Skip to main content
Log in

Optimization of Time Data Codification and Transmission Schemes: Application to Gaia

  • Published:
Experimental Astronomy Aims and scope Submit manuscript


Gaia is an ambitious space observatory devoted to obtain the largest and most precise astrometric catalogue of astronomical objects from our Galaxy and beyond. On-board processing and transmission of the huge amount of data generated by the instruments is one of its several technological challenges. The measurement time tags are critical for the scientific results of the mission, so they must be measured and transmitted with the highest precision – leading to an important telemetry channel occupation. In this paper we present the optimization of time data, which has resulted in a useful software tool. We also present how time data is adapted to the packet telemetry standard. The several communication layers are illustrated and a method for coding and transmitting the relevant data is described as well. Although our work is focused on Gaia, the timing scheme and the corresponding tools can be applied to any other instrument or mission with similar operational principles.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others


  • Bastian, U.: 2004, ‘Reference systems, conventions and notations for Gaia’, Technical note GAIA-ARI-BAS-003.

  • Consultative Committee for Space Data Systems: 2000, ‘Packet telemetry’, CCSDS 102.0-B-5 blue book.

  • Consultative Committee for Space Data Systems: 2002, ‘Time code formats’, CCSDS 301.0-B-3 blue book.

  • De Bruijne, J.: 2003, ‘Gaia clock accuracy and stability’, Technical note GAIA-JdB-004.

  • European Space Agency, Standards Approval Board for Space Data Communications: 1988, ‘Packet telemetry standard’, ESA PSS-04-106 Issue 1.

  • Høg, E.: 2002, ‘Sampling for all magnitudes: Scheme C’, Technical note GAIA-CUO-113.

  • Jordi, C., Babusiaux, C., Katz, D., Portell, J. and Arenou, F.: 2003, ‘Gaia: Instrument and satellite parameters’, Technical note GAIA-SWG-012.

  • Pace, O.: 1998, ‘Clarification on the Probability of Frame Loss (PFL) in data transmission to ground’, Technical note SAG-OP-001.

  • Portell, J., García-Berro, E. and Luri, X.: 2001, ‘Flux data codification: Proposals of simple codification schemes’, Technical note GAIA-BCN-001.

  • Portell, J. et al.: 2002, ‘Payload data handling, compression and telemetry formatting’, Kick-off meeting of the Simulation Working Group of Gaia.

  • Portell, J., García-Berro, E. and Luri, X.: 2004, ‘Timing and transmission schemes for Gaia’, Technical note GAIA-BCN-006.

Download references

Author information

Authors and Affiliations


Corresponding author

Correspondence to J. Portell.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Portell, J., GarcÍA-Berro, E. & Luri, X. Optimization of Time Data Codification and Transmission Schemes: Application to Gaia. Exp Astron 16, 189–212 (2003).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: