VS09i Results
Submitted checklist.txt and checklist.tex is also available		   [Summary | AIPS | Difmap ]
Analyst: Zsolt Paragi
Date Prepared: 31-08-2001
 

Summary
 
Observation code : VS09i    AIPS Version : 31DEC01   
Date of Observation : 2000/289    Difmap Version : 2.3c 
Source Name : J0824+5552    vsop_difmap used : Yes 
Calibration Source(s) : J0927+3902, J1800+7828         
Ground telescopes : KASHIMA, NOTO, KALYAZIN  Model Fitted to data : Yes 
Tracking Station(s) : Usuda (UZ), Tidbinbilla (TZ)    Image made : Yes 
Correlator : Mitaka         

 
Abstract
There were difficulties with the calibration of Kalyazin. The residual fringe rate was huge (several hundreds of mHz) and highly variable (~60-80 mHz) on timescales of minutes. I had to fringe-fit Kalyazin with a solution interval of 15 seconds(!). This way I was able to recover the phases. An amplitude correction factor of 5 was also applied. The rest of the array was OK, FRING succeeded most of the time. An image was made in Difmap: slighlty resolved core. The source was a bit fainter than during the pre-launch VLBA observations. I had to modify the SURVEY run file for AIPS in order to produce non-standard outputs: FRING results for Kalyazin can be found in *FRING01* files while for the rest of the array in *CALIB* files.
Model
Flux (Jy)
Radius (mas)
Theta (deg)
Major (mas)
Axial ratio
Phi (deg)
TB (10^12 K)
0.627601 0.0178240 92.7045 0.422679 0.457667 -77.7969 0.3746
(*) Quoted Brightness temperatures assume Gaussian components and are in the local (z=0) frame.


AIPS Data Reduction Notes
 
Task
Adverbs
CL
in
SN
in
CL
out
SN
out
Comments
FITLD douvcomp 1
digicor -1
delcorr -1
 
 
 
 
 JUW24 (an ULTRA60 computer) in JIVE 
INDXR cparm = 0, 0, 0.1, 0
infile 'indxr.txt'
 
 
1 
 
 The 6 sec. CL interval time is needed to cope with the unstable fringe rates at Kalyazin. 
ACCOR solint 2
 
 
 
1 
 Two minutes solution interval. This way we have only a few bad data points; by applying a longer solint a long timerange is affected by bad data. 
CLCAL opcode = 'cali'
interpol = '2pt'
1 
1 
2 
 
  
ANTAB tyver = 1
gcver = 1
 
 
 
 
 Tsys for Noto is taken from observation logs. Gaincurves and nominal tsys for other antennas are downloaded from VSOP WWW pages. 
APCAL tyver = 1
gcver = 1
 
 
 
2 
  
CLCAL opcode = 'cali'
interpol = '2pt'
2 
2 
3 
 
  
TACOP
3 
 
4 
 
  
TABED optype 'add'
aparm 19, 0, 0, 2, 4, 3
keyval -5E-11 0
4 
 
4 
 
 Shift Kalyazin data in fring rate space by -5E10-11 sec/sec (reported from correlator). 
FRING antennas 1 3
refant = 1
solint = 0.25
aparm = 2, 0, 0, 0, 2, 1, 3
dparm = 3, 400, 1000, 0.5
4 
 
 
3 
 There was a need to fringe-fit Kalyazin first with a very short solint. A high fringe rate window was necessary to do this. Fringes were found with good SNR. 
FRING antennas 1 2 4 5
refant = 1
search = 1, 2
solint = 3
aparm = 2, 0, 0, 0, 2, 1,
   3, 0, 1
dparm = 3, 400, 100, 0.5
4 
 
 
4 
 Fringe-fit for the rest of the array: OK. 
TACOP
4 
 
5 
 
  
CLCAL opcode = 'cali'
interpol = 'ambg'
antennas 1 3
refant 1
4 
3 
5 
 
 Apply solutions for Kalyazin. 
CLCAL opcode = 'cali'
interpol = 'ambg'
antennas 1 2 4 5
refant 1
4 
4 
5 
 
 Apply solutions for the rest of the array. 
POSSM
5 
 
 
 
 Strong phase variations at the edges of the band in Noto data. Flag 10 channels in each sides of both IFs when splitting! 
SPLIT aparm = 2, 0.5, 0, 1
sources 'J0824+55' ''
5 
 
 
 
 Look at data in Difmap. Need to multiply Kalyazin amplitudes by a factor of five. Difmap does not understand MNTSTA=3 for HALCA. 
TABED aparm 5 0 0 2 4 4
keyval = 2
 
 
 
 
 Correct antenna type for VSOP_UZ (MNTSTA: orbiter->2) 
TABED aparm 5 0 0 2 4 5
keyval = 2
 
 
 
 
 Correct antenna type for VSOP_TZ (MNTSTA: orbiter->2) 
CLCOR antennas 3 0
opcode 'gain'
clcorprm 5 0
5 
 
6 
 
 Multiply Kalyazin amplitudes by a factor of 5. 
CLCOR antennas 0
opcode 'gain'
clcorprm 1.063 0
6 
 
7 
 
 Correct for a factor of 1.13 Mitaka losses. See VSOP News No. 129, 25 May 2001. 
SPLIT aparm 2, 0.5, 0, 1
bchan 10
echan 118
7 
 
 
 
 Split all sources. 
FITTP
 
 
 
 
 Data written out for analysis in Difmap. 

AIPS Input Files
INDXR.TXT
ANTAB.TXT		 Comments
- None -

AIPS Output Files
PRTAN.LIS
LISTR.LIS
DTSUM_0.LIS
DTSUM_1.LIS
UVPLT_UV.PS
UVPLT_UVD.PS
UVPLT_UVPA.PS
SN_ACCOR_AMP_1.PS
SN_ACCOR_AMP_2.PS
SN_APCAL_AMP_1.PS		 SN_APCAL_AMP_2.PS
SN_FRING01_DEL_1.PS
SN_FRING01_DEL_2.PS
SN_FRING01_RAT_1.PS
SN_FRING01_RAT_2.PS
SN_FRING01_SNR_1.PS
SN_FRING01_SNR_2.PS
SN_CALIB_DEL_1.PS
SN_CALIB_DEL_2.PS
SN_CALIB_RAT_1.PS		 SN_CALIB_RAT_2.PS
SN_CALIB_SNR_1.PS
SN_CALIB_SNR_2.PS
SN_CALIB_PHA_1.PS
SN_CALIB_PHA_2.PS
POSSM_01_AP_1.PS
POSSM_02_AP_1.PS
POSSM_02_AP_2.PS
POSSM_01_AP_2.PS


Difmap Data Reduction Notes
Phase selfcal applied? Yes
Global amplitude selfcal (gscal) applied? Yes
Amplitude selfcal on non-global timescales used? Yes
Modelfit made and saved? Yes
Image Made and saved? Yes
Comments on Difmap processing
Compact, slightly resolved core. Amplitude correction factors are averages of IF1 and IF2 corrections; there were no significant differences between IF1 and IF2 factors.

Image
Ampl, Phase vs (u,v) Distance
PS (52 kb)
JPEG (47 kb)
 Ampl, Phase vs Time
PS (190 kb)
JPEG 1, 2, 3		 (u,v) Coverage
PS (28 kb)
JPEG (31 kb)
Closure Phase vs Time
PS (159 kb)
JPEG 1		 Clean Image
PS (32 kb)
JPEG (43 kb)
Modelfit
Ampl, Phase vs (u,v) Distance
PS (52 kb)
JPEG (47 kb)
 Ampl, Phase vs Time
PS (190 kb)
JPEG 1, 2, 3		 (u,v) Coverage
PS (28 kb)
JPEG (31 kb)
Closure Phase vs Time
PS (159 kb)
JPEG 1		 Image with model components
PS (33 kb)
JPEG (37 kb)

More details on the Images and Modelfits are found in this page.

Model
Flux (Jy)
Radius (mas)
Theta (deg)
Major (mas)
Axial ratio
Phi (deg)
TB (10^12 K)
0.627601 0.0178240 92.7045 0.422679 0.457667 -77.7969 0.3746
(*) Quoted Brightness temperatures assume Gaussian components and are in the local (z=0) frame.


Last updated on Fri Aug 31 08:59:57 GMT 2001
by db_results.pl version 0.3.