Research For Key Technologies Of The GPS Applications In Police

The GPS system is an important foundation for the PGIS applications.Applications based on e-maps and GPS is most important direction in PGISapplications which will play an important role in Command and Dispatch, PoliceDuty, Traffic Safe Management, Major Events Security and other police business.Police departments currently has a large number of GPS devices connected to theservers. The GPS Systems face a number of challenges: a large number of devicessending data simultaneously, positioning is very high frequency, a large number ofmonitors displaying simultaneously, the display is in real time. The solution canbeen used in police and other department such as Department of Transportation.The GPS applications have several requirements for police tasks: real-time,mass messaging, massive dynamic data display. To meet these requirements,researching the technology of mass information distribution and display is required.The main key technologies include: asynchronous communication mechanism forimprove the capacity of single node; multi-level distribution mechanism for improvesystem throughput amount; subscribe mechanism for reduce the amount of datadistribution; independent caching mechanism&batch refresh mechanism for reducethe workload of the map drawing.The research results have been applied to the actual projects such as MajorEvents Security. The software system implements a flexible, scalable overall systemarchitecture; compatible with multi-vendor equipment, different transmissionchannel positioning information access; to solve a large number of practicalengineering input and display location information transmission performance issuesexist.