1 / 34

Advancements in Radio Telescope Technology: A Glimpse into the Future

Explore the exponential growth and international megaprojects in radio astronomy, future telescope developments, and cutting-edge technology like HEMT receivers and photonics. Learn about consumer cryogenics and digital signal processing for enhancing radio telescopes. Discover how radio telescope arrays combat interference and delve into the possibilities of microprocessor performance in astronomical research.

pawlak
Download Presentation

Advancements in Radio Telescope Technology: A Glimpse into the Future

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. New Technology for Array Telescopes cm wavelength arrays R. D. Ekers National Radio Science Meeting, Boulder, 7 Jan 2000

  2. Jansky 1937 - the beginning Radio Telescope Sensitivity • Exponential increase in sensitivity x 105 since 1940 ! • 3 year doubling time for sensitivity R D Ekers

  3. Exponential Growth • Livingstone Curve • Blewett, Brookhaven 1950 • Fermi 1954 • Livingstone 1962 • De Solla Price 1963 • exponential growth • Little science, big Science • Moore’s Law (1965) • computing power doubles every 18months R D Ekers

  4. No technical reason not to continue this growth Exponential increase in sensitivity x 105 since 1940 ! 3 year doubling time for sensitivity SKA stations in landscape Radio Telescope Sensitivity SETI Institute UC Berkeley Path to the Future Future Radio Telescopes R D Ekers

  5. Radio Astronomy • Provides unique information about the Universe • non-thermal processes: quasars, pulsars, ... • highest angular resolution: VLBI • low opacity: Galactic nuclei R D Ekers

  6. UPGRADES VLA (7mm, 4m) Merlin WSRT Penticton Arecibo (optics) Parkes (FPA) ACTA (10-100GHz) Hat Creek IRAM ..... COMPLETING VLBA GMRT GBT [300’ upgrade?] 1990's the decade of the upgrades NEW STARTS • mmA (ALMA) • SKA • LOFAR, 1hT, KARST... R D Ekers

  7. International Megaprojectsin Radio Astronomy • Dramatic improvements in sensitivity • VLA upgrade and other smaller projects • $US200M • mm arrays in the Atacama dessert in Chile (ALMA) • 1998-2005: $US700M • Redshifted molecular lines • One Square Km telescope at cm wavelengths (SKA) • 2008-2015: $US500M R D Ekers

  8. COBE satellite NASA “Primordial soup” - matter and energy radio ? Square-Kilometre Array “Dark Ages” - before the stars Early galaxies - stars light up light Hubble Space Telescope NASA / ESA Telescopes Look Back in Time

  9. SKA 2008 VLA 1980 Future Sensitivity HST R D Ekers

  10. Communications developments Radio Telescopes of the Future • HEMT receivers • wide band, cheap, small and reliable • Can build low noise systems with many elements • Focal plane arrays • Field of view • Interference rejection • adaptive nulling can work in single dishes and arrays • More computing capacity • computing power doubles every 18months (Moore’s Law) R D Ekers

  11. MMIC (Transistors) • GAs -> InP • Extend frequency range 1GHz - > 150 GHz • Wide instantaneous bandwidth • Large scale integration • Complete receiver system on one chip • Focal plane arrays • Receivers embedded in feed structure • Integrated photonics R D Ekers

  12. Consumer Cryogenics • Driven by changes in the communications industry • cryogenics in all communications towers • Inexpensive low noise receiver packages • Superconducting filters • interference mitigation R D Ekers

  13. Photonics • signal transport via fibers • low loss, high bandwidth, immunity to interference • needs inexpensive transmitters/receivers • Eg Vicsel optical modulator $10-20 • LO transport via fibres • local (on chip) LO generation • Integrated photonics to reduce component count • Time delay arraying • Filters • fibre gratings for tunable wide band microwave filters R D Ekers

  14. Installing the Parkes 21cm Multibeam Receiver R D Ekers

  15. The Multibeam FPA Receiver • 13 beams in focal plane • HI Survey of the local Universe • Complete HI selected galaxy catalog out to z = 0.04 • low-surface brightness galaxies • high-velocity cloud survey • 21cm pulsar survey • 7x faster than any previous survey • FPA makes all sky surveys possible at higher frequencies R D Ekers

  16. Forte satellite: 131MHz Terrestrial Interference R D Ekers FORTÉ satellite: 131 MHz

  17. The RFI Challenge • Sensitivity to increase (100x) • Whole of radio spectrum needed • early Universe studies require “whole” spectrum to see redshifted lines • but only to “listen”, and only from a few locations. • 2% of spectrum is reserved for Radio Astronomy • LEO telecom satellites a new threat • no place on Earth free frominterference from sky • current regulations will be inadequate R D Ekers

  18. - eg pulsar dispersion  Antenna arrays can cancel RFI using all these ! RFI fundamentals • The interference and radio astronomical signals can differ in all these parameters • Frequency • Time • Position • Polarization • Distance • Positivity • We can use one or more of these to separate the interference from the astronomical signals In this phase space the radio sky is very empty!

  19. Adaptive array nulling R D Ekers

  20. Digital • Using Moore’s law • Wide bandwidth signal processing • 2-20GHz • Software radio’s • 20GHz in next decade • consumer market driven • Interference mitigation • Access to entire spectrum • Smart Antennas • Image processing • Can make array’s easy to use R D Ekers

  21. Microprocessor performance R D Ekers

  22. Object Oriented Software • AIPS++ • Astronomical Image Processing System • C++, scripting, GUI’s, libraries, toolkits and applications • Designed by a team of astronomers and programmers • Public release mid 99 • Developed by an international consortium of observatories R D Ekers

  23. Square Kilometer Array • Current large telescope technology dates from 1960/70’s • Era of facilities upgrades approaching its end • Large increase in sensitivity is needed (100x) • epoch of first stars and galaxies • New challenges: • cost • frequency coverage • man-made interference • Technology shift will be required... R D Ekers

  24. Square km telescope: the concept • One square km radio telescope (1kT) in 2010 • 2002 detailed design, prototypes • 2007 construction • 2012 operations • Frequency range 0.03 - 20GHz • Sensitivity 100 x VLA • Multibeam (at lower frequencies) • Need innovative design to reduce cost • International funding unlikely to exceed $500m • 106 sq metre => $500 / sq metre • cf VLA $10,000 / sq metre • GMRT $1,000 / sq metre R D Ekers

  25. Multi beams Element antenna pattern Station antenna patterns Synthesized beams 16 • Observing teams with their own beams • like particle accelerator, but can have all beams simultaneously • Observe before trigger ! • Using baseband buffer 12 8 4 NFRA 1998

  26. Who is Involved ? • Netherlands: SKAI Phased array • NFRA • Australia: 1kT Luneberg lens array • CSIRO • USA: 1hT Small dish array • SETI, UCB, MIT… communications antennas • Canada: LAR Large adaptive reflectors • DRAO long F/D • China: KARST Large adaptive reflectors • BAO spherical • India: -- Medium size dishs • NCRA fine mesh • UK : -- • Jodrell Bank

  27. Netherlands - NFRA:One Square Meter Phased Array • > octave BW: • 1.75 - 4 GHz • 64 active elements • 2 full sensitivity RF beams • 2 full sensitivity adaptive, digitally formed beams • adaptive algorithm on IC (CORDIC) NFRA 1998 R D Ekers

  28. Square-Kilometre ArrayNetherlands 1kT - PMSEIC WG http://www.nfra.nl/skai/

  29. Luneburg Lens • Spherical lens with variable permittivity, er = (2 – r2) • A collimated beam is focussed onto the other side of the sphere • Beam can come from any direction R D Ekers

  30. Luneburg Lens antenna systems • Optim Microwave • A Commercial Luneburg Lens • www.optim-microwave.com R D Ekers

  31. Luneburg Lens All sky coverage multiple simultaneous beams Possible design 5-m spheres Each patch 100 m diameter 100s of patches Square-Kilometre Array CSIRO -Australia R D Ekers http://www.atnf.csiro.au/SKA/

  32. 1hT SETI Institute - UC Berkeley • SETI Institute &UC Berkeley • ~500 x 5 m diameter dishes • 1 ha effective area • 1–10 GHz • 4o FOV at 1 GHz http:// www.seti.org

  33. Large Adaptive ReflectorNRC - Canada • 200m diameter stations • flat panels • large F/R • receivers supported by balloon • 500m above reflector • 250 MHz to 22 GHz. R D Ekers http//www.drao.nrc.ca/science/ska/

  34. KARST Large Radio Telescope - China • BAO - China • Kilometer square Area Radio Synthesis Telescope • 500m diameter • Spherical reflector • 300m locally parabolic http://www.bao.ac.cn/bao/LT/

More Related