Automated image analysis for space debris identification and astrometric measurements

The space debris are a challenging problem for the human activity in the space. Observation campaigns are conducted around the globe to detect and track uncontrolled space objects. One of the main problems in optical observation is obtaining useful information about the debris dynamical state by the images collected. For orbit determination, the most relevant information embedded in optical observation is the precise angular position, that can be evaluated by astrometry procedures, comparing the stars inside the image with star catalogues. This is typically a time consuming process, if done by a human operator, which makes this task impractical when dealing with the large amounts of data, in the order of thousands images per night, generated by routinely conducted observations. An automated procedure is investigated in this paper, capable to recognize the debris track inside a picture, calculate the celestial coordinates of the image’s center and use these information compute the debris angular position in the sky. This procedure has been implemented in a software code, that doesn't require human interaction and works without any supplemental information besides the image itself, detecting space objects and solving for their angular position without a priori information. The algorithm for object detection was developed inside the research team. For the star field computation, the software code astrometry.net was used, released under GPL v2 license. The complete procedure was validated by an extensive testing, using the images obtained in the observation campaign performed in a joint project between the Italian Space Agency (ASI) and the University of Bologna at the Broglio Space center, Kenya.