Rongyu Sun, Purple Mountain Observatory, Chinese Academy of Sciences; Shengxian Yu, Purple Mountain Observatory, Chinese Academy of Sciences
Keywords: optical survey, space debris, catalog, object detection
Abstract:
The growing population of space debris is an increasing threat for operational spacecraft and some unique orbital environments. Optical survey is the main technique for searching space objects, and it is especially efficiency for detecting MEO and GEO objects. Here a survey performing with a large field of view (about 20 square degrees) 50-cm refracting telescope is presented. In our survey, first the dynamical features of space object in high Earth orbital region are investigated to restrain the survey regions, then the searching areas are scheduled accordingly to improve the efficiency. During observation, the survey field is divided into 240 sub-fields in horizonal system, each sub-field is the same size as the field of view of our telescope and the stare mode is adopted during exposure, the field is switched every minute, acquiring around 15 raw CCD images for each sub-field. Within one night, about 4 hours are taken to complete the survey, and around 4800 square degrees of the sky are scanned. A dedicated image processing pipeline is developed to detect objects automatically. To improve the detection efficiency and robustness, in the pipeline several innovative algorithms are introduced to eliminate the noises and promote the object detection ability, e.g. mathematical morphology transformation and iterative linear extrapolation linking for images. Each raw image takes about 4 seconds to extract the information of the objects, which means the raw images can be reduced in real time. The survey was lasting for a month, and for each night not affected by weather condition and the moonlight, around 700 tracklets can be obtained, the efficiency of our reduction technique is evaluated, and the correlation of objects is investigated.
Date of Conference: September 11-14, 2018
Track: Poster