LITTLE THINGS AIPS Reduction of DDO 75, D config.: VLA Obs. of 17 August 2008 , AO215_CJ ===================================================================== calibration recipe v. 2.0: mrupen 10oct08 calibration recipe v. 2.1: mrupen 13oct08 calibration recipe v. 2.1.update: Dana Ficut Vicas 29 Oct 08 (new adverbs in Aips) calibration recipe v. 2.2: Dana Ficut Vicas 11Dec 08(tiny bits) calibration recipe v. 2.3: Dana Ficut Vicas 11 Feb 09(UVCOP ambiguities) calibration recipe v. 2.4: Dana Ficut Vicas 3 Mar 09(team raised issues) calibration recipe v. 2.5: Dana Ficut Vicas 23 September 2009 (no smoothing with WIPER on the source data) DAH: Add naming convention 141010 Latest update: 3rd March 2009 Data reduced by Deidre Hunter, Lowell Observatory 29 July 2011-- 0. Basic stuff D configuration, partial EVLA From observing log (available online at http://www.vla.nrao.edu/cgi-bin/oplogs.cgi): * Wind/API rms phase/clouds: 4.9 to 7.7 m/s 9.1 to 19.7 30-60% cumuliform clouds * ant. ??? stolen for EVLA tests * ant. 2, 3, and 28 moved recently Antenna 8 data lost because subreflector not accepting commands. Antenna 3 data lost because both azimuth motors faulted. 1. FILLM executed on 29Jul11 a. Request archive data: copy public project data : AO215 vla2008-08-17.dat to AO215_d75_d3_1 b. FILLM -> D75-D3.CH 0.1, D75-D3.LINE.1 The organization of this file is thus: Individual galaxies sandwiched between phase cals; then two primary cals observed at all the different frequencies bunched together. The data appropriate to SexA are: 1331+305 0/17:52:50 - 0/18:00:10 0943-083 + SexA 0/19:49:50 - 0/21:32:50 freq id 17 default FILLM datain '/ta/d75d3/AO215_d75_d3_ band 'l';vlaobs ''; doall -1 ; qual -1 $ restricts FILLM to the galaxy+calibrators of interest nfiles 0; ncount 1 $ read one filetget fillm, outna 'd75-d3' outdisk 1; outseq 0 douvcomp= -1 $ allow channel/IF-dependent weights doweight 10 $ use memo 108 weights (i.e., put weights in 1/Jy^2) bparm= -1,-1 $ avoid opacity & gain corrections cparm 0 cparm(4)=25.1 $ one needs to explicitly flag shadowed antennas $ since the ModComps were retired on 27 June 2007 $ this requires FILLM in 31DEC08 after 18Nov08 MNJ cparm(7)= 0 $ assigns new FREQID if frequency changes by more than $ the max. Doppler shift between sources 180 degrees $ apart. Setting this to -1 forces all data to have same $ FREQID. doconcat=-1; $ Change this to DOCONCAT=1 to add data to an existing file timerang = 0 17 52 55 0 18 00 15 =====> AIPS 1: 65 2 D75-D3 .CH 0 . 1 UV 29-JUL-2011 22:00:02 AIPS 1: 66 2 D75-D3 .LINE . 1 UV 29-JUL-2011 22:00:03 timerang 0 19 49 50 0 21 32 55; doconcat 1 ***N.B. FILLM's channel 0 will ONLY be used for initial flagging. We're quite paranoid here. 2. TASAV -> LINSAV.1 executed on 29Jul11 ***We TASAV right away, because VLANT changes the AN table. Did I mention we're paranoid? default TASAV outna 'D75-d3BeTa outcla 'LINSAV' getn *.LINE >getn 66 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINE.1 =====> AIPS 1: 67 2 D75-d3BeTa .LINSAV. 1 UV 29-JUL-2011 22:03:21 3. UVCOP -> LINCOP.1 executed on 29Jul11 ***Discard the first and last channels: 1st and last 10 channels if 127 channels total 1st and last 20 channels if 255 channels total ***We discard these Evil Channels because (1) they're pretty much useless; (2) they seem to confuse BPASS (which takes the solution from channel N as the initial guess for channel N+1); (3) their noise characteristics are quite different from the rest of the channels, which can be confusing e.g. in clipping and imaging. default UVCOP outcla 'LINCOP' bchan 21; echan 255-20 $ Use bchan 21 ; echan 255-20 if 255 channels total uvcopprm 0 uvcopprm(4) 1 $ report progress getn *.LINE >getn 66 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINE.1 =====> AIPS 1: 68 2 D75-D3 .LINCOP. 1 UV 29-JUL-2011 22:04:57 ***From now on we operate on LINCOP data unless otherwise specified. 4. LISTR/SCAN --> D75-D3.listr ***We do this before VLANT because we need to know FREQIDs for VLANT default LISTR optype 'SCAN' docrt -1 outpr '/ta/d75d3/d75-d3.listr getn *.LINCOP >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 =====> d75-d3.listr localhos LISTR(31DEC08) 2 29-JUL-2011 22:38:28 Page 1 File = D75-D3 .LINCOP. 1 Vol = 1 Userid = 2 Freq = 1.418818730 GHz Ncor = 2 No. vis = 183754 Scan summary listing Scan Source Qual Calcode Sub Timerange FrqID START VIS END VIS 1 1331+305 : 0000 A 1 0/17:53:05 - 0/18:00:05 1 1 9702 2 0943-083 : 0000 B 1 0/19:53:55 - 0/19:56:25 1 9703 13866 3 SEXA : 0000 1 0/19:56:55 - 0/20:41:55 1 13867 94632 4 0943-083 : 0000 B 1 0/20:42:25 - 0/20:44:35 1 94633 98878 5 SEXA : 0000 1 0/20:45:05 - 0/21:30:05 1 98879 179654 6 0943-083 : 0000 B 1 0/21:30:45 - 0/21:32:45 1 179655 183754 Source summary Velocity type = ' ' Definition = ' ' ID Source Qual Calcode RA(2000.0) Dec(2000.0) IFlux QFlux UFlux VFlux No. vis 1 1331+305 : 0000 A 13:31:08.2879 30:30:32.958 0.000 0.000 0.000 0.000 9702 2 0943-083 : 0000 B 09:43:36.9443 -08:19:30.812 0.000 0.000 0.000 0.000 12510 3 SEXA : 0000 10:11:00.8000 -04:41:34.000 0.000 0.000 0.000 0.000 161542 ID Source Freq(GHz) Velocity(Km/s) Rest freq (GHz) 1 All Sources 1.4188 0.0000 0.0000 Frequency Table summary FQID IF# Freq(GHz) BW(kHz) Ch.Sep(kHz) Sideband 1 1 1.41881873 1312.2560 6.1035 1 5. VLANT -> AN/1, CL/2 executed on 29Jul11 ***Note that VLANT can be run only for data observed from 1992 onwards. Data earlier than 1991 produce the following error message: VLANT1: Task VLANT (release of 31DEC07) begins VLANT1: ANT DATA UNAVAILABLE FOR YEAR 1991 DATA START WITH 1992 VLANT1: Purports to die of UNNATURAL causes For earlier data we skip baseline corrections entirely, and hope for the best. If there are clear and systematic phase gradients with time, consult the baseline corrections at http://www.vla.nrao.edu/astro/archive/baselines/ and apply corrections via CLCOR (which is basically what VLANT does). ***10oct08: Currently VLANT works on only one FREQID at a time. We therefore have to run VLANT multiple times for data with multiple FREQIDs. Unfortunately VLANT (1) produces a new CL table every time, and (2) updates the AN table positions every time as well. : CL tables: I'd like to maintain the convention that CL/1 is the original CL table and CL/2 has all the corrections that should have been applied on-line but weren't -- mainly, antenna position corrections. For multiple FREQIDs therefore this recipe calls for deleting the intermediate CL tables created by VLANT, using the rather clumsy mechanism of TASAVing to a temporary file, deleting the original CL tables, and copying the latest one back from the TASAV'd data set. Blah. : AN table: For now, this recipe resets to the original AN table just before running VLANT the last time. This means that only one run of VLANT updates the AN entries, leading to a correct AN table as needed for (e.g.) UVFIX. I've e-mailed DAIP to see about fixing all this, by allowing FREQID= -1 to mean "calculate corrections for all FREQIDs" (currently FREQID= -1 is reset to FREQID= 1). We'll see what Eric says. #####VLANT no longer has freqid as a parameter. 5a. default VLANT getn *.LINCOP >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 localh> VLANT1: Task VLANT (release of 31DEC08) begins localh> VLANT1: WARNING: 1 ANTENNAS MAY STILL GET MORE CORRECTION localh> VLANT1: Copied CL file from vol/cno/vers 1 68 1 to 1 68 2 localh> VLANT1: CL version input 1 output 2 localh> VLANT1: VLANT STNID( 2) = 'E5 ' localh> VLANT1: VLANT XCOR( 2) = -0.0048 localh> VLANT1: VLANT YCOR( 2) = 0.0046 localh> VLANT1: VLANT ZCOR( 2) = 0.0087 localh> VLANT1: VLANT STNID( 3) = 'MPD' localh> VLANT1: VLANT XCOR( 3) = 0.0081 localh> VLANT1: VLANT YCOR( 3) = -0.0021 localh> VLANT1: VLANT ZCOR( 3) = -0.0084 localh> VLANT1: VLANT STNID(10) = 'E8 ' localh> VLANT1: VLANT XCOR(10) = -0.0006 localh> VLANT1: VLANT YCOR(10) = 0.0014 localh> VLANT1: VLANT ZCOR(10) = -0.0003 localh> VLANT1: VLANT STNID(16) = 'W6 ' localh> VLANT1: VLANT XCOR(16) = 0.0013 localh> VLANT1: VLANT YCOR(16) = 0.0008 localh> VLANT1: VLANT ZCOR(16) = 0.0002 6. PRTAN AN/1 default PRTAN docrt 132 getn *.LINCOP >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 Location Of VLA Antennas N9 ( 7) N8 ( 9) N7 (13)* N6 (26)* N5 (27) N4 (12) N3 (18)* N2 (25)* N1 (20) *( 1) W1 E1 (15) (22) W2 E2 (21)* *(24) W3 E3 (11)* *(19) W4 E4 ( 5)* *(17) W5 E5 ( 2)* *(16) W6 ( ) ( ) E7 (14)* ( 6) W8 E8 (10) *( 4) W9 E9 (23)* EVLA:MPD ( 3) VLA:_OUT ( 8) VLA:_OUT (28) VPT:_OUT (29) * => EVLA ANTENNA ***To choose the reference antenna the following algorithm should be followed: 1. should be present throughout the run 2. should be on an "inner" pad, but NOT N1/E1/W1 (to avoid shadowing) 3. NOT on the master pad (since those are always weird) 4. NOT an EVLA antenna (since those are often weird) 5. try to avoid the north arm in the smaller configurations (to avoid shadowing) 6. NOT listed in any interesting way in the log file (to avoid problems with the reference antenna) 7. preferably consistent with other recent runs 8. should be a fairly stable antenna (can't tell until TVFLG/CALIB of course...) ===> Refant: E8 (10) (Antenna 22 is missing in primary cal) 7. Calibrators ***Check out the calibrators in the on-line calibrator manual: http://www.vla.nrao.edu/astro/calib/manual/index.shtml ***Max baseline at 21 cm in B array is 54.3 klambda C array is 16.2 klambda D array is 4.9 klambda primary (flux/bandpass) calibrators: 1331+305 J2000 A 13h31m08.287984s 30d30'32.958850" Aug01 3C286 1328+307 B1950 A 13h28m49.657700s 30d45'58.640000" ----------------------------------------------------- BAND A B C D FLUX(Jy) UVMIN(kL) UVMAX(kL) ===================================================== 20cm L S S P P 15.00 secondary (gain) calibrator: 0943-083 J2000 B 09h43m36.944364s -08d19'30.812400" Aug01 0941-080 B1950 B 09h41m08.642400s -08d05'43.986000" ----------------------------------------------------- BAND A B C D FLUX(Jy) UVMIN(kL) UVMAX(kL) ===================================================== 20cm L P P P P 2.70 ===> secondary cal --- unrestricted 7b. SETJY -> SU/1 executed on 29Jul11 ***Set aparm(2) to corespond to date of observation. If date <1990 aparm(2)=3 If 19921998 aparm(2)=0 ***We need to enter a flux density for each primary (flux) calibrator. If we have only one FREQID, this is easy: default SETJY sources '1331+305','' $ primary (flux) calibrator(s) optype 'CALC'; freqid=1 $ First FREQID aparm 0,0 $ data taken after 1998 getn *.LINCOP; >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 =====> localh> SETJY1: A source model for this calibrator may be available localh> SETJY1: Use the verb CALDIR to see if there is one localh> SETJY1: / Flux calculated using known spectrum localh> SETJY1: BIF = 1 EIF = 1 /Range of IFs localh> SETJY1: '1331+305 ' IF = 1 FLUX =14.7340 (Jy calcd) localh> SETJY1: / Using (1999.2) VLA or Reynolds (1934-638) coefficients 7c. CALRD executed on 29Jul11 ***Read in models of flux density calibrators: default CALRD object '3c286';band 'L'; localh> CALRD1: Reading disk file AIPSTARS:3C286_L.MODEL localh> CALRD1: Create 3C286_L .MODEL . 1 (MA) on disk 1 cno 69 =====> AIPS 1: 69 2 3C286_L .MODEL . 1 MA 29-JUL-2011 22:50:06 ***Note: These models are in J2000 coordinates. If your data are in B1950, change the model images to B1950 with EPOSWTCH. We will later use UVFIX to fix the uv-data. 8. PRTUV (used to find integration times on calibrators & sources) default PRTUV cparm 0; cparm(9)=103 $ Pick a baseline -- here, baseline 1-3 docrt 132 getn *.LINCOP >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 ====> calib: 10s source: 10s 9. UVFLG -> FG/1 executed on 29Jul11 ***We toss the EVLA-EVLA baselines, to avoid dealing with aliasing. There should still be plenty of VLA-EVLA baselines to allow antenna-based solutions for the EVLA...but keep an eye out for oddities (e.g., in BPASS)! default UVFLG outfgver 1;opcode 'flag';reason 'EVLA' getn *.CH0 $ Note that we use FILLM's CH0 for initial flags -- we'll $ TACOP later. >getn 65 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.CH 0.1 antenna=EVLA;baseline=EVLA; =====> localh> UVFLG1: Wrote 153 flags to flag table version 1 10. TVFLG -> FG/1 executed on 29Jul11 ***Again, we *only* use the original CH 0 from FILLM for initial flagging. Here we flag calibrators only, to remove any gross, obvious problems. - Check the first scan carefully -- often the system isn't "organized" on this first scan - On-line flagging isn't as reliable as in the old days, so there are plenty of hot pixels and hiccups. - We are NOT quacking, because (1) FILLM's NX table isn't correct; (2) QUACK flags data from the beginning-of-scan, whereas we want to flag data from antennas-on-source. default TVFLG calcode '*' $ calibrators only docat -1 $ avoid saving temporary files dohist -1 $ avoid creation of history entries Freqid 1 $ must step through all FREQIDs! docalib -1 flagver 1;outfgver 1 $ keep all flags in FG/1 dparm 0 dparm(3) 1 $ show baselines twice, to treat all antennas identically -- $ this displays baseline 27-1 as well as 1-27 dparm(6)=10 $ time resolution: should be set to the calibrators' integration $ time, in seconds getn *.CH0 $ note this is the ONLY time we use FILLM's Channel 0! >getn 65 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.CH 0.1 ***Within TVFLG: - Set useful defaults: SMOOTH=1 to avoid averaging date before displays SCAN= 20 to use a long time for median filters (AMP/PH DIFF) FLAG ALL CHANNELS FLAG STOKES FULL (usually -- sometimes you'll want NORR or NOLL) ***If individual Stokes need to be flagged, make sure you set the STOKES FLAG to correspond to the polarization that is displayed on the TV SWITCH SOURCE FLAG to ONE-SOURCE to avoid inadvertantly flagging your galaxy (though sometimes you'll want to of course) - Be sure to inspect BOTH polarizations! ***We suggest the following steps: - Set the above defaults - Flag first integration in every scan (manual QUACK) -- this should be the first integration AFTER most antennas are on-source, which is why we can't use the usual QUACK. - Inspect the following: AMPLITUDE to check for missing records or antennas AMP DIFF to check for variable gains PHS DIFF to check for variable atmosphere/gains - If your data set is in D array(if your source is southern than also check for this problem in the C array) than keep an open eye for solar interference. It will be obvious if in TVFLG you choose a SORT BY BASELINE display, showing you how the short baselines behave,the ones affected by solar interference.If solar interference is affecting your data than in CALIB you should use a UVRANGE. ***Note: occasionally, flagging using UVFLG can be more straightforward (e.g., deleting an antenna). =====> Flag beginnings of each scan. Antennae 1, 8, 22, and 24 missing from primary cal; also half of time missing in 2 and 3 in primary. Clip amp diff and pha diff interactively. Some clipping in primary amp as well. No obvious length of baseline correlation. localh> TVFLG1: Writing flagging information in FG table 1 localh> TVFLG1: Wrote 459 flags in the FG table 10b. TABED FG/1 executed on 29Jul11 ***Here we TABED the CH 0 flags to LINCOP (with FREQID= -1). After this we're done with FILLM's channel 0. default TABED opty 'repl' inext 'fg' inver 1 ; outver 1; bcount 1;ecount 0 ; aparm 0 aparm(1) 3 $ Changing column 3 = FREQID keyval= -1,0 $ ...to FREQID= -1 getn *.CH 0 getona *.LINCOP >getn 65 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.CH 0.1 >getona 68 AIPS 1: Got(O) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 =====> LINCOP FG/1 11. BPASS ***This is a first-order BPASS leading to a new Channel 0. The goal is to avoid closure errors in Channel 0 calibration due to huge delays (phase slopes) on VLA-EVLA baselines. We divide each visibility by the vector average of the inner 3/4 of the band (i.e., an on-the-fly channel 0). Thus we remove source structure (tho' getting the weights wrong) and take care of the amplitude scale. ***There is a split here between the easy case (one FREQID for all sources) and the Galactic HI case (multiple FREQIDs, usually different for the bandpass calibrator and the galaxy (and phase calibrator)). Check LISTR/SCAN to see which you're doing. 11a. BPASS: one FREQID for all sources -> BP/1 executed on 30Jul11 default BPASS calsour '1331+305','' $ Select bandpass calibrators docal 1 ; gainuse 2 $ apply VLANT changes. Probably irrelevant. flagver 1 $ apply initial flags refant 10 $ Change this to your refant Qual -1 solint 0 $ one solution per scan minamper 7 ; minphser 7 $ report closures > 7%/7d smooth 0 $ no smoothing soltype '' ; weightit 0 $ L1, L1R, etc. seem _less_ stable -- weird bpassprm 0 bpassprm(5) 0 $ derive "channel 0" on a record-by-record basis -- $ more biased than averaging first, but avoids $ some subtle pitfalls (see EXPLAIN file) bpassprm(2) 1 $ some closure info is printed bpassprm(6) 2 $ print avg. closure errors > 2% bpassprm(7) 2 $ print avg. closure errors > 2d ichansel 0 $ derive channel 0 from inner 3/4 of the band freqid 1 $ here we have only one FREQID getn *.LINCOP >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 =====> BP/1 11c. POSSM to check BP table 11c1. Plot BP table itself default POSSM $ to check BPASS results flagver 1 aparm 0, 1, 0.7, 1.3, -180, 180, 0, 2, 0, 0 $ Plot BP, with amp/ph ranges source '1331+305','0943-083','' $ POSSM doesn't work with $ source '' for some reason! solint -1 $ Separate plots for each scan nplots 9 $ 9 plots per page bparm 0 dotv 1 freqid 1; bpver 1 $ for single-FREQID data sets tvinit getn *.LINCOP >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 =====> bpass_table_1.jpg, bpass_table_2.jpg, bpass_table_3.jpg, bpass_table_4.jpg, bpass_table_5.jpg, bpass_table_6.jpg They look OK. 11c2. Apply BP table to 2ndary calibrator & plot individual baselines default POSSM flagver 1 aparm 0 $ Plot data solint -1 $ Separate plots for each scan nplots 9 $ 9 plots per page aparm 0 aparm(1) 1 $ vector average source='0943-083','' $ Secondary (phase) calibrator docal 1 ; gainuse 2 ; doband 1 $ average all BP entries dotv 1 tvinit freqid 1; bpver 1 $ for single-FREQID data sets getn *.LINCOP >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 =====> Look OK. 11c3. Apply BP table to 2ndary calibrator & vector average all data default POSSM flagver 1 aparm 0 $ Plot data solint 0 $ average all time nplots 0 $ average all baselines aparm 0 aparm(1) 1 $ vector average source='0943-083','' $ Secondary (phase) calibrator docal 1 ; gainuse 2 ; doband 1 $ average all BP entries dotv 1 tvinit freqid 1; bpver 1 $ for single-FREQID data sets getn *.LINCOP >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 =====> bpass_2cal_vectorave_rr.jpg, bpass_2cal_vectorave_ll.jpg Looks good. ***This plot should be flat in both amp. and phase as a function of frequency, with no slope.. If some channels are off, note which ones those are and keep an eye out for interference or other bad data. If there are large errors consider running BPASS on the secondary calibrator and using that to correct the galaxy. Note that this will be somewhat painful since AIPS does not allow incremental BP tables -- unlike SN or CL tables. Sigh. 12. AVSPC -> NEWCH0.1 (2,3) executed on 30Jul11 ***AVSPC must be run once for each FREQID (unfortunately FREQID=-1 purports to work, but creates an empty data set). This entails some nasty bookkeeping for data sets with multiple FREQIDs. Here I assume we have one or three FREQIDs. If BPASS checks above show that one FREQID is useless, you should ignore that one entirely in this and all subsequent processing. ***We will use these NEWCH0 files for (1) further flagging, and (2) time-dependent gain calibration. 12a. FREQID=1 --> NEWCH0.1 default AVSPC docalib -1;gainuse 0; flagver -1 $ do NOT apply flags doband 1 freqid 1; bpver 1 $ for single-FREQID data sets getn *.LINCOP >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 outname inna ; outcl 'NEWCH0' =====> AIPS 1: 70 2 D75-D3 .NEWCH0. 1 UV 30-JUL-2011 00:33:00 12d. LISTR/SCAN ***It is a VERY good idea to run LISTR/SCAN on each of the NEWCH0 data sets at this point, to be sure each has the data you expect. =====> Looks OK. 13. TABED LINCOP FG/1 -> NEWCH0 FG/1 ***We use TABED to set FREQID to -1 (apply to all FREQIDs) in the FG table, since AVSPC will change all FREQIDs to 1 in the NEWCH0 data sets. 13a. NEWCH0.1 default TABED opty 'repl' inext 'fg' inver 1 ; outver 1 aparm 0 aparm(1) 3 $ Changing column 3 = FREQID keyval= -1,0 $ ...to FREQID= -1 getn *.LINCOP getona *.NEWCH0.1 >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 >getona 70 AIPS 1: Got(O) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 =====> NEWCH0.1, FG/1 14. CALIB -> NEWCH0.1(,2,3) SN/1 executed on 30Jul11 ***If we only have one FREQID, all CALIBs are run on the same NEWCH0.1 . If we have multiple FREQIDs, CALIBs for a given source must be run for all NEWCH0.1,2,3 in which that source appears (probably easiest to check with LISTR/SCAN). ***Note: if 'SN' table must be destroyed: task 'extdest'; inext 'sn'; invers 0 ***If solar interference is affecting your data than in CALIB you should use a UVRANGE. The worst case scenario, baselines up to a distance of 1 kilolambda could be afected, while in the best case scenario baselines are affected only up to 0.5kilolambda distance. We recommend using: UVRANGE 0.7,0 for D array UVRANGE 0.7,0 for C array After calibration, if UVPLT still shows signs of solar interference,it means that not enough short baselines were discarded; therefore the calibration has to be redone and UVRANGE to be reset. Note that the Sun might rise or set, especially during a long B-array run, in which case you might wish to split the calibration by timerange in a set affected and a set without solar interference. 14a. Primary (flux density) calibrators --> SN/1 default CALIB calsour '1331+305','' $ flux density calibrator #1 get2n 3C286_L.MODEL.1 >get2n 69 AIPS 1: Got(2) disk= 1 user= 2 type=MA 3C286_L.MODEL.1 nmap 1 ; ncomp 1e6,0 ; inver 1 ; cmethod 'DFT' freqid -1 docal 1 ; gainuse 2 flagver 1 refant 10 $ Change this to your refant solint 0 aparm 4,0,0,0,0,2; $ min 4 antennas; print closures soltype 'L1'; solmode 'A&P'; weightit 1 $ true L1 minimization solcon 0 minamper 10; minphser 10 $ complain if >10%/10d off cparm 0,0,10,10,1 $ complain if avg > 10%/10d off snver 1 getn *.NEWCH0 $ ***NOTE: must run this for all NEWCH0.1,2,3 in which $ this calibrator appears! >getn 70 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 =====SN/1 localh> CALIB1: CALIB USING D75-D3 . NEWCH0 . 1 DISK= 1 USID= 2 localh> CALIB1: L1 Solution type localh> CALIB1: UVGET: Using flag table version 1 to edit data localh> CALIB1: Selecting, editing and calibrating the data localh> CALIB1: Doing self-cal mode with CC model localh> CALIB1: SETGDS: imaging done with reprojected tangent point(s) localh> CALIB1: FACSET: source model will be scaled to 14.734 Jy localh> CALIB1: FACSET: 15.457486 Jy found from 1424 components localh> CALIB1: FACSET: scaling factor set to 9.53196E-01 localh> CALIB1: QINIT: did a GET of 5120 Kwords, OFF 3568125 localh> CALIB1: VISDFT: Begin DFT component division localh> CALIB1: VISDFT: fields 1 - 1 chns 1 - 1 in 1 CC models localh> CALIB1: VISDFT: Model components of type Point localh> CALIB1: I Polarization model processed localh> CALIB1: Model computation is 80 percent complete localh> CALIB1: Field 1 used 1424 CCs localh> CALIB1: Determining solutions using amp-scalar averaging localh> CALIB1: Writing SN table 1 localh> CALIB1: RPOL, IF= 1 The average gain over these antennas is 3.134E+00 localh> CALIB1: LPOL, IF= 1 The average gain over these antennas is 3.032E+00 localh> CALIB1: Found 46 good solutions localh> CALIB1: Average closure rms = 0.0012 +- 0.0002 localh> CALIB1: No data were found > 99.0 rms from solution 14b. Secondary (phase) calibrator --> SN/1 ***Check uv restrictions for secondary calibrators carefully. For 0943-083: no restrictions, so uvra= 0,0 . =====> Solar interference became obvious when did uvplt later. default CALIB calsour '0943-083','' $ phase calibrator wtuv 0.0 $ may have to set wtuv 0.01 if solutions are $ crazy and uvrange is not 0,0 freqid -1 docal 1 ; gainuse 2 flagver 1 refant 10 $ Change this to your refant solint 0 aparm 4,0,0,0,0,2; $ min 4 antennas; print closures soltype 'L1'; solmode 'A&P'; weightit 1 $ true L1 minimization solcon 0 minamper 10; minphser 10 $ complain if >10%/10d off cparm 0,0,10,10,1 $ complain if avg > 10%/10d off snver 1; UVRANGE 1.0,0 getn *.NEWCH0 $ ***NOTE: must run this for all NEWCH0.1,2,3 in which $ this calibrator appears! >getn 70 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 =====> localh> CALIB1: CALIB USING D75-D3 . NEWCH0 . 1 DISK= 1 USID= 2 localh> CALIB1: L1 Solution type localh> CALIB1: UVGET: Using flag table version 1 to edit data localh> CALIB1: Selecting, editing and calibrating the data localh> CALIB1: Doing cal transfer mode with point model for each source localh> CALIB1: This is not self-calibration localh> CALIB1: Dividing data by source flux densities localh> CALIB1: Determining solutions using amp-scalar averaging localh> CALIB1: Writing SN table 1 localh> CALIB1: Closure errors at 0/20:43:35 0943-083 IF no. 1 Rpol localh> CALIB1: 02-10 6.5% 10d 02-20 22.8% 12d localh> CALIB1: Antenna 2 had 2 excess closure errors, 2 printed localh> CALIB1: Antenna 10 had 1 excess closure errors, 1 printed localh> CALIB1: Antenna 20 had 1 excess closure errors, 1 printed localh> CALIB1: Closure errors at 0/20:43:35 0943-083 IF no. 1 Lpol localh> CALIB1: 02-20 14.6% 10d localh> CALIB1: Antenna 2 had 1 excess closure errors, 1 printed localh> CALIB1: Antenna 20 had 1 excess closure errors, 1 printed localh> CALIB1: Closure errors at 0/21:31:45 0943-083 IF no. 1 Lpol localh> CALIB1: 02-10 13.4% 2d 10-11 17.5% 1d localh> CALIB1: Antenna 2 had 1 excess closure errors, 1 printed localh> CALIB1: Antenna 10 had 1 excess closure errors, 1 printed localh> CALIB1: Antenna 20 had 1 excess closure errors, 1 printed localh> CALIB1: Closure errors at 0/20:43:35 0943-083 IF no. 1 Lpol localh> CALIB1: 02-20 14.6% 10d localh> CALIB1: Antenna 2 had 1 excess closure errors, 1 printed localh> CALIB1: Antenna 20 had 1 excess closure errors, 1 printed localh> CALIB1: Closure errors at 0/21:31:45 0943-083 IF no. 1 Lpol localh> CALIB1: 02-10 13.4% 2d 10-11 17.5% 1d localh> CALIB1: Antenna 2 had 1 excess closure errors, 1 printed localh> CALIB1: Antenna 10 had 2 excess closure errors, 2 printed localh> CALIB1: Antenna 11 had 1 excess closure errors, 1 printed localh> CALIB1: RPOL, IF= 1 The average gain over these antennas is 3.100E+00 localh> CALIB1: LPOL, IF= 1 The average gain over these antennas is 3.067E+00 localh> CALIB1: Found 138 good solutions localh> CALIB1: Average closure rms = 0.0065 +- 0.0008 localh> CALIB1: No data were found > 99.0 rms from solution 15b. GETJY SN/1-3, SU/1 executed on 30Jul11 ***Find flux density of secondary calibrator, and set SN table amplitude gains to reflect a common flux density scale. default GETJY sources '0943-083','' $ Secondary (phase) calibrators) calsour '1331+305','' $ Primary (flux) calibrators freqid -1 snver 0 $ Use all SN tables getn *.NEWCH0.1 >getn 70 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 =====> localh> GETJY1: Source:Qual CALCODE IF Flux (Jy) localh> GETJY1: 0943-083 : 0 B 1 2.67923 +/- 0.02637 16. SN table checks 16a. SNPLT last SN table executed on 30Jul11 16a1. SNPLT phase: default SNPLT inext 'sn';inver 0 pixrange 0 opcode 'alsi';do3col 1;dotv 1; nplots 9 factor 2; symbol 5 xinc 1; optype 'phas'; tvinit getn *.NEWCH0.1 >getn 70 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 ===> Note any phase jumps (on the phase calibrator) for future flagging. The EVLA antennas, even after applying VLANT, still show quite a bit of phase drift. This is OK so long as a linear interpolation between the phases looks like it will work. =====> snplt_table_pha_1.jpg, snplt_table_pha_2.jpg, snplt_table_pha_3.jpg Looks OK. 16a2. SNPLT amplitude: default SNPLT inext 'sn';inver 0 pixrange 0 opcode 'alsi';do3col 1;dotv 1; nplots 9 factor 2; symbol 5 xinc 1; optype 'amp'; tvinit getn *.NEWCH0.1 >getn 70 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 ===> Note whether the amp. is roughly constant for a given antenna/pol'n/IF. ***We have seen a couple cases where the first phase cal scan has a significantly different amplitude gain for the EVLA antennas. The reason is not clear but the raw data do show this effect, so CALIB is doing the right thing. This area warrants further tests, to learn whether we should simply flag the EVLA antennas on the first phase calibrator scan. =====> snplt_table_amp_1.jpg, snplt_table_amp_2.jpg, snplt_table_amp_3.jpg Look OK. 16b. LISTR/GAIN print SN table executed on 30Jul11 default LISTR optype 'gain'; Inext 'sn'; inver 1; freqid -1 dparm 5,0; $ Amp & phase factor 0; docrt -1 outprint '/ta/d75d3/listr_sntable.txt antennas 0; $ may have to list missing antennas explicitly, to avoid $ column overrun. To list missing antennas, use the form $ANTENNAS -3,2,0 to have antennas 3 and 2 left out. getn *.NEWCH0.1 >getn 70 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 --> check for phase jumps and other inconsistencies. ***We have seen a couple cases where the first phase cal scan has a significantly different amplitude gain for the EVLA antennas. The reason is not clear but the raw data do show this effect, so CALIB is doing the right thing. This area warrants further tests, to learn whether we should simply flag the EVLA antennas on the first phase calibrator scan. =====> listr_sntable.txt localhos LISTR(31DEC08) 2 30-JUL-2011 01:31:57 Page 1 File = D75-D3 .NEWCH0. 1 Vol = 1 Userid = 2 IF = 1 Freq= 1.418818730 GHz Ncor= 2 No. vis= 143818 Polarization = R Subarray = 0 Listing SN table, version 1 SN table has not been applied to a CL table Gain amplitudes, 1000 = 10.000000 Stokes = R IF = 1 Freq = 1.418818730 GHz Time Source -- 1-- 2-- 3-- 4-- 5-- 6-- 7-- 8-- 9--10--11--12--13--14--15--16--17--18--19--20--21--22--23--24--25--26--27--28 Day # 0 17:56:45 1331+305 193 254 288 375 274 321 240 317 135 315 350 335 324 363 281 445 332 290 363 370 475 319 253 19:55:35 0943-083 186 262 291 370 275 320 247 317 138 311 351 341 317 370 284 430 318 288 360 377 462 326 249 20:43:35 0943-083 196 265 289 361 280 320 241 314 144 314 348 336 321 324 240 431 311 292 371 325 444 313 254 21:31:45 0943-083 198 291 295 373 276 320 244 316 156 313 357 363 318 342 301 413 308 283 332 365 448 301 257 File = D75-D3 .NEWCH0. 1 Vol = 1 Userid = 2 IF = 1 Freq= 1.418818730 GHz Ncor= 2 No. vis= 143818 Polarization = R Subarray = 0 Listing SN table, version 1 SN table has not been applied to a CL table localhos LISTR(31DEC08) 2 30-JUL-2011 01:31:57 Page 2 File = D75-D3 .NEWCH0. 1 Vol = 1 Userid = 2 IF = 1 Freq= 1.418818730 GHz Ncor= 2 No. vis= 143818 Polarization = L Subarray = 0 Listing SN table, version 1 SN table has not been applied to a CL table Gain amplitudes, 1000 = 10.000000 Stokes = L IF = 1 Freq = 1.418818730 GHz Time Source -- 1-- 2-- 3-- 4-- 5-- 6-- 7-- 8-- 9--10--11--12--13--14--15--16--17--18--19--20--21--22--23--24--25--26--27--28 Day # 0 17:56:45 1331+305 219 295 282 384 296 321 226 322 147 302 322 336 273 375 223 378 329 295 361 326 413 304 246 19:55:35 0943-083 216 298 283 402 297 315 226 321 136 299 323 337 265 384 225 376 320 292 404 356 400 296 243 20:43:35 0943-083 230 298 288 376 300 316 223 323 143 298 322 330 270 366 230 369 325 297 410 330 400 294 246 21:31:45 0943-083 219 315 291 380 298 319 222 320 165 298 328 340 275 390 246 372 357 290 398 379 402 322 243 File = D75-D3 .NEWCH0. 1 Vol = 1 Userid = 2 IF = 1 Freq= 1.418818730 GHz Ncor= 2 No. vis= 143818 Polarization = L Subarray = 0 Listing SN table, version 1 SN table has not been applied to a CL table localhos LISTR(31DEC08) 2 30-JUL-2011 01:31:57 Page 3 File = D75-D3 .NEWCH0. 1 Vol = 1 Userid = 2 IF = 1 Freq= 1.418818730 GHz Ncor= 2 No. vis= 143818 Polarization = R Subarray = 0 Listing SN table, version 1 SN table has not been applied to a CL table Gain phases in degrees Stokes = R IF = 1 Freq = 1.418818730 GHz Time Source -- 1-- 2-- 3-- 4-- 5-- 6-- 7-- 8-- 9--10--11--12--13--14--15--16--17--18--19--20--21--22--23--24--25--26--27--28 Day # 0 17:56:45 1331+305 -84-106 121 84 -28 19 -123 0 -37 136 105 -51 165-138 -38 58 150 33-173 -44 35 -32 3 19:55:35 0943-083 17 -12-158-173 -56 -7 -150 0 59 120-161 52 152 -58 49 151 -99 12 -85 68 122 53 -15 20:43:35 0943-083 10 -10-142-178 -48 1 -143 0 78 124-165 61 157 -41 58 152 -87 18 -81 70 127 60 -12 21:31:45 0943-083 9 -9-124 179 -40 4 -138 0 95 128-168 65 163 -30 68 151 -74 21 -72 75 135 68 -7 File = D75-D3 .NEWCH0. 1 Vol = 1 Userid = 2 IF = 1 Freq= 1.418818730 GHz Ncor= 2 No. vis= 143818 Polarization = R Subarray = 0 Listing SN table, version 1 SN table has not been applied to a CL table localhos LISTR(31DEC08) 2 30-JUL-2011 01:31:57 Page 4 File = D75-D3 .NEWCH0. 1 Vol = 1 Userid = 2 IF = 1 Freq= 1.418818730 GHz Ncor= 2 No. vis= 143818 Polarization = L Subarray = 0 Listing SN table, version 1 SN table has not been applied to a CL table Gain phases in degrees Stokes = L IF = 1 Freq = 1.418818730 GHz Time Source -- 1-- 2-- 3-- 4-- 5-- 6-- 7-- 8-- 9--10--11--12--13--14--15--16--17--18--19--20--21--22--23--24--25--26--27--28 Day # 0 17:56:45 1331+305 177 73 -99-140 -46 36 -7 0-153 78 -12 -8-162-140-115 74 58 25 107 109 39 117 109 19:55:35 0943-083 -85 164 -21 -40 -78 8 -30 0 -60 62 79 93-179 -63 -30 166 166 4-166 -140 124-160 89 20:43:35 0943-083 -91 166 -3 -48 -70 16 -24 0 -40 68 75 102-175 -46 -21 167 178 11-161 -138 133-154 93 21:31:45 0943-083 -90 169 15 -44 -62 21 -21 0 -23 73 72 108-169 -33 -10 166-166 14-153 -132 141-145 98 File = D75-D3 .NEWCH0. 1 Vol = 1 Userid = 2 IF = 1 Freq= 1.418818730 GHz Ncor= 2 No. vis= 143818 Polarization = L Subarray = 0 Listing SN table, version 1 SN table has not been applied to a CL table =====> All phase changes among 2ndary cal NEWCH0.1 FG/1 executed on 30Jul11 ***If the SN table shows a phase jump on the phase calibrator, you should flag the data between the two phase cal scans which show the jump (since those cannot be calibrated). ***Note that we flag NEWCH0.1, *regardless* of whether the galaxy appears in this data set. This is because later on (step 20/TVFLG) we flag the NEWCH0 data in order from inseq 1 through inseq freqid_max, copying the FG table from one file to the next. UVFLG itself doesn't care whether the flags you enter actually do anything -- it just adds entries to the FG table, which are then applied (or ignored if irrelevant) by other tasks. ***This step may of course be skipped if there are no obvious phase jumps. =====> Skip. This example deals with a phase jump on antenna 18. default UVFLG antenna 18,0 $ the antenna which "jumped" timer 0 6 33 0 0 6 59 0; $ the source scan between the offending ph.cal scans opcode 'FLAG' reason 'phase jump' outfgver 1 getn *.NEWCH0.1 --> NEWCH0.1 FG/1 18. CLCAL NEWCH0 --> CL/3 executed on 30Jul11 ***For multi-FREQID data this becomes rather complicated, since we need a new CL table for every NEWCH0 file, to allow detailed checks and second-order flagging. ***Note that there is no need to work around any phase jumps, since the intervening data are flagged (see step 17 above [UVFLG]). 18a. CLCAL for the primary calibrators -> CL/3 default CLCAL sour= '1331+305','' $ Primary (flux) calibrators calsour= sour interpol 'SELF' gainver 2 ; gainuse 3 refant 10 $ Change this to your refant dobtween -1 $ Don't interpolate entries for different sources snver 1 $ if single FREQID getn *.NEWCH0.1 $ do this for all NEWCH0 with primary (flux) $ calibrator data >getn 70 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 =====> localh> CLCAL1: Using interpolation mode SELF localh> CLCAL1: Processing SN table 1 localh> CLCAL1: SNMRG: Merging SN table localh> CLCAL1: SNMRG: Write 92 merged records from 92 input records localh> CLCAL1: SN2CL: Applying SN tables to CL table 2, writing CL table 3 18b. CLCAL for the phase calibrator and galaxy -> CL/3 default CLCAL sour= '0943-083','SexA','' $ Secondary (phase) calibrator + galaxy calsour= '0943-083','' $ Secondary (phase) calibrator interpol 'SIMP' gainver 2 ; gainuse 3 refant 10 $ Change this to your refant dobtween -1 $ Don't interpolate entries for different sources cutoff 120 $ Don't extrapolate/interpolate beyond 120 minutes snver 1 $ if single FREQID getn *.NEWCH0.1 $ do this for all NEWCH0 with secondary (phase) $ calibrator or galaxy data >getn 70 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 =====> localh> CLCAL1: Using interpolation mode SIMP localh> CLCAL1: Processing SN table 1 localh> CLCAL1: WARNING: SN table 1 has already been applied localh> CLCAL1: SNMRG: Merging SN table localh> CLCAL1: SNMRG: Write 92 merged records from 92 input records localh> CLCAL1: SN2CL: Applying SN tables to CL table 2, writing CL table 3 ***At this point we have a new CL table for all NEWCH0 files. 19a. ANBPL executed on 30Jul11 ***We use ANBPL to check the data weights. Data with very high weights (factor 5-10 or more above normal) should be flagged with UVFLG. default ANBPL docalib 1;gainuse 3 flagver 1 bparm 2,17,0 $ Plot antenna-based weight vs. time nplots 9; dotv 1 docrt 132 $ Print as well as plotting weights -- useful for $ finding exact times of bad weights $ Note you can also use outprint to send to a file. opcode 'alsi' $ Plot all IFs together do3col 1 $ ...using different colors tvinit getn *.NEWCH0.1 $ Must do this separately for every NEWCH0 file >getn 70 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 =====> anbpl_1.jpg, anbpl_2.jpg, anbpl_3.jpg There are a few that are 50% high and 50% low, but nothing really bad. 19b. UVFLG to eliminate very high weights ***Should UVFLG on NEWCH0.1, even if Evil Weights are seen in NEWCH0.2 or NEWCH0.3 -- we'll be copying FG/1 from NEWCH0.1 to NEWCH0.2 for subsequent second-order flagging. =====> Skip 20. TVFLG FG/1 executed on 30Jul11 20a. TVFLG on calibrators: NEWCH0.1 The calibrators should now have constant amplitude and zero phase...apart from source structure for the primary (flux) calibrators, and any uvrange for the secondary (phase) calibrators. If we see huge problems on the calibrators we may have to re-run CALIB etc. -- let's hope not!! default TVFLG calcode '*' $ calibrators only docat -1 $ avoid saving temporary files dohist -1 $ avoid creation of history entries docalib 1 ; gainuse 3 $ apply the new CL table flagver 1;outfgver 1 $ keep all flags in FG/1 dparm 0 dparm(3) 1 $ show baselines twice, to treat all antennas identically -- $ this displays baseline 27-1 as well as 1-27 dparm(6)=10 $ time resolution: should be set to the calibrators' $ integration time, in seconds tvinit getn *.NEWCH0.1 >getn 70 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 ***Within TVFLG: - Set useful defaults: SMOOTH=1 to avoid averaging date before displays SCAN= 20 to use a long time for median filters (AMP/PH DIFF) FLAG ALL CHANNELS FLAG STOKES FULL (usually -- sometimes you'll want NORR or NOLL) ***If individual Stokes need to be flagged, make sure you set the STOKES FLAG to correspond to the polarization that is displayed on the TV SWITCH SOURCE FLAG to ONE-SOURCE to avoid inadvertantly flagging your galaxy (though sometimes you'll want to of course) - Be sure to inspect BOTH polarizations! ***We suggest the following steps: - Set the above defaults - Check AMPLITUDE, AMP DIFF, PHS DIFF. Be wary of known source structure and uv-range limits!! ***Note: occasionally, flagging using UVFLG can be more straightforward (e.g., deleting an antenna). =====> Looks OK. 21. Calibration/flagging checks: calibrators 21a. UVPLT executed on 30Jul11 ***Check the amp & phase vs. uv-distance for all calibrators. Amplitude should match the results of SETJY/GETJY. If there are obvious outliers which are not expected due to source structure, go back and flag those (and possibly re-run CALIB etc.). default UVPLT calco '*' docal 1 ; gainuse 3 flagver 1 $ set this to the latest FG version -- may be >1 if $ there are multiple NEWCH0s (FREQIDs). dotv 1 do3col 1 tvinit getn *.NEWCH0.1 $ do this for each NEWCH0 file >getn 70 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 bparm 0 $ amp. vs. uv-distance =====> uvplt_cals_ch0_amp.jpg GETJY1: 0943-083 : 0 B 1 2.67923 +/- 0.02637 SETJY1: '1331+305 ' IF = 1 FLUX =14.7340 (Jy calcd) Levels consistent with that. Secondary cal has high values at shortest baseline. bparm 0,2 $ phase vs. uv-distance =====> uvplt_cals_ch0_pha.jpg Levels around 0, but some high scatter at shortest baselines. 21b. IMAGR executed on 30Jul11 default IMAGR sources '0943-083','' $ calibrator to image docalib 1; gainuse 3 $ apply latest calibration flagver 1 $ apply latest flags -- set this to the $ highest-numbered FG table outname 'cal' $ some obviously cruddy name cellsize 10 $ for D configuration imsize 512 $for C and D array niter 1000 nbox 1 ; clbox 250,250,270,270 $ calibrator should be in the center minpa 121 uvwtfn 'NA'; robust 0.5 dotv -1 uvrange 1.0,0 getn *.NEWCH0.xx $ whichever file has the calibrator you're imaging >getn 70 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 --> shouldn't see obvious calibration errors or striping. CLEANed flux density should roughly match SETJY/GETJY. Note: If uvwtfn is set to 'NA' it will override any value given to robust. =====> 2.72 Jy, expect 2.68 Jy. 22. TVFLG on the galaxy: NEWCH0.xx ***This is our first run of flagging on the galaxy. - Check the first scan carefully -- often the system isn't "organized" on this first scan - On-line flagging isn't as reliable as in the old days, so there are plenty of hot pixels and hiccups. - We are NOT quacking, because (1) FILLM's NX table isn't correct; (2) QUACK flags data from the beginning-of-scan, whereas we want to flag data from antennas-on-source. 22a. If there's only one NEWCH0 (FREQID): default TVFLG calcode '-CAL' $ non-calibrators only docat -1 $ avoid saving temporary files dohist -1 $ avoid creation of history entries docalib 1 ; gainuse 3 $ apply the new CL table flagver 1;outfgver 1 $ keep all flags in FG/1 dparm 0 dparm(3) 1 $ show baselines twice, to treat all antennas identically -- $ this displays baseline 27-1 as well as 1-27 dparm(6)=10 $ time resolution: should be set to the sources' $ integration time, in seconds tvinit getn *.NEWCH0.1 >getn 70 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 ***Within TVFLG: - Set useful defaults: SMOOTH=1 to avoid averaging date before displays SCAN= 20 to use a long time for median filters (AMP/PH DIFF) FLAG ALL CHANNELS FLAG STOKES FULL (usually -- sometimes you'll want NORR or NOLL) ***If individual Stokes need to be flagged, make sure you set the STOKES FLAG to correspond to the polarization that is displayed on the TV SWITCH SOURCE FLAG to ONE-SOURCE to avoid inadvertantly flagging your galaxy (though sometimes you'll want to of course) - Be sure to inspect BOTH polarizations! ***We suggest the following steps: - Set the above defaults - Flag first integration in every scan (manual QUACK) -- this should be the first integration AFTER most antennas are on-source, which is why we can't use the usual QUACK. - Check AMPLITUDE, AMP DIFF, PHS DIFF. Be wary of known source structure and uv-range limits!! ***Note: occasionally, flagging using UVFLG can be more straightforward (e.g., deleting an antenna). =====> Remove a small time range. Definite solar intererence for most of obs. 23. Calibration/flagging checks: sources 23a. UVPLT executed on 30Jul11 ***Check the amp vs. uv-distance for the galaxy. If there are obvious outliers which are not expected due to source structure or RFI (i.e., not mostly on short spacings), go back and flag those. Note any obvious short-spacing horrors, which may be due to solar or terrestrial RFI. default UVPLT docal 1 ; gainuse 3 flagver 1 $ set this to the latest FG version -- may be >1 if $ there are multiple NEWCH0s (FREQIDs). dotv 1 do3col 1 source 'SexA','' tvinit getn *.NEWCH0.1 $ whichever file holds the galaxy >getn 70 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 bparm 0 $ amp. vs. uv-distance =====> uvplt_gal_ch0_amp.jpg Definite solar intererence <1.0 kl. Otherwise looks nice. 23b. IMAGR executed on 30Jul11 default IMAGR sources 'SexA','' $ the galaxy docalib 1; gainuse 3 $ apply latest calibration flagver 1 $ apply latest flags -- set this to the $ highest-numbered FG table outname 'gal' $ some obviously cruddy name cellsize 10 $ for D configuration imsize 512 $ for C and D configurations niter 1000 nbox 0 minpa 121 uvwtfn 'na'; robust 0.5 dotv -1 uvrange 1.0,0 getn *.NEWCH0.xx $ whichever file has the source you're imaging >getn 70 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 --> shouldn't see obvious calibration errors or striping. Note that this "channel 0" includes HI emission, so you may see some odd effects (e.g., very woofly noise in B configuration) -- don't panic! =====> Looks OK. 24. TASAV -> CH0SAV.1,2,3 executed on 30Jul11 default TASAV outna 'D75-D3MidTa outcla 'ch0sav' getn *.NEWCH0 $ loop over NEWCH0 files (= FREQIDs) >getn 70 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 outse inseq =====> AIPS 1: 71 2 D75-D3MidTa .CH0SAV. 1 UV 30-JUL-2011 01:56:32 25. TABED SN, FG tables to LINCOP executed on 30Jul11 ***Use TABED to ensure FREQID=-1 for all tables (paranoia is your friend...) 25a. NEWCH0.xx FG/yy -> LINCOP FG/2 default TABED opty 'repl' inext 'fg' aparm 0 aparm(1) 3 $ Changing column 3 = FREQID keyval= -1,0 $ ...which we change to FREQID= -1 inver 1 $ if single FREQID outver 2 getn *.NEWCH0.1 $ if single FREQID getona *.LINCOP >getn 70 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 >getona 68 AIPS 1: Got(O) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 =====> LINCOP FG/2 25b. NEWCH0.xx SN/yy -> LINCOP SN/1 default TABED opty 'repl' inext 'sn' inver 1 $ if single FREQID outver 0 aparm 0 aparm(1) 6 $ Changing column 3 = FREQID keyval= -1,0 $ ...which we change to FREQID= -1 getn *.NEWCH0 $ if multiple FREQIDs: all should have same merged SN $ table so you can use whichever NEWCH0 file you want getona *.LINCOP >getn 70 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 >getona 68 AIPS 1: Got(O) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 =====> LINCOP SN/1 26. CLCAL LINCOP SN/1 --> CL/3 executed on 30Jul11 ***We do CLCAL directly on LINCOP rather than copying, to avoid (even more) confusion in the multiple-FREQID case. ***Note that there is no need to work around any phase jumps, since the intervening data are flagged (see step 17 above [UVFLG]). 26a. CLCAL for the primary calibrators -> CL/3 default CLCAL sour= '1331+305','' $ Primary (flux) calibrators calsour= sour interpol 'SELF' gainver 2 ; gainuse 3 refant 10 $ Change this to your refant dobtween -1 $ Don't interpolate entries for different sources snver 1 freqid= 1 $ You must run CLCAL once for each FREQID with $ the relevant calibators present getn *.LINCOP >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 =====> localh> CLCAL1: WARNING: SN table 1 has already been applied localh> CLCAL1: SNMRG: Merging SN table localh> CLCAL1: SNMRG: Write 92 merged records from 92 input records localh> CLCAL1: SN2CL: Applying SN tables to CL table 2, writing CL table 3 26b. CLCAL for the phase calibrator and galaxy -> CL/3 default CLCAL sour= '0943-083','SexA','' $ Secondary (phase) calibrator + galaxy calsour= '0943-083','' $ Secondary (phase) calibrator interpol 'SIMP' gainver 2 ; gainuse 3 refant 10 $ Change this to your refant dobtween -1 $ Don't interpolate entries for different sources cutoff 120 $ Don't extrapolate/interpolate beyond 120 minutes snver 1 freqid= 1 $ You must run CLCAL once for each FREQID with $ the phase calibrator or galaxy present getn *.LINCOP >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 =====> localh> CLCAL1: Using interpolation mode SIMP localh> CLCAL1: Processing SN table 1 localh> CLCAL1: WARNING: SN table 1 has already been applied localh> CLCAL1: SNMRG: Merging SN table localh> CLCAL1: SNMRG: Write 92 merged records from 92 input records localh> CLCAL1: SN2CL: Applying SN tables to CL table 2, writing CL table 3 27. Calibration/flagging checks: calibrators 27a. WIPER executed on 30Jul11 ***Check the amp & phase vs. uv-distance for all calibrators. Amplitude should match the results of SETJY/GETJY, and phase should be zero, apart from known structure (reflected in source model for gain calibrators and uvrange for phase calibrators). If there are obvious, unexpected outliers, go back and flag those (and possibly re-run various tasks...). default WIPER calcode '*' docal 1 ; gainuse 3 doband 1; bpver 1 $ for single-FREQID data sets freqid 1 $ set this to match the calibrator flagver 2 $ should be the latest FG table smooth 7, 235 $ boxcar average over all channels -- use $ smooth 7, 235 if you started with 255 channels dotv 1 do3col 1 bparm 0 tvinit imsize 512 512 getn *.LINCOP >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 bparm(2) 1 $ amp. vs. uv-distance =====> wiper_cals_lincop_amp.jpg Looks OK. bparm(2) 2 $ phase vs. uv-distance =====> wiper_cals_lincop_pha.jpg Phase scatters +/-180 deg. 27b. POSSM executed on 30Jul11 ***Check vector average of all data for each calibrator. Amplitude should match the results of SETJY/GETJY; phase should be flat, and consistent with zero (corresponding to a point source at the origin)...apart from known source structure and possibly HI absorption. default POSSM calcode '*' docal 1 ; gainuse 3 doband 1; bpver 1 $ for single-FREQID data sets freqid 1 $ set this to match the calibrator flagver 2 $ should be the latest FG table aparm 0 $ Plot data solint 0 $ average all time nplots 0 $ average all baselines aparm 0 aparm(1) 1 $ vector average source='0943-083','' $ Secondary (phase) calibrator uvrange= 1.0,0 $ should be set to eliminate known source structure, $ as in CALIB dotv 1 tvinit getn *.LINCOP >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 =====> possm_2ndcal_lincop_vecave_rr.jpg, possm_2ndcal_lincop_vecave_ll.jpg Looks good. 27c. IMAGR executed on 30Jul11 default IMAGR docal 1 ; gainuse 3 doband 1; bpver 1 $ for single-FREQID data sets freqid 1 $ set this to match the calibrator flagver 2 $ should be the latest FG table outname 'calline' $ some obviously cruddy name cellsize 10 $ for D configuration imsize 512 $ for C and D array niter 200 $ reasonable for a point source nbox 1 ; clbox 250,250,270,270 $ calibrator should be in the center minpa 121 uvwtfn 'na'; robust 0.5 dotv -1 $ so you can go eat lunch bchan 100; echan 105 source '0943-083','' getn *.LINCOP >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 ***You shouldn't see obvious calibration errors or striping. CLEANed flux density should roughly match SETJY/GETJY. If you _do_ have Evil Stuff, UVLSF will likely take care of it, so don't get too worked up. =====> Looks good. Flux density 2.89 Jy. Expect 2.68 Jy. 28. Calibration/flagging checks: sources 28a.1 WIPER executed on 30Jul11 ***Check the amp vs. uv-distance for the galaxy. If there are obvious outliers which are not expected due to source structure or RFI (i.e., not mostly on short spacings), go back and flag those. Note any obvious short-spacing horrors, which may be due to solar or terrestrial RFI. default WIPER docal 1 ; gainuse 3 doband 1; bpver 1 $ for single-FREQID data sets freqid 1 $ set this to match the galaxy flagver 2 $ should be the latest FG table smooth 0 $do not smooth: smoothing will decrease your noise and $consequently show you a lower flux level than the level $that your data has in fact dotv 1 do3col 1 sources 'SexA','' bparm 0 tvinit imsize 512 512 getn *.LINCOP >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 bparm(2) 1 $ amp. vs. uv-distance =====> wiper_lincop_gal_amp.jpg Solar interference. Flag a little more individual high (>14) points in 19:56:00 - 20:42:00 and a segment of a long baseline in 20:45:00 - 21:31:00. wiper_lincop_gal_amp_moretvflg.jpg Use bparm(3)=1;bparm(6)=0;bparm(7)=20 if you want to force a range to the Y axis of the WIPER plot. ###It shows a plot similar to the UVPLT output just quicker.It is also useful for identifying which antennas or baselines have calibration problems.If you do find things you want to flag, UVFLG is highly recommended. #####CAREFUL with smoothing when doing WIPER on the source, it should NOT be done at this step.Smoothing will decrease your noise and consequently show you a lower flux level than the level that your data has in fact. #######It is very probable that when doing a WIPER on all the line data, some channels with junk will ruin your WIPER display and you will not be able to really make out what the clipping level should be. If the junk consists of random hot pixels then just run another WIPER in which you force the y axis to a 0-20 range (bparm(3)=1;bparm(6)=0;bparm(7)=20). If the junk comes in a structured manner than further investigations are needed to identify which baselines, in which channels might be missbehaving. Use WIPER only to identify the problematic baselines and channels, and use TVFLG or UVFLG to remove them form the data. 28a.2 Up to which level most of the values(leaving aside the very hot pixels) comfortably fit in? 18 Jy ###This is the value that you will be using in CLIP when combining your data!!! 28b. IMAGR executed on 30Jul11 default IMAGR docal 1 ; gainuse 3 doband 1; bpver 1 $ for single-FREQID data sets freqid 1 $ set this to match the calibrator flagver 2 $ should be the latest FG table outname 'galline' $ some obviously cruddy name cellsize 10 $ for D configuration imsize 256 $ for D configuration niter 1000 $ a light clean, just to see what we've got. niter 0 $ would be ok too, esp. if you IMLIN afterwards nbox 0 ; clbox 0 minpa 121 uvwtfn 'NA'; robust 0.5 dotv -1 $ so you can go eat lunch source 'SexA','' uvrang 1.0,0 getn *.LINCOP >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 ***You shouldn't see obvious calibration errors or striping. You should however see of order 100 mJy of continuum sources in the field, as well as some indication of your galaxy. The latter may be quite confusing for B configuration, which resolves out most of the structure. Don't fret until you've combined all the array configurations. ### If you find a strong continuum source rippling your map even after trying a 512x512 imsize D array configuration cube than refer to Elias and Dana for further steps. =====> Looks OK. A negative blob near galaxy. 28c. Noise Estimations: calculated on 30Jul11 ##The easiest way to calculate the expected sensitivity is to say 7 S(mJy) = ---------------------------- sqrt{ N (N-1) delta_nu t} where 7 is a constant that depends on the system temperature of the receivers(a quite conservative value) N = number of antennas in the array, delta_nu = channel resolution in MHz, and t = integration time in hours. You need to use for N the number of Antennas which have on average been giving good data during the run. The total time should be the actual time spent on source. No need to be super precise, of course. One simply wants to get a ballpark figure which is good to 10-20%. ###Note that for data which are Hanning smoothed (archive data) the channel spacing is equal to the resolution delta_nu. Without Hanning smoothing, the resolution is ~1.4 x delta_nu (note that after offline Hanning smoothing, if you preserve all channels, the resolution becomes 2 x delta_nu; it reverts to a new "double the old delta_nu" if you delete every other channel). ####Finally, if you want to know the noise in a single visibility, use N=2 and t = 1/360, and probably multiply by sqrt{2} because a visibility is a single polarisation as well. =====> N = 25 delta-nu: Channel separation is 6.1E-3 MHz; no Hanning smoothing so resolution is 1.4x this = 8.54E-3 MHz int time = 1.5 hrs The Expected noise level is: 2.52 mJy The rms Noise level in a line free channel is: 3.87 mJy/bm 29. TASAV -> EndTaB.LINSAV.1 executed on 30Jul11 default TASAV outna 'D75-D3EndTa outcla 'linsav' getn *.LINCOP >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 =====> AIPS 1: 83 2 D75-D3EndTa .LINSAV. 1 UV 30-JUL-2011 02:29:49 30. FITTP executed on 30Jul11 >getn 65 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.CH 0.1 >dataout '/ta/d75d3/DDO75_D3_CH0_orig.FITS >getn 66 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINE.1 >dataout '/ta/d75d3/DDO75_D3_LINE_orig.FITS >getn 67 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-d3BeTa.LINSAV.1 >dataout '/ta/d75d3/DDO75_D3-BegTasav.FITS >getn 71 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3MidTa.CH0SAV.1 >dataout '/ta/d75d3/DDO75_D3-MidTasav.FITS >getn 83 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3EndTa.LINSAV.1 >dataout '/ta/d75d3/DDO75_D3-EndTasav.FITS >getn 70 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.NEWCH0.1 >dataout '/ta/d75d3/DDO75_D3_UV_CALIB_NEWCH0.FITS >getn 68 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-D3.LINCOP.1 >dataout '/ta/d75d3/DDO75_D3_UV_CALIB_LINCOP.FITS