Vehicles concealed in highly cluttered, vegetated scene environments pose significant challenges for passive sensor systems and algorithms. System analysts working hyperspectral exploitation research require an at-aperture simulation capability that allows them to reliably investigate beyond the highly-limited scenarios that expensive field data sets afford.
To be useful to the analyst, such a simulation should address the following requirements: (1) the ability to easily generate scene representations for arbitrary Earth regions of tactical interest; (2) the ability to represent scene components, like terrain, trees and bushes, to an extremely high spatial resolution for calculation of accurate multiple spectral reflections, occlusions and shadowing; (3) the ability to stimulate the 3D scene with realistic natural spectral irradiances for arbitrary 3D model atmospheres; (4) the ability to appropriately integrate constantly improving, rigorous thermal, spectral signature and atmospheric propagation models; (5) the ability to efficiently render at-aperture hyperspectral data sets in a reasonable run-time.
Herein the authors describe their work toward a comprehensive ray-tracer-based simulation architecture and prototype capability that addresses these requirements. They describe their development of a GIS-based toolset for database generation, tools for 3D vegetated terrain-model development, and a prototype raytracer-based spectral scene generator.