy of a CCD camera ranges from 5 to 25 years.

CCDs consist of a three-dimensional array of pixels, each of which generates an electrical signal proportional to the quantity of light it receives. This analog electrical signal is transferred to another chip where it is converted to digital information. This digital information is processed within the camera and then transmitted to other components of the CCTV system. Some cameras convert the processed signal to analog video prior to transmission.

The surface of the type of CCD used in CCTV cameras resembles an aerial view of a very orderly city. Each of the rooftops represents a light-sensitive element, while the streets represent the electronic timing and control circuits. The proportion of the rooftops (sensor elements) to the streets (circuits) determines the sensitivity to light and the resolution of the CCD. A greater area devoted to sensor elements results in a camera with high sensitivity and finer resolution. Smaller proportions result in lower sensitivity and a more coarse resolution. In addition, some manufacturers offer CCDs with a lens capability for sensor elements to gather more light and increase sensitivity.

Although CCDs are sensitive to visible light, they are also sensitive to NIR light. A sensor’s spectral response is a function of the chemistry of some components and can be further manipulated with filtering technologies. Filters designed to reduce or eliminate IR light, known as “infrared-cut filters,” can be used in front of the sensors to improve a color camera’s image (see Section 3.6.2.8 for a more detailed discussion on filters). Monochrome cameras do not have such filters because they are intended for use near the IR spectrum. During the day, monochrome cameras form an image using both visible and NIR light; therefore, the daytime image may lack some clarity compared to nighttime images.

In order to increase the resolution, some cameras use three CCDs. In this configuration, a prism splits the white light passing through the lens into red, green, and blue. Then, three monochrome CCDs, each filtered to receive one color, calculate and combine the vector output to create a high-resolution image. The same principles can be applied to cameras utilizing three CMOS sensors.

3.1.9.2 CMOS Sensors

Applications requiring high-quality images tend to rely on CCD sensors, but CMOS sensors are commonly used in applications such as network cameras, PC peripherals, and smartphones. This is a result of CMOS sensors using less power than CCDs and being less expensive to manufacture.

Unlike CCD sensors, CMOS sensors address each pixel individually. They process the charge from each pixel on the sensor and transmit a digital bit of information. This technique reduces the need for additional processing along the transmission pathway. CMOS sensors use less power than CCDs because a larger area of the chip is devoted to processing circuits.

3.2 Lenses

The lens on a CCTV camera is the first element in the imaging chain, which consists of the lens, camera, transmission system, image management and analysis software, and monitor. The lens focuses light or IR energy onto the imaging sensor. A lens’s role is to deliver an undistorted, evenly focused, accurate image to the imaging sensor. Systems that require superior quality images start with lenses engineered to produce a high-quality image for the imaging sensor. Other components of the imaging chain cannot compensate for an inferior lens.

Figure 3-4. Representative CCTV Lens

Variables to consider when selecting a lens include the distance required to clearly focus on objects, FOV, size of the camera’s image sensor, and lighting conditions. Lenses are identified by their focal length, usually stated in millimeters; largest aperture, usually stated as an f-number; and the size of the image sensor for which it was designed.

3.2.1 Types of Lenses

Lenses are available in three basic types: fixed focal length, varifocal (variable focal length), and zoom. The focal length of a lens is the distance between the optical center of the lens and the image plane. The lens focal length and the image sensor size determine the camera’s FOV.

3.2.1.1 Fixed Focal Length Lenses

Fixed focal length lenses are built with one set, unchangeable, focal length. Such lenses are useful in situations where the camera remains in a fixed position and the requirements to observe an area do not change.

3.2.1.2 Varifocal Lenses

The focal length of varifocal lenses can be changed within a specific range; however, each change must be accomplished by hand at the camera. In addition, each time the focal length is changed, the iris and focus may also need adjustment. Varifocal lenses offer the flexibility of varying the scene content and are relatively inexpensive when compared to conventional zoom lenses. Once the focal length and iris are set, the camera will maintain the FOV. Varifocal lenses are identified by the focal length range, aperture range, and size of the image sensor the lens is designed for.

3.2.1.3 Zoom Lenses

Unlike the varifocal lens, the zoom lens is designed to maintain the focus setting throughout the focal length range. Zoom lenses in the CCTV industry are often built with integral motors to enable changing the focal length from a remote location. They are used on cameras that monitor different parts of a scene or can pan and tilt to monitor different locations. Zoom lenses are identified by their focal length range, aperture range, and the size of the imaging sensor the lens is designed for.

3.2.1.4 Optical Versus Digital Zoom Ranges

The focal length ranges for varifocal and zoom lenses denote optical focal length ranges, which are a function of the components of the lens. The zoom range is referred to both as a specific range of focal lengths, such as 6 to 24 mm, and as a zoom factor, such as a 4x (four times) multiplier. For the aforementioned focal length range of 6 to 24 mm, the zoom factor is 4x (6 x 4 = 24). It should be noted that zoom factor is not an indication of image magnification;

zoom factor is only indicative of the focal length range.