A Hybrid Adaptive Optics System for Space Situational Awareness

Abstract

We are developing and will commission a space debris and object detection system in New Zealand that will provide high resolution capability to examine orbiting near Earth objects using a simplified, low-cost approach, where acquired data on new candidate objects are updated on a database. We will use a modular wide-field adaptive optics (AO) system to determine spatially variant distortion functions from multiple natural guide stars to compensate for atmospheric turbulence. To achieve this, our custom designed geometric wavefront sensor will provide estimates of phase distortion from each source object. Orbiting satellites and large space debris objects are detected within a wide field of natural stars, where a combination of closed- and open-loop adaptive optics are applied. A closed loop tip/tilt mirror system removes low-order aberrations in real-time, whereas an open-loop system will use deconvolution from wavefront sensing with batch processing to remove high-order distortion. Fast moving target objects will be imaged using a separate detector, where high frame rate-images of relatively bright objects will be used to minimise motion blur, and where synchronisation with AO cameras will allow removal of both low- and high-order aberrations from captured images. The hybrid AO system described in this paper will provide a platform to test novel methods for the detection of small, faint, fast-moving objects using alternative methods to atmospheric tomography.