Paul Chote, University of Warwick; James Blake, University of Warwick; Don Pollacco, University of Warwick
Keywords: LEO light curves, GEO light curves, Imaging, Calibrated photometry, Robotic telescopes
Abstract:
Optical light curves are becoming an essential tool for classifying and characterising the properties of resident space objects. The intensity and colour of reflected sunlight probes the structure and reflectivity of the object, which evolves on a range of timescales due to changes in the objects attitude and the observer-object-sun geometry. Light curves therefore encode a signature of the objects structure and rotational properties, which can be analysed to constrain properties of the objects or applied en-masse to classify unknown objects via machine learning techniques.
A new research group has formed at the University of Warwick with a goal of studying the characteristics and dynamics of man-made objects orbiting the Earth. Here we describe two prototype robotic surveys that we are undertaking to obtain high-cadence, precisely calibrated light curves for objects in both LEO and GEO regimes.
LEO light curves are being obtained for relatively bright (Gaia GBP < 10) targets using the SuperWASP telescope, which has been reconfigured with a ?200 deg2 field of view and GPS-based timing. Targets are observed as streaks in sidereally tracked images that tile ?70% of the pass across the sky, and a custom reduction pipeline extracts light curves with an effective time cadence < 100ms that are calibrated against the Gaia catalogue. The GEO survey uses a temporarily installed 14 f/2.2 telescope and similar observing techniques to obtain a short (?30 minute) first-pass classification light curve at a < 1 s effective cadence to characterise the short-period variability of geosynchronous objects. We provide an overview of the survey strategies and analysis and present some example results obtained during the first month of operations. Date of Conference: September 17-20, 2019
Track: Non-Resolved Object Characterization