KVNKJCC System and Correlation
StatusSe-Jin Oh

Duk-Gyoo Roh, Jae-Hwam Yeom, ChungSik Oh,Dong-Kyu Jung, Hwan Ju-Yeon, Youngjoo Yun, Hyo-Ryoung
Kim, A. Miyazaki, N. Kawaguchi, H. Kobayashi, K. Shibata, T.
Oyamaand staff of Correlator team of KASI/NAOJ

12th VERA user’s meeting, Mitaka, Japan, 24-25, Sept. 2014

Contents
KJCC System Status
KJCC correlation status
KJCC Request and OthersFuture WorkKJCC System status
VCS(VLBI Correlation Subsystem) VCS supports various correlation mode suchas W1, C1, C2, C3, C4 and C5.
OCTDISK In RVDB system, 3 OCTADDB system werechanged to OCTADISK so as to support
VERA(JVN) wideband observation.
 3 OCTADISKs arrived at KJCC, andplaying back and corr was started.

Software development
VDIF Copy software : Between massive
storage and OCTADDB, VSI obs data is
directly possible to copy.
octa_control_rec/octa_control_playARP packet attack
BeforeAfter

Step-like Gain Amp after ACCOR

 In optical connection
between AU and CAB, dustis the reason.
 After cleaning dust, theabove problem wasdisappeared.

KJCC correlation status
KJCC web http://kjcc.kasi.re.kr/doc/corr-status.html
FITS delivery
 DQA will announce to PI by e-mail to
download the FITS file with its link.
FITS regulations
 http://kjcc.kasi.re.kr/doc/fits-dist.html
 KJCC would like to receive PI's response within 2 weeks
after FITS file downloading. At least if there is no response
within 4 weeks, KJCC determined that PI is regarded as hisresponse as "Success" for FITS file(2013.09).

Correlation Status
SeasonObservation

Corr
Finished

Remain Corr

2014B6(in Sep)--2014A57(1 cancelled, 1test)

24

31

13

2013B

2727

027

Disk pack used

Tape used

Remark2926

2014AVERA
KVN

Total
5555

 2013B, 2014A season••

84 obs.
51 corr. finished

FITS
releasePopularity by operator
1. Normal observation with strong fringefinder
2. Frequency switching3. Fast switching Fast switching obs is OK, but start/end time in obs log had
been superposed because of the different telescope slewingspeed.
 If you want to observe this mode, please consider start/end
time between scans.

4. A/B-beam, Multi-Frequency Obs
5. Sub-array Observation is just 1 time, but correlation should be
performed many times. It takes many hours to correlate them.

KJCC Request(1) Short cover report of your observation introduction
 Discuss it DM to improve operation effectively
 How to correlate your observation
 Our operator had some experience recently , butsometimes PI conducted new observation without
any introduction. In that case, correlation time ismore needed by understanding the observation
why it was conducted that way.
 Difference between VEX and Obs log
 Sometimes we found that VEX and log havedifferent information such as frequency setting orLSB/USB or RHCP/LHCP etc.

KJCC Request(2)Support various obs mode
 W1 : 512MHz BW 1stream
 C1 : 256 MHz BW 1stream
 C2 : 128 MHz BW 2streams
 C3 : 64 MHz BW 4streams
 C4 : 32 MHz BW 8streams
 C5 : 16 MHz BW 16streams : Normal  KJCC suggest to PI to do long obs by using
W1~C4 mode, which will be used to do yourresearch and to give confirmation of KJCC
performance with risk-shared.

How to correlate rapidly
Stable operation of VCS
OCTADISK pack
Simple observation mode w/ strong fringefinder No Fast switching No sub-array
VEX and log consistenceShort correlation request
Quick response after analyzing FITS within 1month

OCTADISK-packAdvantage
 Copy work is not needed Fast correlation is possible
 PI will quickly receive FITS fileDisadvantage Point of view by operator, strong pressurefrom PI(AOC) Busy to correlate
 Fast release of disk-media

SiO masers around BX Camr13340b

KaVA/KJCC
By Evolved Star Group(H.Imai et al.)KVN/DiFXKJCC operation
 People in KJCC : Roh(Man), Oh, Yeom(HW/SW), Yun(SW), OhCS, Miyazaki(DQA),Kim(DiFX), Jung, Hwang(Op) New operator arrived : Hwang Ju-yeon from AugustJung Dong-Kyu

Hwang Ju-Yeon

Future WorkArchive system upgrade is neededPolarization correlation
 Test correlation will be also performed soon.