Presentation on theme: "KVN Recent Progress of Daejeon Correlator Se-Jin Oh Duk-Gyoo Roh, Jae-Hwam Yeom, ChungSik Oh, Jinseung Jung, Dong-Kyu Jung, Youngjoo Yun, A. Miyazaki,"— Presentation transcript:
KVN Recent Progress of Daejeon Correlator Se-Jin Oh Duk-Gyoo Roh, Jae-Hwam Yeom, ChungSik Oh, Jinseung Jung, Dong-Kyu Jung, Youngjoo Yun, A. Miyazaki, T. Oyama, N. Kawaguchi, H. Kobayashi, K. Shibata, and staff of Correlator team of KASI/NAOJ 2 nd IVTW, ICC Jeju, Korea , Oct. 2013
Contents Background System Introduction Playback System RVDB System VLBI Correlation Subsystem Correlated VLBI Data Buffer(CVDB) Post Processing SW Recent Status KJCC Operation Experimental Result Future Work
Target Array : EAVN For KVN, KVN+VERA/JVN, and EAVN. And also for Chinese Space-VLBI Antenna(s) in the Space
To establish the bigger, more powerful correlator and get the best performance in East Asian VLBI Network, we concluded that KASI & NAOJ join together to develop new Correlator. MOU between KASI & NAOJ ( ) Development of Korea-Japan Joint VLBI Correlator, Common facility of correlation & data center Joint Development Project was initiated respectively. Japan : 5 years from April 2005 Korea : 5 years from Jan Korea-Japan Joint VLBI Correlator(KJJVC) Development Project Backgrounds
ItemsSpecifications Number of Antennas16 Number of Inputs / Antenna - Input Interface - Maximum Data Rates 4 - 2Gbps VSI-H (32parallels, 64 MHz clk) - Total of 8,192 Mbps Digitization for Each Inputs - Number of Bits - Quantization Levels - Sampling Rates - Input Bandwidth - Sub-stream Specification - 2 bits/sample - 4 levels - 1,024 Msamples/sec MHz - Logically Associated Sub-streams Maximum Delay Compensation (Largest Baseline Length) ±36,000 km Maximum Fringe Tracking (Fastest Phase Drift Cancellation) 1,075 kHz ArchitectureFX type, with FPGA and DSP chips Specification (1) of KJJVC KASI + NAOJ 2006~2010
ItemsSpecifications FFT Processing - Freq. Resolution - Size of FFT points - Word length in FFT - Scaling - Re-quantization - 22GHz - 256k/128k/64k/32k/16k/8k Adjustable bits fixed point for real & imaginary - Yes bits fixed point for real & imaginary △ W Correction Yes Correlations - Number of Correlation Outputs/Input - Total Number of Correlation Outputs - Polarization Mode - Data compression(Binning) - Word length - min. max Integration Time - Max. 120 Cross- and 16 Auto-correlations - Max. 480 Cross- and 64 Auto-correlations - RR or LL ; Full Operation for 16 antennas RR and LL ; Full Operation for 16 antennas RR, RL, LR and LL : Full Op. for 8 antennas - Yes, 8,192 channels / correlation output bits Fixed Point for R & I msec ~ 10.24sec Data Output to Archive (Max.)1.4 GBytes/sec Subarray Operation2 cases (12 + 4, 8 + 8) Specification (2) of KJJVC
KJJVC Framework Mark5B VERA2000 OCTADISK Optical Fiber Raw VLBI Data Buffer (RVDB) VLBI Correlation Subsystem (VCS) Correlated VLBI Data Buffer (CVDB) Correlator Control & Operation S/W Yellow : NAOJ, Green : KASI
Playback Systems Mark5B playback VSI compatible : KVN DIR2000 is in use extensively at VERA. VERA 2000, which is modified by NAOJ according to DIR1000, used for Playing back DIR2000 tape media for VERA. OCTADISK : modified using RVDB with 4Gbps recorder/playback developed by NAOJ. Optical Fiber : Capable of dealing with the full data rate of 8 Gbps. OCTADISK(VDIF) VERA2000Mark5B
Raw VLBI Data Buffer (RVDB) Purpose : Adjust data format as like # of bits per sample, and so on Easily synchronize the data while playback (heterogeneous recorder models) Maintain the buffering between recorder speed(1 Gbps) and correlation speed(8 Gbps) (N. Kawaguchi / NAOJ)
Raw VLBI Data Buffer (RVDB) basic configuration VSI Optical Adapter(OCTAVIA) From Playing Back Units 1Gbps, nominal 10GbE Switch 2Gbps, nominal OCTADDB 4 D-ports 4 C-ports To Correlator Input Ports OCTADISK Control PC VDIF
VLBI Correlation Subsystem (VCS) ( ) 16 Stations, 8Gbps /station Serialized data sub-streams in time domain, and Parallel processing in frequency channels after FFT. Full polarization correlation is supported (up to 8 stations) Two sub-array modes are prepared (12+4 and 8+8). Max. data output rate is 25.6ms integration Antenna Unit Corr & Acu.Unit
CVDB(Correlated VLBI Data Buffer) Max. data rate : integ. (~10% at average operation) need to implement massive storage to save the correlation results with four 10GbE of VCS CVDB (specification) Architecture Infiniband Max. Capacity 1~3 PB for 1 year (EAVN, Space VLBI) 500 TB at initial phase (KVN, KJJVN) ~119 TB
Post-Processing SW configuration Developing with Japanese colleagues, NAOJ(CODA) and Kagoshima Univ.(GFS) CODA file system (CCcoda ver2.1), FITSgen to reduce the developing efforts & cost, and to have compatibility with MTK FX
Recent Status : Hardware(RVDB) By NAOJ In RVDB system, 3 OCTADDB system changed to OCTADISK so as to support VERA(JVN) wideband observation, these are now testing in Mitaka. After completion of test, these will be delivered to KJCC until end of October this year. 2set OCTADISK2 systems were already ordered to manufacturer for supporting VERA wideband data with high speed(over 8 Gbps) recording Please refer to Kono-san’s presentation in detail on Saturday
Recent Status: Hardware(VCS) New firmware was installed DC-like component band start Phase concentration band start FFT operation : 16bit 20bit Experiments of scaling factor/requantization for FFT were performed, so new reasonable factors were determined. Correlation is currently conducted using modified firmware as indicated above.
Recent Status: Software CODAgen/FITSgen By Kan-ya san’s great effort of Leonid/NAOJ, creating time for CODA F/S was reduced within 3~4 hours for 8hours observation with 16MHz-16stream. Also creating time for FITS was reduced within 1 hour for 8 hours observation with 16MHz-16stream. Creating time depends on the observational(correlation) mode.
New Building East Asia VLBI Research Center ( ) KASI
KJCC - Operation Structure Executive Board KVN + VERA(+ EAVN) Oper. Support Group KVN VERA / JVN EAVN Mitaka Correlator Korea-Japan Correlation Center Project manager 1, 1 Operation manager 1, 1 System Engineer 3, 3 Operator 2, 6 Data quality analyzer 2, 4 nowfuture KASI operates KJCC with supporting operational budget and know-how of NAOJ.
Experimental Results To adjust the scaling factor, requantization bit position and verify the performance of Daejeon Correlator Observation Code : r11027b Array : KVN+VERA combined 7stations Observation frequency : 22 GHz Observation time : 9.2hours Correlation mode : C5(16MHz BW, 16stream) Integration time : sec
FFT scale factor, Re-quantization
By S.S. Lee et al (22GHz)
Correlation(backlog) Status Exp.ObjectCorrelationStatus R11027B KVN+VERA Evaluation for KJCC FinishedIn Analyzing K12098C KVN 4channel simultaneous obs FinishedIn Analyzing R11025A KVN+VERA 22GHz FinishedIn Analyzing R11026A KVN+VERA 43GHz FinishedIn Analyzing R12280A KVN+VERA 43GHz survey FinishedIn Analyzing R11088B R11089B R11090B R11091B R11093B R11095B KVN+VERA SgrA* campaign FinishedIn Analyzing R11094A, B 22/43 GHz KVN+VERAFinishedIn Analyzing R13082B R13083B R13084B R13085B R13086B R13102A KVN+VERA SgrA* campaign In progress for correlation Undergoing correlation From 2013, Daejeon correlator is normally operating for C5 mode(16MHz -16channel)
Future plan supporting for other mode(wideband etc) EAVN evaluation observation 24 th Sept KVN, VERA, CVN(Shanghai, Kunming, Urumuqi), JVN ~ 13 stations had been joined These observed data will be correlated by Daejeon correlator Until the end of 2013 C2 (128MHz BW, 2streams) C1 (256MHz BW, 1stream) W1 (512MHz BW) Polarization correlation Test correlation will be also performed soon or within this year.
Change Tape to KJCC/VERA (Planned) 1Gbps 80 min. 4Gpbs 6 Hours or longer In VERA, parallel operation of tape and disk are now going on. VERA2000 OCTADISK