Man or a Gorilla? Performance Issues with CCTV Technology in ...

Man or a Gorilla? Performance Issues with CCTV Technology in Security Control Rooms H.U. Kevala, M.A. Sassea. a

Department of Computer Science, University College of London, London, WC1E 6BT, UK

Abstract Despite increased usage of CCTV, and technological advances of surveillance systems, there is still relatively little understanding of how well it actually works for the many purposes for which it is deployed. Most purposes require that humans detect and respond to events in an appropriate and timely fashion. From a human factors and Human Computer Interaction (HCI) perspective, it is important to identify whether CCTV systems support human operators effectively, and are fit for the purpose. To answer this question, we take a SocioTechnical System (STS) perspective of CCTV: any system is deployed for one or more purposes, and has a number of stakeholders, who carry out a number of activities. In this paper, we focus on one set of stakeholders - CCTV operators, and examine the activities they carry out in control room environments. We use observations and interviews to identify issues they encounter in the operation of the system. Our results show that task performance is currently impaired because of high screen to operator ratio, absence of camera maps, or lack of integration with other databases. Findings in this paper present the challenges CCTV operators are faced within complex city centre control room environments. Keywords: CCTV, Control Rooms, Human Factors, Human Computer Interaction, Socio-Technical System.

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Introduction

Existing research in the domain of video surveillance predominantly looks at the impact of security and surveillance schemes on crime rates, and the perception of town security systems by the public [1,2]. The technological shift of CCTV from analogue to digital has created many opportunities for a large number of stakeholders, including business owners, council authorities, control room managers, security consultants,

installers, and manufacturers. CCTV was used first in 1961 in a London underground train station, and its primary purpose was for train drivers to check if carriage doors were clear before moving off. Today, video surveillance is used for a variety of purposes and many users have different goals for their systems. For example, street surveillance today CCTV is typically used for identifying antisocial behaviour, drug-misuse and dealing, missing persons and so on. It is also used for capturing evidence for criminal investigations and presenting

CCTV evidence to court for prosecution purposes. Changes in technology capabilities have meant that video can now be integrated with other security technologies, such as face recognition, motion detection, person and vehicle tracking and also with ANPR (Automatic Number Plate Recognition) systems. Digital video security systems are also capable of being used as a piece of remote technology. For instance, IP (Internet Protocol) surveillance systems can be used to view an entire city centre from several locations without needing to dig roads and lay cables from cameras to control centres. As the number of CCTV uses become widespread, so does the number and range of stakeholders. For systems to be used effectively, it is essential that the tasks the system requires the observer to perform are understood and supported adequately. Usage scenarios are now varying from highly trained CCTV users, such as the police and forensic experts who use post-recorded CCTV surveillance footage for identification purposes, right through to untrained users, such as the general public who use video for identification and protection purposes. A recent pilot scheme for selected East London residents has allowed the public to view surveillance footage from their television sets. They can view suspicious characters and compare them with an on-screen ‘rogue gallery’ from the comfort of their own living-rooms. This is an example of how CCTV is now being used by untrained public users, not only by the police and the control room operator.

street surveillance system. This test image was provided with permission by the Home Office Scientific Development Branch (HOSDB). This image is unusable because specific face and vehicle information is clearly difficult to identify. Facial features such as: eye colour, face shape, scars and moles as well as hair style and colour would be very hard to make out from this image. The quality of the CCTV video operators work with, are generally quite good. This is because CCTV cameras are directly connected to the control room showing live surveillance video footage, where operators can act upon immediately if required. However, surveillance video that is recorded onto a digital video recorder (DVR) hard disk that is excessively compressed to reserve disk space or transmitted over a limited network will mean that images will be unusable for key observation tasks, i.e. object and people recognition and identification. There are a large number of set-up variables that can affect the end quality of surveillance video. Poor image quality can be a result of the way in which the user sets up the systems within the chosen environment - some of these variables include: cameras positioned and located poorly, not fit for the environment, incorrect configuration, low quality recording equipment, excessive digital video compression and so on.

1.1 CCTV Observation Tasks CCTV video systems are often poorly set-up. Consequently poor quality images are produced, making the process of identifying unfamiliar faces from surveillance footage extremely difficult [3, 4]. Mead [5] stated that video recordings that are used for eye-witness identification purposes can be of no value to the court if the ‘recording is of such poor quality.’ The effects of poor video quality have already created problems for several criminal investigations see [5] for an overview. Figure 1 shows an example of a poor quality CCTV image which has been recorded from a

Fig. 1: Example of an unusable CCTV image Currently, we do not have a framework for understanding how CCTV needs to be configured to support different users performing different tasks. The intention of the research described in this paper is to create that basis. In order to identify the observation problems encountered by

users, this research focuses on one particular stakeholder - the CCTV control room operator in city centre control rooms. As well as problems with tasks, the challenges operators face with control room technology was examined. 2

Related Work – CCTV Control Rooms

Most control room research has focussed on control room operations and working practices in complex industrial environments, such as power plants and transport control rooms. However, very few HCI studies have been conducted in control room environments. Those evaluations that have been conducted in security control room environments have studied the overall effectiveness of CCTV, to assess critically government and police claims that CCTV cameras are highly effective, both in reducing crime and the ‘fear of crime’ among the general public [1, 2, 6, 7 and 8]. A recent ethnographic control room study by Gill [1, 2] assessed the overall effectiveness of CCTV control rooms around the UK, which were mainly CCTV schemes set up under the Home Office Crime Reduction Programme. Various issues such as ownership, design, management, working practices, communication, and the processing of CCTV evidence were examined. Gill’s study focussed on a wide variety of operator issues such as training, pay rates, and communication with external agencies. Very little emphasis was placed on how well operators performed tasks in the control rooms. Gill’s findings were mainly based on observations, and very few one-to-one interviews with operators, managers and other primary stakeholders were made. Furthermore, the issues concerning task performance were not accounted for in the study. Luff and Heath [9] examined how control room personnel utilised technologies to support their everyday work activities within a London Underground control room environment. The work here fundamentally examined how individuals ‘monitor’ their surrounding domain and activities. It was found that the technology operators were using were in fact difficult to manage simply because “there were so many separate interconnected systems.” Luff argued that staff

members see the technology systems as straightforward, however “the use of these systems are thoroughly embedded within the many disparate activities of the personnel.” They proposed an integrated systems approach where tasks can be supported by integrating systems and tools. The work by Luff uncovered the many control room interactions that occur in control room settings; however the range of tasks and the limitations of the technology that were used in the control room were not closely examined. Currently, we know very little about how endusers utilise modern CCTV technologies to perform their observation and other security task activities in CCTV control rooms. This is evident from the limited number of HCI studies within security control room environments. There are a growing and diverse number of CCTV users, and these users have different goals and skills for managing security. The progression in surveillance technology has meant that the variety of tasks and activities for CCTV require careful assessment to ensure that the system is set up for the purpose it is intended for. By understanding the limitations of control room set ups, future improvements can be made to task and system design which can improve the way in which operators work in terms of effectiveness and efficiency. In contrast to Luff and Heath’s study, which looked at the HCI issues in one particular control room within one particular context, we propose a stakeholder perspective for assessing CCTV effectiveness where a range of operator tasks and problems are examined across several control rooms. 3

Qualitative Control Room Study

3.1 Objectives In order to assess the performance and effectiveness of modern CCTV systems with one set of stakeholders - CCTV control room operators, it was first necessary to identify the range of tasks they performed. Field visits to 5 London borough security centres were undertaken to investigate the typical CCTV tasks observers performed on a daily basis. Operators were briefly observed and interviewed about the nature of work they were

involved in. As well as collecting the task activities, operators were asked, using open-ended questions about the difficulties they experienced with the equipment and tools they used. The aims of the fieldwork were to: 1. 2. 3.

Understand the organisation and general practices of control rooms within a large city. Identify the types of technology used by operators and how they were used. Identify limitations concerning task and system design.

3.2 Data Collected from Control Rooms The control rooms that were visited were not specifically targeted for study and were chosen from opportunistic visits granted by security managers from each of the London boroughs. In

total, twenty-six CCTV operators and 5 control room managers were interviewed. 4 of the 5 centres visited were managed on behalf of the local authority by private contractors. For each of the visits, only brief observations were permitted when operators were working. Audio and video recordings and photography was not permitted for confidentiality reasons. Immediately after the observation exercise, each operator was asked to leave their workstation one at a time to discuss their roles, tasks and their concerns specifically with reference to the technology they used. We identified the manager’s goals for each of the control rooms, the type of technology being used, and the type of crime they mostly observed in the control rooms. See Table 1. for a summary of the main characteristics for each of the control rooms.

Table 1. A summary of the characteristics of each control room visited Control Room A: Camera to operator ratio: 19:160; Technology: Analogue & Digital (50%:50%) Security control room manager goals: Traffic enforcement & surveillance Typical crime observed at control centre: Shoplifting, assault, noise, Anti Social Behavioural Orders (ASBO) violated Control Room B: Camera to operator ratio: 16:110; Technology: Analogue (100%) Security control room manager goals: Monitor incidents and crime Typical crime observed at control centre: Teenage ‘hoody’ bike gangs – mobile phone theft, assault Control Room C: Camera to operator ratio: 3:90; Technology: Digital (100%) Security control room manager goals: Prevent crime & protect the public Typical crime observed at control centre: Theft, club/pub late night knife incidents & drug taking in car parks Control Room D: Camera to operator ratio: 6:111; Technology: Digital (100%) Security control room manager goals: Review images on behalf of police Typical crime observed at control centre: Hard drug use and supply, late night drinking & violence Control Room E Camera to operator ratio: 23: 200; Technology: Analogue & Digital (30%:70%) Security control room manager goals: Provide council support & general surveillance Typical crime observed at control centre: Violence, illegal rubbish, car dumping & theft

In the natural environment, the brain is typically required to recognise objects and people when they are at a distance or viewed under sub-optimal conditions [10]. In general, the most common

surveillance tasks CCTV users perform include monitoring and controlling incidents, detection, recognition and identification [11]. For this study, the range of observation tasks and activities control

room operators were involved with on a day-to-day basis varied:
Respond to radio, email and telephone calls from: local police units and council groups for maintenance problems and issues
Monitoring traffic enforcement and CCTV screens to spot traffic contraventions and crime
General surveillance monitoring of CCTV activity
Tape administration: Operators were responsible for making copies of tapes, labelling and storing backup surveillance video
Paper administration: The details of incidents that operators observe were to be fully documented and incident reports were created 3.3

Operator Constraints Identified

the problems operators experienced whilst carrying out their control room tasks. The key operator problems were identified mainly through open discussions with operators and management. The potential impact of the problems found were identified - see Table 2. System problems 1, 2 and 3 were identified as the most frequent and serious problems. One operator reported that they “felt stressed out and annoyed when locating cameras” and contributed these problems to: too many cameras in the list to search for and the fact there was no mapping graphical user interface (GUI) system to search and select the cameras effectively. Although issues with image quality were not found, one operator said that, “one recorded piece of footage was so poor that we couldn’t tell w the moving target was a man or a gorilla!

The second part of this study involved investigating Table 2. A description of operator problems, potential reasons and the impact on tasks System Problems

Impact of Problem on User & Their Tasks

(1) Low operator to screen ratio More cameras were being introduced to the system and control rooms were given extra camera access for better security coverage

- Risk missing vital information during scanning and/or following moving people and objects from camera to camera, particularly when operators had no peer support

(2) Information overload: Operators were exposed to multiple sources of information and communication systems, i.e. radio call groups, telephone, e-mail, and cameras access views

- Risk missing vital audio information over radio as operators were often confronted with other audio and video information simultaneously over long periods of time

(3) Delay in viewing & locating CCTV views: An electronic geographical map linked to camera screens and locations was a needed tool. Some video monitor screens would freeze because of signal loss due to bad weather

- Good local knowledge of the surveillance area was necessary for camera search tasks. Often manual lists go astray in the control room - A manual system could cause delays in passing on the spot information to police officers - Risk of missing miss incident(s) altogether

(4) Dysfunctional Pan, tilt & zoom (PTZ) controls: Legacy systems that were integrated with newer systems and poorly maintained equipment led to electronics to fail and work inefficiently (5) Street cameras were poorly sited Poor planning and assessment of CCTV environment during the installation phase had meant that over grown trees and other objects occluded the camera views

- Operators’ felt ‘embarrassed’ when sharing CCTV video with police control room operators because controls would not allow the cameras to move when given instructions - Cameras positioned too high or near overgrowing trees. Operators were ‘frustrated’ when trying to focus on specific activities such as drug dealing and youth loitering

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Conclusions and Further Directions The research described in this paper aimed to understand the various tasks control room operators were required to perform within city centre control rooms (mainly local authority ones). We have presented the challenges CCTV operators are faced with when under pressure within busy control room environments. One of the common problems we found across all control centres was the high screen to operator ratio. This was a growing problem for operators because the number of cameras which were being made accessible to the control room staff was increasing month-by-month, making it difficult for operators to remember and search for their locations efficiently. We also found that none of the control rooms had supportive tools for searching for cameras effectively and efficiently. The presence of the newer surveillance technologies has meant that security systems are being set up to serve different goals, yet these goals can be quite difficult to apply in reality. As a result, primary users are confronted with several segregated and poorly maintained systems and tools to perform their tasks. The number of stakeholders involved with CCTV is also increasing and their security goals are becoming increasingly diverse. The new generation of technology can be tailored to support this wide range of tasks effectively, but only if security goals and the activities carried out to support them are identified and understood. The HCI problems identified from the field work discussed in this paper provides a stepping stone for our future research. Further field visits to local authority city centre control rooms in and outside London are planned. Results will be used to form a usability framework for CCTV control rooms. 5

Acknowledgments

We would like thank the EPSRC for funding this research. We are grateful to Peter Fry for providing the security control room contacts. 6

References

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