The Eye in the Sky: Our World According to Digital Closed- Circuit TV Security Systems

TASA ID: 620

Remember the 1970's song by The Alan Parsons Project, "The Eye in the Sky"?  A memorable line from the lyrics was, "I am the Eye in the sky looking at you. I can read your mind."  Have you ever walked down a city street and noticed video cameras on the top of light posts or telephone poles? Why on earth would anybody want to see that city street, let alone you walking down that street?  Are public cameras an invasion of privacy, or are they "The Eye in the Sky" trying to read your mind, making adjustments to extraneous elements, and making your life easier?  

Either way, video cameras in public places have become a way of life, and you better get used to them.  They are part of a digital video system that has the capability to control life, regulate extraneous conditions of any given environment, and, most importantly, help control crime. 

That digital video camera is technically a part of a system known as a closed circuit television system (CCTV) and helps keep our busy world safe and hassle-free...well, at least in theory.  It is connected to a huge network of computers that can regulate traffic signals, alert police to automobile accidents, deter crime, solve crime and even save lives. 

Indoors, those same camera systems do similar activities, as well as many others, like keeping babies safe in hospital nurseries and monitoring critical care units.  

The city of Denver, Colorado, has the most intricate, complicated and largest CCTV system in place in its downtown district: hundreds of closed circuit cameras in dozens of municipal locations, both indoor and outdoor, all connected to a very large computer that can be monitored in many different locations.  It is this author's belief that within five years, every major city across America will have a surveillance system similar to Denver's in place.  

There are two formats for Closed Circuit TV (CCTV) security systems.  One is digital, and the other is analog.  Both serve the owner and operator well by recording video of their business or property while their backs are turned.  The analog is tape-based, and the digital is computer-based. Both record camera views onto their system and store them for later viewing, reviewing, or, when a crime is committed, identifying. 

Multiple cameras can be installed at a large or small location and used for viewing, as well as recording simultaneously on either analog or digital format.  Analog incorporates multiplexers; digital incorporates software programs.  The more sophisticated systems, like the ones Indianapolis manufacturer Pelco carries and has in place in Denver, have many adjustments, settings, frame options and video export options, as well as signal routing features.  The lower-end VHS systems are pretty straightforward and easy to operate but have less features and options. 

Both systems can incorporate point- tilt-zoom, or steady non-moving cameras.  The point tilt zoom cameras (PTZ) can move to follow action both automatically and manually.  Non-moving cameras capture the area under security in a stationary fashion. 

Some businesses choose not to record their CCTV channels and instead have security personnel visually monitor the surveillance area.  Other businesses, however, record their CCTV systems in addition to security personnel monitoring. 

The advantage to DVRs (which is really the way to go) is that the quality is far superior to analog, especially when images must be retrieved for identification purposes.  Digital formats and compressions make the recorded files smaller so more of the video will fit for longer periods of time in the computer or DVR.  

One compression type is MP4 compressed video that can be burned and backed up onto a CD Rom CD right in the DVR of the CCTV system.  Once these files have been identified and isolated, they can be kept forever, or at least as long as necessary if a legal case is pending. 

With this digital DVR having the quality of digital video, why would anyone ever use analog video tape?  Law enforcement agencies, as well as businesses, have to jump through hoops when purchasing new equipment, mostly because there is so much equipment to buy and so many manufacturers to choose from!

It's the old adage: if it's not broke, don't fix it.  The tape CCTV system is working fine, so we don't need and cannot afford a new digital CCTV system.  Of course, this seems satisfactory until a crime has been committed and the video footage is crucial to the case.

I have worked as a video forensic expert where analog video was entered as evidence on time lapse VHS tape that had been recycled many times. The examination and authentication process is much different and more difficult for analog that it is for digital.  It is more difficult to produce a high quality image of the crime for the court from a worn out, pixilated, low resolution analog tape.   

When you factor how much money it could cost to recover from the crime and to pay a forensic expert to try and recover an image, purchasing a digital CCTV system is a much better investment and will produce better forensic results.

Tape or analog systems often fail to show useable evidence in a court of law.  The main reason is because tapes are recycled over and over and can even be accidentally erased

Once a crime has been committed and caught on a digital recording device (DVR), a back up digital video can immediately be made of the crime using digital video technology.  This back up, often called "book marking" or "Alarm File," is immediately taken out of the normal refresh cue and stored in a safe area for further forensic examination. 

What could a court do with an analog video surveillance tape?  Make copies for all parties with generation loss?  Factor in that the video tape has been used for 18 months on a one month recycle process?  Try to lift a frame of video off the tape and compare it to a frame of digital video? 

There is no comparison.  The digital video proves time and time again a much clearer image.

Here are some suggested maintenance tips for both Analog and Digital CCTV systems:

Clean your camera lenses and weatherproof housings monthly. Outdoor cameras and weatherproof housings can become especially dirty and be moved by birds, weather and other unexpected elements.  Housings have seals that can wear out and break, letting in vapor that can blur video images.

Test your digital or analog recorder monthly to assure all cameras look good and are pointed at the appropriate areas, and replace any poorly functioning cameras or recording equipment.  Clean the tape heads of your analog video record deck with a head cleaner that can be purchased from Radio Shack or online from many vendors that still carry analog head cleaning tapes.  In addition, demagnetize your analog video recorder tape heads. This will remove magnetic build-up that can cause poor record quality.

Defragment your digital video recorder regularly as you do your computer so your digital system has the available space to function properly and provide a clear, clean image.

Next time you walk down the street and see a camera on top of a light pole, you can feel good about it because it has the potential of saving you some time when traffic becomes congested or even saving a life when a crime might be committed. Now you know the complexity of CCTV systems and some of the digital applications to look for the next time you are sitting in traffic, standing in a bank, or visiting a hospital. 

This article discusses issues of general interest and does not give any specific legal, medical, or business advice pertaining to any specific circumstances.  Before acting upon any of its information, you should obtain appropriate advice from a lawyer or other qualified professional.

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