VS04L Results
Submitted checklist.txt and checklist.tex is also available		   [Summary | AIPS | Difmap ]
Analyst: Richard Dodson
Date Prepared: 15-11-1999
 

Summary
 
Observation code : VS04L    AIPS Version : 15APR99 
Date of Observation : 1999/225    Difmap Version : 2.3c 
Source Name : J0231+1322    vsop_difmap used : Yes 
Calibration Source(s) : J0231+1322         
Ground telescopes : HOBbit  Model Fitted to data : No 
Tracking Station(s) : NZ    Image made : No 
Correlator : Penticton         

 
Abstract
Only Hobart and VSOP observed. DQA showed no fringes, but ~ 2600 was the modal value.

This data set is possibly a perfect example for weak fringes. A brief conclusion; KRING & FRING are very poor at finding these very weak fringes. BLING seemed just a little better. The Russians ASL package solved it, I am writing this up as a paper.

Following the normal procedures this would have failed!


AIPS Data Reduction Notes
 
Task
Adverbs
CL
in
SN
in
CL
out
SN
out
Comments
FITLD douvcomp = 1; clint = 0.25
    ; digicor = -1; delcorr =
   -1
 
 
1 
 
 Created VS04L.MULTI.1 
MSORT
 
 
 
 
 VS04L.MSORT.1 
INDXR cparm = 0, 0, 0.25
 
 
1 
 
  
ANTAB
 
 
 
 
 logs2keyin.pl used for Tsys 
APCAL
 
 
 
1 
  
CLCAL refant=1;opcode='calp';smotyp='ampl';interpol='box';intp=10;
1 
1 
2 
 
 Amplitude calibration and smoothing applied. 
TACOP
2 
 
3 
 
 Copy CL tables 
KRING cparm
   0,0,2,400,200,-1,-1,-1,-1,0;refant=1;
bparm(5)=0.5;solint 0;SOLTYPE
   'NOLS'
3 
 
 
2 
 No LSS as there is only one. 
SPLAT_KRING_CLCOR 1
 
 
 
 
 Search of 20msec of fringe space 400 nsecs at a time 
CLCOR opcode='sbdl'; antennas =
   2,0; clcorprm=2550,2550,0
3 
 
3 
 
 emotional selection (from modal value in dqa1). See delay_dqa1.ps 
FRINGKRING dparm 200,50;refant=1;
bparm(5)=0.5;solint 10;
3 
 
 
3,4 
 Many cycles of deep searches around the "correct" solution. I tried CLCOR SBLD=2550 (CL#2) values from DQA with rates and without (CL#3 & CL#4). Long integrations and short, profane words and pleads where tried. All without success. 
BLINGBLAPP aparm 0.4 0 0 0.1 1 0; stokes
   'll';
timer 0 0 0 0 0 21 20 0;
   refant 1;
dparm 0 0 2550 200 5 50 0;docal
   -1;
 
 
 
14 
 Output BS : 1 Better? No indication of signal to noise, but there was agreement between IFs at times. 
TBIN infile='SNDIRECTORY:SNTABLES/SNTABLE_VS04L
 
 
 
5 
 Defeated I returned to the beginning, and used that 
CLCAL refant=1;opcode='calp';smotyp='ampl';interpol='box';intp=10;
2 
5 
4 
 
 Apply the fringe solutions from penticton DQA 

AIPS Input Files
ANTAB.TXT
KRING_MULTI.TXT.5		 Comments
logs2keyin.pl used

Additional Files
NameDescription
Delay_Hist.psfinder for the solution
Delay_Rate.psfinder for the solution
Delay_Time.psfinder for the solution
difmap_vplot.psdata and model AIPS failed to find the fringes, even when told exactly were they are. ASL succeeded. Shame ASL is a pig to use (even in comparision to AIPS!). A perfect test data set?

AIPS Output Files
DTSUM_1.LIS
DTSUM_0.LIS
PRTAN.LIS		 ASL.UVPLT.PS
CLTAB_DELAY.PS
CLTAB_RATE.PS


Difmap Data Reduction Notes
Phase selfcal applied? No
Global amplitude selfcal (gscal) applied? No
Amplitude selfcal on non-global timescales used? No
Modelfit made and saved? No
Image Made and saved? No
Comments on Difmap processing
A single baseline was obtained; flux was ~0.2 Jy. A one minute average of the data produced resonable phases.



Last updated on Wed Oct 17 17:47:43 GMT 2001
by db_results.pl version 0.3.