VS06e Results
Submitted checklist.txt and checklist.tex is also available		   [Summary | AIPS | Difmap ]
Analyst: Zhi-Qiang Shen
Date Prepared: 21-10-1999
 

Summary
 
Observation code : VS06e    AIPS Version : 15OCT98 (15APR99)   
Date of Observation : 1998/212    Difmap Version : 2.3c 
Source Name : J1549+02    vsop_difmap used : Yes 
Calibration Source(s) : 1611+343         
Ground telescopes : NRAO\_140, HartRAO  Model Fitted to data : Yes 
Tracking Station(s) : RZ,UZ    Image made : Yes 
Correlator : Penticton         

 
Abstract
Fringes were found among all three baselines including 2 ground-space baselines for this 2 GRTs experiment.

The first 1 hr data for baselines to NRAO_140 was too low in amplitude. It was probably due to the fact that its receiver was still cooling at the start of run. Flagged out it in the imaging.

The amplitude scales for both survey source (J1549+02) and calibrator (1611+343) seemed to be lower compared to the PLS results. But no simple constant correction factor can be derived from the data partly because of the time variation.

The image was made with the phase self-calibration only. A 2-comp model was fit the calibrated data. Model components were almost linear. Circular component didn't work as well.

For the calibrator 1611+343, it has a correlated flux density of 0.6Jy on a ground baseline (NRAO_140 -- HartRAO) of 10,000km.
Model
Flux (Jy)
Radius (mas)
Theta (deg)
Major (mas)
Axial ratio
Phi (deg)
TB (10^12 K)
0.931110 0.0215328 3.76982 0.770740 0.150230 0.878037 0.5092
0.201076 0.438714 155.317 0.874306 9.26034e-09 -45.4102 0.0000
(*) 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;dotable=1
 
 
 
 
 load the uv FITS data into AIPS 
MSORT sort='TB'
 
 
 
 
 sort the data to 'TB' order 
INDXR cparm(3)=1
 
 
1 
 
 index uv data with 1 min CL entry interval 
TACOP
1 
 
2 
 
 protect original CL1 
ANTAB
 
 
 
 
 determine the Tsys and gain curve (see ANTAB.TXT file). Tsys=95K for Halca. 
APCAL opcode=' '
 
 
 
1 
 generate an amplitude calibration solution table 
CLCAL opcode='CALI'
smotype='ampl'
refant=0
2 
1 
3 
 
 apply amplitude calibration solution 
FRING docalib=1
flagv=-1;solint=4;refant=1
aparm=2,0,0,0,0,1,5,0
dparm=1,0
antwt=1,1,30
3 
 
 
5 
 final fringe fitting (after several trial runs) 
CLCAL opcode='CALI';interpol='';smotype='VLBI';refant=2
cals=sour='J1549+02'
(cals=sour='1611+343')
3 
5 
7 
 
 apply final fringe fitting solutions 
TACOP
7 
 
8 
 
 save calibration table CL7 
CLCOR antenna=0;opcode='GAIN';clcorprm=0.91,0
8 
 
8 
 
 Penticton gain correction 
TASAV
 
 
 
 
 copy all extension tables to a dummy file 
SPLIT docalib=1;douvcomp=1
flagv=-1;aparm=2,0,0,1,0
8 
 
 
 
 make calibrated single-source data files: J1549+02.SPLIT and 1611+343.SPLIT 
FITTP
 
 
 
 
 export each single-source file in FITS format to disk file for further imaging analysis 

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_APCAL_AMP_2.PS		 SN_APCAL_AMP_1.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
POSSM01_AP_1.PS
POSSM01_AP_2.PS
VPLOT_AP_1.PS
VPLOT_AP_2.PS


Difmap Data Reduction Notes
Phase selfcal applied? Yes
Global amplitude selfcal (gscal) applied? No
Amplitude selfcal on non-global timescales used? No
Modelfit made and saved? Yes
Image Made and saved? Yes
Comments on Difmap processing
average data over 30 sec (uvaver 30,true)

raise the weight of HALCA (selfant VSOP_SC,false,30)

keep non-closing data during phase self-cal (selfflag false,3,4)

clean and phase self-cal with uniform weighting (uvw 2,-1 ... etc)

switch to natural weighting to clean more flux (uvw 0,-1 ... etc)

(*NO* amplitude self-cal with eventually only 3 antennas available)

switch back to obtain a uniform weighting clean image: peak=0.441 Jy/beam, RMS=8.1 mJy/beam; beam=0.759 mas x 0.214 mas @ -25.7 deg

Model-fitting to the calibrated data was tried with a 2-comp model.

Image
Ampl, Phase vs (u,v) Distance
PS (70 kb)
GIF (8 kb)
 Ampl, Phase vs Time
PS (182 kb)
GIF 1, 2		 (u,v) Coverage
PS (36 kb)
GIF (4 kb)
Closure Phase vs Time
PS (70 kb)
GIF 1		 Clean Image
PS (37 kb)
GIF (65 kb)
Modelfit
Ampl, Phase vs (u,v) Distance
PS (70 kb)
GIF (8 kb)
 Ampl, Phase vs Time
PS (183 kb)
GIF 1, 2		 (u,v) Coverage
PS (36 kb)
GIF (4 kb)
Closure Phase vs Time
PS (70 kb)
GIF 1		 Image with model components
PS (45 kb)
GIF (8 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)
0.931110 0.0215328 3.76982 0.770740 0.150230 0.878037 0.5092
0.201076 0.438714 155.317 0.874306 9.26034e-09 -45.4102 0.0000
(*) Quoted Brightness temperatures assume Gaussian components and are in the local (z=0) frame.


Last updated on Wed Oct 27 21:12:19 GMT 1999
by db_results.pl version 0.2.0.