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Observations of transients events at decameter wavelength with the UTR-2 radiotelescope

Observations of transients events at decameter wavelength with the UTR-2 radiotelescope

Alexander Konovalenko
LOFAR Transients Key Project Meeting, Meudon, December 2011

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transientskp

June 23, 2012
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  1. Observations of the pulse and sporadic radio emission at decameter

    wavelengths by using UTR-2 radio telescope Ukraine: A.Konovalenko , V.Zakharenko , V.Kolyadin , O.Ulyanov, I.Falkovich , V.Melnik , G.Litvinenko, M.Sidorchuk, S.Stepkin, I.Bubnov et al. France: Ph. Zarka, L. Denis, A. Coffre, J.-M. Griessmeir, J.Girard, I.Cognard, M.T agger, A. Lecacheux , C. Rosolen, J.-L.Bougeret et al. Austria: H.Rucker , G.Fisher et al. Germany: G. Mann, K. Breitling et al . Sweden: B. Thide, R.Karlsson Transients KSP LOFAR Meeting Meudon, 14 December, 2011 (For now it is in the frame of PICS Project CNRS – NSAU “Development of the low frequency radio astronomy with ultrahigh sensitivity and resolution”)
  2. The tasks of the ground-based low frequency radio astronomy (10-100

    MHz) in the stellar and planetary science Solar system + 1. The Sun (sporadic radio emission) + 2. The Sun (quiet) + 3. Solar wind (IPS, scattering) + 4. Earth ionosphere ⇓ ~ 5. Space weather + 6. Jupiter (DAM) + 7. Planetary lightnings (Saturn, etc.) - 8. The Moon (cosmic rays) Galaxy - 9. Exoplanets (hot jupiters) + 10. Active stars ⇓ - 11. “Galactic” weather + 12. Other stars (i.e. C II regions near B - stars → RRL’s) + 13. Pulsars - 14. Transients
  3. The UTR-2 radio telescope, N-S arm (1.8 km×60m) f =

    8…32 MHz, A eff max = 150 000 sq.m
  4. The UTR-2 radio telescope, E-W arm (900m×60m) March 23, 2007

  5. URAN-1…URAN-4 radio telescopes

  6. UTR-2, URAN -1, URAN-2, URAN -3, URAN-4 on the territory

    of Ukraine
  7. Modern requirements for the low frequency stellar and planetary radio

    astronomy (from the astrophysical point of view as well as in the frame of ionospheric and interference effects mitigation) •    Frequency  range                                                                                                                                                      ~  10  –  100  MHz •    Instant  band                                                                                                                                                                      >  20  MHz •    Max  ;me  resolu;on                                                                                                                                                1µs  …1ms •    Frequency  resolu;on                                                                                                                                        ~  1  kHz •  Dynamic  range                                                                                                                                                              >  90  dB  (16-­‐bit  ADC)      (front-­‐end,  back-­‐end) •  Sensi;vity                                                                                                                                                                                up  to  1  mJy    (with  corresponding  resolu;on,    band,  everaging) •    Effec;ve  area                                                                                                                                                                    104  …106  sq.  m •    Angular  resolu;on                                                                                                                                                  ~10  ang.min…~  1ang.sec.                                                                                                                                                                                                                        (large  effec;ve  area  is  more                                                                                                                                                                                                                                                                                    important  when  the  sensi;vity    is                                                                                                                                                                                                                                      not  limited  by  the  confusion  effect) •    Large  field  of  view,      mul;-­‐beam  capabili;es  (ON-­‐OFF),  all  sky  coveraging  or  full  hemisphere  steering •    So[ware  antenna  structure  (digital  imaging)  or  op;mal  combina;on  of  analog  and  digital  phase                systems •    Distant  antennas  implementa;ons  (100…1000  km)  in  VLBI  and  /  or  synchronized  modes
  8. New digital receivers for the low frequency radio astronomy (

    FPGA technology) 7  sets  are  on  the  Ukrainian  radio  telescopes  (UTR-­‐2,  URAN-­‐2,  URAN-­‐3,  GURT): • 2  sets  were  developed  in  the  frame  of  ANR  Project,  France  (Ph.Zarka); • 5  sets  were  developed  in  the  frame  of  NASU  Special  Program,  Ukraine  (A.  Konovalenko) Instant  frequency  band 32  MHz Number  of  eq.channals 8192 Frequency  resolu;on 4  kHz Max  ;me  resolu;on 0,5  ms Dynamic  range 90  dB(16-­‐bit  ADC) Input  channels 2 Auto-­‐    and  cross-­‐spectra yes Wave-­‐form yes R.Kozhin, V.Vinogradov ,D.Vavriv. Low-noise, high dynamic range digital receiver/ spectrometer for radio astronomy applications. MSMW 07 Symp. Proceedings, Kharkov, Ukraine, June 29-30, 2007, p. 736-738. V.Ryabov, D. Vavriv, Ph.Zarka, B.Ryabov, R.Kozhin, V.Vinogradov, L.Denis. A low-noise, high-dynamic-range, digital receiver for radio astronomy applications: an efficient solution for observing radio-bursts from Jupiter, the Sun, pulsars, and other astrophysical plasmas below 30 MHz. Astronomy and Astrophysics, 2010, v.510.
  9. The set of 5 digital receivers at UTR-2

  10. Solar  bursts  in  2-­‐baseline    operaAon  mode   (“North-­‐West”  and

     “South-­‐West”  antennas  of  UTR-­‐2)
  11. Typical  IPS  and  non-­‐typical  ionospheric  scinAllaAons  of  3C  144  in

     3-­‐beam  operaAon  mode  of  UTR-­‐2
  12. Jupiter  observaAons  by  UTR-­‐2

  13. Saturn  ElectrostaAc  Discharges  (SED)  in  ON-­‐OFF  mode  of  UTR-­‐2

  14. Dynamic  spectrum  of  PSRB1133+16

  15. AD  Leo  burst  detected  by  UTR-­‐2  in  3-­‐beam  operaAon  mode

     
  16. Ukrainian contribution to the development of the low frequency radio

    astronomy            There  is  Special  Programme  of   NaAonal  Academy  of  Sciences  of  Ukraine(2006…2009  and  future): 1. Upgrade  of  world  largest  exis3ng  Ukrainian  decameter          wave-­‐ length  radio  telescope  UTR-­‐2,    URAN-­‐1  …  URAN-­‐4  (  f=  8…32  MHz;   Aeff  max  =  200  000  sq.  m,  Nel  ~  4  000) 2.   Crea3on   of   new   genera3on   Ukrainian   low   frequency   radio   telescope        GURT    –        Giant          Ukrainian          Radio          Telescope       (f=    10…70    MHz;    Aeff  max  >  100  000  sq.  m,    Nel  ≥  1  000,  step  -­‐by  –   step)            (  output  data  format  should  be  compa3ble  to  LOFAR)
  17. Main    requirements    for    the    GURT Main

     goal  is  high  sensi3ve,  broad-­‐band,  high  3me  and  frequency  resolu3on,   high   interference   immune   studies   of   the   Universe     at     extremely   low   frequencies when  the    sensi3vity    is    non  –l  imited    prac3cally    by    the      confusion        effect               (  ∆S  min.fl.   ≤  ∆S  min.conf.     ):  frequency  range  (up  to  ionosphere  limit)                10  –  70    MHz  instant  frequency  band                                                                              60              MHz  effec3ve  area    (  step  -­‐  by  –  step  )                                            104  →  106  sq.m  exceeding  of  antenna  temperature                                    ≥    10  dB  exceeding  of  dynamic  range                                                            ≥    20  dB  two  polariza3on,  mul3-­‐beam  capabili3es    flexibility  
  18. New broad-band, high sensitive, high dynamic range active antenna element

    for Giant Ukrainian Radio Telescope Δf = 10 – 70 MHz, k ≥ 10 dB
  19. Frequency range: 10-70 MHz Gain of amplifier: 16 dB Output

    IP2 : 86 dBm; input IP2 : 70 dBm Output IP3 : 47 dBm; input IP3 : 31 dBm Output P1 dB : 19 dBm Exceeding of antenna temperature: 9 dB (10 MHz), 12 dB (45 MHz), 9 dB (70 MHz) Output VSWR : 1.6 Isolation between polarizations : > 27 MHz 3 dB beam width (40 MHz): 80o (E – plane), 140o (H – plane) Main parameters of the antenna element
  20. Type III solar burst measured by one antenna element (16-65

    MHz, July 2008)
  21. The scans towards 3C405 by UTR-2 E- W and GURT

    sub-array: red – E- W of UTR-2, 25 MHz; green – 25 el.arr., 25 MHz; blue – 25 el.arr., 58 MHz
  22. 25 elements GURT array, III b – III solar burst

    on 7 July, 2009
  23. The steps of 4 x 25 elements GURT array construction,

    2009 year
  24. 4  x  25  elements    GURT    array,  Apr.2010

  25. The existing and future low-frequency radio telescopes in Europe UTR-2

    LOFAR-AU GURT Germany LSS UK Italy Sweden Poland LOFAR GURT-A
  26. Visit      of    French    friends    on

       the    UTR-­‐2    -­‐    GURT  observatory  in  the   frame  of      PICS    Project        (November,  2011)
  27. None
  28. None
  29. Conclusion There is broad field of activity in the planetary

    and stellar LF radio astronomy. The implementation of largest existing radio telescopes, new generation high performance back-ends and methods gave many interesting astrophysical results. The creation and using of new generation low frequency radio telescopes (LOFAR, LWA, E-LOFAR, LSS, GURT, etc.) have good perspectives. It is valied also for the experiments with the distant antennas (up to ~ 1000 km ) in VLBI and/or synchronized modes