Skip to main content
SpringerLink
Log in

Ground-to-satellite optical links: how effective is an uplink Tip/Tilt pre-compensation based on the satellite signal?

  • Original Paper
  • Published:
CEAS Space Journal Aims and scope Submit manuscript

Abstract

This paper investigates tilt decorrelations due to atmospheric anisoplanatism occuring when observing wavefronts emerging from distinct line of sight. The targeted application is ultimately the (pre-)compensation of the atmospheric turbulence experienced by a laser beam during ground-to-satellite optical links. The purpose of the study is to evaluate the effectiveness of the uplink pre-compensation, if the downlink signal (received from the satellite) is used as a reference. Because of the point-ahead angle of the satellite, one expects some decorrelation between the downlink and the uplink signals, which, in turn, impacts the efficacy of the pre-compensation. The larger the beam, the smaller its divergence and the more sensitive it is to pointing errors. In this framwork, a test campaign was carried out in May 2018 at the Optical Ground Station (OGS) of the European Space Agency (ESA), to perform measurements of double stars featuring angular separations representative of the point-ahead angle of GEO/LEO satellites. The differential Tip/Tilt distortion between the double stars is used as an estimator of the typical decorrelation between the downlink and the uplink signal, hence the present study. The algorithm used to extract the tip-tilt error due to anisoplanatism is described, and the experimental results are compared to the numerical predictions. It is then shown how to estimate the jitter of the telescope, based on the common motion of two independent stars as seen in the focal plane of the telescope. Finally, the paper provides a methodology to determine the maximum transmitter aperture of a ground-based terminal, in case a tilt pre-compensation is applied based on the satellite signal.

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

Access this article

Log in via an institution

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

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8

Similar content being viewed by others

References

  1. Henniger, H., Wilfert, O.: An introduction to free-space optical communications. Radioengineering 19(2), 203–212 (2010)

    Google Scholar 

  2. Belmonte, A., Taylor, M.T., Hollberg, L., Kahn, J.M.: Effect of atmospheric anisoplanatism on earth-to-satellite time transfer over laser communication links. Optics Express 25(14), 15676–15686 (2017)

    Article  Google Scholar 

  3. Foy, R., Labeyrie, A.: Feasibility of adaptive telescope with laser probe. Astron. Astrophys. 152, L29–L31 (1985)

    Google Scholar 

  4. Mata-Calvo, R., Calia, D. B., Barrios, R., Centrone, M., Giggenbach, D., Lombardi, G., Becker, P., Zayer, I.: Laser guide stars for optical free-space communications. In: Free-Space Laser Communication and Atmospheric Propagation XXIX, vol. 10096, p. 100960R. International Society for Optics and Photonics (2017)

  5. Beland, R.R.: Propagation through atmospheric optical turbulence. Atmos. Prop. Radiat. 2, 157–232 (1993)

    Google Scholar 

  6. Giggenbach, D.: Optimierung der optischen Freiraumkommunikation durch die turbulente Atmosphäre - FocalArray Receiver, PhD thesis, Universität Der Bundeswehr München (2004)

  7. Comeron, A., Dios, F., Rodriguez, A., Rubio, J. A., Reyes, M., & Alonso, A.: Modeling of power fluctuations induced by refractive turbulence in a multiple-beam ground-to-satellite optical uplink. In: Free-Space Laser Communications V, vol. 5892, p. 58920O. International Society for Optics and Photonics (2005)

  8. Fried, D.L.: Optical resolution through a randomly inhomogeneous medium for very long and very short exposures. J. Opt. Soc. Am. 56, 1372–1379 (1966)

    Article  Google Scholar 

  9. Fried, D.L.: Anisoplanatism in adaptive optics. J. Opt. Soc. Am. A. 72, 52–61 (1982)

    Article  Google Scholar 

  10. Sasiela, R.J.: Electromagnetic wave propagation in turbulence: evaluation and application of Mellin transforms, vol. 18. Springer Science & Business Media (2012)

  11. Foy, R., & Foy, F.C. (Eds.).: Optics in Astrophysics: Proceedings of the NATO Advanced Study Institute on Optics in Astrophysics, Cargèse, France from 16 to 28 September 2002, vol. 198. Springer Science & Business Media (2006)

  12. Andrews, L.C., Phillips, R.L., Sasiela, R.J., Parenti, R.R.: Strehl ratio and scintillation theory for uplink Gaussian-beam waves: beam wander effects. Opt. Eng. 45(7), 076001 (2006)

    Article  Google Scholar 

  13. Sasiela, R.J.: A unified approach to electromagnetic wave propagation in turbulence and the evaluation of multiparameter integrals, Tech. Rep. 807. MIT Lincoln Laboratory, Lexington, MA, (1988)

  14. Valley, G.C.: Isoplanatic degradation of tilt correction and short-term imaging systems. Appl. Opt. 19, 574–577 (1980)

    Article  Google Scholar 

  15. Olivier, S.S., Gavel, D.T.: Tip-tilt compensation for astronomical imaging. JOSA A 11(1), 368–378 (1994)

    Article  Google Scholar 

  16. Sasiela, R.J., Shelton, J.D.: Transverse spectral filtering and Mellin transform techniques applied to the effect of outer scale on tilt and tilt anisoplanatism. JOSA A 10(4), 646–660 (1993)

    Article  Google Scholar 

  17. Sandler, D.G., Stahl, S., Angel, J.R.P., Lloyd-Hart, M., McCarthy, D.: Adaptive optics for diffraction-limited infrared imaging with 8-m telescopes. JOSA A 11(2), 925–945 (1994)

    Article  Google Scholar 

Download references

Acknowledgements

This study was supported by the European Space Agency (ESA) in the framework of the ARTES ScyLight programme. The authors also gratefully acknowledge the Instituto de Astrofisica de Canarias (IAC) as well as the sky quality group (http://www.iac.es) for their support during the measurements campaign.

Author information

Authors and Affiliations

  1. European Space Agency - ESA/ESTEC, Keplerlaan 1, NL-2200 AG, Noordwijk, The Netherlands

    D. Alaluf & J. M. Perdigues Armengol

Authors
  1. D. Alaluf
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. J. M. Perdigues Armengol
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to D. Alaluf.

Appendix

Appendix

1.1 1m OGS telescope—elevation

See Table 5.

Table 5 Measurements of the double stars HIP 71762, performed at various elevations
Full size table

1.2 1m OGS telescope—angular separation

See Tables 6, 7.

Table 6 Measurements of the double stars HIP 52452, performed at various elevations
Full size table
Table 7 Measurements performed for various angular separations
Full size table

1.3 20cm guider telescope—elevation

See Tables 8, 9.

Table 8 Measurements performed for various elevations
Full size table
Table 9 Measurements performed for various elevations
Full size table

1.4 20cm guider telescope—angular separation

See Tables 10, 11.

Table 10 Measurements performed for various angular separations
Full size table
Table 11 Measurements performed for various angular separations
Full size table

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Alaluf, D., Armengol, J.M.P. Ground-to-satellite optical links: how effective is an uplink Tip/Tilt pre-compensation based on the satellite signal?. CEAS Space J 14, 227–238 (2022). https://doi.org/10.1007/s12567-021-00392-2

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12567-021-00392-2

Search

Navigation