The Joint Synthetic Battlespace for the Air Force (JSB-AF) is being developed to provide realistic representations of friendly and threat capabilities and the natural environmental conditions to support a variety of Department of Defense missions including training, mission rehearsal, decision support, acquisition, deployment, employment, operations, and the development of Courses of Action. This paper addresses three critical JSB issues associated with providing environ-mental representations to Modeling and Simulation (M&S) applications. First, how should the requirements for envi-ronmental functionality in a JSB-AF application be collected, analyzed, and used to define an Authoritative Environ-mental Representation (AER)? Second, how can JSB-AF AERs be generated? Third, once an AER has been generated, how should it be “served up” to the JSB-AF components? Our analyses of these issues will be presented from a general M&S perspective, with examples given from a JSB-AF centered view. In the context of this effort, the term “representa-tions” is meant to incorporate both basic environmental “data” (e.g., temperature, pressure, slope, elevation, etc.) and “effects”, properties that can be derived from these data using physics-based models or empirical relationship from the fundamental data (e.g., extinction coefficients, radiance, soil moisture strength, etc.) We present a state-of-the-art review of the existing processes and technologies that address these questions.