The phrase itself — "Site Assessment" — can seem intimidating. However, a thorough site assessment is really a simple exercise that answers a few basic questions specific to your application:
Once you have answered these basic questions, the selection of your video security system components should be simple. If you require help in designing your system, providing the answers to these questions will virtually insure that your sales consultant delivers the right security system for your needs.
So where do you start?
Begin with a basic schematic of your floorplan , from an overhead view. This can be as detailed as a blue print of your building or area, or as simple as a sketch on a napkin.
The most important thing is to identify all possible obstructions and sources of light — as these will largely influence the placement of your cameras and the capabilities of the cameras you choose.
How Many Cameras Will You Need?
Identify the areas that you want to watch with your security cameras . What level of coverage is sufficient? Generally, you want to document all activity that occurs at your facility, and provide positive identification of those coming and going.
Cameras that document criminal activities need to cover a wide area so that they can provide valuable evidence, including: the criminal act itself, direction of travel, objects touched (for fingerprint retrieval), accomplices, and witnesses.
In many cases, homes and small businesses can cover the majority of these important details with as few as four cameras strategically positioned around the facility.
Provide Positive Identification
To achieve good identification of people or vehicles, you must first identify the choke points in your business, and likely avenues of approach. Choke points are areas of your home, business or property that anyone or thing wishing to gain entrance must pass through, such as doors, windows, gates or parking lot entrances.
Cameras dedicated to watching these choke points will provide a clear mug shot of the bad guy that you can quickly hand off to the authorities.
What are the Requirements of Each Camera?
Now that you have identified the number and location of your cameras, it's time to define the requirements of each camera. More specifically, you need to answer the following questions:
Are the cameras to be placed indoors or outdoors?
Indoor cameras are usually less expensive than their outdoor counterparts, while outdoor security cameras are typically designed to withstand both harsh weather and acts of vandalism.
Many of the more popular security cameras sold today are designed to perform in both indoor and outdoor environments, and provide both weather and vandal resistance.
What field of view (FOV) is desired?
Cameras dedicated to providing identification need to be focused solely on choke points. The further these cameras will be away from the choke, the more telephoto capability will be required. Cameras positioned to provide a general overview of activities will typically require less detail, but a greater field of view.
At this point, determine the level of detail desired, and measure the required field of view based on the positioning of each camera.
Tip: Don't forget coverage of areas restricted to your employees! It's proven that 47% of retail theft is due to employee theft, and another 14% due to administration fraud.
Strategically placed cameras can both deter and detect these crimes, and allow you to monitor staff productivity – an often overlooked source of business loss.
What are the lighting conditions for each camera?
A good rule of thumb to figure out how much lighting your cameras will need is to view the area with your own eyes. If there is not enough light for you to gather details about someone you don't know, then it's almost guaranteed that the cameras will need additional lighting as well.
You will likely require a camera equipped with near-invisible infrared lighting (IR) to make clear identifications without alerting the suspect that he is being watched.
Wide dynamic cameras use advanced digital processing to capture two images at different exposures, and then combines them into one image. The result is video with near perfect exposure.
Don't forget to consider all lighting conditions . Are you in an area where the lighting may be turned off? Does your system require outdoor cameras that need to see during the night-time?
Areas with intense back-light conditions will require cameras that compensate for this to capture clear images, called wide dynamic range cameras. Again, make a note of this for your camera selection process.
Lastly, do you have any aesthetic requirements?
The appropriate look and feel of your cameras is critical to maintaining a desired or acceptable level of appearance. Aesthetics can be very important to a housing association, or if your lease includes strict guidelines covering appearance.
Museums or restaurants often disguise their cameras so that their patrons don't feel uncomfortable that they're being watched. Other customers WANT their cameras to stand out, to provide a visible deterrent to would be criminals.
What are the Potential Future Needs of Your System?
Before moving on to your recording decisions, we highly recommend you consider the potential future needs of your security camera system . Specifically, is there the possibility that you will want to add more security camera coverage to your system?
Your digital video recorder (DVR) will either limit or allow for future expansion, because it comes with a fixed capacity of 4, 8 or 16 cameras.
Even if you don't feel you will need additional cameras, we recommend that you consider a DVR that has spare channels to allow for expansion. Planning ahead now can save you significant money and time in the long run.
Where Will You Place Your Recording Device?
During the purchase process, you will select the remaining requirements of your DVR, such as desired features and hard drive size. But first, you must answer the question "where will your DVR be placed?"
The DVR should be placed in a location where the DVR can not only be secured, but where it can be easily connected to both power and the internet. Once you've determined this location, you will then be able to factor in approximate video cable lengths required to connect your cameras to the DVR.
How Much Cabling Will You Need?
The final objective of a site assessment is to determine how to get power to your cameras, and get the video signal from your cameras to your DVR.
Getting power to your cameras
For most applications, installing a camera power supply nearby your DVR is highly recommended. This will make it much easier to leverage your power back up device for both your cameras and your DVR. From that location, you must determine the length of cable needed to run power to each camera.
Keep in mind, the greater the distance between the camera and power supply, the thicker the power cable will need to be due to the natural voltage drop over transmission. However, for most runs of under 100 feet, our standard cable gauge will work just fine.
Getting the video signal from cameras to DVR
If you have followed our recommendations, your video cable lengths will be the same as the power cable lengths required for each camera.
The same principles that apply to power cables apply to cabling required to transmit a video signal back to your DVR, with one significant difference: interference . In order to ensure a clean video signal, you should always use a high quality cable that resists interference from high voltage power lines in your house, appliances, high powered radios, etc.
Once you've answered these questions about cameras, future-proofing, DVRs and cabling, your site assessment is done. You are now completely prepared to begin selecting the components that make up the perfect video security system for your specific application.