Crater detection dependence on resolution, incidence angle, emission angle, and phase angle

Impact crater population detection and measurement is critical to understanding solar system bodies and dynamics. However, the ability to detect all possible craters under different lighting and camera geometries has not been systematically studied except in a few limited cases. This work presents the first systematic study examining crater detection based on resolution, incidence angle, emission angle, and phase angle, by three independent researchers to also test reliability of our conclusions. We found the best incidence angles for crater detection to be ∼74°–82°. We found little dependence on emission angle with geometries as high as ∼60°, while phase angles ∼20°–75° produce reliable crater populations. Resolution requires at least 6 pixels, and it is likely researcher-, geometry-, and terrain-specific. This work reveals potential biases in crater analysts' work and can be used for missions planning encounters so they can achieve the best, most reliable recovery of crater populations.