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Software Correlation at JIVE & Real-time e-VLBI in the EVN  Operations and PI Interaction  Astronomy Gains from SFXC  Real-time e-EVN status  Proposal.

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Presentation on theme: "Software Correlation at JIVE & Real-time e-VLBI in the EVN  Operations and PI Interaction  Astronomy Gains from SFXC  Real-time e-EVN status  Proposal."— Presentation transcript:

1 Software Correlation at JIVE & Real-time e-VLBI in the EVN  Operations and PI Interaction  Astronomy Gains from SFXC  Real-time e-EVN status  Proposal Tool: recent modifications Bob Campbell, JIVE EVN Symposium #12, Cagliari.......................... 2456940.576 (9/x/2014)

2 Ops Flowchart (≤ Correlation)

3 MkIV  SFXC: Astronomy Gains  N sta limited only by available input devices (was 16)  Arbitrary total bit-rate & BW SB (was 1 Gbps & 16 MHz)  ~arbitrarily large number of frequency points (was 2048) Velocity resolution improvements w/o cont. sensitivity penalty Selectable spectral windowing (Hanning, Hamming, cosine, tophat)  ~arbitrarily small integration times (was ¼s)  Large N frq & small t int together  wider-field mapping  Improvements in correlated data Pure station-based fringe rotation to center of earth Decoupled correlation/delay-tracking FFT sizes Consistent cross-polarization handling

4 MkIV  SFXC: as seen by user N sta 2. N sb. N pol. N frq ≤ 131072. R N sta = (4,8,12,16); N pol = (1,2,4); N chan ≤ 16; N frqmax = 2048 Recirculation: R ≤ 16 MHz /BW sb ; N frqmax still 2048 (if 8 MHz SB) 9—16 Sta 1 SB 2 Pol 512 Frq ( R = 2) (if 2 MHz SB) 9—16 Sta 1 SB 2 Pol 2048 Frq ( R = 8) Maximal velocity spacings ( N frq =2048, Δv in [m/s] ) Specify desired velocity spacing & required continuum sensitivity (set BW sb, then N frq ) BW sb [MHz] Δ [Hz]Δ 1420 Δ 1665 Δ 6668 Δ 22235 16781316511408351105 29772061764413 MkIV SFXC

5 SFXC: Completely New Astronomy  Multiple output phase centers within a wider field  Pulsar Gating/Binning Both incoherent and (new) coherent de-dispersion  Space VLBI ( cf. Duev poster, Molera talk ) Near-field correlation (solar-system, GNSS targets) Orbiting antenna (RadioAstron)  “Phasing up” the EVN  Mixed-bandwidth, mismatched-sideband correlation (enables inclusion of wider set of heterogeneous back-ends)

6 SFXC: Pulsar Gating/Binning  Gating = arbitrary start/stop interval within PSR period  Binning = arbitrary number of bins within the gate Each bin  separate correlation / output IDI-FITS file 0329+54 1.4 GHz Pulse profile (1 gate, 100 bins) Sieber et al 1974

7 SFXC: Wide-Field Mapping  Essentially unlimited max-N frq, min-t int : can map area on the sky ~single-dish beam w/ minimal smearing Price = huge output data sets (record soon ~5.5TB FITS files)  Multiple phase-center correlation: outputs only subsets of the full area (user exps. up to ~200-300 phs.ctrs) Typical 1st-correlation N frq ~16k; t int ~ 4—15 ms Further processing-factor “penalty” small Example validation run: same source correlated at two positions 1.4’ apart; |Δφ| Ef-Hh = 0.3 o pk-to-pk. Ef-Hh 6cm

8 SFXC: “Phasing up” the EVN  Most applicable to pulsar observations  Correlate phase-reference obs. “normally”  Obtain fringe solutions for as many sources as possible  Apply fringe solutions back into model for each station  Re-correlate with new model  Output as single (CoE) station in PSR-FITS a.k.a. filter-bank data run through PRESTO to fit for pulsar P, Pdot, etc.

9 SFXC: “Phasing up” the EVN ms-PSR M15A in Glob.Clust. M15 Ar,Ef,Gb,Jb, On,Tr,Wb ~100 min

10 Real-time e-EVN Science  Proposal-driven e-EVN science observations 1 st observation = 16 Mar 2006 (6 stations at 128 Mb/s) Nowadays, a network of 9-10 stations at Gbps is routine Typically ~25-30% of EVN observing time e-EVN network still misses KVAZAR stations & Urumqi  Evolution of e-EVN procedures ~monthly 24-hour runs (+4hr prelim. test) on fixed dates  e-EVN also in regular disk sessions (longer runs) Proposals now within standard proposal-submission cycles  Proposal Class for “triggered” observations (10 since Apr’08)  Proposal Class for “short” observations (35 since May’08)  Any EVN or GLOBAL proposal may contain e-VLBI observation(s) Target of Opportunity Observations (49 since Sep’07)

11 The EVN / e-EVN

12 e-EVN Operational Bandwidth StationConnection Effelsberg1024 Mbps (4x in tests) Westerbork1024 Mbps Jodrell Bank1024 Mbps Medicina1024 Mbps Noto1024 Mbps Onsala1024 Mbps (4x in tests) Torun1024 Mbps Yebes1024 Mbps (4x in tests) Sheshan1024 Mbps HartRAO1024 Mbps Arecibo 512 Mbps Metsahovi1024 Mbps ATNF: 1 Gbps (At,Mp,Pa) SRT expected soon Robledo to start tests Irbene connection in place

13 Observing Request Tab (Array) e-EVN now per observation; controls array, correlation parameter choices

14 Observing Request Tab (Changes to Array Selection) New category: “special” EVN stations (per band) New category-specific help

15 Observing Request Tab (New Help for Array Selection )

16 Observing Request Tab (Out-of-Session Obs) Any observation can contain one or more out-of-session segments; new dialog box for describing criteria for minimally-required array

17 Obs. Rqst Tab (Format & Correlation) Some impossibilities pass undetected Updated for SFXC capabilities; e-EVN selection

18 Solar Activity Remaining in solar-medium range since the previous EVN symp. Moderate uptick near the start of 2014

19 Predictions for this Solar Cycle Sep’10 & ’12 predictions: solar max. in mid-2013 at 140 sfu. Sep’14 pred: solar max. just passed. ref: Space Weather Prediction Center, via www.sec.noaa.gov

20 Summary  Pre-/Post-correlation PI Support Help available — don’t have to wait until last minute Archive: FITS, pipeline, standard plots, feedback RadioNet3 EVN Trans-National Access program  EVN Software Correlator at JIVE (SFXC) Astronomical applications beyond the MkIV correlator More straightforward capacity limitations  e-VLBI now standard/indispensable facet of EVN  Proposal Tool “Observation Request Tab” continually tweaked to reflect new capabilities


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