Before we identify the surveillance cover and the required devices and configurations, the primary decision is to begin with the end in mind. We should be able to identify the surveillance result that we expect from the exercise. The desired objective of surveillance should be chosen out of the below options :
If the aim of surveillance exercise is only to detect abnormal motion or behavior, we use the detection mode of equipment for surveillance. Examples of these could be installations with wide area coverage and specific cameras like Thermal Cameras which have long range of detection capabilities across physical hurdles.
If the aim of surveillance exercise is to recognize a known face/person/object, we use the recognition mode of surveillance wherein the object to be recognized equals at least 17 pixels in the entire frame.
If the aim of surveillance exercise is to do identify a person or an object, the size of the face should be at least 80 pixels for a clear view.