Nanosatellites

23 II-3Ground-based Satellite Tracking

Enrico Stoll¹, Jürgen Letschnik^{2, 3}, and Christopher Kebschull¹

¹Institute of Space Systems, Technical University of Braunschweig, Germany

²Institute of Astronautics, Technical University of Munich, Germany

³Information Management System Architect, Airbus Defence and Space, Taufkirchen, Germany

23.1 Introduction

Sixty years of human spaceflight has left its traces in Earth orbit. The number of objects has significantly increased since the era of Sputnik, the Apollo program, and the Space Shuttle. Figure 23.1 shows the evolution divided into low Earth orbit (LEO), medium Earth orbit (MEO), geostationary orbit (GEO), highly eccentric Earth orbit (HEO), LEO–MEO crossing orbits (LMO), MEO–GEO crossing orbits (MGO), GEO transfer orbit (GTO), navigation satellites orbit (NSO), extended geostationary orbit (EGO), and other orbits. It is evident that the population in LEO dominates the number of objects. This trend of the steady increase of objects will be amplified in the future by the launch of mega constellations [2] that intend to provide a new global knowledge infrastructure by supporting Internet coverage everywhere on the planet.

If an object in Earth orbit is detectable from ground (see Section 23.3), it will be tracked and logged by the Joint Space Operations Center (JSpOC) via a network of space surveillance sensors. More than 40 000 objects were cataloged that way since the days of Sputnik, many of which have since re-entered. The catalog ...