CCTV Video Surveillance System Design 2 — Questions and Answers
Question 1: What is the primary purpose of conducting a site survey before designing a CCTV system?
- To determine the number of monitors needed
- To identify coverage gaps, lighting conditions, and mounting locations (Correct answer)
- To select the brand of cameras to purchase
- To calculate the monthly maintenance cost
Correct answer: To identify coverage gaps, lighting conditions, and mounting locations
A site survey identifies physical layout, lighting, obstructions, and ideal camera placement to ensure complete coverage with no blind spots.
Question 2: Which camera placement strategy is most effective for monitoring a long, narrow corridor?
- Mounting cameras on the side walls at mid-point
- Placing a camera at each end of the corridor aimed inward (Correct answer)
- Installing an overhead fisheye camera at the center
- Using multiple pan-tilt cameras along the ceiling
Correct answer: Placing a camera at each end of the corridor aimed inward
End-mounted cameras aimed down the length of a corridor capture the full length with maximum depth of field and clear facial images.
Question 3: What does 'field of view' (FOV) refer to in camera selection for system design?
- The maximum distance a camera can transmit video
- The angular extent of the scene captured by the camera lens (Correct answer)
- The resolution of the camera sensor
- The number of frames per second the camera records
Correct answer: The angular extent of the scene captured by the camera lens
Field of view is the angular extent of the observable area captured by a lens, typically measured in degrees horizontally and vertically.
Question 4: When designing a system for a parking lot, which camera type is most commonly recommended to cover wide areas efficiently?
- Bullet cameras with telephoto lenses
- Wide-angle or fisheye cameras (Correct answer)
- PTZ cameras set to tour preset
- Pinhole cameras for covert coverage
Correct answer: Wide-angle or fisheye cameras
Wide-angle or fisheye cameras maximize coverage area per camera, reducing the number of units needed for large open spaces like parking lots.
Question 5: What is the significance of the 'overlap zone' in a multi-camera CCTV design?
- It indicates areas where two cameras share coverage, eliminating blind spots (Correct answer)
- It is the region where two camera signals interfere with each other
- It refers to the shared recording storage used by multiple cameras
- It is the area where frame rates are automatically reduced
Correct answer: It indicates areas where two cameras share coverage, eliminating blind spots
Overlap zones ensure that if one camera is obstructed or fails, the adjacent camera still captures activity in that area, preventing coverage gaps.
Question 6: Which factor most directly affects the minimum illumination requirement when selecting cameras for an outdoor night surveillance design?
- The camera's IP rating
- The camera's minimum lux rating (Correct answer)
- The video compression format used
- The network bandwidth available
Correct answer: The camera's minimum lux rating
Minimum lux rating determines how little light a camera needs to produce a usable image, which is critical for low-light outdoor nighttime operation.
Question 7: In CCTV system design, what is 'dead angle' (or blind spot)?
- The time delay between live feed and recorded footage
- An area not covered by any camera in the surveillance system (Correct answer)
- The angle at which IR illuminators become ineffective
- A camera zone blocked by infrared interference
Correct answer: An area not covered by any camera in the surveillance system
A dead angle is any area within the intended surveillance zone that falls outside the field of view of all installed cameras, leaving it unmonitored.
CCTV Video Surveillance System Design 2
What is the primary purpose of conducting a site survey before designing a CCTV system?