Selection Process for Security & Surveillance Equipment
By Robert Fabio Ez-spy.com

This is a preliminary document describing some of the issues in Surveillance equipment. The following topics are covered and in time I will add others with links to product selection. The goal here is to help you design, select and install a surveillance system to meet your needs.

Topics:
Know what you want to accomplish.
Knowing your own skills and limitations.
Understanding the equipment
Knowing the law
Setting a goal for the Installation

A) Know what you want to accomplish.
- Every security installation requires a Plan which begins with a Goal of what you want to accomplish. Some security needs are serious as in life dependent and others are not. Years ago I suspected my neighbor was walking his dog in my driveway. So I setup a camcorder and VCR to start recording at a particular time and record for 6 hours. Afterwards I attempted to play back the recording. It made a dull movie "6 hours in the life of a driveway". No, I didn't watch the whole tape, I fast forwarded thru most of it and probably blinked and missed whatever I was looking for.
- Today, with the advancement in commonly available equipment, much more is possible. But, each piece or group of equipment has certain characteristics which make more or less favorable for a particular application. Therefore, before you spend any money, know what you want to accomplish. Some considerations to set Goals are:

1) Monitor a given area, continually or for a certain period of time, motion activated or not, indoor or outdoor, rain or shine, hidden or in non hidden camera, alarm or no alarm triggering or not, video recording or not, and finally, color or black and white.

2) What are the environmental conditions, temperature, humidity, rain, power outages, portability as in a vehicle, the variance in lighting conditions.

3) The significance of the event you want to capture: customers pocketing valuables, a robber's face, barbiturates activities, Delinquents defacing valuable property. Not like my driveway example above, these activities are more critical, and you would want to capture the event the first and every time it happened.

B) Know your skills and limitations.
The next step is to not attempt something for which you don't have adequate skills. For any given task you may need to understand power requirements, DC versus AC power. Running and connecting video, audio and power connections. Location & tuning of transmitters & receivers. Most devices come with instructions, but without prior technical knowledge you may not be able to understand the instructions. We include additional instructions or notes with the equipment we sell whenever we feel its necessary.

C)Understanding the equipment
Equipment fall into three main categories Capture Devices, Recording & Alarming and Transmission & receiving devices. Sometimes devices come as a combination of the above but have limited installation flexibility.

1) Capture devices are generally cameras and motion detectors. Motion detectors are just that, like the driveway lights which come on when something passes within range, motion detectors trigger something.

Surveillance Cameras come in two popular technologies, CMOS and CCD. CMOS is the less expensive and less bulky. CCD is the technology used in Camcorders. CCD produces better quality images but is usually housed in a larger assembly and more difficult to conceal. Both exhibit characteristics such as light sensitivity, lines of resolution, and element surface area of 1/3 or 1/4 inch square. the 1/3 inch is the larger element and generally produces the better image. Some cameras have a built in mic and/or built in illumination. All cameras need a lens to focus the image on the element. The CMOS Cameras have either a small glass or pinhole lens. The glass lens is an inexpensive piece of glass which work well but may add distortion to the image. The pin hole does not distort but can allow contaminants to contact the element. CCD Cameras usually require a separate lens purchase. Most of these cameras have the industry standard CMount which would allow a variety of CMount Lens to be used. More on lenses later.

2) Recording & alarming devices.
Most of us are familiar with Video Cassette Recorders, VCRs. The home variety can record up to 2,4 or 6 hours on the common t-120 VCR Tape. These VCRs, unless otherwise programmed or commanded, are either recording or not and as in my example above have limited use in surveillance. A variation of the VCR is the Time LAPSE Recorder. These TLRs record continuous snapshots, about one every half second, continuously on a tape. We've seen the results of these on the local news when someone robs a convenience store. Some TLRs have added features such as sound recording, alarm to full motion recording, extended 24-36 hours record on a tape, and time stamping of the recording.

With the evolution of digital computers came the ability to view, record and edit video from a variety of sources. Now there are add on devices such as video capture cards, USB capture devices or parallel port input devices, which when coupled with cameras and the proper software can transform a computer to sophisticated security monitoring station. Multiple cameras can be connected, certain zones in the image can be set for monitoring. for example if we're monitoring a driveway, we would want to trigger the recording for ground traffic, but not for a flying bird or a tree swaying in the breeze. Some of these programs can be setup for special action when triggered, such as sending a telephone page, call the police, send a fax image, email or upload an image to the internet. Images are often time stamped and recorded on the hard drive.

3) Transmission & receiving devices. These devices transport/transmit the video/audio signal from the camera to the monitoring/recording device. The simplest and most secure transmission/receiving device as a cable, and for short runs its generally the best solution. Exceptions are cameras used in vehicles, running wire through thick walls or across a room, or when camera location require frequent changing.
Next, there's the standard broadcast frequency transmitters. These convert the video/audio signals to a common broadcast frequency (most common is TV UHF channels 15-16). Thus any TV within the transmission range(usually 100-300 feet) if tuned to that station can pick up the transmission, this includes your neighbor's TV. However, if the TV is hooked to cable TV or satellite, additional equipment or hookup will be needed to inject ( receive) the image.
A third method uses 900MHz and 2.4GigHz transmitters & receiver combinations.
When a video/audio signal is transmitted it cannot be picked up by a TV, only a receiver within range & tuned to the frequency.

D) Knowing the law:
The US Constitution gives us many rights, some of which are the right to privacy and freedom of speech. Federal and various State laws further define those rights. As an installer and/or user of surveillance equipment you are legally responsible for how it's used use. We do not give legal advice but see legal notice for general information.

E) Setting a goal for the Installation
As mentioned above, the importance or value of the Object or Person to be secured or monitored is the basis of setting a goal. The results you which to achieve will determine what equipment to use. We can help you select and even pre-configure equipment for you. Contact us for more information at info@ez-spy.com.