Current status of OCTAVE Yusuke Kono1, Tomoaki Oyama1, Noriyuki Kawaguchi1, Kotaro Niinuma2, Kenta Fujisawa2, Hiroshi Takaba3, Kazuhiro Sorai4, Mamoru Sekido5, Shinobu Kurihara6, Yasuhiro Murata7 National Astronomical Observatory of Japan1, Yamaguchi university2,Gifu university3, Hokkaido university4 NICT5, GSI6, JAXA7 My name is Yusue Kono from NAOJ. the title of my talk is Current status of OCTAVE

Contents OCTAVE Array OCTAVE Family EHT application I’wll talk about our eVLBI array ,octave, and the instruments in the array. Lastly we show an example of applications of OCTAVE technologies.

OCTAVE : Optically ConnecTed Array for Vlbi Exploration eVLBI network in Japan High sensitivity, on-the-fly result and low cost operation The longest baseline is 1,300km Hokkaido univ. 11m JAXA Usuda 64m* Octave means ****. There are many radio telescopes in Japan. OCTAVE project is to connect some of them with broadband communication lines to carried out realtime VLBI obs. feature of OCTAVE are High sensitivity, on-the-fly result and low cost operation except cost communication lines. Four stations in orange color are connected and under operation. Unfortunately, stations in blue were connected and are disconnected now. I will talk about this. Yamaguchi univ. 32m GSI Tsukuba 32m Ibaraki Univ.* 32m x 2 NAOJ NRO 45m* NICT Kashima 34m* Gifu univ. 11m

Communication lines Supplied by academic network (SINET4) and Test bed network (JGN-X) 10GbE to nodes 2x10GbE to Correlator at HQ of NAOJ in Tokyo Kashima and Ibaraki are offline now. Trying to connect. Usuda and NRO are offline now Network configuration (Plan) Local Recorders, OCTADISK and K5, are installed into Usuda, NRO, Ibaraki and Tomakomai for a while. Com lines are supplied by Academic net SINET4 and test bed network JGN/Nict. they provide a 10gbE port /station. Kas and ibaraki are offline due to cross connection between them. I think problem will be solved soon. Usds and NRO are also offline now. It is difficult to connect them for our budget. We installed Local recorder in to them for while. we carried out post prcessing correlation. if offline stations were joined th observations. OCTAVE is not only realtime VLBI array but also post processing array at this time.

Observation capability X-band Usuda64, Kashima34*, Yamaguchi32, Ibaraki32 8192-8704MHz, BW512MHz x 1/2pols K-band NRO45, Kashima34*, Yamaguchi, Ibaraki32, Gifu11, Tomakomai11m 21.5-23.8GHz, BW512MHz x 1/2pols This shows Obs capabilitiy of OCTAVE Two band obs are capabile. one is Xband by Us…. band is fixed to 500MHz of a single or dual circular polarizations. Kashima34* will be available if the network is connected.

Data processing and results Image of 4C32.44 X-band, BW512 MHz, 4stations software: AIPS VLBI Detections of Parsec-Scale Nonthermal Jets in Radio-Loud Broad Absorption Line Quasars, Doi et al., 2009 VLBI Observation of Fermi/LAT Un-associated Gamma-ray Sources, Niinuma et al.,2013 Science Obs. proposals are selected and operated by JVN(Japanese VLBI Network) This is an example of image obtained by OCTAVE Xband. with 4 sta. Left figure is image by VLBA the right is ours. We can see two components as VLBA shows. Needless to say, Imaging power is extreamly weaker than VLBA. But There are many thing to do by OCTAVE. Doi et al categolized a lot of BAL quasers. Niinuma etal made a follow up VLBI obsertvation of ganma ray sources after Felmi satellite observation. Science Obs. proposals are selected and operated by JVN(Japanese VLBI Network)

International Observation Recording and copying function at NAOJ/Tokyo Fringe test with EAVN (East Asia VLBI Network) September 2013, 14 stations Fringe test with Noto April 2013 K5 (NiCT) Mark5B+ (Haystack) OCTADISK (NAOJ) DF We join International VLBI obs. HQ of NAOJ has various kinds of termnals such as K5, Mark5B, and OCTADISKour diskstrage module. we can copy them with digital filtering. EAVN team carried out first EAVN fringe test last month. OCTAVE copy system worked well. Fringe test with noto in Italy was also carried out in April.

Octave family We have developed several instruments for OCTAVE. We call them Octave family. OCTAVIA OCTAVe optIcal Adapter OCTADISK OCTAve Recorder OCTACOR OCTAve Correlator OCTAD OCTave ADc OCTADIV OCTAve DIVider We have developed several instruments for OCTAVE. We call them Octave family. Some of them act like gang of trouble/bug maker. they also members of the family. Many non-OCTAVE family instruments are also used in the array, such as ASD1000/3000, K5(NICT) and Mark5B(Haystack).

OCTAVIA (OCTAVe optIcal Adapter) Converter between VSI and 10GbE Electrical I/O VSI-H 4 Ports Total 8 Gbps Optical I/O 10GbE Protocol VDIF/UDP/IP/10GbE VSI 10GbE ADC etc OCTAVIA Network etc VIA is a convertor between VSI and 10GbE. so VIA is a terminal adapter to network. El. IO is VSIs upto 8Gbps. Optical IO is single 10GbE.the protocol is …. Work by Dr Oyama (NAOJ)

OCTADISK DISK Recorder I/O Portable module 10GbE (up to 4Gbps) Use with OCTAVIA Portable module 12 HDDs /module dedicated format. Under Operation at the VERA stations. OD is disk recorder IO is 10gBE. It contains two portable disk modules OD are installed into VERA stations and under operation. Work by Dr Oyama (NAOJ)

OCTADISK2 OCTADISK2 is under development Parts discontinuance of OCTADISK COTS base, except Chassis OS:Linux, Linux file system Portable module same to OCTADISK Prototype We developing OD2 now, because of patrs discontinuance of OCTADISK. Parts discontinuance is a important problem for us. Any way we have to continue OD that are already installed into vera by developing OD2. OD2 is COTSbase exxcept shassis. os is linuxx and data are recorded on linux file sysmtem. This is a figure of proto type of OD2. tye are perfectly COTS by using desktop PCs. “Perfect COTS” Work by Mr Suzuki and Dr Oyama (NAOJ)

OCTAVIA/DISK in KJCC NAOJ supplied Raw VLBI Data Buffer to KJCC VSI Input from various terminals Storage on HDD output Synchronized data to VCS Origin of OCTAVIA and OCTADISK http://kvn-web.kasi.re.kr/en/en_under_correlator.php

Correlators for OCTAVE Real time correlator FPGA correlator FX and XF type 2Gbps/station Post processing correlator Software correlator Engine(GICO3) by NICT Integration by NAOJ with NICT Work by Dr Oyama (NAOJ) Soft Correlators Hard Correlators

OCTAD (ADC) Direct RF sampling Wide bandwidth 22GHz (43GHz, under test) Wide bandwidth 8.192Gsps-3bit use with a RF band pass filter For next generation VERA system Wideband observation enable us to use weaker and closer reference sources of dVLBI astrometry

OCTAD Lab. test of sampling jitter Fringe test observation 0.17 psec (Lc<1% @43GHz) Fringe test observation Mizusawa 10m x 20m BL=60m 16Gbps x 2 OCTAD Jitter　0.17psec Lc <1% PI: Dr Oyama (NAOJ)

Upgraded OCTAD We add two functions DBBC Backward compatibility BW:16MHz~2048MHz/ch External AD module up to 50GHz V-connector Direct receiving 50GHzModule

Telescopes and Phasing EHT / ALMA Phasing Event Horizon Telescope Japanese contribution Data transfer from AOS to OFS AOS: Telescope site OSF: Operations Support Facility 64Gbps(8Gbps x8ch) A single dark fiber Design started at 2011. Telescopes and Phasing Optical link 30km VLBI Recorder Storage Transfer and Correlation PI: Prof. Honma (NAOJ)

EHT / ALMA Phasing WDM of 16 wavelengths by 10GbE-ZR XFP OFS AOS PIC XFP –ZR lambda1 AWG1 AWG1 XFP –ZR lambda2 XFP REC AWG2 AWG2 PIC XFP XFP –ZR lambda3 AWG3 AWG3 XFP –ZR lambda4 XFP REC AWG4 AWG4 PIC XFP XFP –ZR lambda5 AWG5 AWG5 XFP –ZR lambda6 XFP REC AWG6 AWG6 PIC XFP XFP –ZR lambda7 AWG7 AWG7 XFP –ZR lambda8 XFP REC AWG8 AWG8 PIC XFP XFP –ZR lambda9 AWG9 AWG9 XFP –ZR lambda10 XFP REC AWG10 AWG10 ZR with ITUT wavelength selection 900,000 yen x18 =16,200,000 yen 10 Gigabit Small Form Factor Pluggable 10GBASE-SR (Short Reach) 26 -80m PIC XFP XFP –ZR lambda11 AWG11 AWG11 XFP –ZR lambda12 XFP REC AWG12 AWG12 PIC XFP XFP –ZR lambda13 AWG13 AWG13 XFP –ZR lambda14 XFP REC AWG14 AWG14 PIC XFP XFP –ZR lambda15 AWG15 AWG15 XFP –ZR lambda16 XFP REC AWG16 AWG16 Monitor Power Power Monitor Power Power Moni. (Ethernet)

EHT / ALMA Phasing OFL (Opical Fiber Link) NAOJ/Elecs corp. High Cost performance “Error Free” is confirmed OFLs for AOS and OSF optical attenuator Expected Attenuation between AOS and OFS OFL at Haystack

Summary Introduction of Octave and Octave family Application of OCTAVE technology to EHT/WDM

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Jitter measurement Synchronized SG input Phase are extracted by FFT GOD SG AD storage input SG CLK DIST FFT FFT FFT Synchronized SG input Phase are extracted by FFT ・・・

Phase fluctuations 18.424GHz 14.328GHz 10.232GHz 6.136GHz 2.040GHz Time (sec)

Phase rms and jitter Linear fitting Φrms=2πｆδT+σ JitterδT 0.17psec

Allan standard deviation VSOP- 2 SPEC. ASD 9E-13@1sec （WPM－45GHz Lc 1% ）