From analysts@aoc.nrao.edu Fri Jul 9 09:09:23 1999 Date: Thu, 08 Jul 1999 15:25:15 -0600 (MDT) From: Data Analysts To: jive@RZMWS0.NFRA.NL Subject: GM033B P.I. Letter Dear PI, We have examined the data for project GM033B on 04 Jun. 1999. The contact person for this project was Geoff Bower. 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/jun99/gm033b/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 GM033B can be found at: /home/aspen6/astronomy/jun99/gm033b/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: 9920-9922 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: GO: Slightly variable weights on reverse passes. RFI in channel 6. RO: Gap in FS log at 19:35 to 20:00 UT; no data. RFI in channels 4 and 5. EB: RFI in channel 2. Sloping bandpass in channels 4 and 8 in autocorrelation plots. VLA27: Slightly variable weights at 20:30 - 22:30 UT. RFI in channels 1, 6, and 7. Sloping bandpasses in channels 7 and 8 of autocorrelation plots. Low amplitudes and no fringes in channels 1 and 8 in cross-correlation plots. Non-linear phase slope in channel 2 and sloped amplitude bandpass in channel 7 of cross-correlation plots. No fringes seen to channel 1 in amplitude/phase/delay plots. From analysts@aoc.nrao.edu Tue Jul 27 08:57:39 1999 Date: Mon, 26 Jul 1999 10:12:25 -0600 (MDT) From: Data Analysts To: foley@NFRA.NL, jive@RZMWS0.NFRA.NL, kb@astro.uni.torun.pl, p062gra@mpifr-bonn.mpg.de, tuccari@ira.noto.cnr.it, vlbi@jb.man.ac.uk, vlbifriend@astbo1.bo.cnr.it, vlbifriend@ira.noto.cnr.it Subject: GK019 P.I. Letter Dear PI, We have examined the data for project GK019 on 30 May 1999. The contact person for this project was Chris Fassnacht. 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/may99/gk019/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 GK019 can be found at: /home/aspen6/astronomy/may99/gk019/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: 3720-3734 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 in channels 3 and 4 at L-band. HN: OK KP: OK LA: OK MK: In and out of SEARCH at 19:30 - 23:00 UT; variable weights; recorder problem. NL: RFI in channel 2 at X-band. OV: OK PT: Variable weights at 00:45 - 2:00 UT; weights vary between 80% - 100%. SC: Poor weights (20% - 90%) at 18:00 - 00:15 UT; recorder problem. Channels 1 and 2 dead on one or two early scans. Also, some RFI in channels 3 and 4 at X-band. Non-VLBA Stations: CM: No fringing seen through entire run. Track 28 was dead; weights at 50%. In the autocorrelation plots the first two channels looked dead; channel 3 has a bandpass edge spike. EB: No fringing seen on a few early scans in the cross-correlation plots. MC: RFI in channels 3 and 4. NT: In SEARCH at 14:00 - 14:15 UT. Channels 1 and 2 appear dead near beginning of the project in the autocorrelation plots. TR: Station observed a slightly different schedule, so only intermittent fringing. WB: OK From analysts@aoc.nrao.edu Wed Jul 28 11:03:47 1999 Date: Tue, 27 Jul 1999 15:50:31 -0600 (MDT) From: Data Analysts To: foley@NFRA.NL, jive@RZMWS0.NFRA.NL, kb@astro.uni.torun.pl, p062gra@mpifr-bonn.mpg.de, tuccari@ira.noto.cnr.it, vlbi@jb.man.ac.uk, vlbi@oso.chalmers.se, vlbifriend@astbo1.bo.cnr.it, vlbifriend@ira.noto.cnr.it Subject: ED014 P.I. Letter Dear PI, We have examined the data for project ED014 on 01 Jun. 1999. The contact person for this project was Craig 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/jun99/ed014/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 ED014 can be found at: /home/aspen6/astronomy/jun99/ed014/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: Pass 1: 8950-8952; Pass 2: 8953-8956 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: The first correlation pass was the polarization pass. The second correlation pass was the high spectral channel pass. CM: Track #28 was dead in both correlation passes; weights at 50% at 20:00 - 23:00 UT, 2:00 - 5:00 UT and 8:00 - 10:00 UT. The poor weights affected channels 3 and 4. In the autocorrelation plots there were low amplitudes in channels one and two, and channels 3 and 4 were occasionally dead. RFI seen in channel 2 in the first correlation pass, and RFI seen in channel 1 in the second correlation pass. No fringes seen in the cross-correlation plots for the first two channels, and the last two channels were intermittently dead. EB: Poor weights at 4:00 - 5:15 UT in both correlation passes; weights vary between 0% - 80%. JB: Poor weights throughout both correlation passes. Track #32 was very poor and track 20, 22, 28, and 30 were weak; weights vary between 5% - 90%. Tape was in SEARCH at 20:00 - 22:00 UT; no data. Low amplitude seen in channel 3 of the autocorrelation plots of the first correlation pass. RFI seen in channel 3 of the first pass and in channels 1, 3, and 4 of the second pass. Some RFI seen in the cross-correlation plots. In the first pass no fringes were seen in channel 1 and channel 3 appears weak. In the second pass, channel 4 appears dead in the cross-correlation plots. MC: RFI and low amplitudes in channels 1 and 2 of the autocorrelation plots in first correlation pass. RFI seen in all four channels in the second correlation pass. NT: DC offset spikes seen in all channels of the autocorrelation plots in both correlation passes. ON: Poor weights at 21:30 - 23:00 UT, 00:30 - 2:15 UT, and 5:00 - 6:45 UT in correlation pass one; weights vary between 25% - 90%. RFI seen in channels 1 and 2 of the autocorrelation plots of the second correlation pass. No fringes seen in channel 3, pass 1, of the cross-correlation plots. No fringes seen in channel 4, pass 2, of the cross-correlation plots. TR: The observing log had to be edited to reflect the correct channels that were observed. Poor weights at 20:00 - 2:05 UT in correlation pass two; weights vary between 0% - 70%. In the autocorrelation plots, half of the bandpass appears to be dead in channels 1 and 2. Possibly the wrong filter was used during observation. No fringing seen in the cross-correlation plots of the first two channels as well. WB: RFI spike in channel 1 of second correlation pass. From analysts@aoc.nrao.edu Wed Jul 28 11:03:54 1999 Date: Tue, 27 Jul 1999 16:09:36 -0600 (MDT) From: Data Analysts To: foley@NFRA.NL, jive@RZMWS0.NFRA.NL, p062gra@mpifr-bonn.mpg.de, tuccari@ira.noto.cnr.it, vlbi@jb.man.ac.uk, vlbifriend@ira.noto.cnr.it Subject: GM035D P.I. Letter Dear PI, We have examined the data for project GM035D on 10 Jun. 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/jun99/gm035d/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 GM035D can be found at: /home/aspen6/astronomy/jun99/gm035d/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: 2120 - 2134 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: OK HN: OK NL: OK FD: Slightly variable weights. LA: OK PT: OK KP: OK OV: OK BR: OK MK: Variable weights at 17:30 - 18:10; weights vary between 50% - 90%. Non-VLBA Stations: EB: Poor weights at 22:05-22:30 UT; weights near 0%. JB: Poor weights; weak on all tracks; weight vary between ~ 20% - 80%; the problem was on the tape. DC offset spikes seen in channels 3, 4, and 8 in the autocorrelation plots. Amplitudes were low also in channels 4 and 8, along with poor fringing in the cross-correlation plots. NT: Autocorrelation amplitudes in channels 1 and 2 occasionally low. WB: Poor weights at 18:00 - 20:45 UT; weights vary between 30% - 80%; problem was on the tape. Y27: Steeply sloped bandpasses in channels 6 and 7; low amplitude in channel 8 and an upper edge spike and dip in channel 1 in the autocorrelation plots. No fringing in channel 8; poor fringing in channel 7; and non-linear phase slopes in channels 1 and 6. This was all due to observing outside of the VLA passband. From sjouwerman@jive.NFRA.NL Tue Oct 12 14:46:34 1999 Date: Fri, 08 Oct 1999 16:32:31 +0200 (MET DST) From: Lorant Sjouwerman To: Mike Garrett Subject: SESSION2: DEAR_PI_doubleyous Phone in Dwingeloo: +31-521-596517 (switch 596500, fax 597332) At home, on the road: +31-653-831122 or a subject-line to +31653831122@gin.nl X-Mailer: ELM [version 2.4 PL23] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Length: 30331 Dear PI, We have examined the data for project W018F on 28 May 1999. 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/may99/w018f/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 EB 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 W018F can be found at: /home/aspen6/astronomy/may99/w018f/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: 7820-7827 NOTES: JB weights are severly diminished. GB and GO have slightly diminished weights. SH has strong RFI in IF 1. RZ has RFI in IF 1, as does JB,ON & GO. WB has an extra 'spike' outside the 10MHz band. MC has moderate RFI in IF 2. RO has RFI in IF 2. GZ-EB fringes the entire pass. NZ-EB fringes at the end of the pass. RZ-EB fringes most of the pass. TZ-EB fringes almost the entire pass. All other GRTs have good fringes, except that SH doesn't fring at the beginning of the experiment. Dear PI, We have examined the data for project W027B1 on 29 May 1999. The contact person for this project was Vivek Dhawan. 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/may99/w027b1/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 W027B1 can be found at: /home/aspen6/astronomy/may99/w027b1/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: 6543-6550, 6528-6542 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: In General: RFI was extensive in this observation. It seems every station was effected at some point in the observation. I will only mention the times when the RFI came through the cross-correlation, when saturation could have occurred. SC: Playback was good, and besides some RFI, this station worked very well. None of the RFI came through the cross-correlation. HN: There was an unexplained gap in the data from 00:50 to 1:20 UT. This was one of the few stations not effected by RFI. NL: There is a dead channel (IF 1) from 18:15 to 18:45, otherwise playback was OK. FD: There is a gap in the data from 8:55 UT until the end of the observation, reason unknown. Other than RFI, this station was fine. LA: Playback was good, no fringes from 21:36 to 22:22 UT. The operator's log has the explanation. PT: OK KP: Extensive poor playback. Quite a bit of the data should be flagged carefully. OV: OK BR: Playback was good, but the RFI comes throught the cross-correlation at 18:00 UT. MK: OK SH: There was an unexplained gap from 18:00 to 18:25 UT. Playback was good otherwise Fringes weren't seen to this telescope until 20:19 UT, and an RFI spike comes through the cross-correlation from 21:36 UT until the end of the observation. Judging by the apd plots, fringes don't appear until almost as late as 21:45. WB: There were gaps in data at: 21:00 to 21:30 UT and 21:50 to 22:15 UT. Otherwise playback was good, and strong fringes. ON: Playback was good, and other than RFI, this station worked very well. EB: OK GB: Very good, one of the few stations uneffected by RFI. NT: Playback was good. No fringes in IF 1 at 1:51 UT. Also, a little noisy at: 1:45 to 2:15 UT and 9:20 to 9:30 UT. There were some bandpass edge problems, possibly arising from RFI, but I'm not certain. MC: Playback was good. RFI comes throught the cross-correlation in IF 1 at 19:43 UT. JB: It seems the high even tracks (26, 28, 30, and 32) had poor playback. This was pretty extensive. Spacecraft: Four tracking stations tracked , all had excellent playback. NZ: There were a couple of 'bumps' in the bandpass, it didn't look like RFI, but I haven't seen this feature before. There were very good fringes to this station. The NZ-PT baseline had a residual delay of 140 nsec, and a rate of 0 mHz. GZ: Strong fringes, a residual delay (on the GZ-SC baseline) of -200 nsec, and a rate of 10 to 30 mHz. TZ: Strong fringes were seen, except from 5:30 to 6:45 UT. Apogee occurred at 6:15, so I would guess the source became resolved at this point in time. The residual delay (TZ-FD) was at 140 nsec, rate of -10 to 0 mHz. UZ: Good fringes, with a delay to EB of 2580 nsec, and a rate from -5 to -20 mHz. 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 / 150 00:48:20.0 ! stn_id = GZ *! 150 02:07:29.9 ! stn_id = GZ *! 150 04:54:30.0 ! stn_id = TZ *! INDXR 150 08:05:19.9 ! stn_id = UZ *! Dear PI, We have examined the data for project W035G on 31 May 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/may99/w035g/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 W035G can be found at: /home/aspen6/astronomy/may99/w035g/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: 8220 - 8225 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 four passes: from about 00:55 to 02:20 UT from the Tz tracking station, from about 02:25 to 04:00 UT from the Gz tracking station, from about 07:30 to 08;40 UT, again from the Tz tracking station, and finally from about 08:43 to 10:00 from the Uz tracking station. Tape recording/playback from most stations, was pretty reasonable for the entire run. Jb was the ex ception. Very poor recording/playback is noted at Jb from about 0200 to 0400, and minor problems at Jb at other times. There are clear fringes to the spacecraft from Eb in the sniffer plots, for all four tracking passses. There is very strong radio frequency interference (RFI) in the autocorrelation sniffer plots throughout the experiment and in both IFs for Sh. The RFI at Sh has many spectral features. The RFI from Sh sometimes comes through in the cross-correlation plots to Eb. Strong RFI in IF 2 can be seen nearly throughout the experiment at Ro and in IF 1 from Jb. There is weaker (but still strong !) and more variable RFI in IF 1 at Eb. There is also some strong RFI coming through at times in both IFs at Mc and in IF 1 at Wb. RFI in IF 1 at On and Nt can also be easily seen near the end of the experiment. There is some weak RFI in IF 1 of the spacecraft during the Gz pass. 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 / 151 00:55:40.0 ! stn_id = TZ *! 151 02:27:20.0 ! stn_id = GZ *! 151 07:30:30.0 ! stn_id = TZ *! 151 08:47:40.0 ! stn_id = UZ *! 151 08:58:20.0 ! stn_id = UZ *! 151 09:05:20.0 ! stn_id = UZ *! Dear PI, We have examined the data for project W035F on 14 Jun. 1999. The contact person for this project was Amy Mioduszewski. 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/jun99/w035f/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 . 4. Cross-correlation bandpass plots were generated for all baselines to ON for scans on . 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 W035F can be found at: /home/aspen6/astronomy/jun99/w035f/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: 8336, 8337, 8338,8339, 8340 NOTES: EB - looks good GB - looks good JB - Really bad playback most of the time, tracks 28-33 poor. - 4976 MHz band much more noisy than other band MC - looks good NT - DC spike in 4978 MHz band NZ - poor playback first couple passes, every other even track (8, 12 etc) seemed to be poor at the beginning. ON - looks good SH - playback a little ratty but mostly O.K. - no fringes first ~20 minutes WB - weird bandpass; only center 10MHz observed TZ - DC spikes in both bands UZ - looks good 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 / 165 01:45:29.9 ! stn_id = NZ *! 165 06:39:50.0 ! stn_id = TZ *! 165 07:01:00.0 ! stn_id = TZ *! 165 07:08:10.0 ! stn_id = TZ *! / Dear PI, We have examined the data for project W035E on 14 Jun. 1999. The contact person for this project was Amy Mioduszewski. 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/jun99/w035e/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 . 4. Cross-correlation bandpass plots were generated for all baselines to EB for scans on . 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 W035E can be found at: /home/aspen6/astronomy/jun99/w035e/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: 9820, 9821, 9822, 9823, 9824 NOTES: EB - looks good GZ - fringes at a delay of -520 to -480 ns and rate of between -10 and +20 mHz JB - horrible playback on forward passes, probably caused by poor even tracks 28-32. - amplitude in 4978 MHz band fluctuates, connected to above? - does not fringe for first 45 minutes, see EVN feedback facility: http://www.nfra.nl/jive/evn/session/may99/w035e.hdr - seems to have a rate of about 5 mHz MC - looks good NT - DC spikes ON - looks good SH - looks good WB - signal only in center of band, see EVN feedback facility TR - sent blank tapes TZ - fringes at a delay of -200ns and a rate between 10 and 0 mHz KA - no fringes for first 5 minutes, looks great after that. Note that the KA tape used was copied at Mitaka and they produced an erroneous log file, which only showed even tracks on the tape. We assumed that the copy started on even tracks and switched to odd tracks, and back etc.. This seemed to have worked, given that KA produced good fringes. 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 / 166 00:38:30.0 ! stn_id = TZ *! / Dear PI, We have examined the data for project W027A2 on 16 Jun. 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/jun99/w027a2/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 W027A2 can be found at: /home/aspen6/astronomy/jun99/w027a2/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: 7020 --- 7037 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 four passes: from about 15:00 to 18:11 UT from the Rz tracking station; from about 21:17 to 00:30 UT from the Nz tracking station; from about 01:38 to 05:50 UT from the Tz tracking station, and from 05:53 to 06:45 from the Uz tracking station. According to the EVN summary, Tr had only minor failures; however we were unable to find any data on the Tr tape. We carefully checked the tape; and could find no data. We left Tr out of the production correlation. As noted in the VLBA log, several of the southwest U.S. stations had some power problems which caused the antennas to autostow; at times for several tens of minutes. La was on generator power for roughly 6 hours (00:57 to 06:23 UT). This means that, even though the tape was turning, and data being recorded, the antenna was not pointing during this time. The flag table will reflect this. When it began raining at Nl (at about 2200 UT), the Tsys in both IF channels varied by as much as 20 K during the 2 hours of rain. We noticed a peculiarity in the residual fringe rate and delay to Sc (and to a lesser extent to Mk). The source sets at Sc at about 1600 UT, and rises again at about 1945 UT. The residual rate before the source set was about -50 mHz, and after it rises again, the residual rate is about +50 mHz. These high residual rates occur when the source is below about 9 degrees eelvation. As the source rises above about 12 degrees elevation, the rate goes to near zero and stays there for the rest of the experiment. We spent quite a bit of time trying to track down the cause of this, and finally conviced ourselves that this is due to the correlator model not accounting well for the wet atmosphere at these low elevations. The tape recording/playback from Jb was quite poor; IF 2 was completely dead for a lot of this experiment. The recording from Nt began having problems on alternate passes at about 01:30 UT and continued to about 05:40 UT. Mc had a dead channel from about 01:45 UT to 02:00 UT. Fd had rather poor playback/recording from about 02:15 UT to 03:15 UT. There were some brief unexplained gaps from Nl (00:40 to 00:50 UT) and Pt (00:30 to 01:15 UT). The tape recording/playback from the rest of the stations was pretty reasonable for the entire run. No radio frequency interference (RFI) was noted for this 6 cm run. The autocorrelation plots from the sniffer show a DC spike at Nt, especially in the second IF. The bandpass from On rolls off rather rapidly. The phase-cal tones from Wb, especially in IF 1, are rather too strong near the DC edge, and get progressively weaker across the band. By the high-frequency edge of the bandpass, they are no longer discernible. The tones are a bit too strong at Sh as well. Fringes to the spacecraft are evident from all tracking passes on many baselines, but always on the baseline to Eb. The residual delay at the Rz tracking station is about -100 ns. There appears to be a delay jump to -170 ns at Rz at about 1745 UT. The residual delay at Nz appears close to zero on baselines to Eb. The residual delay at Tz begins at +200 ns, jumps to -200 ns at about 0220 UT, and jumps back to about +130 ns at about 0305 UT and stays at +130 ns for the rest of the tracking pass. The residual delay at Uz is about +3100 ns. 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 / 167 15:03:00.0 ! stn_id = RZ *! 167 17:52:29.9 ! stn_id = RZ *! 167 21:17:40.0 ! stn_id = NZ *! 168 00:00:19.9 ! stn_id = NZ *! 168 01:39:59.9 ! stn_id = TZ *! 168 02:17:00.0 ! stn_id = TZ *! 168 03:01:50.0 ! stn_id = TZ *! 168 05:54:19.9 ! stn_id = UZ *!