VS02a Results
Submitted checklist.txt and checklist.tex is also available		   [Summary | AIPS | Difmap ]
Analyst: William Scott
Date Prepared: 28-09-1999
 

Summary
 
Observation code : VS02a    AIPS Version : 15OCT98   
Date of Observation : 1998/94    Difmap Version : 2.3c 
Source Name : J0609-15    vsop_difmap used : Yes 
Calibration Source(s) :          
Ground telescopes : Hh, Mp, Ud, Hb, Sh  Model Fitted to data : Yes 
Tracking Station(s) : RZ, UZ    Image made : Yes 
Correlator : Penticton         

 
Abstract
Model
Flux (Jy)
Radius (mas)
Theta (deg)
Major (mas)
Axial ratio
Phi (deg)
TB (10^12 K)
3.31858 0.0117893 91.5710 0.114084 1.00000 -10.8497 12.4429
(*) 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 DIGICOR=DELCOR=-1
 
 
 
 
 Output file name = VS02A.FITLD 
MSORT
 
 
 
 
 Input file name = VS02A.FITLD, Output file name = VS02A.UVSRT 
FIXWT IF=1
CHAN=100
XINC=10
 
 
 
 
 Not used. 
INDXR
 
 
1 
 
 Deleted CL(1) and NX(1), then reran INDXR since number input vis != number output vis after running FIXWT Output file name = VS02A.FIXWT 
OBTAB
 
 
 
 
 Not Used 
TBOUT
 
 
 
 
 Changed entries in AN(1) for MNTSTA, ie: VSOP_SC from 3 to 2, Hobart 2 --> 0 Hart from 1 to 0. 
UVFLG
 
 
 
 
 Manually editted Hh-Ho baseline (IF 1) since it caused IBLED to choke. Hh-Ho (IF 2) also caused IBLED to choke (for no obvious reason), but it did not need any flagging. Edits stored in FG(1). 
IBLED
 
 
 
 
 (all baselines except Hh-Ho) Edits stored in FG(1). 
ACCOR
 
 
 
 
 Not Used 
ANTAB
 
 
 
 
 INFILE='CAL:VS02A_CAL.DAT'. Output sent to TY(1) and GC(1). A few of the Tsys values for Ho were very odd (either extremely large, or negative). These were editted out. For Usuda, used nominal Tsys values. For Mopra, used a typical tsys values from experiment VS04p (obs date Apr. 23/98). Had Tsys values for all other GRTs! For Halca, had to extrapolate tsys values from experiment V047n (obs date Apr. 11/98). Used a nominal DPFU value of 0.1 for Hobart and Mopra. For other antennas, had non-nominal gain curves. 
APCAL
 
 
 
1 
 Input: Ty(1) + GC(1) 
SNSMO INTERPOL = MWF
SMOTYPE = AMPL
1) ANTEN = 1,4,5,6
BPARM(1)=1
(window width = 1 hour)
2) ANTEN = 2
BPARM(1)=0.25
3) ANTEN = 3
BPARM(1)=10
 
1 
 
2 
  
CLCAL OPCODE = CALI
INTERPOL = 2PT
REFANT 3 (Hobart)
1 
2 
2 
 
  
FRING APARM(1)=1
APARM(7)=4 (SNR=4)
APARM(9)=1
DPARM(1)=1 (no baseline
   stacking)
DPARM(3)=100 (100mHz rate
   window)
DPARM(4)=0.5 (0.5 sec integration
   time)
DPARM(6)=1 (don't average
   in frequency)
BCHAN 30, ECHAN 220
SEARCH 4,5,6
REFANT 3 (Hobart)
2 
 
 
3 
 These are the standard parameters I used (unless otherwise specified). 
FRING Standard+
DOCALIB 1, GAINUSE 2
CALSOUR='1213-172'
TIMER 0 6 20 0 0 6 25 0
SOLINT 2
2 
 
 
3 
 Obtained solutions for Mp and Se...solutions looked good. 
TBOUT
 
3 
 
3 
 Removed the rate solutions and made sure there was only one solution for the relevant antennas (Ho, Mo, Se). Also had to renumber the rows. 
CLCAL OPCODE = CALP
INTERPOL = 2PT
SMOTYPE = VLBI
2 
3 
3 
 
  
FRING Standard+
SOLINT=4
TIMER 0 10 0 0 0 10 20 0
DOCALIB 1, GAINUSE 3
3 
 
 
4 
 Got good solutions for other 3 antennas. 
TBOUT
 
4 
 
4 
 Removed the rate solutions and made sure there was only one solution for each antenna. Also had to renumber the rows. 
CLCAL OPCODE = CALP
INTERPOL = 2PT
SMOTYPE = VLBI
3 
4 
4 
 
  
FRING Standard+
SOLINT=4
DPARM(3) 200
DOCALIB 1, GAINUSE 4
4 
 
 
5 
 Good solutions except for Halca baselines. 
FRING Standard+
SOLINT=6
DPARM(2) 5000
DPARM(3) 50
APARM(7) = SNR = 3
TIMER 0 4 30 0 0 5 0 0
DOCALIB 1, GAINUSE 4
4 
 
 
6 
 No Halca Solutions. 
FRING Standard+
SOLINT=2
DPARM(2) 5000
DPARM(3) 50
APARM(7) = SNR = 2
TIMER 0 4 30 0 0 5 0 0
DOCALIB 1, GAINUSE 4
4 
 
 
6 
 Generated Halca solutions, although the delays looked somewhat random. There appears to be a delay jump in IF 1. Halca has perigee at 5:23, so it makes sense that a smaller SOLINT is better. Still have high SNR on non-space baselines. 
FRING Standard+
SOLINT=1, and later 2
DPARM(2) 5000
DPARM(3) 50
APARM(7) = SNR = 3
TIMER 0 4 30 0 0 5 0 0
DOCALIB 1, GAINUSE 4
4 
 
 
7 
 Sparse, somewhat random Halca delay solutions... it looks like I need SNR = 2 to generate enough solutions, even though they might be bogus. Deleted SN tables 5 through 7. 
FRING Standard+
SOLINT=2
DPARM(2) 5000
DPARM(3) 50
APARM(7) = SNR = 2
DOCALIB 1, GAINUSE 4
4 
 
 
5 
 Good solutions for all GRTs. Halca delays around 5:00 look somewhat random, but delays around 10:00 look slightly better. 
SNEDT
 
5 
 
6 
 Editted inconsistent delay/rates (except for Halca). 
CLCAL OPCODE='CALI'
INTERPOL = '2PT'
4 
6 
5 
 
  
CALIB
 
 
 
 
 Not used. 
TACOP
5 
 
6 
 
  
CLCOR ANTENNAS=0
OPCODE=GAIN
CLCORPRM=0.9055
GAINVER=6
6 
 
6 
 
 Correction for Van Vleck normalization. 
CLCOR ANTENNAS=3
OPCODE=GAIN
CLCORPRM=0.6
GAINVER=6
6 
 
6 
 
 Had assumed that the "tsys" values from Ho were truly "tsys" values. Instead, they are only proportional. ANTAB Ho Tsys values are about a factor of 2.8 too big, so multiply Ho baselines by 1/(2.8)**0.5. 
CLCOR ANTENNAS=0
OPCODE=GAIN
CLCORPRM=1.6
GAINVER=6
6 
 
6 
 
 Based upon AT light curves and PLS data, it looks like all visibilities are low by about a factor of 2.5. So, multiply all antenna gains by (2.5)**0.5. 
TASAV OUTSEQ = 2
 
 
 
 
 Input file: VS02A.FIXWT, Output file: VS02A.TABLES 
SPLIT SOURCES 'J0609-15'
BCHAN 0, ECHAN 0
DOCALIB 1, GAINUSE 6
APARM(1)=2 (average each
   IF separately)
APARM(2)=0.5
APARM(4)=1
4 
 
 
 
 Input file: VS02A.FIXWT, Output file: J0609-15.FITS (OUTSEQ=2) 
FITTP
 
 
 
 
 Input file: J0609-15.FITS Output file: J0609-15.FITS 

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

Additional Files
NameDescription
image.ps.gzThe final Difmap image (gzipped).

AIPS Output Files
DTSUM_0.LIS
DTSUM_1.LIS
LISTR.LIS
PRTAN.LIS
POSSM01_AP_1.PS
POSSM02_AP_1.PS
SN_APCAL_AMP_1.PS		 SN_APCAL_AMP_2.PS
SN_CALIB_DEL_1.PS
SN_CALIB_DEL_2.PS
SN_CALIB_PHA_1.PS
SN_CALIB_PHA_2.PS
SN_CALIB_RAT_1.PS
SN_CALIB_RAT_2.PS		 UVPLT_UV.PS
SN_CALIB_SNR_1.PS
SN_CALIB_SNR_2.PS
UVPLT_UVD.PS
UVPLT_UVPA.PS


Difmap Data Reduction Notes
Phase selfcal applied? Yes
Global amplitude selfcal (gscal) applied? Yes
Amplitude selfcal on non-global timescales used? No
Modelfit made and saved? Yes
Image Made and saved? Yes
Comments on Difmap processing
Phase self-cal was run after adding clean components with solution intervals from 10 minutes down to one minute. Clean components were added in the central core, then on later iterations were added to the NE, where there was a large residual which did not correspond to any dirty beam sidelobe. This residual seems consistent with USNO images of the source. Gscale was run, with correction factors of: IF 1: VSOP_SC 1.11 HARTRAO 1.01 HOBART 1.00 MOP 0.94 SESHAN25 0.95 USUDA64 1.03 IF 1: VSOP_SC 1.04 HARTRAO 1.01 HOBART 0.97 MOP 0.94 SESHAN25 0.99 USUDA64 1.02 After gscale, the residuals were very small, and could not be differentiated from beam sidelobes, so non-global amp self-cal was not carried out. Final image: Source consisted of a core with a peak amplitude of 3.06 Jy/beam, and a secondary component to the NE.

Image
Ampl, Phase vs (u,v) Distance
PS (86 kb)
JPEG (37 kb)
 Ampl, Phase vs Time
PS (334 kb)
JPEG 1, 2, 3, 4		 (u,v) Coverage
PS (45 kb)
JPEG (26 kb)
Closure Phase vs Time
PS (495 kb)
JPEG 1, 2		 Clean Image
PS (44 kb)
JPEG (44 kb)
Modelfit
Ampl, Phase vs (u,v) Distance
PS (86 kb)
JPEG (37 kb)
 Ampl, Phase vs Time
PS (333 kb)
JPEG 1, 2, 3		 (u,v) Coverage
PS (45 kb)
JPEG (26 kb)
Closure Phase vs Time
PS (496 kb)
JPEG 1, 2		 Image with model components
PS (41 kb)
JPEG (40 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)
3.31858 0.0117893 91.5710 0.114084 1.00000 -10.8497 12.4429
(*) Quoted Brightness temperatures assume Gaussian components and are in the local (z=0) frame.


Last updated on Wed Aug 25 07:23:36 GMT 2004
by db_results.pl version 0.3.