From analysts@aoc.nrao.edu Mon Mar 20 09:38:31 2000 Date: Fri, 17 Mar 2000 16:04:40 -0700 (MST) From: Data Analysts To: foley@nfra.nl, jive@jive.nfra.nl, kb@astro.uni.torun.pl, p062gra@mpifr-bonn.mpg.de, sjouwerm@jive.nl, tuccari@ira.noto.cnr.it, vlbi@jb.man.ac.uk, vlbi@oso.chalmers.se, vlbifriend@astbo1.bo.cnr.it, vlbifriend@ira.noto.cnr.it, xhuang@center.shao.ac.cn Subject: GA018 P.I. Letter Dear PI, We have examined the data for project GA018 on 11 Feb. 2000. The contact person for this project was Data Analysts. 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/feb00/ga018/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 AND WB 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 GA018 can be found at: /home/aspen6/astronomy/feb00/ga018/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: 8940,8941,8922-8931,8937 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: BR: OK FD: RFI seen in IF channel 3 of autocorrelation plots. HN: RFI seen in IF channel 2 of autocorrelation plots. KP: OK LA: RFI seen in IF channels 1, 2, 3, and 4 of autocorrelation plots. Some of the RFI appears in the cross-correlation plots as well. MK: OK NL: Variable weights at 12:30 - 19:30 UT. PT: Variable weights at 14:30 - 17:00 UT. RFI seen in IF channel 1 of autocorrelation plots. SC: Variable weights at 12:30 - 13:30 UT. RFI seen in IF channels 1 of autocorrelation plots. Non-VLBA stations: EB: RFI seen in IF channel 1 of autocorrelation plots. No fringes around 7:30 UT and 12:00 UT. JB: RFI seen in IF channels 1, 2, and 4 of autocorrelation plots. No fringing at 7:30 - 10:00 UT and at 11:50 - 12:50 UT, possibly due to slewing. MC: RFI seen in IF channels 2 and 3 of autocorrelation plots. RFI also seen in the cross-correlation plots. No fringes at ~7:30 - 10:00 UT. NT: On the first tape pass track #11 was dead. IF channel 3 was dead during the time track #11 was dead. Lower edge bandpass spike in IF channels 3 and 4. ON: RFI seen in IF channel 1 of autocorrelation plots. RFI seen in IF channel 1 of autocorrelation plots. No fringes seen at 7:30 - 9:00 UT. SH: RFI seen in IF channels 3 and 4 of autocorrelation plots. Lower edge bandpass spike in IF channel 1 of autocorrelation plots. TR: Track #6 was dead for entire experiment. IF channel 1 is dead due to the dead track. Lower edge bandpass spike in channel 2 seen of autocorrelation plots. WB: Weights on the third tape pass were variable at ~ 80%. RFI seen in IF channels 1 and 2 of autocorrelation plots. From analysts@aoc.nrao.edu Mon Mar 27 13:42:03 2000 Date: Fri, 24 Mar 2000 10:05:45 -0700 (MST) From: Data Analysts To: sjouwerman@jive.nl, jive@jive.nl Subject: GS016A PI Letter Dear PI, We have examined the data for project GS016A on 14 Feb. 2000. The contact person for this project was Data Analysts. 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/feb00/gs016a/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 J0650+6001, J1740+5211, J115000.1+55, J120152.2+38, J134158.5+54, and J140942.4+36. 4. Cross-correlation bandpass plots were generated for all baselines to EB for scans on J0650+6001, J1740+5211, J115000.1+55, J120152.2+38, J134158.5+54, and J140942.4+36. 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 GS016A can be found at: /home/aspen6/astronomy/feb00/gs016a/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: 9020-9026 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: EB: RFI seen in IF channels 4 of autocorrelation plots. JB: RFI seen in all IF channels of autocorrelation plots. Low amplitudes in IF channel 3 seen in autocorrelation plots. RFI seen in cross-correlation plots as well. MC: RFI seen in IF channels 1 and 4 of autocorrelation plots. NT: OK ON: IF channel 3 dead for entire experiment (track #3). SH: RFI seen in all IF channels of autocorrelation plots. Good fringes to both polarizations. TR: Track #6 dead for roughly 66% of experiment affecting IF channel 1. Lower edge bandpass spike in IF channel 2. WB: OK General Notes: Except for the dead IF channels mentioned above, weight are above 70% for all IF channels for all stations for at least 95% of the time. Some RFI showing up in cross-correlation plots. Most target sources do not fringe well. From clewis@cv3.cv.nrao.edu Mon Mar 27 13:43:49 2000 Date: Fri, 24 Mar 2000 16:55:32 -0700 From: Craig Lewis To: leon@astro.rug.nl Cc: p062gra@mpifr-bonn.mpg.de, agg@jb.man.ac.uk, jive@jive.nfra.nl, 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, kb@astro.uni.torun.pl, rf@astro.uni.torun.pl, foley@nfra.nl Subject: PI Letter GK020 [ Part 2: "Attached Text" ] Dear PI, We have examined the data for project GK020 on 14 Feb. 2000. The contact person for this project was Steve Meyers. 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/feb00/gk020/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. 4. Cross-correlation bandpass plots were generated for all baselines to LA for scans on ALL. 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 GK020 can be found at: /home/aspen6/astronomy/feb00/gk020/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: 6825, 6821- 6824 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: NT, WB, MK, KP, FD, have slightly diminished weights. NL has diminished weights, especially for 4 passes of the tape from 0800 to 1000. PT has one scan with diminished weights. TR has weights of 50%. There is strong RFI at MC in IF1, JB in IF 4, TR in IF 2, and NT in IFs 2 and 4. There are good fringes on all base- lines to 1510+570 throughout the experimen [ Part 3: "Attached Text" ] [IMAGE]NATIONAL RADIO ASTRONOMY OBSERVATORY POST OFFICE BOX O SOCORRO, NEW MEXICO 87801-0387 ________________________________________________________________________________ Dear PI, We have examined the data for project GK020 on 14 Feb. 2000. The contact person for this project was Steve Meyers. 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/feb00/gk020/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. 4. Cross-correlation bandpass plots were generated for all baselines to LA for scans on ALL. 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 GK020 can be found at: /home/aspen6/astronomy/feb00/gk020/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: 6825, 6821- 6824 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: NT, WB, MK, KP, FD, have slightly diminished weights. NL has diminished weights, especially for 4 passes of the tape from 0800 to 1000. PT has one scan with diminished weights. TR has weights of 50%. There is strong RFI at MC in IF1, JB in IF 4, TR in IF 2, and NT in IFs 2 and 4. There are good fringes on all base- lines to 1510+570 throughout the experiment. ________________________________________________________________________________ Craig Lewis Orbiting Very Long Baseline Interferometry Data Analyst From analysts@aoc.nrao.edu Fri Mar 31 05:03:52 2000 Date: Wed, 29 Mar 2000 09:12:01 -0700 (MST) From: Data Analysts To: jive@jive.nl, p062gra@mpifr-bonn.mpg.de, sjouwerm@jive.nl, tuccari@ira.noto.cnr.it, vlbi@hut.fi, vlbi@jb.man.ac.uk, vlbi@oso.chalmers.se, vlbifriend@astbo1.bo.cnr.it, vlbifriend@ira.noto.cnr.it Subject: GD014 P.I. Letter Dear PI, We have examined the data for project GD014 on 22 Feb. 2000. The contact person for this project was Data Analysts. 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/feb00/gd014/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 DA193, 1611+343, and J1719+4803. 4. Cross-correlation bandpass plots were generated for all baselines to HN for scans on DA193, 1611+343, and J1719+4803. 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 GD014 can be found at: /home/aspen6/astronomy/feb00/gd014/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: 2520-2544 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: BR: OK FD: OK HN: OK KP: OK LA: OK MK: Poor weights at 4:40 - 5:30 UT; tape was overwritten at the site. NL: Slightly variable weights on forward passes at 5:30 - 13:00 UT. Slightly variable weights at 23:30 - 4:30 UT. OV: Slightly variable weights at 14:00 - 16:30 UT. PT: OK SC: OK Non-VLBA Stations: CM: Small RFI spike in IF channel 2. Lower edge bandpass spike in IF channel 4 of autocorrelation plots. Poor fringing in IF channels 2 and 4. EB: Tape was in SEARCH at 5:40 - 6:05 UT and 0:00 - 3:00 UT; data lost. Variable weights at 16:40 - 17:10 UT; weights vary between 30% - 100%. JB: OK MH: Poor weights through-out correlation; tape tracks 6, 7, 20, and 28-33 are poor; weights vary between 0% - 70%; tape was moved during correlation with no improvement. IF channel 4 usually dead and IF 2 intermittently dead in autocorrelation plots due to poor weights. MC: OK NT: Poor fringing in IF channel 1 of cross-correlation plots. ON: OK From clewis@cv3.cv.nrao.edu Fri Mar 31 05:05:25 2000 Date: Thu, 30 Mar 2000 16:59:55 -0700 From: Craig Lewis To: vlemming@strw.strw.leidenuniv.nl Cc: jive@jive.nfra.nl, 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, kb@astro.uni.torun.pl, rf@astro.uni.torun.pl, foley@nfra.nl Subject: PI Letter for EV009 [ Part 2: "Attached Text" ] Dear PI, We have examined the data for project EV009 on 16 Feb. 2000. The contact person for this project was Lorant Sjourman. 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/feb00/ev009/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 UHER RAQL RSVIR OH127.8 OH37.1 WXPSC J0102 0059+581 J0152+2207 0149+218 etc. 4. Cross-correlation bandpass plots were generated for all baselines to WB for scans on UHER RAQL RSVIR OH127.8 OH37.1 WXPSC J0102 0059+581 J0152+2207 0149+218 etc. 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 EV009 can be found at: /home/aspen6/astronomy/feb00/ev009/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: 6530- 6538 NOTES: TR weights are ~0.75 for the first four tape passes. Again at 0900 to 1045. Again from 1630- 1700. EB weights are slightly diminished. EB weights are somewhat worse after 0800 in a systematic pattern that is probably associated with one group of tracks. WB has severly diminished weights 0645. WB weights are diminished and averaging about 0.75 1230 - 1415. NT weights are severly diminished and at times. NT loses sync for entire passes of the tape or has weights of zero from 0800 to 1230 due to the failure of the VLBA formatter. RFI and DC spikes are common in this program. JB IF 1 does not fringe, the cause of this problem is not understood. NT fringes are a factor of three times weaker when the MKIV formatter is being used than when the VLBA formatter is being used and the cause of this problem is also unknown. Otherwise all stations fringe on calibrator sources at various times and on all baselines throughout the progra [ Part 3: "Attached Text" ] [IMAGE]NATIONAL RADIO ASTRONOMY OBSERVATORY POST OFFICE BOX O SOCORRO, NEW MEXICO 87801-0387 ________________________________________________________________________________ Dear PI, We have examined the data for project EV009 on 16 Feb. 2000. The contact person for this project was Lorant Sjourman. 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/feb00/ev009/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 UHER RAQL RSVIR OH127.8 OH37.1 WXPSC J0102 0059+581 J0152+2207 0149+218 etc. 4. Cross-correlation bandpass plots were generated for all baselines to WB for scans on UHER RAQL RSVIR OH127.8 OH37.1 WXPSC J0102 0059+581 J0152+2207 0149+218 etc. 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 EV009 can be found at: /home/aspen6/astronomy/feb00/ev009/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: 6530- 6538 NOTES: TR weights are ~0.75 for the first four tape passes. Again at 0900 to 1045. Again from 1630- 1700. EB weights are slightly diminished. EB weights are somewhat worse after 0800 in a systematic pattern that is probably associated with one group of tracks. WB has severly diminished weights 0645. WB weights are diminished and averaging about 0.75 1230 - 1415. NT weights are severly diminished and at times. NT loses sync for entire passes of the tape or has weights of zero from 0800 to 1230 due to the failure of the VLBA formatter. RFI and DC spikes are common in this program. JB IF 1 does not fringe, the cause of this problem is not understood. NT fringes are a factor of three times weaker when the MKIV formatter is being used than when the VLBA formatter is being used and the cause of this problem is also unknown. Otherwise all stations fringe on calibrator sources at various times and on all baselines throughout the program. ________________________________________________________________________________ Craig Lewis Orbiting Very Long Baseline Interferometry Data Analyst From analysts@aoc.nrao.edu Mon Apr 10 14:57:48 2000 Date: Thu, 6 Apr 2000 11:26:35 -0600 (MDT) From: Data Analysts To: agg@jb.man.ac.uk, apolatid@oso.chalmers.se, foley@nfra.nl, jive@jive.nl, kb@astro.uni.torun.pl, p062gra@mpifr-bonn.mpg.de, snellen@ast.cam.ac.uk, trigilio@ira.noto.cnr.it, tuccari@ira.noto.cnr.it, tventuri@astbo1.bo.cnr.it, xhuang@center.shao.ac.cn Subject: GS016B data Dear PI, We have examined the data for project GS016B on 02 Mar. 2000. The contact person for this project was Data Analysts. 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/mar00/gs016b/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 4C39.25,J0715,J0831,J1049,J1431,J1340,J1613. 4. Cross-correlation bandpass plots were generated for all baselines to HN for scans on 4C39.25,J0715,J0831,J1049,J1431,J1340,J1613. 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 GS016B can be found at: /home/aspen6/astronomy/mar00/gs016b/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: 5520-5529 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: SC: OK HN: OK NL: Bad readbacks on track 33, though recording looks OK. FD: OK LA: OK PT: OK KP: OK OV: OK BR: OK MK: High wind gusts were detected at 1:29 UT. EB: There are a couple of gaps in the data: 00:00 to 1:00, 2:40, 4:40,and 6:30 UT. These were related to gaps in the monitor data, and are unrecoverable. EB was unable to observe from 2:45 to 3:20 UT, and from 7:35 to 7:50 UT (snowfall). MC: OK NT: OK ON: Playback was good, but the tape was in stall briefly at 10:30 UT. TR: Track 6 was dead for essentially the whole project. When BBC 1 (track 6) is working, the amplitude in the cross correlation plots is abnormally high. SH: Playback was good. One anamoly: even BBCs have unusually low amplitudes at 6:46 UT. WB: Tracks 7 and 25 are dead for a part of the observation. The times immediately before the tracks go dead, the bandpasses look rather abnormal, so it's questionable how useful they are. JB: There were a couple of instances where the tape was in search: at the very beginning of the project 00:00 UT and 9:15 UT, each for no longer than 5 minutes. Otherwise Playback was fine. Amplitudes in BBC 3 were lower than the others over the whole observation. From clewis@cv3.cv.nrao.edu Thu Apr 20 11:58:36 2000 Date: Tue, 11 Apr 2000 15:10:55 -0600 From: Craig Lewis To: greenhill@cfa.harvard.edu Cc: jive@jive.nfra.nl, 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 Subject: PI Letter GG042A [ Part 2: "Attached Text" ] Dear PI, We have examined the data for project GG042A on 21 Feb. 2000. 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/feb00/gg042a/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 3C48 0234+285 0528+134 NGC1068. 4. Cross-correlation bandpass plots were generated for all baselines to EB & Y for scans on 3C48 0234+285 0528+134 NGC1068. 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 GG042A can be found at: /home/aspen6/astronomy/feb00/gg042a/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- 7473 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: NL, ON, PT, OV have slightly diminished weights. LA has severely diminished weights at the end of the experiment for 2 passes of the tape. BR has about 4 passes of the tape at the end of the experiment with severely diminished weights. There is mild to moderate RFI scattered throughout this experiment, but not generally strong enough to 'correlate' in the cross correlation bandpass plots. JB does not fring in the upper two IFs in both passes. ON does not fring in the uppermost IF in pass1. HN fringes are very weak, but get better at 20:37. NT fringes are very weak. Otherwise there are good fringes to all stations on all baselines throughout the experiment on 0234+285. ADDED BY CRAIG WALKER: JB very weak fringes in basebands 3 and 4 of Pass 1 (22131 and 22145 MHz). The processing has had the IFs juggled. These channels were scheduled as basebands 2 and 4 and are the ones on IF 2A. The same goes for basebands 3 and 4 of Pass 2 (22159 and 22173 MHz) These were scheduled as 6 and 8 and are also on IF 2A. It is clear that IF 2A is only getting weak fringes. I'll hazard a guess that it is cross polarized. There is no good way to tell because everyone else is on LCP only. JB IF 4 very low amplitudes in auto and in cross noise. Probably low power levels not reaching upper threshold of the 4 level sampling. That is one of the channels with weak fringes. ON no fringes in IF 4 of Pass 1 (22145 MHz). Actuall maybe just very weak. They seem to be detected in the fringe fit. All other IF's, including all in Pass 2 appear to be o [ Part 3: "Attached Text" ] [IMAGE]NATIONAL RADIO ASTRONOMY OBSERVATORY POST OFFICE BOX O SOCORRO, NEW MEXICO 87801-0387 ________________________________________________________________________________ Dear PI, We have examined the data for project W088B4 on 16 Mar. 2000. The contact person for this project was John Benson. 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/mar00/w088b4/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. 4. Cross-correlation bandpass plots were generated for all baselines to LA for scans on ALL. 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 W088B4 can be found at: /home/aspen6/astronomy/mar00/w088b4/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: 5220-5230 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: SC starts late due to a warm 20CM receiver. FD has diminished weights. GZ has a brief period of diminished weights. RO has strong RFI in IF2. LA has RFI in IF1. 0627 RZ has RFI in IF1. TZ has RFI in IF1 also. KP also has a strange repsonse at 0743. OV has RFI in IF1. MK has RFI in IF1 & 2. GZ has RFI in both IFs. There are good fringes on all baselines. Fringes to GZ are stronger than other tracking stations. TI fringes go away from 1250 to 1313. When they come back, the clock has jumped 600 nano seconds ________________________________________________________________________________ Craig Lewis Orbiting Very Long Baseline Interferometry Data Analyst From analysts@aoc.nrao.edu Tue May 2 11:42:21 2000 Date: Wed, 29 Mar 2000 09:12:01 -0700 (MST) From: Data Analysts To: jive@jive.nl, p062gra@mpifr-bonn.mpg.de, sjouwerm@jive.nl, tuccari@ira.noto.cnr.it, vlbi@hut.fi, vlbi@jb.man.ac.uk, vlbi@oso.chalmers.se, vlbifriend@astbo1.bo.cnr.it, vlbifriend@ira.noto.cnr.it Subject: GD014 P.I. Letter Dear PI, We have examined the data for project GD014 on 22 Feb. 2000. The contact person for this project was Data Analysts. 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/feb00/gd014/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 DA193, 1611+343, and J1719+4803. 4. Cross-correlation bandpass plots were generated for all baselines to HN for scans on DA193, 1611+343, and J1719+4803. 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 GD014 can be found at: /home/aspen6/astronomy/feb00/gd014/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: 2520-2544 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: BR: OK FD: OK HN: OK KP: OK LA: OK MK: Poor weights at 4:40 - 5:30 UT; tape was overwritten at the site. NL: Slightly variable weights on forward passes at 5:30 - 13:00 UT. Slightly variable weights at 23:30 - 4:30 UT. OV: Slightly variable weights at 14:00 - 16:30 UT. PT: OK SC: OK Non-VLBA Stations: CM: Small RFI spike in IF channel 2. Lower edge bandpass spike in IF channel 4 of autocorrelation plots. Poor fringing in IF channels 2 and 4. EB: Tape was in SEARCH at 5:40 - 6:05 UT and 0:00 - 3:00 UT; data lost. Variable weights at 16:40 - 17:10 UT; weights vary between 30% - 100%. JB: OK MH: Poor weights through-out correlation; tape tracks 6, 7, 20, and 28-33 are poor; weights vary between 0% - 70%; tape was moved during correlation with no improvement. IF channel 4 usually dead and IF 2 intermittently dead in autocorrelation plots due to poor weights. MC: OK NT: Poor fringing in IF channel 1 of cross-correlation plots. ON: OK From analysts@aoc.nrao.edu Tue May 2 11:43:03 2000 Date: Thu, 6 Apr 2000 11:26:35 -0600 (MDT) From: Data Analysts To: agg@jb.man.ac.uk, apolatid@oso.chalmers.se, foley@nfra.nl, jive@jive.nl, kb@astro.uni.torun.pl, p062gra@mpifr-bonn.mpg.de, snellen@ast.cam.ac.uk, trigilio@ira.noto.cnr.it, tuccari@ira.noto.cnr.it, tventuri@astbo1.bo.cnr.it, xhuang@center.shao.ac.cn Subject: GS016B data Dear PI, We have examined the data for project GS016B on 02 Mar. 2000. The contact person for this project was Data Analysts. 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/mar00/gs016b/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 4C39.25,J0715,J0831,J1049,J1431,J1340,J1613. 4. Cross-correlation bandpass plots were generated for all baselines to HN for scans on 4C39.25,J0715,J0831,J1049,J1431,J1340,J1613. 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 GS016B can be found at: /home/aspen6/astronomy/mar00/gs016b/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: 5520-5529 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: SC: OK HN: OK NL: Bad readbacks on track 33, though recording looks OK. FD: OK LA: OK PT: OK KP: OK OV: OK BR: OK MK: High wind gusts were detected at 1:29 UT. EB: There are a couple of gaps in the data: 00:00 to 1:00, 2:40, 4:40,and 6:30 UT. These were related to gaps in the monitor data, and are unrecoverable. EB was unable to observe from 2:45 to 3:20 UT, and from 7:35 to 7:50 UT (snowfall). MC: OK NT: OK ON: Playback was good, but the tape was in stall briefly at 10:30 UT. TR: Track 6 was dead for essentially the whole project. When BBC 1 (track 6) is working, the amplitude in the cross correlation plots is abnormally high. SH: Playback was good. One anamoly: even BBCs have unusually low amplitudes at 6:46 UT. WB: Tracks 7 and 25 are dead for a part of the observation. The times immediately before the tracks go dead, the bandpasses look rather abnormal, so it's questionable how useful they are. JB: There were a couple of instances where the tape was in search: at the very beginning of the project 00:00 UT and 9:15 UT, each for no longer than 5 minutes. Otherwise Playback was fine. Amplitudes in BBC 3 were lower than the others over the whole observation. From analysts@aoc.nrao.edu Mon May 15 08:54:15 2000 Date: Tue, 9 May 2000 17:13:09 -0600 (MDT) From: Data Analysts To: apolatid@oso.chalmers.se, bartel@polaris.phys.yorku.edu, foley@nfra.nl, jive@jive.nl, p062gra@mpifr-bonn.mpg.de, pwolken@jftl.jpl.nasa.gov, trigilio@ira.noto.cnr.it, tuccari@ira.noto.ira.it, tventuri@astbo1.bo.cnr.it, valery.i.altunin@jpl.nasa.gov Subject: GB034 data Dear PI, We have examined the data for project GB034 on 24 Feb. 2000. The contact person for this project was J. 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/feb00/gb034/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 M81, 0954+658, OQ208. 4. Cross-correlation bandpass plots were generated for all baselines to SC for scans on M81, 0954+658, OQ208. 5. Gzipped PostScript plots of Tsys and other monitor data for each available VLBA antenna can be found at /home/aspen6/astronomy/feb00/gb034. 6. The jobs associated with the correlation of GB034 can be found at: /home/aspen6/astronomy/feb00/gb034/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: 2220-2230, 2232-2240 7. Operations staff have devised a web browser to navigate the file server aspen, as well as view and retrieve its text and PostScript files, gzipped or not. This browser can be reached through the VLBA homepage http://www.aoc.nrao.edu/vlba/VLBA.hmtl, initially under What's New but eventually under Observing. All of the files mentioned above can be accessed either with this browser or by FTPing to the vlbiobs account on aspen. 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 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: SC: OK HN: OK NL: OK FD: OK LA: Poor recording from 8:12 to 8:41 UT, otherwise OK. PT: OK KP: OK OV: OK BR: OK MK: OK Y27: Good recording. Spikes in BBCs 7 and 8 for the duration of the observation (probably internal). The bandpass in BBC 8 at 23:02 to 23:04 UT looks terrible, and should probably get flagged. In the APD plots, there are 2 distinct delays; the reason for this is unknown. EB: First two passes were recorded at 266 ips, recording is poor. Otherwise, recording hovers around 0.75 in the wts plot, accompanied with weak fringes. MC: Poor recording from 21:00 to 21:05 UT and 3:00 to 4:00 UT. BBCs 7 and 8 are dead at 21:00 UT, 1 and 2 are dead from 3:10 to 3:15 UT. All around, weak fringes, accompanied with noisy APD plots. NT: Poor recording from 3:00 to 3:30 UT. Large, sloping spike in BBC 4 at 21:28 UT, continuing. WB: Recording is pretty bad, usually averaging 0.50 in the wts plots. Usually BBCs 7 and 8 are dead, at other times it's 5 and 6. ON: OK GO: Variable recording quality, from excellent to very poor, over the course of the observation. BBCs 1, 2, 5, and 6 are dead at 7:52 UT. Bandpass edge spikes in all BBCs at 4:34 UT. Fringes are very weak on the SC-GO baselines. RO: OK YB: Failed to observe, due to lack of inclusion in the drudg file. NOTE: Additional EVN comments can be found in the feedback printout (hardcopy only).