Space debris orbit determination from an ISS onboard camera

An autonomous system for the orbit determination of space debris has been studied for a new payload on the ISS. Space based observations could be a very important source for optical observations. An ISS onboard camera could provide measurements for a large class of satellites on different orbits. The high chances of observations and the possibility of scanning large regions of the sky suggest that the camera should be in continuous activity with different modes. This article will present a possible site for the installation of the camera, the treatment of the images to obtain the angular measurements and a genetic algorithm to estimate the orbital parameters of the observed object. The genetic algorithm will use the time-tagged orbital angular observations and a very accurate estimation of the camera site in order to evaluate the target orbit. The algorithm will use only two variables to determine the output: the initial and the final relative distance between observer and target, these two values will identify uniquely the orbit of the observed object. The camera will be mounted on a pan-tilt system to obtain longer observations by tracking the object. The possible high angular velocities, the conditions of illumination and the relative positions force the orbit determination algorithm to be efficient and reliable also on very short arc passes. The camera system will be characterized by a very compact design, low power consumption and low mass. The electric system will be capable to operate continuously in the space environment. The system will downlink data from the angular observations, the on-board estimated orbital parameters and some images to allow the testing of the performances and the off-line processing to obtain a better estimation.