An effective algorithm for generation of crater gray image

Crater-based visual navigation method is a promising and precise method for future planetary landing missions. To develop and test the crater-based visual navigation algorithms, in this paper, we present an original and effective algorithm for generating the synthetic crater gray image. The presented crater gray image simulation algorithm is flexible and relies on the basic camera pinhole model and the Lambertian reflection model. First, the 3D terrain model of the planetary surface containing craters is established. Second, the intensity of each pixel in the image plane of the simulated camera, whose attitude and position are set in advance, is calculated by analyzing the intersections of the 3D terrain model with the optical line passing through the optical center and the given pixel. The experimental results demonstrate that the proposed algorithm is effective in simulating the crater gray image for developing and validating the algorithms of detecting craters and estimating the position and orientation of the spacecraft landing on the planetary surface.