Automatic Reacquisition of Satellite Positions by Detecting Their Expected Streaks In Astronomical Images

Artificial satellites, and particularly space junk, drift from their known orbits. In the surveillance-of-space context, they must be observed frequently to ensure that their corresponding orbital elements are up-to-date. Autonomous ground-based optical systems are regularly tasked to observe these objects, measure their positions, and then update their orbital parameters accordingly. The real satellite positions are provided by the detection of the satellite streaks in the astronomical images specifically acquired for this purpose. This paper presents the image processing techniques used to detect and extract the satellite positions. The methodology includes several processing steps including: image background estimation and removal, star detection and removal, an iterative matched filter for streak detection, and finally false alarm rejection algorithms. This detection methodology is able to detect very faint objects. Simulated data were used to evaluate the methodology’s performance and determine the sensitivity limits where the algorithm can perform detection without false alarm, which is essential to avoid corruption of the orbital parameter database.