Calibrating a multi-spectral scene for objective measurements of multi-band camera systems

Modern electro-optical systems increasingly incorporate multiple electro-optical sensors, each adding unique wavebands, alignment considerations, and distortion effects. Laboratory testing of these systems traditionally requires multiple measurement setups to determine metrics such as inter-sensor alignment/distortion, near/far focus performance, latency, etc.; a multi-spectral scene has been created to support many simultaneous, objective measurements from a single mounting position. In some cases, a multi-spectral scene is the only way to test new system-of-system type units because traditional tests don't engage with or demonstrate their built-in algorithms (ex: fusion). In 2023 Parker et. al. developed a diverse multi-band scene with a diverse target set in order to test camera systems. In this correspondence, we describe a comprehensive and precise calibration of the scene. Among the methods used was a pair of reference cameras (reflective and emissive with a fixed extrinsic relations) translated across the entire field of view. The transformation matrices were determined to map pixel locations to angle; subsequent imaging of the target scene will yield precise locations of each feature, and comparisons between modelled and recorded images based on varied camera positions will validate the success of the calibration. This process will allow various measurements, across multiple wavebands, to be taken simultaneously and efficiently for a wide range of modern electro-optical systems.