Metric accuracy improvements of space-based visible using spacecraft attitude drift corrections

The Midcourse Space Experimentsatellite, sponsored by the Ballistic Missile Defense Organization, was launched in April 1996 into an 898-km altitude, near sun-synchronous orbit. One of the principal sensors onboard the spacec raft is the Space-Based Visible, a visible-band, electro-optical camera des igned to perform the first technical and functional demonstration of space based space surveillance. The principal task of the Space-Based Visible is to gather metric and photometric information on a wide variety of resident space objects. To assess the metric performance of the sensor, routine on-o rbit metric calibration is performed. In addition, a complete independent e rror assessment was made using actual flight data. The goal of producing 4- arc-s (1-sigma) observations of resident space objects was set during desig n, and results show that this goal is being met. A method is presented that improves the metric observations of resident space objects to better than 2-arc-s (1-sigma) by estimating the drift of the spacecraft attitude during staring events and removing the effect from the observations. Compensating for this error source brings into agreement the results of on-orbit calibr ation and the independent error assessment.