From analysts@aoc.nrao.edu Thu Oct 21 08:41:55 1999 Date: Wed, 20 Oct 1999 17:20:07 -0600 (MDT) From: Data Analysts To: agg@jb.man.ac.uk, apolatid@oso.chalmers.se, foley@NFRA.NL, jive@RZMWS0.NFRA.NL, kb@astro.uni.torun.pl, p062gra@mpifr-bonn.mpg.de, rts@RZMWS0.NFRA.NL, support@dots.jpl.nasa.gov, tminter@zia.aoc.NRAO.EDU, tventuri@astbo1.bo.cnr.it, vsog@vsop.isas.ac.jp, xhuang@center.shao.ac.cn Subject: V085G data Dear PI, We have examined the data for project V085G on 18 Sep. 1999. The contact person for this project was K. Desai. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. However, you may want to be more cautious when dealing with non-VLBA stations. The easiest way to estimate the best weight threshold is by looking at the tape weights vs. time plots generated here. You can find the weights plots at /home/aspen6/astronomy/sep99/v085g/sniffer/final/wtsfile.ps. If your experiment involves more than one distribution tape then there will be a tape# subdirectory between /final and wtsfile.ps. See /home/aspen6/README.sniffer for instructions on how to interpret this plot. 2. Delay, rate, phase, and amplitude plots were made for the observation. 3. Autocorrelation bandpass plots were generated for all antennas for scans on all sources. 4. Cross-correlation bandpass plots were generated for all baselines to EB for scans on all sources. 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). 6. The jobs associated with the correlation of V085G can be found at: /home/aspen6/astronomy/sep99/v085g/jobs. These files provided the correlator with all ancillary data needed for VLBI, including: correlation parameters and telescopes correlated in the final production. The job numbers are: 7420-7425 Automated Calibration Transfer for VLBA Correlator Output --------------------------------------------------------- The first phase of automated calibration transfer for data from the VLBA correlator has been completed, and was used for your observation. This transfer of calibration information includes data from the 10 VLBA antennas, as well as selected information from the VLA, Green Bank, and Effelsberg, which currently provide VLBA-style monitor data. Significant changes to AIPS have been required to introduce calibration transfer, so users must have the patched version of 15OCT98 AIPS, or any later version, beginning with 15APR99. Help files for a number of AIPS tasks have been updated to reflect the new calibration procedures. There also is a new version of the VLBI chapter of the AIPS cookbook, available from http://www.cv.nrao.edu/aips/aipsdoc.html, that includes more details on how to cope with the calibration transfer process. The calibration-transfer process relieves observers of the burden of creating and inputting calibration files for VLBA antennas. Instead, this information is now provided as tables attached to the FITS data sets output by the VLBA correlator. The ancillary data include antenna gain (GC table), system temperature (TY table), pulse calibration (PC table), flags (FG table), and weather (WX table). The wise observer will not modify these original tables; processing errors might then force the data to be reloaded using FITLD. See the description of MERGECAL in Section 9.2.1.7 of the new cookbook chapter for more detail. Of course, skeptical users can simply delete the appropriate tables created by FITLD and generate their tables in the old manner. Phase 2 of calibration transfer will include supply of data from more external telescopes, and probably will proceed incrementally, depending on both the availability of the external information and the implementation of new software in Socorro. At present, ancillary data from most external telescopes must still be loaded in the old manner, and observations of strong sources may be needed for manual pulse calibration at those telescopes. Up-to-date instructions on coping with observations including external telescopes can be found at http://www.nrao.edu/vlba/html/OBSERVING/cal-transfer/cal-transfer.html. Please send comments on calibration transfer to julvesta@nrao.edu, and send bug reports to daip@nrao.edu, with a copy to julvesta@nrao.edu. NOTES: JB: The telescope was offline due to high winds between about 13:45 and 18:00 UT. Otherwise, all was well at this station. WB: Playback was slightly diminished, but nothing serious. ON: Playback was good. There were a couple of instances where the cable unwraps, giving a couple of spots where the data is useless. MC: OK SH: OK TR: Was not correlated, due to a problem at the station, probably related with the new upgrade to MkIV. EB: OK NT: Failed to observe due to a problem with the recorder. Spacecraft: All tracking passes (GZ,RZ,NZ) fringed well to EB, but not so well to the other GRTs. The only notable irregularity: NZ weights are markedly lower on every other (FWD) pass. From analysts@aoc.nrao.edu Thu Oct 28 12:48:25 1999 Date: Wed, 27 Oct 1999 09:53:41 -0600 (MDT) From: Data Analysts To: foley@NFRA.NL, jive@RZMWS0.NFRA.NL, p062gra@mpifr-bonn.mpg.de, sjouwerman@RZMWS0.NFRA.NL, tuccari@ira.noto.cnr.it, vlbi@jb.man.ac.uk, vlbifriend@ira.noto.cnr.it Subject: GM035E P.I. Letter Dear PI, We have examined the data for project GM035E on 22 Sep. 1999. The contact person for this project was Joan Wrobel. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. However, you may want to be more cautious when dealing with non-VLBA stations. The easiest way to estimate the best weight threshold is by looking at the tape weights vs. time plots generated here. You can find the weights plots at /home/aspen6/astronomy/sep99/gm035e/sniffer/final/wtsfile.ps. If your experiment involves more than one distribution tape then there will be a tape# subdirectory between /final and wtsfile.ps. See /home/aspen6/README.sniffer for instructions on how to interpret this plot. 2. Delay, rate, phase, and amplitude plots were made for the observation. 3. Autocorrelation bandpass plots were generated for all antennas for scans on all sources. 4. Cross-correlation bandpass plots were generated for all baselines to HN for scans on all sources. 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). 6. The jobs associated with the correlation of GM035E can be found at: /home/aspen6/astronomy/sep99/gm035e/jobs. These files provided the correlator with all ancillary data needed for VLBI, including: correlation parameters and telescopes correlated in the final production. The job numbers are: 6320-6338 Automated Calibration Transfer for VLBA Correlator Output --------------------------------------------------------- The first phase of automated calibration transfer for data from the VLBA correlator has been completed, and was used for your observation. This transfer of calibration information includes data from the 10 VLBA antennas, as well as selected information from the VLA, Green Bank, and Effelsberg, which currently provide VLBA-style monitor data. Significant changes to AIPS have been required to introduce calibration transfer, so users must have the patched version of 15OCT98 AIPS, or any later version, beginning with 15APR99. Help files for a number of AIPS tasks have been updated to reflect the new calibration procedures. There also is a new version of the VLBI chapter of the AIPS cookbook, available from http://www.cv.nrao.edu/aips/aipsdoc.html, that includes more details on how to cope with the calibration transfer process. The calibration-transfer process relieves observers of the burden of creating and inputting calibration files for VLBA antennas. Instead, this information is now provided as tables attached to the FITS data sets output by the VLBA correlator. The ancillary data include antenna gain (GC table), system temperature (TY table), pulse calibration (PC table), flags (FG table), and weather (WX table). The wise observer will not modify these original tables; processing errors might then force the data to be reloaded using FITLD. See the description of MERGECAL in Section 9.2.1.7 of the new cookbook chapter for more detail. Of course, skeptical users can simply delete the appropriate tables created by FITLD and generate their tables in the old manner. Phase 2 of calibration transfer will include supply of data from more external telescopes, and probably will proceed incrementally, depending on both the availability of the external information and the implementation of new software in Socorro. At present, ancillary data from most external telescopes must still be loaded in the old manner, and observations of strong sources may be needed for manual pulse calibration at those telescopes. Up-to-date instructions on coping with observations including external telescopes can be found at http://www.nrao.edu/vlba/html/OBSERVING/cal-transfer/cal-transfer.html. Please send comments on calibration transfer to julvesta@nrao.edu, and send bug reports to daip@nrao.edu, with a copy to julvesta@nrao.edu. NOTES: VLBA Stations: SC: Slightly variable weights from 8:00 - 10:00 UT. HN: OK NL: OK FD: OK LA: OK PT: OK KP: RFI in IF channel 3 of autocorrelation plots. OV: Variable bandpasses in autocorrelation plots at 8:10 UT and 9:34 UT. Fringes disappear at ~8:04 - 8:45 UT and 9:20 - 9:40 UT; reason unknown. BR: OK MK: OK Non-VLBA Stations: JB: Slightly variable weights at 4:00 - 10:00 UT. Poor weights at 7:30 - 8:10 UT; weights vary between 0% - 90%. Missed last two scans of observation. IF channel 5 dead at 7:57:32 UT in autocorrelation plots. High amplitudes in most channels of cross-correlation plots at 7:51 - 8:00 UT. EB: No fringes at 9:30 - 12:49 UT due to a one day jump of the day counter at the station during observation. RFI in IF channels 3 and 4 at 11:30 - 12:16 UT. Low amplitude in autocorrelation plot at 12:12:50 UT. Low amplitudes in all channels of cross-correlation plots at 11:32 UT and 12:12 UT. WB: Tape in SEARCH (not in sync) at 4:15 - 4:45 UT and at 11:15 - 11:35 UT. Slightly variable weights throughout playback; weights vary between 85% - 100%. IF channel 3 is spikey until ~9:00 UT; possibly RFI. NT: Observation starts at 16:28 UT. VLA27: Poor weights at 12:50 - 13:50 UT; weights vary between 0% - 75%. Last three IF channels are outside the VLA bandpass. Non-linear phase slope in IF channel 1 of the cross-correlation plots. No fringes in last two IF channels due to being outside of the bandpass. From analysts@aoc.nrao.edu Thu Nov 4 09:28:22 1999 Date: Tue, 02 Nov 1999 15:10:28 -0700 (MST) From: Data Analysts To: agg@jb.man.ac.uk, apolatid@oso.chalmers.se, foley@NFRA.NL, jive@RZMWS0.NFRA.NL, p062gra@mpifr-bonn.mpg.de, rts@RZMWS0.NFRA.NL, support@dots.jpl.nasa.gov, tminter@zia.aoc.NRAO.EDU, trigilio@ira.noto.cnr.it, tventuri@astbo1.bo.cnr.it, vsog@vsop.isas.ac.jp, xhuang@center.shao.ac.cn Subject: V085I data Dear PI, We have examined the data for project V085I on 19 Sep. 1999. The contact person for this project was K. Desai. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. However, you may want to be more cautious when dealing with non-VLBA stations. The easiest way to estimate the best weight threshold is by looking at the tape weights vs. time plots generated here. You can find the weights plots at /home/aspen6/astronomy/sep99/v085i/sniffer/final/wtsfile.ps. If your experiment involves more than one distribution tape then there will be a tape# subdirectory between /final and wtsfile.ps. See /home/aspen6/README.sniffer for instructions on how to interpret this plot. 2. Delay, rate, phase, and amplitude plots were made for the observation. 3. Autocorrelation bandpass plots were generated for all antennas for scans on all sources. 4. Cross-correlation bandpass plots were generated for all baselines to EB for scans on all sources. 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). 6. The jobs associated with the correlation of V085I can be found at: /home/aspen6/astronomy/sep99/v085i/jobs. These files provided the correlator with all ancillary data needed for VLBI, including: correlation parameters and telescopes correlated in the final production. The job numbers are: 5720-5728 NOTES: SH: OK ON: Playback was good. Fringes disappear at these times: 19:40 to 19:45 UT and 21:40 to 22:00 UT. MC: Playback was good. The log ended at 16:30, though it was scheduled to observe until 22:00. The reason for this is unknown. There was a power failure from 12:14 to 12:30 UT, during this time there are no fringes. EB: OK WB: OK JB: The playback was good, but there was a brief in data at 14:29 UT. This coincided with a tape change. It is probably due to the tape change. At 9:38 UT BBC 2 loses fringes, and the associated amplitudes get noisy. Spacecraft: All tracking stations use (RZ, NZ, TZ) had good playback. Fringes were good to EB, at certain times. Anther thing worth noting are some bandpass edge spikes for RZ 8:32, and they are strong enough to come through the cross-correlation plots. Discontinuities in the fringe signal on baselines to the Halca orbiter occur at each handoff from one tracking station to another, and at any dropouts in the phase-transfer link that occur during a tracking pass. Fringe fits should be broken at each such discontinuity to avoid de- correlation. This will happen automatically at handoffs because the tracking-station name assigned to Halca changes, but at link dropouts it is necessary to force an AIPS scan break by passing the following table to AIPS task INDXR via the INFILE adverb. SUBARRAY = 1 / 262 08:42:19.9 ! stn_id = RZ *! 262 09:10:20.0 ! stn_id = RZ *! 262 12:25:10.0 ! stn_id = RZ *! 262 16:14:09.9 ! stn_id = NZ *! 262 19:11:59.9 ! stn_id = NZ *! Telescopes that failed: NT (due to capstan problems), KA (reason unknown), and TR (due to field system problems. From analysts@aoc.nrao.edu Tue Nov 9 12:05:22 1999 Date: Fri, 05 Nov 1999 09:44:01 -0700 (MST) From: Data Analysts To: agg@jb.man.ac.uk, apolatid@oso.chalmers.se, foley@NFRA.NL, jive@RZMWS0.NFRA.NL, kb@astro.uni.torun.pl, p062gra%mpifr-bonn.mpg.t@dots.jpl.nasa.gov, rts@RZMWS0.NFRA.NL, trigilio@ira.noto.cnr.it, tventuri@astbo1.bo.cnr.it, vsog@vsop.isas.ac.jp, xhuang@center.shao.ac.cn Subject: V085K data Dear PI, We have examined the data for project V085K on 20 Sep. 1999. The contact person for this project was K. Desai. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. However, you may want to be more cautious when dealing with non-VLBA stations. The easiest way to estimate the best weight threshold is by looking at the tape weights vs. time plots generated here. You can find the weights plots at /home/aspen6/astronomy/sep99/v085k/sniffer/final/wtsfile.ps. If your experiment involves more than one distribution tape then there will be a tape# subdirectory between /final and wtsfile.ps. See /home/aspen6/README.sniffer for instructions on how to interpret this plot. 2. Delay, rate, phase, and amplitude plots were made for the observation. 3. Autocorrelation bandpass plots were generated for all antennas for scans on all sources. 4. Cross-correlation bandpass plots were generated for all baselines to EB for scans on all sources. 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). 6. The jobs associated with the correlation of V085K can be found at: /home/aspen6/astronomy/sep99/v085k/jobs. These files provided the correlator with all ancillary data needed for VLBI, including: correlation parameters and telescopes correlated in the final production. The job numbers are: 7320-7326 NOTES: EB: OK JB: Playback was OK. The telescope had some problems from 10:30 UT onwards. It was reported as a clock problem (refer to the feedback printout). There were no fringes seen at these times: 10:30 to 12:00 UT, 15:30 to 16:00 UT, along with a couple of brief spots in between. MC: Playback was OK. There were no fringes from 6:00 to 6:15 UT. The feedback from this telescope reports: 'We have lost some scans.' This was the only instance of lost fringes seen. WB: Playback was OK. Fringes are essentially nonexistent until 8:00 UT (refer to the telescope feedback printout). ON: Playback was a little ratty early on, but improves by 7:00 UT. Spacecraft: RZ: There were huge bandpass edge spikes in both BBCs from 11:51 to 13:53 UT. This tracking station fringed strongly to EB, and rather well to the other GRTs. Playback was good. TZ: Playback was good. This tracking station fringed well to EB until 8:26 UT and to the other GRTs until 8:21 UT. GZ: Playback was good. This tracking station fringed very well for the whole pass, to all GRTs. Discontinuities in the fringe signal on baselines to the Halca orbiter occur at each handoff from one tracking station to another, and at any dropouts in the phase-transfer link that occur during a tracking pass. Fringe fits should be broken at each such discontinuity to avoid de- correlation. This will happen automatically at handoffs because the tracking-station name assigned to Halca changes, but at link dropouts it is necessary to force an AIPS scan break by passing the following table to AIPS task INDXR via the INFILE adverb. SUBARRAY = 1 / 263 06:18:30.0 ! stn_id = RZ *! 263 11:02:50.0 ! stn_id = RZ *! 263 11:21:10.0 ! stn_id = RZ *! 263 11:42:50.0 ! stn_id = RZ *! 263 11:53:20.0 ! stn_id = RZ *! 263 12:02:50.0 ! stn_id = RZ *! 263 12:47:10.0 ! stn_id = RZ *! 263 13:23:50.0 ! stn_id = RZ *! 263 13:37:50.0 ! stn_id = RZ *! 263 14:02:59.9 ! stn_id = RZ *! Telescopes which failed to observe: KA, SH (due to hardware failure), TR, and NT. From analysts@aoc.nrao.edu Thu Nov 18 15:30:11 1999 Date: Wed, 17 Nov 1999 09:23:00 -0700 (MST) From: Data Analysts To: apolatid@oso.chalmers.se, foley@NFRA.NL, jive@RZMWS0.NFRA.NL, p062gra@mpifr-bonn.mpg.de, pwolken@jftl.jpl.nasa.gov, support@dots.jpl.nasa.gov, tminter@zia.aoc.NRAO.EDU, trigilio@ira.noto.cnr.it, tuccari@ira.noto.cnr.it, tventuri@astbo1.bo.cnr.it, valery.i.altunin@jpl.nasa.gov, xhuang@center.shao.ac.cn Subject: PI letter for W018E Dear PI, We have examined the data for project W018E on 27 Sep. 1999. The contact person for this project was M. Claussen. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. However, you may want to be more cautious when dealing with non-VLBA stations. The easiest way to estimate the best weight threshold is by looking at the tape weights vs. time plots generated here. You can find the weights plots at /home/aspen6/astronomy/sep99/w018e/sniffer/final/wtsfile.ps. If your experiment involves more than one distribution tape then there will be a tape# subdirectory between /final and wtsfile.ps. See /home/aspen6/README.sniffer for instructions on how to interpret this plot. 2. Delay, rate, phase, and amplitude plots were made for the observation. 3. Autocorrelation bandpass plots were generated for all antennas for scans on all sources. 4. Cross-correlation bandpass plots were generated for all baselines to EB for scans on all sources. 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). 6. The jobs associated with the correlation of W018E can be found at: /home/aspen6/astronomy/sep99/w018e/jobs. These files provided the correlator with all ancillary data needed for VLBI, including: correlation parameters and telescopes correlated in the final production. The job numbers are: 9720 --- 9729 Automated Calibration Transfer for VLBA Correlator Output --------------------------------------------------------- The first phase of automated calibration transfer for data from the VLBA correlator has been completed, and was used for your observation. This transfer of calibration information includes data from the 10 VLBA antennas, as well as selected information from the VLA, Green Bank, and Effelsberg, which currently provide VLBA-style monitor data. Significant changes to AIPS have been required to introduce calibration transfer, so users must have the patched version of 15OCT98 AIPS, or any later version, beginning with 15APR99. Help files for a number of AIPS tasks have been updated to reflect the new calibration procedures. There also is a new version of the VLBI chapter of the AIPS cookbook, available from http://www.cv.nrao.edu/aips/aipsdoc.html, that includes more details on how to cope with the calibration transfer process. The calibration-transfer process relieves observers of the burden of creating and inputting calibration files for VLBA antennas. Instead, this information is now provided as tables attached to the FITS data sets output by the VLBA correlator. The ancillary data include antenna gain (GC table), system temperature (TY table), pulse calibration (PC table), flags (FG table), and weather (WX table). The wise observer will not modify these original tables; processing errors might then force the data to be reloaded using FITLD. See the description of MERGECAL in Section 9.2.1.7 of the new cookbook chapter for more detail. Of course, skeptical users can simply delete the appropriate tables created by FITLD and generate their tables in the old manner. Phase 2 of calibration transfer will include supply of data from more external telescopes, and probably will proceed incrementally, depending on both the availability of the external information and the implementation of new software in Socorro. At present, ancillary data from most external telescopes must still be loaded in the old manner, and observations of strong sources may be needed for manual pulse calibration at those telescopes. Up-to-date instructions on coping with observations including external telescopes can be found at http://www.nrao.edu/vlba/html/OBSERVING/cal-transfer/cal-transfer.html. Please send comments on calibration transfer to julvesta@nrao.edu, and send bug reports to daip@nrao.edu, with a copy to julvesta@nrao.edu. NOTES: Tracking for the spacecraft was scheduled for three passes: from about 10:00 to 10:30 UT from the Rz tracking station; from about 12:25 to 16:50 UT from the Nz tracking station; and from about 18:45 to 22:00 UT from the Gz tracking station. Jb had a problem with the LO/IF settings, and so the data were taken at the wrong frequency. We didn't find any good data from Tr in our clock searches, and so Tr was left out of the final correlation. The recording from Ro was very poor; data was missing and the playback was quite bad. The recording/ playback at Nt started out poor but improved rapidly. At On there were times of poor playback; the worst time was from 13:30 to 13;50 UT. Wb had poor recording/playback until 11:30 UT. The forward passes at Nz had less than satisfactory weights. The rest of the stations had generally good recording/ playback for the experiment. Fringes could easily be seen in the sniffer plots to the spacecraft during the Nz pass and the Gz pass to Eb and Go, but they weren't apparent in the Rz pass to any station. During the Nz pass, fringes to the spacecraft could also be seen to many of the smaller GRTs (e.g. Mc, Nt, On). Strong radio frequency interference (RFI) was seen at several stations for this 20 cm run. In particular RFI was seen throughout the experiment (and covering a good fraction of the band) at Sh. Single "spikes" of RFI was seen during a lot of the experiment at On, Mc, and especially strong at Ro. Some RFI could be seen from the spacecraft as well. Discontinuities in the fringe signal on baselines to the Halca orbiter occur at each handoff from one tracking station to another, and at any dropouts in the phase-transfer link that occur during a tracking pass. Fringe fits should be broken at each such discontinuity to avoid de- correlation. This will happen automatically at handoffs because the tracking-station name assigned to Halca changes, but at link dropouts it is necessary to force an AIPS scan break by passing the following table to AIPS task INDXR via the INFILE adverb. SUBARRAY = 1 / 270 12:28:09.9 ! stn_id = NZ *! 270 18:56:00.0 ! stn_id = GZ *! 270 19:10:40.0 ! stn_id = GZ *! 270 21:50:10.0 ! stn_id = GZ *! From clewis@cv3.cv.nrao.edu Tue Nov 23 13:15:41 1999 Date: Thu, 18 Nov 1999 09:01:31 -0700 From: Craig Lewis To: p062gra@mpifr-bonn.mpg.de, agg@jb.man.ac.uk, vlbi@jb.man.ac.uk, tventuri@astbo1.bo.cnr.it, vlbifriend@astbo1.bo.cnr.it, trigilio@ira.noto.cnr.it, tuccari@ira.noto.cnr.it, vlbifriend@ira.noto.cnr.it, apolatid@oso.chalmers.se, vlbi@oso.chalmers.se, xhuang@center.shao.ac.cn, kb@astro.uni.torun.pl, rf@astro.uni.torun.pl, foley@NFRA.NL, valery.i.altunin@jpl.nasa.gov, pwolken@jftl.jpl.nasa.gov, support@dots.jpl.nasa.gov, jive@RZMWS0.NFRA.NL Subject: [Fwd: W018h PI Letter] -- _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ [_X_X_X_X_X_X_X_X_X_X_X_X_X_X_X_X_X_X_X_X_X_X_X_X_X_X_X_X_X_X_] Craig Lewis________________________________________Data Analyst Socorro, New Mexico________National Radio Astronomy Observatory http://www.nrao.edu/~clewis _____P.O. Box O, Socorro, NM 87801 [ Part 2: "Included Message" ] Date: Fri, 12 Nov 1999 15:07:11 -0700 (MST) From: Mark Claussen To: snellen@ast.cam.ac.uk Cc: mclausse@zia.aoc.NRAO.EDU, jromney@zia.aoc.NRAO.EDU, vsog@vsop.isas.ac.jp, clewis@zia.aoc.NRAO.EDU, ahale@zia.aoc.NRAO.EDU Subject: W018h PI Letter Dear PI, We have examined the data for project W018H on 28 Sep. 1999. The contact person for this project was M. Claussen. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. However, you may want to be more cautious when dealing with non-VLBA stations. The easiest way to estimate the best weight threshold is by looking at the tape weights vs. time plots generated here. You can find the weights plots at /home/aspen6/astronomy/sep99/w018h/sniffer/final/wtsfile.ps. If your experiment involves more than one distribution tape then there will be a tape# subdirectory between /final and wtsfile.ps. See /home/aspen6/README.sniffer for instructions on how to interpret this plot. 2. Delay, rate, phase, and amplitude plots were made for the observation. 3. Autocorrelation bandpass plots were generated for all antennas for scans on all sources. 4. Cross-correlation bandpass plots were generated for all baselines to EB for scans on all sources. 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). 6. The jobs associated with the correlation of W018H can be found at: /home/aspen6/astronomy/sep99/w018h/jobs. These files provided the correlator with all ancillary data needed for VLBI, including: correlation parameters and telescopes correlated in the final production. The job numbers are: 2231, 2221, 2224 --- 2230 NOTES: Tracking for the spacecraft was scheduled for three passes: from about 20:15 to 00:45 UT from the Tz tracking station; from 02:25 to 05:10 UT from the Rz tracking station; and from about 06:40 to 07:25 UT, again from the Tz tracking station. The recording from Ro was not correlated due to problems with the log from that station. Tr observed at the wrong frequency; see the experiment feedback log. Tape recording/playback was generally good for most stations for this experiment. The playback/recording from On was not particularly good for several tape passes. Fringes could be seen in the sniffer plots to the spacecraft during the Rz pass and the second Tz pass to Eb, Jb, and Go, but they weren't apparent in the first Tz pass to any station. Strong radio frequency interference (RFI) was seen at several stations for this 20 cm run. In particular RFI was seen throughout the experiment (and covering a good fraction of the band) at Sh. Single "spikes" of RFI was seen during a lot of the experiment at Jb and Mc. Discontinuities in the fringe signal on baselines to the Halca orbiter occur at each handoff from one tracking station to another, and at any dropouts in the phase-transfer link that occur during a tracking pass. Fringe fits should be broken at each such discontinuity to avoid de- correlation. This will happen automatically at handoffs because the tracking-station name assigned to Halca changes, but at link dropouts it is necessary to force an AIPS scan break by passing the following table to AIPS task INDXR via the INFILE adverb. SUBARRAY = 1 / 272 02:24:39.9 ! stn_id = RZ *! 272 06:42:39.9 ! stn_id = TZ *! From analysts@aoc.nrao.edu Thu Nov 25 16:11:07 1999 Date: Wed, 24 Nov 1999 08:36:31 -0700 (MST) From: Data Analysts To: agg@jb.man.ac.uk, apolatid@oso.chalmers.se, foley@nfra.nl, jive@jive.nfra.nl, kb@astro.uni.tr.pl, p062gra@mpifr-bonn.mpg.de, support@dots.jpl.nasa.gov, trigilio@ira.noto.cnr.it, tuccari@ira.noto.cnr.it, tventuri@astbo1.bo.cnr.it, vsog@vsop.isas.ac.jp Subject: V026B2 data Dear PI, We have examined the data for project V026B2 on 21 Sep. 1999. The contact person for this project was R. C. Walker. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. However, you may want to be more cautious when dealing with non-VLBA stations. The easiest way to estimate the best weight threshold is by looking at the tape weights vs. time plots generated here. You can find the weights plots at /home/aspen6/astronomy/sep99/v026b2/sniffer/final/wtsfile.ps. If your experiment involves more than one distribution tape then there will be a tape# subdirectory between /final and wtsfile.ps. See /home/aspen6/README.sniffer for instructions on how to interpret this plot. 2. Delay, rate, phase, and amplitude plots were made for the observation. 3. Autocorrelation bandpass plots were generated for all antennas for scans on all sources. 4. Cross-correlation bandpass plots were generated for all baselines to HN for scans on all sources. 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). 6. The jobs associated with the correlation of V026B2 can be found at: /home/aspen6/astronomy/sep99/v026b2/jobs. These files provided the correlator with all ancillary data needed for VLBI, including: correlation parameters and telescopes correlated in the final production. The job numbers are: 5820-5825 Automated Calibration Transfer for VLBA Correlator Output --------------------------------------------------------- The first phase of automated calibration transfer for data from the VLBA correlator has been completed, and was used for your observation. This transfer of calibration information includes data from the 10 VLBA antennas, as well as selected information from the VLA, Green Bank, and Effelsberg, which currently provide VLBA-style monitor data. Significant changes to AIPS have been required to introduce calibration transfer, so users must have the patched version of 15OCT98 AIPS, or any later version, beginning with 15APR99. Help files for a number of AIPS tasks have been updated to reflect the new calibration procedures. There also is a new version of the VLBI chapter of the AIPS cookbook, available from http://www.cv.nrao.edu/aips/aipsdoc.html, that includes more details on how to cope with the calibration transfer process. The calibration-transfer process relieves observers of the burden of creating and inputting calibration files for VLBA antennas. Instead, this information is now provided as tables attached to the FITS data sets output by the VLBA correlator. The ancillary data include antenna gain (GC table), system temperature (TY table), pulse calibration (PC table), flags (FG table), and weather (WX table). The wise observer will not modify these original tables; processing errors might then force the data to be reloaded using FITLD. See the description of MERGECAL in Section 9.2.1.7 of the new cookbook chapter for more detail. Of course, skeptical users can simply delete the appropriate tables created by FITLD and generate their tables in the old manner. Phase 2 of calibration transfer will include supply of data from more external telescopes, and probably will proceed incrementally, depending on both the availability of the external information and the implementation of new software in Socorro. At present, ancillary data from most external telescopes must still be loaded in the old manner, and observations of strong sources may be needed for manual pulse calibration at those telescopes. Up-to-date instructions on coping with observations including external telescopes can be found at http://www.nrao.edu/vlba/html/OBSERVING/cal-transfer/cal-transfer.html. Please send comments on calibration transfer to julvesta@nrao.edu, and send bug reports to daip@nrao.edu, with a copy to julvesta@nrao.edu. NOTES: VLBA: OK EB: OK ON: OK MC: OK WB: Playback was good. Pcal seemed unusually strong. JB: Playback was poor until 7:30 UT (with the exception of good playback from 5:30 to 6:30 UT). Also worth noting: fringes are rougher than they should be. Possibly related to this: amplitudes in IF 1 are very noisy, and higher in strength than the other IFs. NT: Failed TR: Was not correlated due to recording problems. Spacecraft: RZ was the only tracking station used. It tracked from 4:45 to 7:40 UT, and from 11:05 to 14:47 UT. There was about 10 minutes worth of zero wts at about 6:15 UT. The best fringes seen to the spacecraft were on the RZ-EB baseline. Discontinuities in the fringe signal on baselines to the Halca orbiter occur at each handoff from one tracking station to another, and at any dropouts in the phase-transfer link that occur during a tracking pass. Fringe fits should be broken at each such discontinuity to avoid de- correlation. This will happen automatically at handoffs because the tracking-station name assigned to Halca changes, but at link dropouts it is necessary to force an AIPS scan break by passing the following table to AIPS task INDXR via the INFILE adverb. SUBARRAY = 1 / 264 04:53:39.9 ! stn_id = RZ *! 264 04:59:49.9 ! stn_id = RZ *! 264 05:15:00.0 ! stn_id = RZ *! 264 05:27:50.0 ! stn_id = RZ *! 264 05:33:20.0 ! stn_id = RZ *! 264 07:24:00.0 ! stn_id = RZ *! 264 11:31:50.0 ! stn_id = RZ *! 264 11:51:30.0 ! stn_id = RZ *! 264 12:10:20.0 ! stn_id = RZ *! 264 12:22:20.0 ! stn_id = RZ *! 264 12:37:00.0 ! stn_id = RZ *! 264 12:48:30.0 ! stn_id = RZ *! 264 14:23:10.0 ! stn_id = RZ *! From analysts@aoc.nrao.edu Wed Dec 8 14:38:03 1999 Date: Tue, 7 Dec 1999 14:47:26 -0700 (MST) From: Data Analysts To: agg@jb.man.ac.uk, apolatid@oso.chalmers.se, foley@nfra.nl, jive@jive.nl, kawagu@vsop.isas.ac.jp, p062gra@mpifr-bonn.mpg.de, support@dots.jpl.nasa.gov, tminter@zia.aoc.NRAO.EDU, trigilio@ira.noto.cnr.it, tuccari@ira.noto.cnr.it, tventuri@astbo1.bo.cnr.it, vsog@vsop.isas.ac.jp, xhuang@center.shao.ac.cn Subject: PI letter for W048A Dear PI, We have examined the data for project W048A on 16 Sep. 1999. The contact person for this project was M. Claussen. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. However, you may want to be more cautious when dealing with non-VLBA stations. The easiest way to estimate the best weight threshold is by looking at the tape weights vs. time plots generated here. You can find the weights plots at /home/aspen6/astronomy/sep99/w048a/sniffer/final/wtsfile.ps. If your experiment involves more than one distribution tape then there will be a tape# subdirectory between /final and wtsfile.ps. See /home/aspen6/README.sniffer for instructions on how to interpret this plot. 2. Delay, rate, phase, and amplitude plots were made for the observation. 3. Autocorrelation bandpass plots were generated for all antennas for scans on all sources. 4. Cross-correlation bandpass plots were generated for all baselines to LA for scans on all sources. 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). 6. The jobs associated with the correlation of W048A can be found at: /home/aspen6/astronomy/sep99/w048a/jobs. These files provided the correlator with all ancillary data needed for VLBI, including: correlation parameters and telescopes correlated in the final production. The job numbers are: 5320 - 5343, 5373 - 5399 Automated Calibration Transfer for VLBA Correlator Output --------------------------------------------------------- The first phase of automated calibration transfer for data from the VLBA correlator has been completed, and was used for your observation. This transfer of calibration information includes data from the 10 VLBA antennas, as well as selected information from the VLA, Green Bank, and Effelsberg, which currently provide VLBA-style monitor data. Significant changes to AIPS have been required to introduce calibration transfer, so users must have the patched version of 15OCT98 AIPS, or any later version, beginning with 15APR99. Help files for a number of AIPS tasks have been updated to reflect the new calibration procedures. There also is a new version of the VLBI chapter of the AIPS cookbook, available from http://www.cv.nrao.edu/aips/aipsdoc.html, that includes more details on how to cope with the calibration transfer process. The calibration-transfer process relieves observers of the burden of creating and inputting calibration files for VLBA antennas. Instead, this information is now provided as tables attached to the FITS data sets output by the VLBA correlator. The ancillary data include antenna gain (GC table), system temperature (TY table), pulse calibration (PC table), flags (FG table), and weather (WX table). The wise observer will not modify these original tables; processing errors might then force the data to be reloaded using FITLD. See the description of MERGECAL in Section 9.2.1.7 of the new cookbook chapter for more detail. Of course, skeptical users can simply delete the appropriate tables created by FITLD and generate their tables in the old manner. Phase 2 of calibration transfer will include supply of data from more external telescopes, and probably will proceed incrementally, depending on both the availability of the external information and the implementation of new software in Socorro. At present, ancillary data from most external telescopes must still be loaded in the old manner, and observations of strong sources may be needed for manual pulse calibration at those telescopes. Up-to-date instructions on coping with observations including external telescopes can be found at http://www.nrao.edu/vlba/html/OBSERVING/cal-transfer/cal-transfer.html. Please send comments on calibration transfer to julvesta@nrao.edu, and send bug reports to daip@nrao.edu, with a copy to julvesta@nrao.edu. NOTES: Tracking for the spacecraft was scheduled for following passes: Begin UT (Day) End UT (Day) Tracking Station 23:00 (258) 03:10 (259) Tz 04:35 (259) 08:45 (259) Rz 11:00 (259) 15:00 (259) Nz 17:15 (259) 21:30 (259) Gz 23;35 (259) 02:10 (260) Uz 02:15 (260) 04;30 (260) Tz 05:55 (260) 10:00 (260) Rz 12:15 (260) 16:20 (260) Nz 18:35 (260) 22:50 (260) Gz A long experiment with a lot of stations! I'll try to mention most things, but it's possible I may miss a few. Generally speaking the recording/playback was pretty good. Jb, On, and Nz had some poor weights at some times. On and Nz had the worst recording/playback, generally of all stations. At the times that On and Jb had weights problems, IF 1 was apparently dead at both stations. In the Uz tracking pass, the tape wouldn't sync up after UT midnight, apparently due to a problem with the log, and so most of this tracking pass was lost. Some radio frequency interference (RFI) was seen at several stations for this 6 cm run. In particular RFI was seen throughout the experiment at Nt, On, and Jb. There was occasional RFI at Wb, Eb, and from the spacecraft. During the run, there were weather problems at several of the VLBA stations. Effects of the weather can be seen in the Tsys at various stations. Hurricane Floyd affected the weather at Hn. Check the VLBA operator log. Fringes could be seen on all sources from La to the VLBA stations and Eb, Y, Wb and sometimes Jb. Fringes from La to other European stations are weaker but are usually seen on the calibrators. No fringes are evident to the spacecraft from any ground station (on the target source, of course). Discontinuities in the fringe signal on baselines to the Halca orbiter occur at each handoff from one tracking station to another, and at any dropouts in the phase-transfer link that occur during a tracking pass. Fringe fits should be broken at each such discontinuity to avoid de- correlation. This will happen automatically at handoffs because the tracking-station name assigned to Halca changes, but at link dropouts it is necessary to force an AIPS scan break by passing the following table to AIPS task INDXR via the INFILE adverb. SUBARRAY = 1 / 259 04:39:59.9 ! stn_id = RZ *! 259 05:34:30.0 ! stn_id = RZ *! 259 08:36:10.0 ! stn_id = RZ *! 259 17:17:59.9 ! stn_id = GZ *! 259 23:34:49.9 ! stn_id = UZ *! 259 23:42:59.9 ! stn_id = UZ *! 260 00:15:19.9 ! stn_id = UZ *! 260 02:19:10.0 ! stn_id = TZ *! 260 02:35:00.0 ! stn_id = TZ *! 260 02:44:40.0 ! stn_id = TZ *! 260 02:50:00.0 ! stn_id = TZ *! 260 01:15:40.0 ! stn_id = UZ *! 260 03:26:20.0 ! stn_id = TZ *! 260 03:40:50.0 ! stn_id = TZ *! 260 03:47:09.9 ! stn_id = TZ *! 260 05:56:39.9 ! stn_id = RZ *! 260 08:45:10.0 ! stn_id = RZ *! 260 12:15:49.9 ! stn_id = NZ *! 260 18:36:00.0 ! stn_id = GZ *! 260 20:49:10.0 ! stn_id = GZ *!