Attitude Angle Estimation of Space Probe through Wide-Field Integration of Optic Flow

This paper applies Wide-Field integration (WFI) of optic flow to the state estimation of a space probe. By utilizing nonlinear forms for optic flow instead of linearized expressions used in a standard method, this study enables the estimation of the probe's attitude angles as well as its velocity components. First, this paper describes the estimation principle of a new WFI method for three-dimensional motion of a space probe. Then, numerical simulations are conducted to verify the effectiveness of the proposed method. Through the simulation results, this paper discusses the effects of the following three factors on the estimation accuracy: resolution of optical images, roughness of target surface, and noise included in optic flow.