DeSS4SatOp is a service that offers to satellite operators the orbit determination through optical observations improving the results obtained.

Operations on a fleet of spacecraft require orbit determination in order to support its routine operations, perform collision avoidance, determine and calibrate station keeping manoeuvres and to generate products to support payload(s) operations and the related on-ground data processing. Usually, the orbit determination for a GEO fleet is performed using ranging measurements taken from a primary ranging station (PRS) and a backup ranging station (BRS).

This approach has proven adequate with respect to mission requirements for the nominal operations of the GEO constellations. However, it is known that, when observations are taken always with similar observational geometries, there can be biases that cannot be eliminated. These biases can also arise when performing orbit determination using homogeneous sensors and observables.

Deimos offers a supplementary service of optical observations and orbit determination, with the objective of evaluating a robust solution fully integrated in the operational system.

Elecnor Deimos offers a supplementary service of optical observations and orbit determination, with the objective of evaluating a robust solution fully integrated in the operational system. The optical observations provide not only observations with different geometries, but also different observables (angles instead of ranges), and generated by independent systems.

Optical observations are taken nominally from the primary location, the Deimos Sky Survey (DeSS) facilities in Puertollano, Spain. The remaining optical facilities are activated only when the weather forecasts in the primary site do not allow ful lling the objective. The optical measurements obtained by this network complement the ranging measurements that are taken routinely from ranging stations.

This kind of service is available since June 2018 for clients like EUMETSAT, which GEO fleet comprising four satellites in a regular basis uses the optical measurements to enhance the orbit determination.


DEIMOS provides support to satellite operators by contributing to the daily operational activities.  This support includes:

  • Provision of optical observations that can be processed by the satellite operators within the flight dynamics.
  • Computing, at our premises, the orbits from those observations, independently, or in combination with the ranging stations data.
  • Computing and calibrating the manoeuvres executed by the satellites.

The accuracy of DeSS observations, and the capability to reach objects in LEO, MEO and GEO regimes, allow us to provide services to satellite operators in the communication, earth observation, science and other fields.

Other services provided are:

  • Conjunction Analysis Support: a complete service to minimize the impact of the conjunction events on missions and the evaluation of recommended avoidance manoeuvres.
  • Contingency and other Support: support mission operators in the contingency events, where the satellite has lost control with the ground stations being able of obtain information on the position and satellite behaviour with no active contribution from the satellite.

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