32 4 Vol. 32, No. 4 2014 11 PROGRESS IN ASTRONOMY Nov., 2014 doi: 10.3969/j.issn.1000-8349.2014.04.01 DiFX CVN 1,2,3 1,2 1,2 1 1,2 1,2 (1. 200030 2. 200030 3. 100049) VLBI DiFX DiFX DiFX VLBI (CVN DiFX CVN VLBI VLBI DiFX P228.6 A 1 VLBI VLBI ( ) [1] VLBI VLBI [2, 3] 2014-03-12 2014-05-13 (287151002) (11003039 11173046) jiangwu@shao.ac.cn
4 DiFX CVN 517 2 2.1 DiFX DiFX (Distributed FX Correlator) Adam Deller 2006 ( VLBA Haystack ) [3 5] DiFX VLBI IRA KVN DiFX DiFX Mark5 VLBA DiFX 24 232 14 Mark5 40 Gb Infiniband VLBA 10 MPIfR DiFX 60 480 14 Mark5 505 TB 20 Gb Infiniband 10 IVS KVN DiFX 16 200 TB 36 592 720 TB 56 Gb Infiniband 11 TFLOPS DiFX 1 vex log Mark5 machine DiFX v2d input Mark5 SWIN FITS Mark4 DiFX FFTW Inter IPP OpenMPI FFTW C MPI Intel IPP Intel cpu OpenMPI 1 DiFX
518 32 DiFX FX FX FFT zoom binconfig UV (UV-shifting) VLBI [6] FITS Mark4 CIRA VLBA MPIfR DiFX DiFX DiFX1.0 DiFX1.5 DiFX2.0 DiFX 2.3 DiFX DiFX 2.2 CVN CVN 4 5 25 m 65 m 50 m 40 m 25 m CVN 3000 km 2000 km S/X L C VLBI CDAS [7] Mark5B [8] internet Mark5 [9 13] CVN VLBI IVS APSG 500 m FAST 110 m VLBI VLBI 2.3 SHAO-DiFX (SHAO) [14] [15] DiFX CVN 2009 CVN PSR B0329+54 DiFX CVN [16] 4 DiFX 3 2 6 Intel E5-2620 2.0 GHz CPU 2 8 Intel E5-2609 2.4 GHz CPU 6 Mark5 Mark5 1 Gb/s
4 DiFX CVN 519 50 TB DiFX2.2 DiFX2.3 HOPS3.8, HOPS3.9 [17] 4 1024 Mb s 1 / 6 580 Mb s 1 / 50% DiFX DiFX DiFX 3 DiFX 3 Mark5 VDIF [18] DiFX Mark5 Mark5 VSN Mark5 Mark5 jive5ab [19] Mark5 [3, 4] sched skd sked vex log DiFX v2d 1 DiFX errmon m5mon Mark5 1 DiFX 1 vex2difx v2d, vex calc, input, machine, threads 2 calcif2 calc im 3 Startdifx input, machine, threads, im difx 4 difx2fits/difx2mark4 difx, vex, input FITS/Mark4 FITS Mark4 DiFX HOPS difxsniff HOPS/fourfit HOPS/fourfit type-ii fourfit difx2mark4 Mark4 fourfit pt c
520 32 cf 1234 1234/No0001 pt c cf 1234 cf 1234 1234/No0001 Mark4 scan 3.1 DiFX ZOOM ZOOM v2d addzoomfreq [4] VLBI v2d addphasecentre [6] UV DiFX 2.5 DiFX DiFX [16, 20] VLBI (1) Tempo Tempo2 [21] (2) 3 5 (1) bin bin FITS AIPS FITS [16, 22] (2) DiFX profile CVN J1939+2134 CVN 25 m 40 m 25 m 8.5 h S 16 16 MHz 2 bit 1024 Mb s 1 J1939+2134 1400 MHz 13 mjy J1939+2134 2300 MHz 10 mjy 3 DiFX profile profile J1939+2134 binconfig binconfig 40 bin 1 SRUNCH FALSE bin 2 (a) J1939+2134 2 (b) J1939+2134 AIPS [22, 23]
4 DiFX CVN 521 19h39min38s.56132 (RA) +21 34 59.1256 (Dec) Parkes 19h39min38s.5614 (RA) + 21 34 59.1244 (Dec) CVN [24] 2 (a) Profile J1939+2134 (b) J1939+2134 CVN (beam size=7.95 4.28 mas) DiFX DiFX VLBI (bin) 3.2 DiFX Mark4 IVS DiFX IVS VLBI CVN IVS DiFX 2013 CVN HOPS DiFX Calc/Solve PCAL PCAL DiFX1.5 PCAL PCAL PCAL Mark4 IVS HOPS fourfit alist aedit [17] 3 (a) 3 (b) fourfit
522 32 3 HOPS/fourfit (Kunming) (Seshan25) (a) S 6 (b) X 8 3 (a) 3 (b) 3 ( ) ( ) ( ) ( ) ( ) ( ) ( ) PCAL S X S 6 X 8 2 8 MHz 1 bit 256 Mb s 1 24 h Mark5 DiFX 5.8 h 3 S 6 X S X PCAL PCAL PCAL PCAL fourfit 3 (a) 3 (b)
4 DiFX CVN 523 4 DiFX VLBI DiFX DiFX VLBI DiFX DiFX DiFX CVN J1939+2134 2013 3 3 24 h 256 Mb s 1 5.8 h DiFX HOPS IVS Mark4 VLBI VLBI DiFX VLBI DiFX VLBI IVS DiFX [25] VLBI DiFX VLBI VLBI DiFX DiFX Adam Deller Walter Brisken DiFX [1] Thompson A R, Moran J M, Swenson Jr G W. Interferometry and synthesis in radio astronomy. Berlin:Wiley-VCH, 2004: 304 [2] Deller A T, Tingay S J, Bailes M, et al. PASP, 2007, 119: 318 [3] Deller A T, Brisken W F, Phillips C J, et al. PASP, 2011, 123: 275 [4] Brisken W. A Guide to the DiFX Software Correlator, version 2.2. http://cira.ivec.org/dokuwiki/lib/exe/ fetch.php/difx/difxuserguide.pdf, 2013 [5] Alef W, Rottmann H, Bertarini A, et al. Proceedings of the 20th EVGA Meeting. Alef W, Bernhart S, Nothnagel A, eds. Bonn:MPIfR. 2011, 1: 57 [6] Morgan J S, Mantovani F, Deller A T, et al. A&A, 2011, 526: A140 [7],,,., 2011, 29: 207
524 32 [8] Whitney A R. ASPC, 2003, 306: 123 [9] Li J L, Guo L, Zhang B. Proceedings of the International Astronomical Union. Jin W J, Platais I, Perryman M A C, eds. Cambridge: Cambridge University Press, 2007, 248: 182 [10],,., 2013, 38: 386 [11] Zhang X Z, Zhu X Y, Kong D Q, et al.research in Astronomy and Astrophysics, 2009, 9: 367 [12] Hao L F, Wang M, Yang J. Research in Astronomy and Astrophysics, 2010, 10: 805 [13] Yusup A, Liu X, Zhang M. IVS 2011 Annual Report. Baver K D, Behrend D, eds. Washington:NASA, 2012: 115 [14],,,., 2001, 19: 312 [15],,., 2008, 29:18 [16],,., 2011, 29: 309 [17] http://www.haystack.mit.edu/tech/vlbi/hops.html, 2014 [18] Whitney A R, Kettenis M, Chris P, et al. IVS 2010 General Meeting Proceedings, Behrend D, Baver K D, eds. Washington: NASA, 2010: 192 [19] http://www.jive.nl/ verkout/evlbi/,2013. [20] Guo L, Zheng X W, Zhang B, et al. Science China Physics, Mechanics and Astronomy, 2010, 53: 1559 [21] Hobbs G B, Edwards R T, Manchester R N. MNRAS, 2006, 369: 655 [22] Greisen E W. Astrophysics and Space Science Library, 2003, 285: 109 [23] Shepherd M C. ASPC, 1997, 125: 77 [24] Verbiest J P W, Bailes M, Coles W A, et al. MNRAS, 2009, 400: 957 [25] Lanyi G, Border J, Benson J, et al. IPN Progress Report 42-162. California: JPL, 2005: 1 The Progress of Adapting DiFX Correlator for Chinese VLBI Network JIANG Wu 1,2,3, SHEN Zhi-qiang 1,2, SHU Feng-chun 1,2, GUO Li 1, YAN Zhen 1,2, CHEN Zhong 1,2 (1. Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, China; 2. Key Laboratory of Radio Astronomy, Chinese Academy of Sciences, Shanghai 200030, China; 3. University of Chinese Academy of Sciences, Beijing 100049, China) Abstract: The correlator is crucial in the data processing of VLBI observations. Its output can be used for astronomical imaging, reduction of geodetic measurements and radiometry of spacecraft. DiFX is a well-known software correlator operating in a distributed computing and shared memory environment. The status of the DiFX platform in Shanghai Astronomical Observatory and its progress in the correlation of CVN sessions were reported in the paper. The platform can be used for data correlation of CVN and international VLBI observations. We hope this report could provide some valuable reference to the researchers related. Key words: radio astronomy; VLBI; DiFX; pulsar; geodesy