From analysts@aoc.nrao.edu Thu Jan 6 10:08:13 2000 Date: Tue, 4 Jan 2000 15:27:29 -0700 (MST) From: Data Analysts To: agg@jb.man.ac.uk, apolatid@oso.chalmers.se, foley@nfra.nl, garrett@jive.nl, jive@jive.nl, kb@astro.uni.torun.pl, p062gra@mpifr-bonn.mpg.de, pwolken@jftl.jpl.nasa.gov, trigilio@ira.noto.cnr.it, tuccari@ira.noto.cnr.it, tventuri@astbo1.bo.cnr.it Subject: EM035B data Dear PI, We have examined the data for project EM035B on 13 Nov. 1999. 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/nov99/em035b/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 J1241, J1234, J0927, OQ208. 4. Cross-correlation bandpass plots were generated for all baselines to EB for scans on J1241, J1234, J0927, OQ208. 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 EM035B can be found at: /home/aspen6/astronomy/nov99/em035b/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: 8420-8430 NOTES: WB: Observed the wrong frequency, it wasn't correlated. TR: Used Mk III 1-bit; not correlated. CM: IFs 1 and 4 were dead for the whole observation. Also, this station missed a scan at 22:00, for reasons unknown. There is a large bandpass edge spike in IF 8, for the whole observation. No fringes were seen to this station until 16:18. Also, the amplitude scale in the apd plot is negative. ON: IF 5 is dead until 16:30. There was some poor recording in spots. RFI is in IFs 1 and 2 starting at 18:01 UT, and it seems to come and go. EB: Wts are diminished on the reverse passes until 3:30 UT (tape change is at 3:50 UT). There was some isolated RFI in IFs 3 and 4 at 21:55 UT. JB: There was some poor playback on the forward passes from 18:00 to 21:15 UT. There was strong RFI in IFs 1-3, 7, and 8 for the whole observation. This was strong enough to come through the cross-correlation plots. IF 7 (at 16:18 UT) and IF 5 (at 5:04 UT) both have unusually low amplitudes, continuing until the end of the observation. There were no fringes seen until 16:36 UT. There was a scan missed at 22:00 UT. NT: Playback was good but scans were missed at these times: 22:00 and 3:50 UT. There were bandpass edge spikes in the even IFs. MC: Playback was good, but there was strong RFI which drifts between IFs 3 to 6 over the course of the whole observation. RO: Playback was good, RFI is severe in BBC 8, also seen in the cross-correlation plots. From analysts@aoc.nrao.edu Thu Jan 6 10:08:22 2000 Date: Wed, 5 Jan 2000 15:17:38 -0700 (MST) From: Data Analysts To: foley@nfra.nl, jive@jive.nl, kb@astro.uni.torun.pl, p062gra@mpifr-bonn.mpg.de, pwolken@jftl.jpl.nasa.gov, 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 Subject: P.I. Letter for EM035A. Dear PI, We have examined the data for project EM035A on 12 Nov. 1999. The contact person for this project was Geoffrey Bower/ 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/nov99/em035a/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 NT 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 EM035A can be found at: /home/aspen6/astronomy/nov99/em035a/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: 8320-8329 NOTES: CM: Track 2 and 28 dead; tape or recorder problem. IF channels 1 and 4 are dead; DC spike in channel 8. Occasional RFI in IF channel 3. No fringes fringes in channels 2, 7 and 8 due to limited bandwidth; non-linear fringe solutions in channels 3, 5, and 6. EB: Variable weights at 2:45-6:10 UT; weight vary between 80% - 100%. Occasional RFI in IF channels 1 - 4. JB: Track #4 dead at ~2:50 UT. RFI in IF channels 1 - 8; low amplitudes in IF channel 7 of autocorrelation plots and cross-correlation plots. MC: Slightly variable weights at 15:00-20:50 UT. RFI in all IF channels. Phase cals cross-correlating around 6:30 UT with NT. NT: In SEARCH and variable weights at 20:50-21:30 UT during correlation; slightly variable weights at 00:00-2:30 UT. RFI in IF channel 2. ON: RFI in IF channels 1 and 2 in auto-correlation plots. RO: Only has LCP, so all odd (RCP) IF channels are dead. RFI in IF channel 8. No data at 6:25-6:41 UT and 6:50-6:56 UT. TR: Was not correlated; observed in MKIII one-bit mode. WB: Was not correlated; observed different frequency From analysts@aoc.nrao.edu Mon Jan 10 10:17:20 2000 Date: Thu, 6 Jan 2000 09:05:23 -0700 (MST) From: Data Analysts To: agg@jb.man.ac.uk, apolatid@oso.chalmers.se, foley@nfra.nl, jive@jive.nl, kb@astro.uni.torun.pl, nektaria@dragoeiro.umn.pt, p062gra@mpifr-bonn.mpg.de, trigilio@ira.noto.cnr.it, tuccari@ira.noto.cnr.it, tventuri@astbo1.bo.cnr.it Subject: EG021 data Dear PI, We have examined the data for project EG021 on 15 Nov. 1999. The contact person for this project was L. Kogan. 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/nov99/eg021/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 J1649, OQ208, J1642. 4. Cross-correlation bandpass plots were generated for all baselines to EB for scans on J1649, OQ208, J1642. 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 EG021 can be found at: /home/aspen6/astronomy/nov99/eg021/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: 7920-7923 NOTES: CM: IFs 1 and 2 are dead for the whole observation. There are RFI spikes in IFs 3 and 4, strong enough to come through the cross-correlation plots. The fringes in the cross-correlation plots are not linear. WB: The recording at this station produced very low wts. No fringes were seen to this station; poor recording seems to be the problem. NT: The first hour (until 8:30 UT) of recording produced shaky wts, after this time, everything looks good. There are bandpass edge spikes in IFs 2 and 4. JB: Playback was good. There is RFI in IF 1 for the whole observation, and IF 4 starting at 11:39 UT. IF 3 has an unusually low amplitude. This RFI is strong enough to come through the cross-correlation plots. Also, no fringes were seen at these times: 11:35 and 11:39 UT (see feedback printout), as well as at 18:18. EB: OK MC: RFI was seen at this station at these times: 11:34 UT (IFs 2-4) until 14:29 UT when they appear in IFs 1 and 2, and finally in IFs 1-3 at 14:46 UT. Only the RFI in IFs 1 and 2 come through the cross-correlation plots at 17:33 UT. ON: OK TR: Observed Mk III 1-bit mode, not correlated. From analysts@aoc.nrao.edu Tue Jan 11 11:03:38 2000 Date: Mon, 10 Jan 2000 15:43:21 -0700 (MST) From: Data Analysts To: agg@jb.man.ac.uk, apolatid@oso.chalmers.se, jive@jive.nl, kb@astro.uni.torun.pl, p062gra@mpifr-bonn.mpg.de, tventuri@astbo1.bo.cnr.it, vincent@oso.chalmers.se Subject: EM033A data Dear PI, We have examined the data for project EM033A on 29 Nov. 1999. The contact person for this project was J. 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/nov99/em033a/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 J1743,J2002,J2322,DA193,W48,CEPA. 4. Cross-correlation bandpass plots were generated for all baselines to JB for scans on J1743,J2002,J2322,DA193,W48,CEPA. 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 EM033A can be found at: /home/aspen6/astronomy/nov99/em033a/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: 9520-9522, 9526-9528 NOTES: EB: The focus-drive failed at about 2:30 UT, refer to the experiment feedback printout for more information. The last few minutes of data at this station had poor playback. No line structure was seen to CepA at 7:47 UT, probably related to the focus- drive failure. JB: There was no data produced until 21:30, though this station was scheduled to start at 16:00 UT; the reason for this is unknown. MC: Playback was good. The only anomoly was that there was no line structure seen to CepA at 1:29 UT. ON: There was some diminished playback at these times (UT): 22:00- 23:45, 00:20-3:15, 6:00-7:45. There is a large bandpass edge spike in IF 1 at 22:46 UT. TR: The playback is poor, hovering around 0.50. IF 1 is dead at 5:34 and 6:51 UT. Otherwise, IF 1 is pretty noisy. This poor playback seems to have reduced the useful data significantly. From analysts@aoc.nrao.edu Tue Jan 11 11:03:43 2000 Date: Mon, 10 Jan 2000 16:31:49 -0700 (MST) From: Data Analysts To: agg@jb.man.ac.uk, foley@nfra.nl, jive@jive.nl, p062gra@mpifr-bonn.mpg.de, pdiamond@jb.man.ac.uk Subject: GD013 data Dear PI, We have examined the data for project GD013 on 14 Nov. 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/nov99/gd013/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 OH127.8, 3C84, 3C454.3. 4. Cross-correlation bandpass plots were generated for all baselines to NL for scans on OH127.8, 3C84, 3C454.3. 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 GD013 can be found at: /home/aspen6/astronomy/nov99/gd013/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: 3020-3026 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: WB: Recording was poor at this telescope. The sources after 3:38 UT are below the horizon (except 3C84 at 3:38), though the tapes keep rolling. Dead IFs are evident over the course of the observation. There is a large spike in IF 1 at 22:37, IF 2 at 2:49 UT. IF2 also has a rough bandpass at 3:26. Data gets pretty noisy after 3:45 UT. MK: Poor recording causes shaky weights from 00:00 to 4:00 UT, and again at 6:30 to 6:55 UT. OV: A couple of rough spots in recording: 00:00 to 00:45, 2:15 to 3:30, and 5:15 to 6:55 UT. BR: Playback was good, but there were rough bandpasses in all IFs at 5:16 UT. General comments on RFI: These stations had RFI: PT (19:11 UT), SC (19:11, 5:42), JB (severe for the whole observation), FD (20:57), KP (1:43), LA (2:46, 5:42). No line structure was on the NL-MK baseline at 1:48 and 6:31 UT. No line structure was seen to all telescopes (except SC and HN) to OH127 at 19:11 and 00:08 UT. There was a wide spread of delays between stations and IFs, probably due to the narrow baseband filters. From vlbiobs@aoc.nrao.edu Wed Jan 12 09:44:26 2000 Date: Tue, 11 Jan 2000 14:38:50 -0700 (MST) From: VLBI Observers To: foley@nfra.nl, jive@jive.nl, p062gra@mpifr-bonn.mpg.de, tuccari@ira.noto.cnr.it, vlbi@oso.chalmers.se, ylva@oso.chalmers.se Subject: GP024 Summary Dear PI, We have examined the data for project GP024 on 17 Nov. 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/nov99/gp024/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 3C147, J0921+62, 4C39.25, 3C273, 3C279, OQ208 and 3C345. 4. Cross-correlation bandpass plots were generated for all baselines to EB & Y for scans on 3C147, J0921+62, 4C39.25, 3C273, 3C279, OQ208 and 3C345. 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 GP024 can be found at: /home/aspen6/astronomy/nov99/gp024/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: 2920-2923, 2950, 2925-2934; Pass 2: 2935-2949 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: Not used. Secured for hurricane Lenny. HN: RFI(?) at 12:32 UT. Odd pcal counts on ch. 3 & 4. NL: OK. FD: OK. LA: RFI in IF's 1 & 3 throughout observing. PT: OK. KP: No pcals after 12:00 UT. OV: Small ripples in weights 10:30 - 18:00 UT. BR: OK. MK: OK. Y : Strong RFI at 12:32 UT. Part of bandpass is outside Y tuning capability. EB: Strong RFI throughout observing. ON: RFI at 12:32. WB: Tape degaussed prior to correlation. From analysts@aoc.nrao.edu Tue Jan 25 09:10:36 2000 Date: Thu, 13 Jan 2000 17:14:46 -0700 (MST) From: Data Analysts To: agg@jb.man.ac.uk, apolatid@oso.chalmers.se, jive@jive.nl, kb@astro.uni.torun.pl, p062gra@mpifr-bonn.mpg.de, phillips@jive.nfra.nl, tventuri@astbo1.bo.cnr.it Subject: EP028 data Dear PI, We have examined the data for project EP028 on 30 Nov. 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/nov99/ep028/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 J1830, J1743, J2334, G34.24+0.13. 4. Cross-correlation bandpass plots were generated for all baselines to EB for scans on J1830, J1743, J2334, G34.24+0.13. 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 EP028 can be found at: /home/aspen6/astronomy/nov99/ep028/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: 9120-9125 NOTES: EB: Playback was OK, there were a couple of scans where no line structure was seen to G34: 15:24, 17:15, and 18:00 UT. JB: The telescope was stowed from 14:38 to 19:00 UT, also the first two scans were not recorded properly. The lack of line structure for the 14:59 scan of G34 bears this out. MC: Playback was good, but there were some tracking problems during the observation. The exact times for these are not known. There is a spike in IF 1 at 18:45 UT. ON: The observation ends early (at 11:30 UT) due to high winds. There are two small spikes (one in each IF) at about the center of the bandpass during the observation at this station. TR: Recording was poor, IF 1 is dead at times (16:07 and 17:30 UT). When IF 1 is there, it is noisy, with no fringes until 10:51 UT. At 11:33 UT IF 2 gets noisy, with no fringes until 13:04 UT. Also worth noting is a small spike in IF 2 for the whole observation, and a large bandpass edge spike in IF 1 starting at 14:03 UT, continuing until the end of the observation. From analysts@aoc.nrao.edu Tue Jan 25 09:10:54 2000 Date: Tue, 18 Jan 2000 14:40:23 -0700 (MST) From: Data Analysts To: foley@nfra.nl, jive@jive.nl, 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, vlbiro@zia.aoc.NRAO.EDU Subject: GB035A P.I. Letter Dear PI, We have examined the data for project GB035A on 28 Sep. 1999. The contact person for this project was Michael Rupen. Here's a summary: 1. Tape weights vs. time plots have been generated for the entire time range of your experiment. These are a measure of tape record/playback quality, representing the fraction of valid data samples. Data with weights below 70-75% should be flagged. However, you may want to be more cautious when dealing with non-VLBA stations. The easiest way to estimate the best weight threshold is by looking at the tape weights vs. time plots generated here. You can find the weights plots at /home/aspen6/astronomy/sep99/gb035a/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, J0927+39, J1407+28, and J1642+39. 4. Cross-correlation bandpass plots were generated for all baselines to HN for scans on M81, 0954+658, J0927+39, J1407+28, and J1642+39. 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 GB035A can be found at: /home/aspen6/astronomy/sep99/gb035a/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: 8920 - 8937, Pass 2: 8940 - 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: VLBA Stations SC: RFI at 1675 MHz USB seen in autocorrelation plots of the first correlation pass. No fringes on SC baseline after ~10:49 UT since the antenna was stowed due to a power problem. HN: Diminished weights at 10:00 - 14:00 UT; weights at 90%. NL: RFI at 1675 MHz USB seen in autocorrelation plots. FD: Slightly variable weights at 7:30 - 11:15 UT in first correlation pass. LA: RFI at 1675 MHz USB seen in autocorrelation plots. PT: Minimal RFI at 1675 MHz USB seen in autocorrelatio plots. KP: RFI at 1675 MHz USB seen in autocorrelation plots. OV: Variable weights at 7:30 - 11:30 UT in second correlation pass; weights vary between 20%-100%. RFI at 1675 MHz USB seen in autocorrelation plots. BR: Variable weights in first correlation pass at 18:17-18:40 UT; then no weights until end of observation. In correlation pass two, weights are variable at 8:10 - 8:20 UT, 8:45 - 9:00 UT, and 18:15 - 19:00 UT; weights vary between 0% - 100%. RFI at 1660 MHz USB seen in autocorrelation plots. MK: RFI at 1675 MHz USB seen in autocorrelation plots. Non-VLBA stations VLA27: RFI at 1675 MHz USB seen in autocorrelation plots. Variable weights at 7:30 - 8:45 UT in second correlation pass; weights vary between 80% - 100%. EB: OK JB: Variable weights at 7:30 - 8:00 UT in second correlation pass; weights vary between 20% - 50%. RFI in all IF channels seen in autocorrelation plots. Low SNR at 14:00 - 15:00 and 9:50 - 11:05 UT in amplitude/phase/delay plots. MC: Variable weights at ~8:15 - 11:10 UT in first correlation pass; weights vary between 0% - 100%. RFI at 1660 MHz LSB and 1675 MHz USB seen in autocorrelation plots. NT: Variable weights at 7:30 - 8:00 UT in both passes; weights vary between 0% - 100%. ON: Lost vacuum at site at 10:00 - 10:20 UT. RO: RFI at 1660 MHz USB seen in autocorrelation plots. No fringes in RCP channels; RO only has LCP at L-band. WB: Poor weights in first correlation pass; weight near 0% at beginning, then vary between 30% - 75% until 13:00 UT, then vary around 90% until the end of observation; tape was moved with no improvement. Variable weights during second correlation pass at 7:30 - 13:00; weights vary between 80% - 100%. IF channels 5 and 6 are missing during first part of run due to poor weights. No fringing near end of observation due to source beyond antenna limits. From analysts@aoc.nrao.edu Tue Feb 1 10:19:28 2000 Date: Mon, 31 Jan 2000 08:43:08 -0700 (MST) 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, trigilio@ira.noto.cnr.it, tuccari@ira.noto.cnr.it, tventuri@astbo1.bo.cnr.it Subject: PI letter for EP032 Dear PI, We have examined the data for project EP032 on 18 Nov. 1999. The contact person for this project was Jim Ulvestad. 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/nov00/ep032/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 NT 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 EP032 can be found at: /home/aspen6/astronomy/nov00/ep032/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: 8654-8675 NOTES: General - Comments on telescope performance provided by the stations are in the EVN Experiment Feedback form, and not repeated here. Note that Effelsberg was out for most of the observation. Several stations had abysmal recording. Notes on the recording will be included below. We occasionally tried changing playback drives with no success, but did not make heroic efforts to recover data. The recording problems meant that some/most IFs were often/always dead. NT - In search for first 50 minutes, 2200-2250. DC spikes in most channels. WB - Abysmal recording, typical weigths in the 20% range. This resulted in Channel 1 always being dead, and channels 2 and 3 often being dead. CM - Tracks 2 and 28 dead, typical weights around 75%. This resulted in Channels 1 and 4 often being dead. Significant phase curvature vs. frequency in individual IFs. JB - Poor weights on forward passes, no improvement from moving tape. Channel 3 has low amplitude at 1641.99 MHz. RFI spike in IF 4. TR - Observed in 1-bit mode, not correlated. MC - Substantial RFI problems, showing up in both auto- and cross-correlation. Good recording. ON - Good recording. EB - Out due to snow for all but 1.5 hours. Fringes - NT, WB, MC, CM, JB show fringes to DA193. Channels depend on recording. Weak fringes can be seen on the phase-ref source J0830+2410 when the IF channels work. From clewis@cv3.cv.nrao.edu Mon Mar 6 14:30:29 2000 Date: Thu, 02 Mar 2000 16:55:53 -0700 From: Craig Lewis To: emily@jb.man.ac.uk Cc: jive@jive.nfra.nl, p062gra@mpifr-bonn.mpg.de, agg@jb.man.ac.uk, vlbi@jb.man.ac.uk, foley@nfra.nl Subject: PI Letter GX006 [ Part 2: "Attached Text" ] Dear PI, We have examined the data for project GX006 on 12 Feb. 2000. 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/feb00/gx006/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 NL 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 GX006 can be found at: /home/aspen6/astronomy/feb00/gx006/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- 5228 Automated Calibration Transfer for VLBA Correlator Output --------------------------------------------------------- The first phase of automated calibration transfer for data from the VLBA correlator has been completed, and was used for your observation. This transfer of calibration information includes data from the 10 VLBA antennas, as well as selected information from the VLA, Green Bank, and Effelsberg, which currently provide VLBA-style monitor data. Significant changes to AIPS have been required to introduce calibration transfer, so users must have the patched version of 15OCT98 AIPS, or any later version, beginning with 15APR99. Help files for a number of AIPS tasks have been updated to reflect the new calibration procedures. There also is a new version of the VLBI chapter of the AIPS cookbook, available from http://www.cv.nrao.edu/aips/aipsdoc.html, that includes more details on how to cope with the calibration transfer process. The calibration-transfer process relieves observers of the burden of creating and inputting calibration files for VLBA antennas. Instead, this information is now provided as tables attached to the FITS data sets output by the VLBA correlator. The ancillary data include antenna gain (GC table), system temperature (TY table), pulse calibration (PC table), flags (FG table), and weather (WX table). The wise observer will not modify these original tables; processing errors might then force the data to be reloaded using FITLD. See the description of MERGECAL in Section 9.2.1.7 of the new cookbook chapter for more detail. Of course, skeptical users can simply delete the appropriate tables created by FITLD and generate their tables in the old manner. Phase 2 of calibration transfer will include supply of data from more external telescopes, and probably will proceed incrementally, depending on both the availability of the external information and the implementation of new software in Socorro. At present, ancillary data from most external telescopes must still be loaded in the old manner, and observations of strong sources may be needed for manual pulse calibration at those telescopes. Up-to-date instructions on coping with observations including external telescopes can be found at http://www.nrao.edu/vlba/html/OBSERVING/cal-transfer/cal-transfer.html. Please send comments on calibration transfer to julvesta@nrao.edu, and send bug reports to daip@nrao.edu, with a copy to julvesta@nrao.edu. NOTES: JB has sync. trouble and is in stall, but according to the operator, the telescope is stowed due to high winds for most of the experiment. BR, KP, WB, EB have diminished weights. When the sources are up above the horizon mask, and the weights are good, there are fringes on all baselines throughout the experiment except for JB which is mostly stowed as mentioned above. LA has very strong RFI; especially in IFs 1 and 4. [ 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 GX006 on 12 Feb. 2000. 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/feb00/gx006/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 NL 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 GX006 can be found at: /home/aspen6/astronomy/feb00/gx006/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- 5228 Automated Calibration Transfer for VLBA Correlator Output --------------------------------------------------------- The first phase of automated calibration transfer for data from the VLBA correlator has been completed, and was used for your observation. This transfer of calibration information includes data from the 10 VLBA antennas, as well as selected information from the VLA, Green Bank, and Effelsberg, which currently provide VLBA-style monitor data. Significant changes to AIPS have been required to introduce calibration transfer, so users must have the patched version of 15OCT98 AIPS, or any later version, beginning with 15APR99. Help files for a number of AIPS tasks have been updated to reflect the new calibration procedures. There also is a new version of the VLBI chapter of the AIPS cookbook, available from http://www.cv.nrao.edu/aips/aipsdoc.html, that includes more details on how to cope with the calibration transfer process. The calibration-transfer process relieves observers of the burden of creating and inputting calibration files for VLBA antennas. Instead, this information is now provided as tables attached to the FITS data sets output by the VLBA correlator. The ancillary data include antenna gain (GC table), system temperature (TY table), pulse calibration (PC table), flags (FG table), and weather (WX table). The wise observer will not modify these original tables; processing errors might then force the data to be reloaded using FITLD. See the description of MERGECAL in Section 9.2.1.7 of the new cookbook chapter for more detail. Of course, skeptical users can simply delete the appropriate tables created by FITLD and generate their tables in the old manner. Phase 2 of calibration transfer will include supply of data from more external telescopes, and probably will proceed incrementally, depending on both the availability of the external information and the implementation of new software in Socorro. At present, ancillary data from most external telescopes must still be loaded in the old manner, and observations of strong sources may be needed for manual pulse calibration at those telescopes. Up-to-date instructions on coping with observations including external telescopes can be found at http://www.nrao.edu/vlba/html/OBSERVING/cal-transfer/cal-transfer.html. Please send comments on calibration transfer to julvesta@nrao.edu, and send bug reports to daip@nrao.edu, with a copy to julvesta@nrao.edu. NOTES: JB has sync. trouble and is in stall, but according to the operator, the telescope is stowed due to high winds for most of the experiment. BR, KP, WB, EB have diminished weights. When the sources are up above the horizon mask, and the weights are good, there are fringes on all baselines throughout the experiment except for JB which is mostly stowed as mentioned above. LA has very strong RFI; especially in IFs 1 and 4. ________________________________________________________________________________ Craig Lewis Orbiting Very Long Baseline Interferometry Data Analyst