LITTLE THINGS AIPS Reduction of DDO 75, C config.: VLA Obs. of 16 March 2008 , AO215_BC ===================================================================== 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 C configuration, partial EVLA From observing log (available online at http://www.vla.nrao.edu/cgi-bin/oplogs.cgi): * Wind/API rms phase/clouds: 1.9 to 6.1 m/s 780.3 2.2 to 778.4 2.5 20-50% stratiform clouds * ant. ??? stolen for EVLA tests * ant. 2, 4, 7, 15, 25, 26, and 27 moved recently 1. FILLM executed on 30Jul11 a. Request archive data: copy public project data : AO215 vla2008-03-16.dat to AO215_d75_c3_1 b. FILLM -> D75-C3.CH 0.1, D75-C3.LINE.1 The organization of this file is thus: 1331+305 from 04:47:45 (Use 04:47:35) 0943-083 + SexA sandwiches end 07:33:50 and go on to another galaxy default FILLM datain '/ta/d75c3/AO215_d75_c3_ 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-c3' 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 4 47 35 0 7 34 00 =====> AIPS 1: 78 2 D75-C3 .CH 0 . 1 UV 30-JUL-2011 13:59:11 AIPS 1: 79 2 D75-C3 .LINE . 1 UV 30-JUL-2011 13:59:14 ***N.B. FILLM's channel 0 will ONLY be used for initial flagging. We're quite paranoid here. 2. TASAV -> LINSAV.1 executed on 30Jul11 ***We TASAV right away, because VLANT changes the AN table. Did I mention we're paranoid? default TASAV outna 'D75-c3BeTa outcla 'LINSAV' getn *.LINE >getn 79 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.LINE.1 =====> AIPS 1: 80 2 D75-c3BeTa .LINSAV. 1 UV 30-JUL-2011 14:20:11 3. UVCOP -> LINCOP.1 executed on 30Jul11 ***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 79 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.LINE.1 =====> AIPS 1: 81 2 D75-C3 .LINCOP. 1 UV 30-JUL-2011 14:21:11 ***From now on we operate on LINCOP data unless otherwise specified. 4. LISTR/SCAN --> D75-C3.listr ***We do this before VLANT because we need to know FREQIDs for VLANT default LISTR optype 'SCAN' docrt -1 outpr '/ta/d75c3/d75-c3.listr getn *.LINCOP >getn 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.LINCOP.1 =====> d75-c3.listr localhos LISTR(31DEC08) 2 30-JUL-2011 14:22:37 Page 1 File = D75-C3 .LINCOP. 1 Vol = 1 Userid = 2 Freq = 1.418798910 GHz Ncor = 2 No. vis = 332693 Scan summary listing Scan Source Qual Calcode Sub Timerange FrqID START VIS END VIS 1 1331+305 : 0000 A 1 0/04:47:55 - 0/04:51:35 1 1 8073 2 0943-083 : 0000 B 1 0/04:53:55 - 0/04:56:15 1 8074 12658 3 SEXA : 0000 1 0/04:56:45 - 0/05:32:45 1 12659 88035 4 0943-083 : 0000 B 1 0/05:33:15 - 0/05:35:25 1 88036 92730 5 SEXA : 0000 1 0/05:35:55 - 0/06:12:55 1 92731 168647 6 0943-083 : 0000 B 1 0/06:13:25 - 0/06:15:25 1 168648 173210 7 SEXA : 0000 1 0/06:15:55 - 0/06:51:55 1 173211 248896 8 0943-083 : 0000 B 1 0/06:52:25 - 0/06:54:35 1 248897 253391 9 SEXA : 0000 1 0/06:55:05 - 0/07:31:05 1 253392 328130 10 0943-083 : 0000 B 1 0/07:31:45 - 0/07:33:45 1 328131 332693 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 8073 2 0943-083 : 0000 B 09:43:36.9443 -08:19:30.812 0.000 0.000 0.000 0.000 22901 3 SEXA : 0000 10:11:00.8000 -04:41:34.000 0.000 0.000 0.000 0.000 301719 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 1.41879891 1312.2560 6.1035 1 5. VLANT -> AN/1, CL/2 executed on 30Jul11 ***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 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.LINCOP.1 localh> VLANT1: WARNING: 1 ANTENNAS MAY STILL GET MORE CORRECTION localh> VLANT1: Copied CL file from vol/cno/vers 1 81 1 to 1 81 2 localh> VLANT1: CL version input 1 output 2 localh> VLANT1: VLANT STNID( 4) = 'W18' localh> VLANT1: VLANT XCOR( 4) = 0.0066 localh> VLANT1: VLANT YCOR( 4) = -0.0122 localh> VLANT1: VLANT ZCOR( 4) = 0.0057 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 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.LINCOP.1 Location Of VLA Antennas N18 ( 7) N16 (13)* N14 (27) N12 (18)* N8 ( 9) N6 (26)* N4 (12) N2 (25)* N1 (15) (22) W2 E2 (21)* *(19) W4 E4 ( 2) *(16) W6 E6 (28) ( 6) W8 E8 (10) *( 1) W10 E10 (11)* *(24) W12 E12 (20) *(17) W14 E14 ( 3) ( 8) W16 E16 (14)* *( 4) W18 E18 (23)* VLA:_OUT ( 5) 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: (22) W2 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 30Jul11 ***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 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.LINCOP.1 =====> localh> SETJY1: / Flux calculated using known spectrum localh> SETJY1: BIF = 1 EIF = 1 /Range of IFs localh> SETJY1: '1331+305 ' IF = 1 FLUX =14.7341 (Jy calcd) localh> SETJY1: / Using (1999.2) VLA or Reynolds (1934-638) coefficients 7c. CALRD executed on 30Jul11 ***Read in models of flux density calibrators: default CALRD object '3c286';band 'L'; =====> 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 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.LINCOP.1 ====> calib: 10s source: 10s 9. UVFLG -> FG/1 executed on 30Jul11 ***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 78 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.CH 0.1 antenna=EVLA;baseline=EVLA; =====> localh> UVFLG1: Wrote 105 flags to flag table version 1 10. TVFLG -> FG/1 executed on 30Jul11 ***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 78 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.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 and 2 are high throughout entire obs. No obvious solar interference. 10b. TABED FG/1 executed on 30Jul11 ***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 78 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.CH 0.1 >getona 81 AIPS 1: Got(O) disk= 1 user= 2 type=UV D75-C3.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 22 $ 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 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.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 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.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 Looks 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 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.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 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.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 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.LINCOP.1 outname inna ; outcl 'NEWCH0' =====> AIPS 1: 82 2 D75-C3 .NEWCH0. 1 UV 30-JUL-2011 16:53:47 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 fine. 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 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.LINCOP.1 >getona 82 AIPS 1: Got(O) disk= 1 user= 2 type=UV D75-C3.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 22 $ 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 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.NEWCH0.1 =====SN/1 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 9.53203E-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 3.036E+00 localh> CALIB1: LPOL, IF= 1 The average gain over these antennas is 2.986E+00 localh> CALIB1: Found 54 good solutions localh> CALIB1: Average closure rms = 0.0009 +- 0.0001 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 . 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 22 $ 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 0,0 getn *.NEWCH0 $ ***NOTE: must run this for all NEWCH0.1,2,3 in which $ this calibrator appears! >getn 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.NEWCH0.1 =====> 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 0/06:53:40 0943-083 IF no. 1 Lpol localh> CALIB1: 09-22 11.2% 2d localh> CALIB1: Antenna 9 had 1 excess closure errors, 1 printed localh> CALIB1: Antenna 22 had 1 excess closure errors, 1 printed localh> CALIB1: Closure errors at 0/07:32:49 0943-083 IF no. 1 Rpol localh> CALIB1: 16-22 10.3% 1d localh> CALIB1: Antenna 16 had 1 excess closure errors, 1 printed localh> CALIB1: Antenna 22 had 1 excess closure errors, 1 printed localh> CALIB1: RPOL, IF= 1 The average gain over these antennas is 1.813E+00 localh> CALIB1: LPOL, IF= 1 The average gain over these antennas is 1.827E+00 localh> CALIB1: Found 266 good solutions localh> CALIB1: Failed on 4 solutions localh> CALIB1: Average closure rms = 0.0133 +- 0.0005 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 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.NEWCH0.1 =====> localh> GETJY1: Source:Qual CALCODE IF Flux (Jy) localh> GETJY1: 0943-083 : 0 B 1 2.76079 +/- 0.03069 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 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.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 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.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/d75c3/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 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.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 17:20:00 Page 1 File = D75-C3 .NEWCH0. 1 Vol = 1 Userid = 2 IF = 1 Freq= 1.418798910 GHz Ncor= 2 No. vis= 332693 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 = 1.418798910 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 04:49:55 1331+305 202 205 266 288 274 317 288 241 318 252 286 341 352 305 346 281 418 327 302 344 264 368 295 435 327 255 300 04:55:20 0943-083 205 211 272 291 279 323 294 243 326 255 290 342 353 312 342 281 411 323 310 337 269 358 302 439 324 259 305 05:34:25 0943-083 206 211 275 299 279 323 293 243 329 241 288 343 342 310 315 239 390 310 305 315 271 296 280 427 305 255 307 06:14:30 0943-083 211 273 298 280 322 294 243 326 253 290 341 314 309 247 405 326 311 339 273 335 449 313 257 304 06:53:40 0943-083 208 209 276 283 282 320 294 247 324 249 288 346 359 311 327 257 400 327 313 343 271 337 307 448 314 256 304 07:32:50 0943-083 208 209 271 280 324 301 249 326 254 286 344 348 309 302 222 376 309 306 317 269 301 267 458 297 257 301 File = D75-C3 .NEWCH0. 1 Vol = 1 Userid = 2 IF = 1 Freq= 1.418798910 GHz Ncor= 2 No. vis= 332693 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 17:20:00 Page 2 File = D75-C3 .NEWCH0. 1 Vol = 1 Userid = 2 IF = 1 Freq= 1.418798910 GHz Ncor= 2 No. vis= 332693 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 = 1.418798910 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 04:49:55 1331+305 250 213 299 276 292 315 254 225 297 326 263 315 343 268 357 230 371 327 312 346 258 346 353 378 299 250 300 04:55:20 0943-083 256 216 307 279 297 321 257 226 301 326 264 322 345 271 358 228 373 335 316 339 258 340 356 384 302 255 302 05:34:25 0943-083 254 217 309 274 298 322 255 224 302 307 264 318 338 271 338 206 368 330 313 320 263 309 335 382 300 254 304 06:14:30 0943-083 411 217 306 286 297 321 258 226 300 329 265 319 376 271 341 229 381 331 319 372 260 310 355 527 296 254 305 06:53:40 0943-083 258 214 311 281 298 322 258 229 297 326 264 327 350 269 357 237 379 343 319 378 261 341 353 381 298 253 304 07:32:50 0943-083 258 214 304 275 298 323 263 230 300 324 262 317 343 268 357 233 380 339 317 377 265 344 361 397 295 253 300 File = D75-C3 .NEWCH0. 1 Vol = 1 Userid = 2 IF = 1 Freq= 1.418798910 GHz Ncor= 2 No. vis= 332693 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 17:20:00 Page 3 File = D75-C3 .NEWCH0. 1 Vol = 1 Userid = 2 IF = 1 Freq= 1.418798910 GHz Ncor= 2 No. vis= 332693 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 = 1.418798910 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 04:49:55 1331+305 -68 141 -56-144 -139 -65 37 69 -66 -13 7-115-169 157 -18 173 -53-106 -76 -23 0 154-104 68-142-130 166 04:55:20 0943-083 -70 144 -56-150 -140 -57 38 72 -63 -20 11-111-170 159 -20 162 -49-104 -73 -27 0 149-104 65-144-121 166 05:34:25 0943-083 -77 132 -58-157 -139 -58 40 70 -63 -28 12-120 172 159 -26 151 -60-112 7 -35 0 138-107 54-154-121 166 06:14:30 0943-083 132 -54-166 -139 -53 36 73 -59 -31 13-126 174 160 143 -63-118 8 -42 0 136 49-159-119 169 06:53:40 0943-083 -94 134 -56-173 -139 -50 36 73 -61 -40 12-132 167 159 -40 134 -71-128 7 -51 0 125-127 40-169-118 168 07:32:50 0943-083-100 134 -56 -136 -49 37 75 -60 -43 13-139 161 162 -49 130 -79-137 9 -57 0 120-138 32-174-116 169 File = D75-C3 .NEWCH0. 1 Vol = 1 Userid = 2 IF = 1 Freq= 1.418798910 GHz Ncor= 2 No. vis= 332693 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 17:20:00 Page 4 File = D75-C3 .NEWCH0. 1 Vol = 1 Userid = 2 IF = 1 Freq= 1.418798910 GHz Ncor= 2 No. vis= 332693 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 = 1.418798910 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 04:49:55 1331+305 -85 2 162-134 6 -9 -92 81 -44-127 -4-164-116 39 177 103 140-132-166 155 0 -77-129 -1 55 58 -78 04:55:20 0943-083 -85 6 163-139 6 1 -90 87 -39-132 1-158-115 42 176 93 146-129-162 152 0 -80-127 -3 55 69 -77 05:34:25 0943-083 -91 -3 162-143 6 1 -87 86 -38-139 3-166-128 42 171 83 137-135 -82 145 0 -90-129 -9 47 69 -75 06:14:30 0943-083-101 -5 163-157 4 4 -93 86 -37-145 1-174-132 41 162 74 131-143 -84 137 0 -94-141 -18 39 69 -75 06:53:40 0943-083-110 -4 163-163 5 8 -92 87 -38-152 1 180-139 40 155 66 124-153 -83 128 0-104-152 -24 30 71 -76 07:32:50 0943-083-116 -3 163-169 7 8 -92 89 -37-156 2 173-145 42 146 63 116-161 -82 122 0-109-159 -31 24 73 -75 File = D75-C3 .NEWCH0. 1 Vol = 1 Userid = 2 IF = 1 Freq= 1.418798910 GHz Ncor= 2 No. vis= 332693 Polarization = L Subarray = 0 Listing SN table, version 1 SN table has not been applied to a CL table =====> Amp jump ant 1 and 25 3rd secondary scan Pha missing RR only ant 4 last secondary scan, and 16 and 24 3rd secondary scan Pha jump ant 20 1st seconary scan, both RR and LL 1st secondary loses: 04:56:30 - 05:32:55 ant 20 3rd secondary loses: 05:35:45 - 06:52:05 ant 1, 16, 24, 25 last secondary loses: 06:55:00 - 07:31:15 ant 4 17. UVFLG -> 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. 1st secondary loses: 04:56:30 - 05:32:55 ant 20 default UVFLG antenna 20,0 $ the antenna which "jumped" timer 0 4 56 30 0 5 32 55 $ the source scan between the offending ph.cal scans opcode 'FLAG' reason 'phase jump' outfgver 1 getn *.NEWCH0.1 >getn 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.NEWCH0.1 ====> NEWCH0.1 FG/1 localh> UVFLG1: Wrote 1 flags to flag table version 1 3rd secondary loses: 05:35:45 - 06:52:05 ant 1, 16, 24, 25 default UVFLG antenna 1,16,24,25,0 $ the antenna which "jumped" timer 0 5 35 45 0 6 52 5 $ the source scan between the offending ph.cal scans opcode 'FLAG' reason 'phase jump' outfgver 1 getn *.NEWCH0.1 >getn 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.NEWCH0.1 ====> NEWCH0.1 FG/1 localh> UVFLG1: Wrote 4 flags to flag table version 1 last secondary loses: 06:55:00 - 07:31:15 ant 4 default UVFLG antenna 4,0 $ the antenna which "jumped" timer 0 6 55 0 0 7 31 15 $ the source scan between the offending ph.cal scans opcode 'FLAG' reason 'phase jump' outfgver 1 getn *.NEWCH0.1 >getn 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.NEWCH0.1 ====> NEWCH0.1 FG/1 localh> UVFLG1: Wrote 1 flags to flag table version 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 22 $ 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 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.NEWCH0.1 =====> localh> CLCAL1: Using interpolation mode SELF localh> CLCAL1: Processing SN table 1 localh> CLCAL1: SNMRG: Merging SN table localh> CLCAL1: SNMRG: Write 162 merged records from 162 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 22 $ 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 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.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 162 merged records from 162 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 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.NEWCH0.1 =====> anbpl_1.jpg, anbpl_2.jpg, anbpl_3.jpg Very low weights RR only (ant 23 as ex): 05:36:25 to 05:42:15 But these are very LOW weights and not very HIGH weights. 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 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.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 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.NEWCH0.1 bparm 0 $ amp. vs. uv-distance =====> uvplt_cals_ch0_amp.jpg Look good. No sign of any solar interference in cal. bparm 0,2 $ phase vs. uv-distance =====> uvplt_cals_ch0_pha.jpg Looks good. 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 3.5 $ for C 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 0,0 getn *.NEWCH0.xx $ whichever file has the calibrator you're imaging >getn 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.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. =====> 2.77 Jy, expect 2.77 Jy. Looks good. 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 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.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). =====> Delete area of all antennas 05:35:28 - 05:42:41, high values in amp Delete first scans of all segments. Short baselines show some high values. 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 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.NEWCH0.1 bparm 0 $ amp. vs. uv-distance =====> uvplt_gal_ch0_amp.jpg Looks good. 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 3.5 $ for D configuration imsize 512 $ for C and D configurations niter 1000 nbox 0 minpa 121 uvwtfn 'na'; robust 0.5 dotv -1 uvrange 0,0 getn *.NEWCH0.xx $ whichever file has the source you're imaging >getn 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.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. Some woofly stuff due to continuum source off FOV? 24. TASAV -> CH0SAV.1,2,3 executed on 30Jul11 default TASAV outna 'D75-C3MidTa outcla 'ch0sav' getn *.NEWCH0 $ loop over NEWCH0 files (= FREQIDs) >getn 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.NEWCH0.1 outse inseq =====> AIPS 1: 83 2 D75-C3MidTa .CH0SAV. 1 UV 30-JUL-2011 21:56:49 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 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.NEWCH0.1 >getona 81 AIPS 1: Got(O) disk= 1 user= 2 type=UV D75-C3.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 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.NEWCH0.1 >getona 81 AIPS 1: Got(O) disk= 1 user= 2 type=UV D75-C3.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 22 $ 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 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.LINCOP.1 =====> localh> CLCAL1: Using interpolation mode SELF 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 162 merged records from 162 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 22 $ 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 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.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 162 merged records from 162 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 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.LINCOP.1 bparm(2) 1 $ amp. vs. uv-distance =====> wiper_cals_lincop_amp.jpg Looks good. bparm(2) 2 $ phase vs. uv-distance =====> wiper_cals_lincop_pha.jpg Looks good. 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= 0,0 $ should be set to eliminate known source structure, $ as in CALIB dotv 1 tvinit getn *.LINCOP >getn 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.LINCOP.1 =====> possm_2ndcal_lincop_vecave_rr.jpg, possm_2ndcal_lincop_vecave_ll.jpg Look 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 3.5 $ 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 105; echan 110 source '0943-083','' getn *.LINCOP >getn 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.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 2.78 Jy. Expect 2.77 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 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.LINCOP.1 bparm(2) 1 $ amp. vs. uv-distance =====> wiper_lincop_gal_amp.jpg Some interference at a few discrete baselines: 7-9.5 kl and 13-15; all channels; in time range 5:35:00 - 6:13:00. ====> TVFLG--ant 21 in that timerange. Ant 21 is also high, although not as high, in other time ranges. So delete it from all. ----> Flagver 2 wiper_lincop_gal_amp_afterflag.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? 11 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 3.5 $ for D configuration imsize 512 $ for C 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 0,0 getn *.LINCOP >getn 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.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. 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 = 27 - antenna 21 = 26 delta-nu: Channel separation is 6.1E-3 MHz; no Hanning smoothing so resolution is 1.4x this = 8.54E-3 MHz int time = 2.42 hrs The Expected noise level is: 1.9 mJy The rms Noise level in a line free channel is: 2.1 mJy/bm 29. TASAV -> EndTaB.LINSAV.1 executed on 30Jul11 default TASAV outna 'D75-C3EndTa outcla 'linsav' getn *.LINCOP >getn 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.LINCOP.1 =====> AIPS 1: 89 2 D75-C3EndTa .LINSAV. 1 UV 31-JUL-2011 00:58:43 30. FITTP executed on 31Jul11 >getn 78 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.CH 0.1 >dataout '/ta/d75c3/DDO75_C3_CH0_orig.FITS >getn 79 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.LINE.1 >dataout '/ta/d75c3/DDO75_C3_LINE_orig.FITS >getn 80 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-c3BeTa.LINSAV.1 >dataout '/ta/d75c3/DDO75_C3-BegTasav.FITS >getn 83 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3MidTa.CH0SAV.1 >dataout '/ta/d75c3/DDO75_C3-MidTasav.FITS >getn 89 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3EndTa.LINSAV.1 >dataout '/ta/d75c3/DDO75_C3-EndTasav.FITS >getn 81 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.LINCOP.1 >dataout '/ta/d75c3/DDO75_C3_UV_CALIB_LINCOP.FITS >getn 82 AIPS 1: Got(1) disk= 1 user= 2 type=UV D75-C3.NEWCH0.1 >dataout '/ta/d75c3/DDO75_C3_UV_CALIB_NEWCH0.FITS