Michael Copeland, Australian National University; Francis Bennet, Australian National University; Celine d’Orgeville, Australian National University; Visa Korkiakoski, Australian National University; Marcus Lingham, Australian National University; Ian Price, Australian National University; Francois Rigaut, Australian National University; Craig Smith, EOS Space Systems
Keywords: Adaptive Optics, Object Characterisation, Tracking
Abstract:
High resolution imaging to characterise objects can provide necessary information to improve orbital models. The size, shape and orientation of an object will affect how external forces act on the orbit, and therefore will influence the accuracy of orbital models and collision prediction. The Research School of Astronomy and Astrophysics (RSAA) at the Australian National University (ANU), in partnership with the Space Environment Research Centre (SERC) uses an adaptive optics system on the EOS Space Research Centre 1.8 m telescope to perform object characterisation.
Turbulence in the atmosphere causes distortion and reduces the effective resolution of the imaging system. Adaptive optics can compensate for the atmospheric effects and restore the resolution of the telescope. The Adaptive Optics Imaging (AOI) system enables us to achieve a resolution of 50 cm for objects at 800 km range when imaging at 850 nm, which enables features such as satellite bodies and solar panels to be resolved. We will present the results obtained from a campaign to observe satellites in low Earth orbit (LEO). We capture images between 30 and 60 Hz to remove field rotation and so the best quality images can be selected using lucky imaging. A laser guide star (LGS) capability will be added to the system in 2019 which will allow smaller and fainter objects to be observed. We will compare the results when using the LGS to produce the high order correction instead of splitting light from the object of interest and analyse the performance increase that is obtained.
The adaptive optics system has also been used for precise tracking of objects in geostationary orbit (GEO). We capture images as an object passes by a reference star from the Gaia catalogue, and can determine position with an accuracy of approximately 1 m. We will make simultaneous observations of GEO objects with the adaptive optics system in the visible and a lucky imaging camera operating in the near infra-red (NIR). The effectiveness of the measurements over the two wavelength ranges will be compared.
Date of Conference: September 17-20, 2019
Track: Adaptive Optics & Imaging