The rapidly expanding use of low-cost, distributed, interactive, networked simulation is reshaping the requirements for terrain database creation, modification, and distribution. The terrain database no longer resides exclusively on the visual image generator, but is shared by the many components of the network simulator, including computer generated and semi-automated force simulations, electronic map displays, communication models, mobility models, and paper maps. Additionally, the substance of the terrain database can no longer be bound by the visual needs, but must contain correlated information essential to the various components of the networked simulation.

We must create and maintain a complete synthetic environment. The creation of the synthetic environment requires the integration of a broad assembly of structures and attributes needed by the various components of the network simulator. Modifications to the correlated synthetic environment database must be made both as a matter of database enhancement (adding a house, or road), and as a result of the run-time interaction (excavation of an anti-tank ditch or destroying a bridge). Common correlated sources for the distribution of the shared synthetic environment are fundamental to simulator interoperability. Database sharing for large networked simulations, with hundreds of individual simulators, requires efficient methods for both pre-distributions and run-time modification distributions. Standards should be considered to provide a common architecture and standard communication protocol to support cost-effective database creation, modification, and distribution in a distributed interactive simulation.