A security system can perform a systematic test to generate a visualization of the security camera coverage for an area. The test can be performed using a network of security cameras, a central system, and a mapping entity. The mapping entity may hold or be attached to a sign with a pattern. The mapping entity can move the sign from one location to another throughout a zone to be mapped. At each location, the mapping entity may send a message with the coordinate of its current position and optionally the pattern it is carrying to the central system.