CA082 (2000 March 21-22) ======================== Correlator notes: Algonquin: No phase cal, so fringe with manual phases. Hobart: High clock rate. S channel 1 phase cal weaker by factor of 3 than in other S channels in prepass scan 081-1922 -- note comments below in Hobart ops messages. S1 fringe phase is also ~50 deg out of line. According to log, VC09 was set manually around 081-2256 -- fringes look OK after then. Matera: No fringes or phase cal in S channel 3 in prepass scans. Does not appear to be an RFI problem, as judged from Tsys and tpi numbers in log. Tsys is generally higher in channel 3 than in other channels, but not by enough to explain lack of fringes. Between 082-0623 and 082-0839, channel 3 tpi is the same as tpzero, but otherwise the tpi values look OK, albeit rather low. (Channel 3 tpi was low in CA083 as well, when fringes and phase cal were fine.) Had to correlate Matera prepass scans twice because there were no type 307 records for Matera in the first try except for two scans. About 2/3 of the way through the production pass, the calculation of the axis offset contribution to the correlator delay/rate model was properly enabled for the first time. The improvement in the scatter of the correlator residuals is very obvious in the MBD on baselines to the stations with nonzero axis offsets, which are Gilcreek, HartRAO, and Hobart. After production pass -- Hobart: S1 phase cal improves between 081-2238 and 081-2242, in that pcal amplitude in latter scan is comparable to that in other channels, and fringe phase lines up with other channels. (Of course the latter is true simply because the additive phases in cf_2837 are based on prepass data after 081-2242.) There doesn't appear to be a single additive phase for channel S1 before 081-2242 that works consistently, so refringe all Hobart data before 081-2242 with channel S1 deleted. Included in reprocessing list: missed scans non-detections short scans all error codes (B,D,E,G) scans with channel 1 pcal amp < .001 for normal pcal stations scans during which fringes in 1 or 2 channels disappeared part way through the scan (see C2839) -- supplements the G codes: 081-2045_2128-123, AT 081-2127_2128-123, AT 081-2202_2128-123, AT 081-2256_OJ287, A baselines scans discovered to have poor playback but which were not D codes or short scans: 081-1800_0119+115, I baselines 081-2311_1144-379, JI 082-0254_1622-253, JI 082-0304_2121+053, J baselines 082-0312_1606+106, JI 082-0818_1954-388, JI 082-1507_1357+769, I baselines 082-1548_1044+719, A baselines As in CA083, Hobart/Tsukuba baseline shows low fringe amps in lower X channels for sources 1741-038 and 1908-201, apparently due to source structure. See DBS/BEC email exchange in C2839. June 9: Due to improper software configuration of the correlator, some data in the cleanup pass had bad channel fringe phases at S. All such files, which were correlated after 159-2319 (root code ogbfce) and before 161-2000 UT, were deleted, and the scans were re-recorrelated. Fringing dates: DOY 152 production pass DOY 170 repro pass, Hobart data before 081-2242, 1 E code, and mismatched FRTs Hobart S-band data before 081-2242 were refringed as follows: After fringing the production and repro passes with the normal cf_2837 (which used all 6 S-band channels for Hobart), all type-2 files (S and X) in scans that included Hobart before 081-2242 were deleted, and those scans were completely refourfitted (Hobart and non-Hobart baselines). Post repro pass: Of the 36 G codes in the set of best type-2 data, 30 are S-band Matera baselines and so are mostly legitimate (i.e., not due to the correlator bug that causes intermittent loss of fringes in single channels). June 29: After CA082 was exported, discovered that part of the cleanup pass had been afflicted by a problem in SU5, which caused the Gilcreek phase cal amplitudes to be weak (between .001 and .01) and the phase cal phases to be unreliable, which in turn caused the Gilcreek MBDs to be in error by tens of ps at X and hundreds of ps at S. Only scans correlated on June 13 were affected. Those 25 Gilcreek scans were recorrelated on June 27, and a new export that includes the new data will be made. **************************************************************************** Station Mail: **************************************************************************** Date: Tue, 21 Mar 2000 19:31:23 +0200 (SAST) From: HartRAO VLBI Operator To: ivs-ops Subject: ca082 HartRAO is ready to start ca082. First source is 1124-186 at 17:59:40. Weather: Raining. Clock offset = 14.06 microsecs.(MASER LATE) All systems are normal. **********5 thin large tapes ****** Regard VLBI Team From: GSI VLBI group Date: Wed, 22 Mar 2000 02:30:32 +0900 To: ivs-ops@ivscc.gsfc.nasa.gov Subject: CA082 ready at Tsukuba32m Tsukuba32m is ready for CORE-A082. First source is 1124-186 at 18:00:00(UT). Sky is rainy. Temp:4.7C, Hum:97%, Pres:1011.2hPa Formatter - GPS = +115 nsec at 21-Mar 17:28(UT). Tsys: X-band =92.6 K, S-band=74.0 K (EL=90) SEFD: X-band =459.1 Jy, S-band=349.3 Jy (Virgo-A, AZ=231.4, EL=56.5) All systems are normal. Sincerely, ====================================================== GSI VLBI group Geographical Survey Institute, Ministry of Construction Japan e-mail:gsi32m@gaos.gsi-mc.go.jp web:http://vldb.gsi-mc.go.jp/sokuchi/vlbi/english/ ====================================================== From: "VLBI - ASI/CGS Matera" To: "ops bb" Subject: marea ready core-a082 Date: Tue, 21 Mar 2000 18:36:37 +0100 Matera is ready for Core-a082 exp. We have partially cloudy sky. Source: Cas-a; Position: 317/48; Sefd:1076/1102; Tsys: 47/77; First source is 0119+115 at 17:59:40 utc time. Tommaso Matera Vlbi Team From: Sylvain Brazeau Subject: CA082 To: ivs-ops@ivscc.gsfc.nasa.gov (nasa; ops) Date: Tue, 21 Mar 2000 17:52:02 GMT ARO is ready and tracking 1st source 0119+115 WX=10.2C, 1000.0mb, 35.66% hum, sky is covering up SEFD on 3c380 Az=304.8 El=37.4 X=261.5 S=230.5 3c123 Az=83.2 El=36.7 X=214.9 S=206 Tape drive is at 22C and 21% hum. Formater-GPS=_1.502us Regards ARO team. -- Sylvain Brazeau Geodetic Survey of Canada Ottawa, Ontario, Canada Internet: brazeau@geod.nrcan.gc.ca Date: Tue, 21 Mar 2000 17:59:25 +0000 (UTC) From: oper@blizzard.gcgo.nasa.gov (Gilmore Creek) To: ivs-ops@ivscc.gsfc.nasa.gov Subject: ca082, Gilmore Creek, Ready-message Session ca082 ready message for Gilmore Creek. ---------------------------------------------- Comments: receiver dewar still cool down. System checks are normal First source: 0119+115 at 1800 UT GPS-FMOUT: 6.8 microseconds Wx: Temperature (C): -5.9 Pressure (mBar): 960.2 Humidity (%): 59.4 Sky Conditions: clear Cable difference is: longer cable makes the reading smaller by 704 microseconds and is nominal Pointing values: SEFD X/S Source Az/El Offset1 Offset2 781/797 casa 80/66 .016 .010 Tsys (x1/s/x2): 70/40/62 Recorder Humidity (%): <20 Date: Tue, 21 Mar 2000 17:59:40 +0000 (UTC) From: oper@blizzard.gcgo.nasa.gov (Gilmore Creek) To: ivs-ops@ivscc.gsfc.nasa.gov Subject: ca082, Gilmore Creek, Autostart-message Session ca082 ready message for Gilmore Creek. ---------------------------------------------- Started recording with source: 0119+115 at 081.17:59:40 UT From: Sylvain Brazeau Subject: CA082 To: ivs-ops@ivscc.gsfc.nasa.gov (nasa; ops) Date: Tue, 21 Mar 2000 18:04:35 GMT ARO as started CA082 on time. WE will be runnig without phase cal, we are working on the problem. Regards ARO team -- Sylvain Brazeau Geodetic Survey of Canada Ottawa, Ontario, Canada Internet: brazeau@geod.nrcan.gc.ca From: "VLBI - ASI/CGS Matera" To: "ops bb" Subject: matera start core-a082 Date: Tue, 21 Mar 2000 19:05:18 +0100 Matera started on time Core-a082 Gps-Mark IV=12,365 usec The recorder humidity is 28% Tommaso Matera Vlbi Team From: GSI VLBI group Date: Wed, 22 Mar 2000 03:04:12 +0900 To: ivs-ops@ivscc.gsfc.nasa.gov Subject: CA082 start at Tsukuba32m Tsukuba32m started CORE-A082 on time. First source is 1124-186. Sky is rainy. Temp:4.68C, Hum:97%, Pres:1011.1hPa Formatter - GPS = +101 nsec at 21-Mar 18:01(UT). All systems are normal. Sincerely, ====================================================== GSI VLBI group Geographical Survey Institute, Ministry of Construction Japan e-mail:gsi32m@gaos.gsi-mc.go.jp web:http://vldb.gsi-mc.go.jp/sokuchi/vlbi/english/ ====================================================== From: David Legge Reply-To: David Legge Subject: Hobart has started experiment CA082 Hobart has started experiment CA082 ------------------------------------------------------------- The first scheduled source was 1124-186 @ 175940/081 UT/DOY Formatter (H-maser) lags GPS 36.1 microsec @ 1800/081 UT/DOY Cable Cal 786.5 microsec, shorter cable gives longer delay Tape recorder humidity 27 % relative at experiment start Weather and Sky: cool, 0 % cloud, 11 km/h wind at expt start Comments/Problems: Communication problems with vc09 causing bad tsys measurements for this vc. The local oscillator is locked and the upper side band power is normal, so we beleive it is producing correct data, despite occasional error messages in the log regarding this vc. Regards, David Legge Date: Wed, 22 Mar 2000 18:13:17 +0000 (UTC) From: oper@blizzard.gcgo.nasa.gov (Gilmore Creek) To: ivs-ops@ivscc.gsfc.nasa.gov Subject: ca082gc, Gilmore Creek, Stop-message Session ca082gc stop message for Gilmore Creek. ----------------------------------------------- Comments: All scans recorded. 353 scans. Weather at end partly cloudy. Dewar was warming during observing. Never broke vacuum. Tape Inventory: 8 thin 0 thick Observation finished at: 1800 UT Date: Wed, 22 Mar 2000 20:14:57 +0200 (SAST) From: HartRAO VLBI Operator To: ivs-ops Subject: ca082 Hartrao has completed ca082. Weather 50% cloud cover. Clock offset 14.23microsecs (MASER LATE). All system are normal. Regard VLBI Team From: "VLBI - ASI/CGS Matera" To: "ops bb" Subject: Core-A 82 end Date: Wed, 22 Mar 2000 19:17:31 +0100 Matera station completed Core-A 82 without problems Start up measured delta time was Gps - MK IV = 12,365 usec Completion delta time was Gps - MK IV = 12,452 usec Log file is going to be stored at CDDIS subdir Tape label is VLBA1135,AE5C The recorder humidity was 28% at start up; it was 28% at completion time M. Nicoletti From: GSI VLBI group Date: Thu, 23 Mar 2000 03:24:45 +0900 To: ivs-ops@ivscc.gsfc.nasa.gov Subject: CA082 finished at Tsukuba32m Tsukuba32m finished ca082. All scans recorded. Sky is fine. Temp:0.13C, Hum:80%, Pres:1022.2hPa Formatter - GPS = 133 nsec at 22-Mar 18:18(UT) Tsys : X=47.3 K S=67.0 K (at El=90) SEFD : X=265.5 S=342.5 (at virgoa-a Az 250.5 El 42.8 ) We put the file "ca082ts.log" on vlbigeo@cddisa.gsfc.nasa.gov/mar00. ====================================================== GSI VLBI group Geographical Survey Institute, Ministry of Construction Japan e-mail:gsi32m@gaos.gsi-mc.go.jp web:http://vldb.gsi-mc.go.jp/sokuchi/vlbi/english/ ====================================================== From: Normand Servant Subject: ca082 completed To: ivs-ops@ivscc.gsfc.nasa.gov Date: Wed, 22 Mar 2000 18:56:53 GMT Greetings from Algonquin Park. Algonquin has completed experiment ca082.Two sources were missed due to our dish limit and direction. Missed:2121+053 at 13:20:02ut and 2234+282 at13:27:43ut. SEFD'S 3c123 az=95.1 el=48.2 x=186 s=223 overcast wx,temp=14.5c pressure=998.4 humidity=48.4 100% coverage Tape drive temp=22c humidity=22% Formatter-gps=-1.5245microseconds # of tapes left=31 Phase cal in receiver was not functionning during experience. Regards from Algonquin team. -- Norman Servant Geodetic Survey of Canada Ottawa, Ontario, Canada Internet: servant@geod.emr.ca From: Lincoln Hanslow Subject: Hobart has completed CA082 Hobart has completed experiment CA082. -------------------------------------------------------------------- The PCFS log file has been put in directory mar00 on host cddisa. ------------------------------------------------ Tape Label UT start UT stop MEDI3129,2A7C 081/1759 082/0706 IRAM0140,379B 082/0715 082/1759 ------------------------------------------------ Scans Missed UT start UT stop 2255-282 082/0553 082/0556 0727-115 082/0602 082/0603 0454-234 082/0606 082/0608 (due to wind slews of telescope) 0119+041 082/0715 082/0716 0458-020 082/0718 082/0721 (due to problems with the telescope tracking system) ------------------------------------------------ Formatter (H-maser) lags GPS 34.7 microsec @ 1813/082 UT/DOY. Cable Cal 781.5 microsec longer delay. Tape recorder humidity: 27% relative at experiment end. Weather and Sky: fine, cool, and mostly clear. Comments/Problems: There were a few wind slews of the telescope, which resulted in the loss of data from the sources indicated above. Tracking problems also resulted in the loss of a couple of sources. Unlikely there were further missed sources. There were problems with VCO9 - nonsensical Tsys, and weak phase cal. Eventually it had to be locally set to fit with the appropriate settings. Regards, Lincoln Hanslow. Date: Thu, 23 Mar 2000 12:08:15 -0500 From: Stephen Farley To: ops Subject: Tapes from ca082 form ALgonquin Tapes from Algonquin for ca082 should leave Ottawa going to Haystack to day via FEDEx. Two tapes noaa0165, 07c3 and ign00034, e6c7 Logfile has been placed on cddisa/mar00 Have a good day. Stephen -- =========================================================== Stephen Farley Email farley@geod.nrcan.gc.ca Geodetic Survey Phone (613) 992-2236 Natural Resources Canada ******************************************************************************* From: Brian Corey Subject: CA082 correlator report To: ivsmail@ivscc.gsfc.nasa.gov (IVS Mail) Date: Fri, 23 Jun 2000 17:21:55 EDT CA082 #2837 tar-save has been created 2000 Mar 21-22 Processing factor = ?? DOY 081-082 97% have fourfit Quality Codes of 5-9. Algonquin: No phase cal at S or X, so fringed with manual phases. Gilcreek: OK. HartRAO: OK. Hobart: Phase cal in S channel 1 was weak and could not be used to align the fringe phase for the first 4 hours -- channel was deleted in fringing for this time period. Problem was coincident with a communications problem with VC09, and both problems disappeared when the VC was set up manually. High clock rate: 10 ps/s. Matera: No fringes or phase cal in S channel 3 -- deleted in fringing. Tsukuba: OK. QC=5-9 AI 98% A - Gilcreek AT 99% G - Algonquin GA 99% H - Hobart HT 96% I - Matera JH 96% J - HartRAO T - Tsukuba ******************************************************************************* From: Brian Corey Subject: CA082 data problem To: dgg@leo.gsfc.nasa.gov (David Gordon), cma@gemini.gsfc.nasa.gov (Chopo Ma) Date: Tue, 27 Jun 2000 13:30:34 EDT Cc: aniell@haystack.mit.edu (Arthur Niell) David and Chopo, We have just discovered that, during one day of cleanup processing on CA082, a problem with one of the correlator station units caused the phase cal phases and amplitudes for Gilcreek to be reported incorrectly. As a result, the multiband delays for ~5% of the exported Gilcreek data are corrupted by tens of ps at X and hundreds of ps at S. We plan to recorrelate the affected scans and generate a new export. The export will likely not be available until after July 4 (when Mike Titus will be back from his once-per-millenium vacation), unless you feel quicker action is called for. Please advise. Thanks. --Brian