UNIVERSITY OF NAIROBI VIDEO SURVEILLANCE SYSTEM DESIGN PRJ 107 BY: MWONGEERA MURUNGI REG NO. F17/9351/2002

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1 UNIVERSITY OF NAIROBI VIDEO SURVEILLANCE SYSTEM DESIGN PRJ 107 BY: MWONGEERA MURUNGI REG NO. F17/9351/2002 SUPERVISOR: DR. MANG OLI EXAMINER: DR. ABUNGU

2 OBJECTIVE The aim of the project was to design a video surveillance system, and assessment of the effectiveness of such a system as a means of monitoring an area to ascertain its security.

3 WHAT IS A VIDEO SURVEILLANCE SYSTEM It is a system composed of a camera, a lens, a monitor, and (for wired systems) cables that carry the signal from one place to another and video recorders that record the video footage.

4 OVERVIEW OF VIDEO SURVEILLANCE SYSTEMS Video Surveillance Systems Video Capture Units Video Stream Control Data Network Transmission Video Stream Control Data Central Control Module Digital Cameras Analogue Cameras Encoders and Switchers DVRs and NVRS IP Networks P.C Monitor Control Keyboard

5 CHOOSING A CCTV CAMERA (CRITERIA) Lighting conditions Position of camera Field of view Focal length Sensitivity and resolution Colour or monochrome Price

6 IP VIDEO ARCHITECTURES IP video surveillance systems architectures

7 INSTALLING A VIDEO SURVEILLANCE SYSTEM Site Study and Analysis Field of View- Width and height of the scene as viewed by the lens. It depends upon the focal length and distance of the object. Prevailing light conditions Calculations of minimum scene illumination Choice of camera and data transmission modes Choice of Camera- wired cameras Choice of data transmission mode -IP based

8 Identification of scene Estimation of distance from scene to camera Calculation of focal length STEPS IN DETERMINATION OF FIELD OF VIEW Determine whether critical viewing area required is for detection, action or identification Calculation of Critical viewing area of scene Change either focal length or camera distance NO Is value of calculated CVA the same as expected value? YES Focal length is used

9 DATA FROM FIELD SURVEY Area to be viewed: Building wall Distance from subject to camera: (10m) Average horizontal illumination: 100 lux average (50% minimum) Plane of subject to be viewed: vertical Reflectivity of subject: wall, average 30%(minimum) Intensity of lighting off wall: candelas Reflectivity of ground in front of the wall: average 37%(minimum)

10 CAMERA DATA Minimum faceplate illumination of the chosen camera: 0.1 lux for good pictures Minimum scene illumination of chosen camera: 0.6 lux F1.4 (f-stop value) 50% reflection

11 AVAILABLE ILLUMINATION AT THE CAMERA LENS Minimum light falling in front of the wall: 50% of average = 50 lux Minimum light reflected from ground onto the wall: 37% of minimum at ground = 18.5 lux. Minimum light from the wall toward the camera: 30% of that arriving on wall from ground = 5.55 lux. Intensity at this point is candelas(given) Loss of light due to distance to camera (assuming light reflected directly towards camera E = I/d 2 E= lux

12 CAMERA SCENE ILLUMINATION LEVEL Practical illumination Faceplate Illumination is given by (E*C) C = 1/4f 2. Hence Faceplate illumination = lux * = 0.39 lux. Given Camera minimum faceplate illumination = 0.1 lux lux is more than 0.1 thus theoretical illumination is enough.

13 CAMERA DISTANCES AND FACEPLATE ILLUMINATIONS Faceplate illuminations at different distances At 19.92m the faceplate illumination is at 0.1 lux which is the threshold, beyond this distance the camera cannot be useful.

14 CAMERA SCENE ILLUMINATION LEVEL Rule of Thumb1: Required faceplate illumination(indicated on data sheet) X 200 <= average horizontal illumination available at scene Rule of Thumb2: Camera illumination level required for good picture X 10 <= average horizontal illumination available at scene

15 VIDEO SURVEILLANCE SYSTEM DESIGN USING VIDEOCAD SOFTWARE Any object, which is at the height between these bounds, and on a horizontal plane within the limits of horizontal projection of the view area, will be visible on the screen.

16 IDENTIFICATION OF THE AREA UNDER SURVEILLANCE Snapshot of a modelled Bank lower ground floor

17 CAMERA PLACEMENT Camera mounting (Cameras in the back office are not visible from this projection and hence are not indicated)

18 CAMERA PLACEMENT Image as seen from camera 8

19 VIEWING THE SURVEYED AREA ON A MONITOR View of the area under monitor

20 INSTALLING A VIDEO SURVEILLANCE SYSTEM Installation of the system After identifying the sites, the cameras cables are laid down from the cameras to the DVR. The DVR is connected to the router using LAN cables. The PC computer ( ) is there to set up the DVR via a user interface that is accessible via the LAN connection. The ADSL modem provides internet access to the system

21 THE INSTALLATION OF THE SYSTEM The DVR-Camera setup

22 CONCLUSION The system design parameters were used to model a Video Surveillance System using VideoCAD software, which was able to produce a useful security monitoring tool. The importance of such a model was also demonstrated by the fact that tedious camera mounting and removal exercises to ascertain optimum camera placement positions would be eliminated. This would be beneficial to fast deployment of such a system by cutting down on design time and cost of implementation.

23 RECOMMENDATIONS FOR FURTHER WORK Incorporation of an alarm system. Incorporation of an access control system into the surveillance monitoring. Fire detection capabilities. Introduction of motion detection capabilities into the system by use of Video Motion Detectors (VMDs) Addition of Audio capability.

24 THANK YOU