| VS03g Results
Submitted checklist.txt and checklist.tex is also available |
[Summary | AIPS | Difmap ] |
| Observation code | : | VS03g | AIPS Version | : | 15APR99 |
|
||
| Date of Observation | : | 1998/227 | Difmap Version | : | 2.3c | |||
| Source Name | : | J2158-1501 | vsop_difmap used | : | No | |||
| Calibration Source(s) | : | 2255-282 | ||||||
| Ground telescopes | : | Shanghai, Hartebeesthoek, Hobart, Mopra | Model Fitted to data | : | Yes | |||
| Tracking Station(s) | : | TZ | Image made | : | Yes | |||
| Correlator | : | Penticton |
| Abstract
Only ~1 h HALCA tracking at the beginning. Fringes found on all baselines. Correlated flux density is ~300 mJy on the longest projected baselines (370 Mlambda). Due to the fortunate beam orientation, extended source structure is visibleto S-SW on ~1 mas scale, in similar PA seen on the pre-launch survey image. |
|
|
|
in |
in |
out |
out |
|
| FITLD |
|
|
|
|
||
| MSORT |
|
|
|
|
uv file received was already sorted in TB order | |
| FIXWT | bif = 1 bchan = 100 xinc = 10 detime = -1 |
|
|
|
|
|
| INDXR | cparm = 0, 0, 0.25, 0 |
|
|
|
|
Input scan break taken from PI letter. |
| TABED | inext = 'an' inver = 1 outver = 1 optyp = 'repl' aparm = 5, 0, 0, 6, 0 bcount = 1 ecount = 1 keyvalue = 0 |
|
|
|
|
fix incorrect antenna type (MNTSTA: altaz->0) in column 5, row 1 of AN table for HartRAO |
| TABED | same as above, except: bcount = 2 ecount = 2 keyvalue = 0 |
|
|
|
|
fix incorrect antenna type (MNTSTA: altaz->0) in column 5, row 2 of AN table for HOBART |
| TABED | same as above, except: bcount = 5 ecount = 5 keyvalue = 2,0 |
|
|
|
|
fix incorrect antenna type (MNTSTA: orbiter->2) in column 5, row 5 of AN table for VSOP_SC |
| ANTAB |
|
|
|
|
Gain curve information from VSOP calibration web page. Nominal Tsys used for Hobart, Mopra and HALCA. Slight difference between HALCA IF1 and IF2 (96 & 102 K) based on earlier experience. | |
| APCAL |
|
|
|
|
||
| CLCAL | opcode = 'cali' interpol = '2pt' refant = 3 |
|
|
|
|
Amplitude calibration solutions applied |
| FRING | docalib = 1 gainuse = 2 flagver = -1 refant = 3 search = 2, 4, 1 solint = 5 aparm = 2, 0, 0, 0, 2, 1, 3, 0, 1, 0 dparm = 3, 400, 100, 0 |
|
|
|
|
Delay & rate search windows 400 ns & 100 mHz. SNR threshold 3. 440/4 good/bad solutions, found what was expected from correlator DQA plots. SOLINT=3 and 8 gave not much difference as tried for a 30 min period where space baselines available. |
| CLCAL | opcode = 'cali' interpol = 'ambg' |
|
|
|
|
Fringe-fit solutions applied. |
| TACOP |
|
|
|
|
Prepare a copy of CL table before amplitude scaling. | |
| CLCOR | opcode = 'gain' antenn = 0 clcorprm = 0.906, 0 |
|
|
|
|
Gain correction for Penticton data correlated before 14 Feb 1999. |
| TACOP |
|
|
|
|
Prepare a copy of CL table before amplitude scaling. | |
| CLCOR | opcode = 'gain' antenn = 2,0 clcorprm = 0.8, 0 |
|
|
|
|
HO gain correction after investigating data in Difmap |
| CLCOR | opcode = 'gain' antenn = 4,0 bif=eif=1 clcorprm = 1.3, 0 |
|
|
|
|
SH gain correction after investigating data in Difmap (separately for IF1) |
| CLCOR | opcode = 'gain' antenn = 4,0 bif=eif=2 clcorprm = 0.9, 0 |
|
|
|
|
SH gain correction after investigating data in Difmap (separately for IF2); Except for HO and SH, all other antenna gains are left as they are |
| SPLIT | aparm = 2, 1.44, 0, 1, 0 |
|
|
|
|
Create single-source file, IF-s not averaged. |
| FITTP |
|
|
|
|
Data written out for analysis in Difmap. |
AIPS Input Files
| ANTAB.TXT INDXR.TXT |
Comments Measured Tsys for SH, HH and HO, nominal values are used for MP and HALCA. HO Tsys values are suspiciously large (by a factor of ~3), nominal values are used instead. |
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
Shortest baseline correlated flux density (~0.8 Jy) seems lower than expected from pre-launch survey/ATCA lightcurve data (~2 Jy). The gains at the antennas of the only baseline below 100 Mlambda (HO-MP) can not be properly calibrated, and they probably became too low. 'gscal' amplitude corrections (for IF1/IF2 separately!): HH, HO, MO, SH, HALCA 1.11/1.09, 0.84/0.85, 0.97/0.99, 1.08/1.08, 1.05/1.00 |
| Image | ||||
| Ampl, Phase vs (u,v) Distance PS (60 kb) GIF (7 kb) |
Ampl, Phase vs Time PS (206 kb) GIF 1, 2, 3 |
(u,v) Coverage PS (29 kb) GIF (4 kb) | Closure Phase vs Time PS (163 kb) GIF 1 |
Clean Image PS (32 kb) GIF (57 kb) |
| Modelfit | ||||
| Ampl, Phase vs (u,v) Distance PS (60 kb) GIF (7 kb) |
Ampl, Phase vs Time PS (206 kb) GIF 1, 2, 3 |
(u,v) Coverage PS (29 kb) GIF (4 kb) | Closure Phase vs Time PS (163 kb) GIF 1 |
Image with model components PS (37 kb) GIF (7 kb) |
More details on the Images and Modelfits are found in this page.
