Experimental Astronomy

, Volume 26, Issue 1–3, pp 79–94 | Cite as

Back to the future: science and technology directions for radio telescopes of the twenty-first century

Historical Review


The early days of radio astronomy showed incredibly diverse experimentation in ways to sample the electromagnetic spectrum at radio wavelengths. In addition to obtaining adequate sensitivity by building large collection areas, a primary goal also was to achieve sufficient angular resolution to localize radio sources for multi-wavelength identification. This led to many creative designs and the invention of aperture synthesis and VLBI. Some of the basic telescope types remain to the present day, now implemented across the entire radio spectrum from wavelengths of tens of meters to submillimeter wavelengths. In recent years, as always, there is still the drive for greater sensitivity but a primary goal is now to achieve very large fields of view to complement high resolution and frequency coverage, leading to a new phase of experimentation. This is the “back to the future” aspect of current research and development for next-generation radio telescopes. In this paper I summarize the scientific motivations for development of new technology and telescopes since about 1990 and going forward for the next decade and longer. Relevant elements include highly optimized telescope optics and feed antenna designs, innovative fabrication methods for large reflectors and dipole arrays, digital implementations, and hardware vs. software processing. The emphasis will be on meter and centimeter wavelength telescopes but I include a brief discussion of millimeter wavelengths to put the longer wavelength enterprises into perspective. I do not discuss submillimeter wavelengths because they are covered in other papers.


Astrobiology Cosmology Galaxies General relativity Radio telescopes Digital processing 



I thank the organizers for putting together a stimulating program that both celebrated the invention of the telescope and its first astronomical use by Galileo and also looked toward the future. For useful conversations I thank Woody Sullivan and my colleagues in the National Astronomy and Ionosphere Center, the National Radio Astronomy Observatory, the U.S. SKA Consortium, and the SKA Program Development Office. This work was supported in part by a grant from the National Science Foundation to Cornell University.


  1. 1.
    Rogers, A.E.E., et al.: Deuterium abundance in the interstellar gas of the galactic anticenter from the 327 MHz line. Astrophys. J. Lett. 630, L41 (2005)CrossRefADSGoogle Scholar
  2. 2.
    Hinshaw, G., et al.: Five-year Wilkinson Microwave Anisotropy Probe (WMAP) observations: data processing, sky maps, and basic results. Astrophys. J. Suppl. 180, 225–245 (2009)CrossRefADSGoogle Scholar
  3. 3.
    Braatz, J.A., Reid, M.J., Greenhill, L.J., Condon, J.J., Lo, K.Y., Henkel, C., Gugliucci, N.E., Hao, L.: Investigating dark energy with observations of H_2O megamasers. In: Bridle, A.H, Condon, J.J., Hunt, G.C. (eds.) Frontiers of Astrophysics: A Celebration of NRAO’s 50th Anniversary. Astronomy Society of the Pacific Conference Series, vol. 395. Astronomy Society of the Pacific, San Francisco (2008)Google Scholar
  4. 4.
    Kramer, M., et al.: Tests of general relativity from timing the double pulsar. Science 314, 97–102 (2006)CrossRefADSGoogle Scholar
  5. 5.
    Foster, R.S., Backer, D.C.: Constructing a pulsar timing array. Astrophys. J. 361, 300 (1990)CrossRefADSGoogle Scholar
  6. 6.
    Jenet, F.A., et al.: Upper bounds on the low-frequency stochastic gravitational wave background from pulsar timing observations: current limits and future prospects. Astrophys. J. 653, 1571 (2006)CrossRefADSGoogle Scholar
  7. 7.
    Loeb, A., Zaldarriaga, M.: Eavesdropping on radio broadcasts from galactic civilizations with upcoming observatories for redshifted 21 cm radiation. J. Cosmology Astropart. Phys. 1, 20 (2007)CrossRefADSGoogle Scholar
  8. 8.
    Harwit, M.A.: Cosmic Discovery: The Search, Scope and Heritage of Astronomy. Basic Books, New York (1981)Google Scholar
  9. 9.
    Cordes, J.M.: Axes of discovery: the time domain and the radio synoptic survey telescope. In: Bridle, A.H., Condon, J.J., Hunt, G.C. (eds.) Frontiers of Astrophysics: A Celebration of NRAO’s 50th Anniversary. Astronomy Society of the Pacific Conference Series, vol. 395, p. 225. Astronomy Society of the Pacific, San Francisco (2008)Google Scholar
  10. 10.
    Condon, J.J.: Deep radio surveys. In: Afonso, J., Ferguson, H.C., Mobasher, B., Norris, R. (eds.) Deepest Astronomical Surveys. Astronomy Society of the Pacific Conference Series, vol. 380, p. 189. Astronomy Society of the Pacific, San Francisco (2007)Google Scholar
  11. 11.
    Hankins, T.H., Eilek, J.A.: Radio emission signatures in the crab pulsar. Astrophys. J. 670, 693 (2007)CrossRefADSGoogle Scholar
  12. 12.
    Rees, M.J.: A better way of searching for black-hole explosions. Nature 266, 333 (1977)CrossRefADSGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  1. 1.Astronomy DepartmentCornell UniversityIthacaUSA

Personalised recommendations