KVN
Recent Status of KJCC
for KaVA and EAVN
Se-Jin Oh, Duk-Gyoo Roh, Jae-Hwan Yeom, DongKyu Jung, Chungsik Oh, Hyo-Ryoung Kim, Ju-Yeon
Hwang, Jeong-Sook KImand NAOJ Corr. Team2019 VERA UM @ MIZ, Dec. 13~14, 2019

Contents
vKJCC correlation status
vKJCC Development status

Korea-Japan Correlation Center(KJCC)

Executive Board

Daejeon HW Correlator

DiFX SW Correlator on HPC

Correlation ModeaC1Bandwidth
[MHz]
256

C2128221024

32

C364

42102432

C432

82102432

C516162102432bW1

512 x 4band

42819264W2512 x 4band

1IFcx2Pd
2IFx1P28192

64W3

512 x 4band

2IFx2P28192

64

Corr.
mode

Outputstreams#bits

12Outputdata rate[Mbps]
1024

a, Narrow band, b. Wideband, c. IF, d. Polarization

Clock rate
[MHz]
32

Correlation Status
http://radio.kasi.re.kr

Number of correlations
180

Number of Correlation

150

1162

120

1627

14EAVN

90

37

KaVA Hybrid
KaVA

6098

11266

30020172018~2019.11

KaVA Hybrid : VERA 2 Beam + KVN Multi Band or KVN Dual Pol. Observation

Correlation Processing Time after Obs.
1400.0

Correlation Time(hr)1200.01000.0
800.0

129.2

117.4

236.4

295.3
EAVN
KaVA Hybrid

600.0
400.0

483.1

388.7

726.6

KaVA

696.1

200.0

392.50.0
2017

2018

~2019.11

KaVA Hybrid : VERA 2 Beam + KVN Multi Band or KVN Dual Pol. Observation

Average Corr. and Media Delivery Period

140.0
125.8
120.0

100.0
82.0
80.0

83.7

63.4
60.0

40.0

51.1
46.2

40.2
38.0

28.0
20.0

57.3

34.4

21.70.0
2017
KaVA(corr )2018
EAVN(corr)~2019.11
KaVA(delivery)

EAVN(delivery)

Number of Science Working Group
180150120

64105171052116GA
ES

90
60108118123

20172018~2019.11SFRAGN300
GA: Galactic Astrometry, ES: Evolve Star, SFR: Star Formation Region, AGN: Active Galactic Nuclei

# of Fringe Detection Failures by Cause

2134
4

FSBSWC

11Unknown

FS: Field System, BS: Backend System, WC: Weather Condition
Unknown: miss operation? and/or unreported problems?

# of Fringe Detection Failures by Station
14121

10842645342018
201710116233KyKu

30KtVm~2019.1111Vr5112

211Vo

Vs

Ny

T6

Ur

Ky: Yonsei, Ku: Ulsan, Kt: Tamna, Vm: Mizusawa, Vr: Iriki, Vo: Ogasawara, Vs: Ishigakijima
Ny: Nobeyama, T6: Tianma, Ur: Urumqi

Problems during Corr.
1. Increased correlation period due to delayed
data shipment
2. Difficulties in detecting fringes for unknown
reasons
3. Setting mismatches(frequency, polarization,etc…)
4. Data storage
5. Log and antab files

What is Extended KVN?

S-T, Han
Candidates
PYONGCHANGYONSEIYOUNGWOLSEJONGSpace Geodetic Observation Center(2/8/22/43GHz)

Baseline 50 – 500km(increase 3 to 6)

ULSAN

TAMNA

Compact Triple-band Receiver(CTR) 22/43/86 GHz+ 150 GHz (D-band)+ 230 GHz for EHT+ 8 GHz (X-band, 7.8GHz)E-KVN DASKVN observe full polarization with v OCTAD Specification§ 4 ADC (4 x 16Gsps)
4 frequencies§ Input Freq. 8 – 16GHz
22 R/L, 43 R/L, 86 R/L, 129 R/L§ Digital Down
• Sampler & Digital Filter (DBBC)•OCTAD x 2Set

• Recorder (and playback, 64Gbps)•Mark6, FlexBuff, or Peta DataRecorder§§§Converter
Digital Filter
4 x 10GbE Output
VDIF Format

Correlator now in KASI

Daejeon Correlator- Hardware Correlator- KaVA, EAVN
- 16 Stations, 8Gbps– Both correlators are not able to use in E-KVN– cannot process higher than 8Gbps data
– Need a new correlator able to correlate 64Gbps
data with full polarization

DiFX Correlator- Software Correlator- KVN 3 Stations onlyNew Correlator’s Goalv 32Gbps R/L in real time modev 64Gbps R/L in run time mode within 2 - 3 times forobservation timev Maximum 5 stations(Yonsei, Ulsan, Tamna, Sejong, and another site)v GPU and network based, e-transfer using KREONET(Korea Research Environment Open NETwork)v until 2024

How transfer data to correlation center– Elementary concept is to use theKREONET– Request 40Gbps speed rate until 2024
– Recorded data 8, 16Gbps, 32Gbps(?)
correlate simultaneously with e-transfer(seems like e-VLBI)– 32 , 64Gbps data, stored to local
storage on correlation center, and thencorrelate

Lab Test– Supermicro 4029GP TRT• CPU Intel XEON Gold 6154 x 2ea• RAM 384GByte DDR4
• SAS RAID Card x 2ea• 10Gb Ethernet NIC SFP+ x 2ea• 100GbE Mellanox NIC• Nvidia Titan V GPU– Storage• Stardom RAID Box x 2ea• 24TByte(3TB x 8), 64TByte(8TB x 8)
• Support SAS 12Gb

Correlation Control GUI(Graphical User Interface)For this lab test
□ Test data
▪ Experiment Code: k17kh03b (r17289c)▪ Observation Date: 2017y290d02h43m25s▪ Data Rate: 2.048Gbps (1.024Gsps), 2bit
▪ Site: KVN 3 stations (Yonsei, Ulsan, Tamna)▪ 3 cross power + 3 auto power spectrum▪ 4,096 FFT channels▪ Observation duration 103 seconds▪ GPU correlation processing time 98 - 101 seconds (97%)
using 1 Titan V GPU card only
▪ Now, lab testing time split correlation using 2 GPU cards▪ Complete in this year

Test Result

Correlation Center Peoples