A system 10 which is adapted to receive global positioning signals 14 from a satellite assembly 12 and which determines, displays, and selectively disseminates that error associated with the received signals to selected users at selected locations and at selected times. The system 10 also provides several other applications, including but not limited to the acquisition and selectively display of selective weather information, physical attributes of a facility, such as an airport, time distribution, collection and dissemination of user information as well as allowing one to simulate the performance of a global positioning acquisition and dissemination system. Such a simulation allows a user to dynamically specify the location and movement of signal generating satellites, the location of the various ground or reception stations, and to display certain other attributes or desired system characteristics. The simulation efficiently recognizes monitored ionospheric ground points which are used to allow for a more accurate overall simulation that can be delivered to selected users at selected locations and at selected times.