GIS—from “qualitative” security to “quantitative” security**

The integration of GIS and security was first seen in RFID, GPS or wireless positioning applications. Whether it is RFID or wireless positioning, the basic model is to display the location information of people, vehicles or other objects carrying wireless terminals. Of course, the best way to present the location is to display the location on the map. At this time, the GIS system takes for granted. Reflecting its unique advantages, it has become the basic platform for these positioning applications. The most typical is the vehicle location management system, which uses GPS positioning information and GIS maps for integration. The entire vehicle fleet's location information can be displayed in front of others.

When Security Meets GIS

If the integration of location-based security applications and GIS is still obvious, the integration of video surveillance and GIS is less straightforward. The integration of video surveillance and GIS has two functions in terms of functionality. One is to map the position information of the camera on the map so that the camera can be quickly selected. Such applications are often more prominent in urban surveillance-type large-scale CCTV systems. Shanghai's urban monitoring network has begun to use such technologies to improve management efficiency in the late 1990s, but such GIS or GIS-based applications cannot Embodies the digital nature of GIS.

The second type of application that truly embodies the effectiveness of GIS digital quantitative monitoring is the integration of PTZ motion and GIS maps. As we all know, common camera PTZ actions can only direct the camera to rotate up, down, left, or right, or zoom in and out, but if you carefully study the PELCO-D's extended protocol, it's not hard to find that there is also a left turn in the protocol. How many degrees go, how many orders to look down. With this command protocol, you can easily imagine how to react to "fusion" in GIS. Integrate PTZ cameras that support PELCO-D (or similar protocols) with GIS, then the positioning of the target can be completely separated from the “qualitative” management of preset positions or manual positioning. The operator can select the map by selecting the map. A goal, and then through the GIS system to calculate the angle and distance between the camera, then by calling the absolute positioning of the command protocol can be a one-time positioning target, to achieve the target of accurate video monitoring, the artificial "qualitative" operation process is simplified to a The "quantitative" process of "precise positioning, instant arrival". In fact, as early as the beginning of this century, certain successful applications of this type of application existed in certain departments of the Shanghai municipal government.

In PELCO-D's extended protocol, the horizontal angular decomposition can be accurate to 36,000 equal parts, which means that the accuracy of a circle can reach 0.01 degrees (Figure 1). Maybe someone will ask if the precise position of 0.01 degree is valuable for monitoring? Indeed, if the monitoring range is tens of meters or more than 100 meters, whether this need is really worth discussing, but if the monitoring is extended to 10km? Taking a 1100mm lens with a 1/3” CCD camera as an example, the horizontal image field is 0.25 degrees (horizontal image field width 43m), an error of 0.01 degree, and the line error is 10 meters away is 1.8m, if the target is at the edge, then It is entirely possible to lose the target.Imagine if you manually rotate the PTZ camera based on the traditional "qualitative" monitoring method, it is actually impossible to achieve 0.01 degrees so accurate, only 1 degree of error, the front-end 174m deviation even if the target is a The house is also enough to lose the target. Under such harsh conditions, only the accurate calculation based on GIS and the PTZ camera with absolute positioning function can perform “quantitative” monitoring to truly capture the target. In fact, this function is super. Long-distance monitoring has extremely high application value.In addition to the Pelco series PTZ cameras and Honeywell ACUIX series cameras supporting the extended PELCO-D absolute positioning protocol, there are also some Japanese PTZ camera manufacturers, such as Kenko, Japan. It also provides positioning accuracy of 0.001 degrees or more, and these excellent features are only based on GIS-based "quantitative" monitoring applications. We can play a real effect, and it is this "quantitative" security applications, the security industry only to see farther, see better.

"Great Security" & GIS

If we develop to a deeper level, the widely used "Daan security" application model is inseparable from the basic platform of GIS. The so-called big security solution actually integrates multi-technology categories such as location applications, alarm applications, and video applications to achieve a specific user requirement. Taking the RVS radar perimeter of a certain brand as an example, the characteristics of the target location and the real-time location of the intruder's target are used to realize the management objective of tracking and reviewing the video camera. This is a typical multi-technical application in which radar is a device that provides "quantitative" information, providing intruders from pre-invasion to post-invasion trajectory to computer systems as location point information, while computer systems need to “A particular technical means” “translates” this location information into angle and distance information that can be recognized by the PTZ camera, while the PTZ camera constantly adjusts the information according to the angle and distance information it can recognize. The position can trace the intruder in a continuous form, thus giving security management personnel the basis for judgment and processing. This "specific technical means" is actually a GIS, which "translates" the position of the intruder provided by the radar into a geographic coordinate and calculates the angle information that can be recognized by the camera so that the camera can always track the target. It can be seen that the ability of RVS to expand perimeter management from “line” to “face” and provide pre-, intra- and post-event judgments is based on GIS.

Since its inception, security has moved from purely low-voltage applications to digital applications. It can be predicted that in the next 5-10 years, security applications will completely get rid of the traditional weak-power forms and form an all-digital engineering category dominated by IT technology. Many concepts and technologies in IT technology will continue to infiltrate into security applications. Whether it is image-based digital processing or location-based GIS management, it will be an important technology means in the field of security. In IT applications, "digital" and "quantitative" "The concept of security will gradually change the basic concept of security," quantitative "will make security more accurate and faster, and the location of the "quantitative" application is undoubtedly GIS, geographic information systems.