International VLBI Service for Geodesy and Astrometry

Delivering high-quality products and embarking on observations of the next generation


The International VLBI Service for Geodesy and Astrometry (IVS) regularly produces high-quality Earth orientation parameters from observing sessions employing extensive networks or individual baselines. The master schedule is designed according to the telescope days committed by the stations and by the need for dense sampling of the Earth orientation parameters (EOP). In the pre-2011 era, the network constellations with their number of telescopes participating were limited by the playback and baseline capabilities of the hardware (Mark4) correlators. This limitation was overcome by the advent of software correlators, which can now accommodate many more playback units in a flexible configuration. In this paper, we describe the current operations of the IVS with special emphasis on the quality of the polar motion results since these are the only EOP components which can be validated against independent benchmarks. The polar motion results provided by the IVS have improved continuously over the years, now providing an agreement with IGS results at the level of 20–25 \(\upmu \)as in a WRMS sense. At the end of the paper, an outlook is given for the realization of the VLBI Global Observing System.

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

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14


  1. Abbondanza C, Chin T, Gross R, Heflin M, Parker J, van Dam T, Wu X (2016) JTRF2014, the 2014 JPL realization of the ITRS. Geophysical research abstracts, vol 18, EGU2016-10583

  2. Altamimi Z, Collilieux X, Métivier L (2011) ITRF2008: an improved solution of the international terrestrial reference frame. J Geod 85(8):457–473

    Article  Google Scholar 

  3. Bare C, Clark BG, Kellermann KI, Cohen MH, Jauncey DL (1967) Interferometer experiment with independent local oscillators. Science 157(3785):189–191

    Article  Google Scholar 

  4. Bizouard C, Gambis D (2009) The combined solution C04 for Earth orientation parameters consistent with international terrestrial reference frame 2005. In: Drewes H (ed) Geodetic reference frames, IAG symposia, vol 134. Springer, Berlin, Heidelberg, pp 265–270. doi:10.1007/978-3-642-00860-3_41

  5. Broten NW, Legg TH, Locke JL, McLeish CW, Richards RS, Chisholm RM, Gush HP, Yen JL, Galt JA (1967) Long base line interferometry: a new technique. Science 156(3782):1592–1593. doi:10.1126/science.156.3782.1592

    Article  Google Scholar 

  6. Campbell J, Nothnagel A (2000) European VLBI for crustal dynamics. J Geodyn 30(3):321–326

    Article  Google Scholar 

  7. Carter WE, Robertson DS (1986) Projects POLARIS and IRIS: monitoring polar motion and UT1 by very long baseline interferometry. In: Anderson AJ, Cazenave A (eds) Space geodesy and geodynamics. Academic Press, Orlando, pp 269–279

    Google Scholar 

  8. Clark TA, Corey BE, Davis JL, Elgered G, Herring TA, Hinteregger HF, Knight CA, Levine JI, Lundqvist G, Ma C, Nesman EF, Phillips RB, Rogers AEE, Ronnang BO, Ryan JW, Schupler BR, Shaffer DB, Shapiro II, Vandenberg NR, Webber JC, Whitney AR (1985) Precision geodesy using the Mark-III very-long-baseline interferometer system. IEEE Trans Geosci Remote Sens GE-23:438–449

  9. Coates RJ, Frey H, Mead GD, Bosworth JM (1985) Space-age geodesy—the NASA crustal dynamics project. IEEE Trans Geosci Remote Sens (ISSN 0196-2892) GE-23:360–368

  10. Cohen MH, Shaffer DB (1971) Positions of radio sources from long-baseline interferometry. AJ 76:91–100

    Article  Google Scholar 

  11. Dehant V, Lambert S, Koot L, Trinh A, Folgueira M (2012) Recent advances in applications of geodetic VLBI to geophysics. In: Behrend D, Baver KD (eds) Seventh IVS General Meeting Proceedings, Madrid, Spain, March 4–9, 2012, NASA, pp 362–369

  12. Hinteregger HF, Shapiro II, Robertson DS, Knight CA, Ergas RA, Whitney AR, Rogers AEE, Moran JM, Clark TA, Burke BF (1972) Precision geodesy via radio interferometry. Science 178:396–398. doi:10.1126/science.178.4059.396

    Article  Google Scholar 

  13. IERS (2015) In: Dick WR, Thaller D (eds) IERS Annual Report 2014. Verlag des Bundesamts für Kartographie und Geodäsie, Frankfurt am Main

  14. Jacobs CS, Arias F, Boboltz D, Böhm J, Bolotin S, Bourda G, Charlot P, de Witt A, Fey A, Gaume R, Gordon D, Heinkelmann R, Lambert S, Ma C, Malkin Z, Nothnagel A, Seitz M, Skurikhina E, Souchay J, Titov O (2014) ICRF-3: Roadmap to the next generation ICRF. In: Capitaine N (ed) Proc. Journées 2013, Systèmes de référence spatio-temporels, Paris, France, 16–18 September 2013, pp 51–56

  15. Luzum B, Nothnagel A (2010) Improved UT1 predictions through low-latency VLBI observations. J Geod 84(6):399–402. doi:10.1007/s00190-010-0372-8

    Article  Google Scholar 

  16. Ma C, Arias EF, Eubanks TM, Fey AL, Gontier A-M, Jacobs CS, Sovers OJ, Archinal BA, Charlot P (1998) The international celestial reference frame as realized by very long baseline interferometry. AJ 116:516–546. doi:10.1086/300408

    Article  Google Scholar 

  17. Malkin Z (2009) On comparison of the Earth orientation parameters obtained from different VLBI networks and observing programs. J Geod 83:547–556. doi:10.1007/s00190-008-0265-2

    Article  Google Scholar 

  18. Matveenko LI, Kardashev NS, Sholomitskii GB (1965) Large base-line radio interferometers. Radiophys Quantum Electron 8(4):461–463. doi:10.1007/BF01038318

    Google Scholar 

  19. Moran JM, Crowther PP, Burke BF, Barrett AH, Rogers AEE, Ball JA, Carter JC, Bare CC (1967) Spectral line interferometry with independent time standards at stations separated by 845 kilometers. Science 157(3789):676–677

    Article  Google Scholar 

  20. Nothnagel et al (2015) The IVS data input to ITRF2014. International VLBI Service for Geodesy and Astrometry. doi:10.5880/GFZ.1.1.2015.002

  21. Petrachenko B, Niell A, Behrend D, Corey B, Böhm J, Charlot P, Collioud A, Gipson J, Haas R, Hobiger T, Koyama Y, MacMillan D, Malkin Z, Nilsson T, Pany A, Tuccari G, Whitney A, Wresnik J (2009) Design aspects of the VLBI2010 system—progress report of the IVS VLBI2010 Committee. NASA/TM-2009-214180

  22. Petrachenko WT, Niell AE, Corey BE, Behrend D, Schuh H, Wresnik J (2012) VLBI2010: next generation VLBI system for geodesy and astrometry. In: Kenyon S, Pacino MC, Marti U (eds) Geodesy for Planet Earth, International Association of Geodesy Symposia, vol 136. Springer, Berlin, Heidelberg, pp 999–1006. ISBN: 978-3-642-20337-4

  23. Petrachenko W, Behrend D, Hase H, Ma C, Niell A, Schuh H, Whitney A (2013) EGU General Assembly 2013, 7–12 April, 2013, Vienna, Austria, id. EGU2013-12867

  24. Plank L, Lovell J, Shabala S, Böhm J, Titov O (2015) Challenges for geodetic VLBI in the southern hemisphere. Adv Space Res 304–313. doi:10.1016/j.asr.2015.04.022

  25. Richter B, Dick W, Schwegmann W (2005) Proceedings of the IERS Workshop on site co-location, Matera, Italy, 23–24 October 2003. In: Richter B, Schwegmann W, Dick WR (eds) (IERS Technical Note; 33). Frankfurt am Main: Verlag des Bundesamts für Kartographie und Geodäsie. ISBN 3-89888-793-6

  26. Robertson DS, Carter WE, Campbell J, Schuh H (1985) Daily earth rotation determinations from IRIS very long baseline interferometry. Nature 316:424–427

    Article  Google Scholar 

  27. Schlüter W, Behrend D (2007) The International VLBI Service for Geodesy and Astrometry (IVS): current capabilities and future prospects. J Geod 81(6–8):379–387. doi:10.1007/s00190-006-0131-z

    Article  Google Scholar 

  28. Schlüter W, Himwich WE, Nothnagel A, Vandenberg NR, Whitney AR (2002) IVS and its important role in the maintenance of the global reference systems. Adv Space Res 30(2):145–150 (Elsevier Science Ltd.)

    Article  Google Scholar 

  29. Schuh H, Behrend D (2012) VLBI: a fascinating technique for geodesy and astrometry. J Geodyn 61:68–80

    Article  Google Scholar 

  30. Seitz M, Angermann D, Bloßfeld M, Drewes H, Gerstl M (2012) The 2008 DGFI realization of the ITRS: DTRF2008. J Geod 86(12):1097–1123

  31. Shapiro II, Robertson DS, Knight CA, Counselman CC, Rogers AEE, Hinteregger HF, Lippincott S, Whitney AR, Clark TA, Niell AE, Spitzmesser DJ (1974) Transcontinental baseline and the rotation of the Earth measured by radio interferometry. Science 186:920–922

  32. Smith DE, Baltuck M (1993) Introduction (to the Crustal Dynamics Project). In: Smith DE, Turcotte DL (eds) Contributions of space geodesy to geodynamics: crustal dynamics, vol 23. Geodynamics series. AGU, Washington, DC

  33. Sovers OJ, Fanselow JL, Jacobs CS (1998) Astrometry and geodesy with radio interferometry: experiments, models, results. Rev Mod Phys 70(4):1393–1454

    Article  Google Scholar 

  34. Thompson AR, Moran JM, Swenson GW (2007) Interferometry and synthesis in radio astronomy, 2nd edn. Wiley, Weinheim

    Google Scholar 

  35. UN (2015) Global geodetic reference frame for sustainable development (GGRF). Resolution of the United Nations, Ref. No. A/69/L.53, adopted by the United Nations General Assembly on Feb. 26, 2015, New York

  36. Whitney AR (2000) How Do VLBI correlators work? In: Vandenberg NR, Baver KD (eds) International VLBI Service for Geodesy and Astrometry 2000 General Meeting Proceedings, NASA/CP-2000-209893, pp 187–205

  37. Wooden W, Luzum B, Stamatakos N (2010) Current status and future directions of the IERS RS/PC predictions of UT1. Highlights Astron 15:218. doi:10.1017/S1743921310008872

    Google Scholar 

  38. Yoshino T (1999) Overview of the Key Stone Project. J Commun Res Lab 46(1):3–6 (Tokyo)

    Google Scholar 

Download references

Author information



Corresponding author

Correspondence to A. Nothnagel.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Nothnagel, A., Artz, T., Behrend, D. et al. International VLBI Service for Geodesy and Astrometry. J Geod 91, 711–721 (2017).

Download citation


  • VLBI
  • Polar motion
  • Product quality
  • VLBI Global Observing System