Tanner Campbell, University of Arizona; Vishnu Reddy, University of Arizona; Richard Linares, Massachusetts Institute of Technology; Jeffery Larsen, United States Naval Academy; Roberto Furfaro, University of Arizona
Keywords: Optical LEO tracking, SSA, orbit determination
Abstract:
Tracking of artificial Earth satellites is typically performed with ground based radar, however optical sensors can be operated unmanned and sometimes have better pointing accuracy or resolution. Moreover, optical sensors are typically far less expensive to operate despite being weather limited. Commercial off the shelf (COTS) optical sensors can be used as an inexpensive alternative to radar for initial orbit determination (IOD) and tracking of artificial satellites with the added benefit of also providing characteristic photometry. This makes the ability to track and observe Earth satellites much more accessible to the research and academic community. Optical sensors can not only provide a backup for radar tracking, but can also offer better global coverage and confirmation of radar results. This research focuses on developing methods for automatically processing and reducing COTS optical sensor images from telescopes to be used for tracking and characterization of artificial satellites in all three main orbital regimes (Low, Mid, and Geosynchronous). Preliminary work has been done tracking multiple artificial Earth satellites, including the now defunct Chinese Space Station, Tiangong 1, as it descended back to our atmosphere. With algorithms successfully verified, current work focuses on validation by analyzing and characterizing sources of error to improve astrometric and photometric accuracy. To accomplish this, error in the observed positions of several satellites will be compared to their predicted locations. Observations of the geostationary telecommunication satellite GALAXY 15 are compared to predicted locations using published ephemeris showing a good characterization of the errors present in our system. The geostationary satellites ANIK F1, ANIK F1R, ANIK G1, and ECHOSTAR 17 have their observations compared to predicted locations using less accurate, two-line element (tle) data since no published ephemerides are available. Likewise, the observations of Tiangong 1 are also compared to tle data. This type of analysis gives a qualitative characterization of systematic errors in our process. Finally, catalog star positions are compared to our astrometric solutions to characterize the limiting noise in our data.
Date of Conference: September 11-14, 2018
Track: Poster