Michael Copeland, Australian National University; Francis Bennet, Australian National University; Francois Rigaut, Australian National University; Visa Korkiakoski, Australian National University; I. Price, Australian National University; Celine d’Orgeville, Australian National University; Craig Smith, EOS Space Systems
Keywords: Adaptive Optics, Imaging, Characterisation, Tracking
Abstract:
The Research School of Astronomy and Astrophysics (RSAA) at the Australian National University (ANU) has developed, in partnership with the Space Environment Research Centre, an adaptive optics system to characterise and track satellites and debris using the EOS Space Research Centre 1.8 m telescope. The Adaptive Optics Imaging (AOI) system will enable us to observe specific features of satellites in low Earth orbit (LEO) so we can characterise the size, shape and orientation. For objects in geostationary orbit (GEO) we will obtain high accuracy positional measurements for improved tracking capability.
Characterisation through high resolution imaging is needed to improve orbital modelling and collision prediction. With better depiction of objects the effects of parameters such as atmospheric drag and solar radiation can be predicted with higher accuracy. AOI will have a resolution of 50 cm for objects at 800 km range and 850 nm imaging wavelength. We will therefore be able to resolve features such as the body shape and solar panels. Observations of the objects will be made over time so we can also measure the rotation.
AOI will enable us to achieve higher accuracy tracking satellites in GEO. The AO correction will allow smaller objects to be tracked as we have removed the speckle caused by atmospheric turbulence and the light is focussed in a smaller spot. We will measure the position of a satellite relative to a reference star from the gaia catalogue. With this technique Satellites are tracked as they pass within 15 arcseconds of a reference star and the position measured relative to this star. We will achieve positional accuracy of approximately 1 m for objects square metre or larger.
We will present the results from the first on-sky observations using AOI in its natural guide star mode. A campaign to observe and image satellites in LEO will be undertaken and we will report the analysis of the images captured such as feature detection and rotational measurement. The imaging camera operates at a speed of 30 to 60 Hz to eliminate field rotation and enable lucky imaging. We will investigate different imaging techniques and compare to determine the scenarios which provide optimal imaging quality. The results we obtain from observations will serve as a baseline for system performance, and these results will be compared to results obtained when the system is upgraded with a laser guide star (LGS) in 2019.
Date of Conference: September 11-14, 2018
Track: Adaptive Optics & Imaging