| VS01s Results
Submitted checklist.txt and checklist.tex is also available |
[Summary | AIPS | Difmap ] |
| Observation code | : | VS01s | AIPS Version | : | 15APR99 |
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| Date of Observation | : | 1997/336 | Difmap Version | : | 2.3c | |||
| Source Name | : | 3C446 | vsop_difmap used | : | Yes | |||
| Calibration Source(s) | : | 1921-293 | ||||||
| Ground telescopes | : | Mo, Sh, Hh | Model Fitted to data | : | Yes | |||
| Tracking Station(s) | : | TZ, RZ | Image made | : | Yes | |||
| Correlator | : | Penticton |
| Abstract
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| FITLD | DIGICOR=DELCOR=-1 |
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Output file name = VS01S.FITLD |
| MSORT |
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Input file name = VS01S.FITLD, Output file name = VS01S.UVSRT | |
| FIXWT | CPARM(1)=3 CPARM(3)=0.25 = Cl table time interval |
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Input file name = VS01S.UVSRT, Output file name = VS01S.FIXWT |
| INDXR |
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Created NX(1) | |
| OBTAB |
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Not Used | |
| TBOUT/TBIN |
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Changed entries in AN(1) for MNTSTA by externally editting the table. Changed VSOP_SC from 3 to 2, Hart from 1 to 0. | |
| IBLED |
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Edits stored in FG(1). | |
| ACCOR |
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Not Used | |
| ANTAB |
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INFILE='CAL:VS01S_CAL.DAT' Output sent to TY(1) and GC(1). Nominal values were used for Mo, DPFU=0.1, Tsys=34K. For Halca, used nominal Tsys' values of 95K, 98K for IFs 1 and 2 respectively. | |
| APCAL |
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Input: Ty(1) + GC(1) | |
| SNSMO |
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Did not use | |
| CLCAL | OPCODE = CALI INTERPOL = 2PT REFANT 5 (Mopra) |
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| TACOP |
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| CLCOR | ANTENNAS=0 OPCODE=GAIN CLCORPRM=0.9055 GAINVER=3 |
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| CLCOR | OPCODE='SBDL' ANTENNAS = 4 (Seshan) CLCORPRM= 454, 454 GAINVER=3 |
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| CLCOR | OPCODE='SBDL' ANTENNAS = 3 (VSOP) CLCORPRM= 200, 200 GAINVER=3 |
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| CLCOR | OPCODE='SBDL' ANTENNAS = 2 (Hart) CLCORPRM= -1524, -1524 GAINVER=3 |
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| FRING | APARM(1)=2 APARM(7)=3 (SNR=3) APARM(9)=1 DPARM(1)=1 (no baseline stacking) DPARM(2)=500 (500ns delay window) DPARM(3)=100 (100mHz rate window) DPARM(4)=0.5 (0.5 sec integration time) DPARM(6)=1 (don't average in frequency) BCHAN 0, ECHAN 0 SEARCH 4, 2 REFANT 5 (Mopra) DOCALIB 1 GAINUSE 3 |
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These are the standard parameters I used (unless otherwise specified). Note: SN(2) was deleted after every trial of FRING except the last (final) trial. |
| FRING | Standard+ SOLINT=3 DPARM(2) 1000 DPARM(3) 500 CALSOUR '1921-293' DPARM(5)=1 only do FFT solution |
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Got good solutions for Se-Mp, IF1 (Sh channel 2 was bad). Delay solution were less than 10ns (as expected). Deleted SN(2). |
| FRING | Standard+ APARM(7) 2 DPARM(2) 5000 DPARM(3) 500 SOLINT=3 TIMER 0 10 0 0 0 10 30 0 DPARM(5)=1 only do FFT solution |
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All "high" SNR solutions had abs(delay) less than 400ns, so will reduce delay window to 1200ns. All "high" SNR solutions had abs(rate) less than 100MHz, so will reduce rate window to 200mHz. range were DQA1 didn't get them. "Good" Halca solutions had relatively low SNR, so increase solint to 5 minutes. |
| FRING | Standard+ APARM(7) 2 DPARM(2) 1200 DPARM(3) 200 SOLINT=5 TIMER 0 10 0 0 0 10 30 0 DPARM(5)=1 only do FFT solution |
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Can reduce rate window down still further, to 100mHz, since abs(rate) for high SNR solutions was less than 30MHz. Halca solutions had slightly higher SNR. |
| FRING | Standard+ SOLINT 5 DPARM(2) 1200 DPARM(3) 100 APARM(7)=SNR=2 (Can edit out bad solns later) DPARM(3)=200 DPARM(2)=200 |
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Solutions look good...comparable to DQA1 solutions. |
| SNEDT |
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Editted inconsistent delays and rates. | |
| CLCAL | OPCODE='CALI' INTERPOL = '2PT' |
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| CALIB |
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Not used. | |
| TASAV |
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Input file: VS01S.FIXWT, Output file: VS01S.TABLES | |
| SPLIT | SOURCES '3C446' BCHAN 0, ECHAN 0 DOCALIB 1, GAINUSE 4 APARM(1)=2 (average each IF separately) APARM(2)=0.5 APARM(4)=1 |
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Input file: VS01S.FIXWT, Output file: 3C446.FITS |
| FITTP |
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Input file: VS01S.FITS, Output file: FITS:3C446.FITS |
AIPS Input Files
| ANTAB.TXT INDXR.TXT |
Comments - None - |
Additional Files
| Name | Description |
| image.ps.gz | The final Difmap image (gzipped). |
AIPS Output Files
| 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
Ran uvaver 30,true (averaged over 30 seconds and redo the weights). Cleaning/Phase self-cal: Cleaned out central component, which turned out to be two closely spaced components. Cleaning/Phase+Amp self-cal: Gscale corrections: IF 1: HARTRAO 0.98 MOP 0.91 SESHAN25 0.97 VSOP_SC 1.11. IF 2: HARTRAO 0.00 MOP 0.00 SESHAN25 0.00 VSOP_SC 0.00. IF2 ampselfcal corrections were all zero, since Se IF 2 was bad. Hence, lost all IF2 data after ampselfcal. Only made one iteration of amp/phase selfcal after gscale. Added model components to the east although I'm not convinced they are real. They are consistent with the jet orientation of lower resolution VLBA images of 3C446 however. Final residual map had an RMS of 2 mJy. Corrections after Gscale were small. Used a very large solint for further amp+phase self-cal since there was only the minimum of 4 antennas to constrain the amp self-cal. Only two iterations of amp+phase self-cal were made. Final residual map had an RMS of 1.6 mJy. Final image: Source was partially resolved out with two central components along an East-West axis. Peak flux was 0.357Jy/beam. |
| Image | ||||
| Ampl, Phase vs (u,v) Distance PS (17 kb) JPEG (34 kb) |
Ampl, Phase vs Time PS (104 kb) JPEG 1, 2 |
(u,v) Coverage PS (10 kb) JPEG (24 kb) | Closure Phase vs Time PS (88 kb) JPEG 1 |
Clean Image PS (33 kb) JPEG (43 kb) |
| Modelfit | ||||
| Ampl, Phase vs (u,v) Distance PS (17 kb) JPEG (34 kb) |
Ampl, Phase vs Time PS (102 kb) JPEG 1, 2 |
(u,v) Coverage PS (10 kb) JPEG (24 kb) | Closure Phase vs Time PS (88 kb) JPEG 1 |
Image with model components PS (35 kb) JPEG (39 kb) |
More details on the Images and Modelfits are found in this page.
