Pin-holes Based Description of the PANCAM, a Hyper-hemispherical Lens

Hyper-hemispherical lenses are optical objectives characterized by an ultra-wide field of view. Due to their extreme field of view, geometric calibration poses significant configuration challenges. Various methods have been developed to simplify the geometric calibration of cameras in short-range fields in controlled environments, such as clean rooms, and the use of simple calibration checkerboards. The lens analyzed in this study (PANCAM) is intended to be a planetary payload for an ESA mission with photogrammetric objectives. Consequently, the current state-of-the-art for this type of lens has been reviewed and extended to improve the descriptive model for the hyper-hemispherical field of view projection. While the resulting dewarping is essential for photogrammetric applications, it became necessary to define an approximate model to represent a single capture as a composite of multiple pinhole models. Each of these models can be individually leveraged as a data source for scientific analyses relying on this specific geometric framework.