Object Image Linking of Earth Orbiting Objects in the Presence of Cosmics

TL;DR

This paper presents a two-step method for linking Earth orbiting object images in telescope surveys, effectively filtering cosmic ray events and associating images to track objects despite cosmic interference.

Contribution

It introduces a novel cosmic filtering approach and a linking algorithm based on linear accelerated movement assumptions, tested on ESA space debris data.

Findings

Four cosmic filtering methods compared and tested.

Successful linking of object images despite cosmic ray interference.

Enhanced orbit determination accuracy from tracklet extraction.

Abstract

In survey series of unknown Earth orbiting objects, no a priori orbital elements are available. In surveys of wide field telescopes possibly many nonresolved object images are present on the single frames of the series. Reliable methods have to be found to associate the object images stemming from the same object with each other, so-called linking. The presence of cosmic ray events, so-called Cosmics, complicates reliable linking of non-resolved images. The tracklets of object images allow to extract exact positions for a first orbit determination. A two step method is used and tested on observation frames of space debris surveys of the ESA Space Debris Telescope, located on Tenerife, Spain: In a first step a cosmic filter is applied in the single observation frames. Four different filter approaches are compared and tested in performance. In a second step, the detected object images are linked on observation series based on the assumption of a linear accelerated movement of the objects over the frame during the series, which is updated with every object image, that could be successfully linked.