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EISCAT 3D workshop, Uppsala, 19 – 21 May 2010 The LOIS project Part of the Nature OnLine collaboration Bo Thidé Swedish Institute of Space Physics, IRF,

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Presentation on theme: "EISCAT 3D workshop, Uppsala, 19 – 21 May 2010 The LOIS project Part of the Nature OnLine collaboration Bo Thidé Swedish Institute of Space Physics, IRF,"— Presentation transcript:

1 EISCAT 3D workshop, Uppsala, 19 – 21 May 2010 The LOIS project Part of the Nature OnLine collaboration Bo Thidé Swedish Institute of Space Physics, IRF, Uppsala, Sweden With contributions from the LOIS OAM/radio topology collaboration

2 EISCAT_3D Workhop. Uppsala, 19 – 21 May 2010 LOIS vector radio facilities in southern Sweden and labs in Uppsala for OAM radio and radar system assessments Bo Thidé2 Computer cluster (funded by two Shared University Research grants from IBM) The control room at the LOIS Test Station Risinge/Växjö. 9m×8m × 6m antenna chamber, Ångström Lab, Uppsala Magnetometer, LOIS Test Station, Risinge/Växjö Radio Sweden’s transmitter located about 100 km south of the Växjö LOIS test station and 100 km south-west of the Ronneby prototype station site. Will be used for space radar tests.

3 EISCAT_3D Workhop. Uppsala, 19 – 21 May 2010Bo Thidé3 LOIS radio idea: Sample the entire field vectors in time and space (LOIS stn true superset of LOFAR stn)

4 EISCAT_3D Workhop. Uppsala, 19 – 21 May 2010 LOIS prototype station under construction in Ronneby To be augmented by two outer, concentric rings, with 16 and 24 radio units, respectively, for a total of 48 units with three dipoles each (consortium funding) Bo Thidé4

5 EISCAT_3D Workhop. Uppsala, 19 – 21 May 2010Bo Thidé5 REAL Seminar, BTH, Ronneby, 23 January, 2009 LOIS prototype station site at Angelskog, Ronneby Left photos taken 21 December, 2007, at 14:00 local time. Right photo from eniro.se

6 EISCAT_3D Workhop. Uppsala, 19 – 21 May 2010Bo Thidé6 Swedish LOFAR Science Meeting, Stockholm, 15 January, 2009 LOIS prototype station centre at BTH in Ronneby Eight ex-SWEGRID PC blades provided by UPPMAX, Uppsala University (SNIC/VR) 21/101 Gbit/s light path provided by the Blekinge Institute of Technology (BTH)

7 EISCAT_3D Workhop. Uppsala, 19 – 21 May 2010Bo Thidé7 Use three orthogonal electric and magnetic antennas to sample the entire EM field vector To be tried at EISCAT, 2010

8 EISCAT_3D Workhop. Uppsala, 19 – 21 May 2010 3D vector sensing allows new radio diagnostics Better SNR, polarisation in real time, DOA,… Bo Thidé8 Click on pictures for animation! Real data from a real, live outdoor vector receiver at Ångström Lab in Uppsala. On line since 2003. Vector coherency gives superior SNR relative to conventional scalar intensity Instantaneous wave polarisation from one single vector antenna

9 Bo Thidé9 Swedish LOFAR Science Meeting, Stockholm, 15 January, 2009 2D LOFAR/SKA-type interferometers exhibit polarisation aberration. 3D interferometers do not

10 EISCAT_3D Workhop. Uppsala, 19 – 21 May 2010Bo Thidé10 Close collaboration with IBM Research, NY, on the analysis of streaming data from digital radio sensors

11 EISCAT_3D Workhop. Uppsala, 19 – 21 May 2010 Fork holograms are an example of such devices. If the hologram presents N bifurcations, then at the m-th diffraction order it imposes a OAM value equal to N m ħ (Vaziri et al. 2002). 11 The generation of beams carrying OAM proceeds thanks to the insertion in the optical path of a phase modifying device which imprints a certain vorticity on the phase distribution of the incident beam. s = total thickness of the plate, Δn = difference of refraction indices. Imparting OAM onto a light beam Spiral Phase Plate On-axis off-axis spectrum of OAM

12 EISCAT_3D Workhop. Uppsala, 19 – 21 May 2010 Properties of radio OAM generated by antenna arrays 12 Thidé et al., Phys. Rev. Lett., 99, 087701, 2007

13 EISCAT_3D Workhop. Uppsala, 19 – 21 May 2010 Theory predicts that a circular polarised radio beam in a pure OAM eigenstate with azimuthal phase dependence exp(ilφ), frequency ω, and energy H, should have a total angular momentum component J z EM = lH/ω along the z (beam) axis. Bo Thidé13 The OAM radio results agree with theory

14 EISCAT_3D Workhop. Uppsala, 19 – 21 May 2010 Exchange of OAM between plasma and radio/radar Bo Thidé14 Brillouin = ion line Raman = plasma line

15 EISCAT_3D Workhop. Uppsala, 19 – 21 May 2010 Improving resolving power of telescopes by one order of magnitude Super Resolution with OVs in diffraction-limited telescopes and other optical instruments 15 The James Webb Space Telescope Credit: ESA (C. Carreau)

16 EISCAT_3D Workhop. Uppsala, 19 – 21 May 2010 Field vector sensing means total configurability 16 The ultimate radio coronagraph!

17 EISCAT_3D Workhop. Uppsala, 19 – 21 May 2010 OV manipulation for detection at the telescope. Producing Optical Vortices with starlight and the problem of atmospheric seeing Upps ala, Celsiu s Work shop 2010 17 1

18 EISCAT_3D Workhop. Uppsala, 19 – 21 May 2010 Optical Vortices and Stellar Coronagraphy We place the phase mask in the focal plane of the telescope to generate an ℓ = 2 OV with the on-axis star, then followed by a ring- shaped Lyot stop to block that vortex. The off-axis secondary star light, instead, will pass through the Lyot mask without being affected. We place the phase mask in the focal plane of the telescope to generate an ℓ = 2 OV with the on-axis star, then followed by a ring- shaped Lyot stop to block that vortex. The off-axis secondary star light, instead, will pass through the Lyot mask without being affected. Pictures taken @the Lyot mask position of two artificial stars with increasing angular distance Fabrizio TamburiniUppsala, Celsius Workshop 2010 18 2 1 2 3 4 OVC Lyot stop ordinary Lyot stop

19 EISCAT_3D Workhop. Uppsala, 19 – 21 May 2010 First OVC @ T122 Asiago telescope 19 2.8x10 -10 (b) 2-3 /D (a) 2-8 / D (a) 4-5 / D (a) 9.3x10 -11 (b) 6.4x10 -11 (b) Theoretical contrast for a monochromatic source (b) versus the separation (a). Sufficient resolution for direct detection of extra-solar planets.

20 EISCAT_3D Workhop. Uppsala, 19 – 21 May 2010Bo Thidé20 Supporting Sardinia Radio Telescope for OAM


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