Global-scene Architecture for Integrated atmosphere, terrain, and cloud Analysis (GAIA™)
GAIA™ is a robust, physics-based model for accurately and rapidly generating terrain and cloud scenes in the ultraviolet (UV), visible (VIS) and infrared (IR) portions of the spectrum (0.2 – 50 microns). The model can simulate high-fidelity imagery at any point on Earth, at any time of the year. GAIA™ was funded by the Missile Defense Agency (MDA) SBIR program in order to provide the ability to characterize the UV/VIS/IR battlespace radiation environment, providing for the development of effective next generation ballistic missile warning, defense, and surveillance systems. GAIA™ can also be used as a general analysis tool for supporting environmental and remote sensing applications.
GAIA™ is database driven, incorporating a large amount of remotely-sensed and other measured data, such as terrain altitude, land cover, terrain material optical and thermal properties, satellite cloud imagery, and cloud products. These global databases contain information about both locational and seasonal variation, and can be updated as new remotely-sensed data becomes available. This data is used to define the terrain and cloud structure for the user-defined scene, including altitude, composition and temperature of each terrain pixel. If clouds are desired a cloud map, cloud top altitude and cloud base altitude are calculated from measured cloud data, allowing GAIA™ to create cloud structures that are fully consistent with the underlying terrain for the given time of year. Atmospheric effects and radiance values to support scene simulation are provided by the AETHER™ radiative transfer model. This includes atmospheric transmission, path radiance, incident direct diffuse solar irradiance, incident direct and diffuse lunar irradiance, and incident diffuse thermal irradiance, all on a three-dimensional grid (latitude, longitude and altitude). GAIA™ can calculate at-aperture radiance for any reasonable sensor geometry, including space-based, airborne and ground-based systems.
The GAIA™ architecture was designed to allow efficient and consistent interface with existing computer modeling environments, such as the Fast Line-of-sight Imagery for Target and Exhaust-plume Signatures (FLITES) scene generation code. The OCEANUS™ model has also been integrated into GAIA™ to provide enhanced ocean scene capabilities, for a scene-generation model that covers the earth.
More details on the modeling capabilities can be found in the GAIA™ brochure.