Precision Optical Light Curves of LEO and GEO Objects
Precision Optical Light Curves of LEO and GEO Objects
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发表时间：
2019
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通讯作者：
P. Chote;J. Blake;D. Pollacco
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作者：
P. Chote;J. Blake;D. Pollacco
光学光变曲线正在成为对常驻空间物体进行分类和表征属性的重要工具。反射阳光的强度和颜色探测物体的结构和反射率，由于物体姿态和观察者-物体-太阳几何形状的变化，物体的结构和反射率在一系列时间尺度上演变。因此，光曲线对物体的结构和旋转属性的特征进行编码，可以对其进行分析以约束物体的属性，或者通过机器学习技术将其整体应用以对未知物体进行分类。华威大学成立了一个新的研究小组，目标是研究绕地球运行的人造物体的特征和动力学。在这里，我们描述了两个原型机器人勘测，我们正在进行这些勘测，以获得 LEO 和 GEO 体系中物体的高节奏、精确校准的光变曲线。使用 SuperWASP 望远镜可以获取相对明亮（盖亚英镑 < 10）目标的 LEO 光变曲线，该望远镜已重新配置为 ∼ 200 deg2 视场和基于 GPS 的定时。目标被观察为恒星跟踪图像中的条纹，覆盖天空的 70%，并且定制的缩减管道以有效的时间节奏提取光曲线。根据 Gaia 目录校准的 100ms。 GEO调查使用临时安装的14“f/2.2望远镜和类似的观测技术，以<1秒的有效节奏获得短（约30分钟）的首次通过分类光曲线，以表征地球同步物体的短期变化。我们概述了调查策略和分析，并介绍了在运行第一个月期间获得的一些示例结果。
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 object’s 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.