A practical detection of non-cooperative satellite based on ellipse fitting

As some of the valuable satellites can maintain working after on-orbit servicing, it's meaningful to study on the autonomous rendezvous. Most of these satellites are non-cooperative, more specifically, they have no target location markers or rendezvous sensors. This paper extracts the edge of the adapter ring as natures for recognition, measurement or even mechanical docking. A practical detection method of non-cooperative satellite based on ellipse fitting is proposed in this paper. By detecting the contours of the input image, we can estimate the ellipse parameters at the curve level. Linear segmentation method is used to extract straight-line segments from edge contours. After that, we construct a graph model to segment each line contour into elliptical arcs of a possible ellipse. Finally, ellipse detection based on least square algorithm is used to get the expression of the quadric curve in the pixel coordinate system of the image. The corresponding algorithm is experimented on the image in all directions with complex backgrounds, it can provide a real-time result with high accuracy compared with conventional methodologies.