Because it is a common database specification, any database built to the CDB specification is referred to as a Common Database (CDB). The CDB is a single-copy data repository from which various simulator client-devices are able to simultaneously retrieve, in real-time, relevant information for performing their respective runtime simulation tasks. A CDB that conforms to the CDB specification contains datasets organized in layers and tiles that represent the features of a synthetic environment for distributed simulation applications. Also, a CDB can be readily used by existing simulation client-devices, such as legacy IGs, radars, and CGF, through a publishing process performed in real-time.
While improving database maintainability, the CDB specification also enhances unity and correlation between various simulator level client-devices, such as visual and radar. As a result, one of the main benefits of the CDB specification is the elimination of correlation errors arising from alternating and sometimes conflicting data representations required by each of the simulator client-devices. The specification achieves this by allowing all simulator client-devices to share, in runtime, a single repository for the synthetic environment information. In addition, a CDB can also be used as a master repository for the authoring tools, thereby enabling the interchange of CDB content between DB workstations. And, because the CDB specification internal data representation model is based on the native formats used by industry-standard toolsets, it eliminates the time consuming off-line database compilation process for each client.
The CDB specification has been standardize on formats adopted by the industry, meaning that the data structures used in CDB specification synthetic environment databases are different than those used in relational databases. These data structures facilitate the adaptation of existing authoring tools to read/write/modify the CDB as well as the development of runtime publishers designed to operate on these data structures. CDB internal data representation is based on three commercial data formats endorsed by leaders of the simulation database tools industry:
1. Tiff/GeoTiff -for the representation of terrain altimetry, terrain raster imagery, terrain surface characteristics relevant to simulation, as well as texture for 3D culture.
2. OpenFlight-for the representation of 3D culture and moving models.
3. Shapefile-for the instancing and attribution of statically positioned point, lineal, and areal 2D/3D culture features.