A virtual global positioning broadcast and receiver system for use in military distributed virtual environments

Current military distributed virtual environments (DVEs) do not allow systems to navigate using Global Positioning System (GPS) timing and position signals. To address this deficit we modified the Solar System Modeler (SM) to broadcast virtual GPS timing and position signals and designed and implemented the Virtual Global Positioning System Receiver (VGPSR) unit so that any distributed virtual environment entity can use it to calculate its position within the DVE. In this paper we summarize the algorithms used to compute GPS satellite position and the current ephemeris. We also describe the calculations the VGPSR performs to calculate position using the virtual GPS broadcasts. The system achieves acceptable accuracy, and the VGPSR and virtual GPS satellites in the SM accurately portray the level of accuracy achieved in the real-world GPS. We suggest further research in the development of a virtual GPS for DVEs.