Satellite Ephemeris Estimator -Satellite Ephemeris Estimator for LEOP, Geostationary orbital move, MEO and LEO satellites.


Objectives of the project:

  • To study and prove that it’s possible to estimate accurate ephemeris with a fully passive ranging method for:
    • LEOP: from the start of the launch to the final position of the satellite;
    • Orbital move for Geostationary satellite: when a satellite changed its longitude position;
    • MEO: for satellites in Medium Earth Orbit;
    • LEO: for satellites in Low Earth Orbit.
  • When it’s possible, to give expected accuracy of the system;
  • To define the architecture of the system.


To find which parameters the system shall process for an accurate satellite’s ephemeris, the to define hardware and software architectures

For system modelisation, to define accuracy assessment.


With a very simple, light and low cost stations, even transportable, the system will be able to estimate orbits with high accuracy.


This product or system will provide:

  • Satellite ephemeris,
  • Measurement for ephemeris estimation (in this case ephemeris processing will be done by the customer).

System Architecture

Architecture of the system will be based on several passives small stations.


From standard orbits, study of parameters drift, range. Overall system modelisation for simulation.

From these parameters, statistical study to define which parameters can be processed

Architecture definition for hardware and software modules.

Current status

  • TLE conversion to osculatory elements --> Done
  • LEOP for chemical propulsion satellite --> Done for simulation and measurement with BulgariaSat
  • LEOP for electrical propulsion satellite --> In progress. ZDS tries to catch signal from Eutelsat 172B


ESA Contacts

Status date

Tuesday, October 17, 2017 - 09:07