From vlbiobs@aoc.nrao.edu Mon Jan 4 09:26:41 1999 Date: Mon, 21 Dec 1998 09:40:44 -0700 (MST) From: VLBI Observers To: vslysh@dpc.asc.rssi.ru Cc: agg@jb.man.ac.uk, apolatid@oso.chalmers.se, jive@RZMWS0.NFRA.NL, kb@astro.uni.torun.pl, p062gra@mpifr-bonn.mpg.de, tventuri@astbo1.bo.cnr.it Subject: ES026 Correlation Dear PI, We have examined the data for project ES026 on 16 Nov. 1998. The contact person for this project was Leonia 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/mmmyy/exp/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 GL2789, L1206, J0102+58, 3C286 and J2202+42. 4. Cross-correlation bandpass plots were generated for all baselines to MC for scans on GL2789, L1206, J0102+58, 3C286 and J2202+42. 5. Weather and Tsys plots for the VLBA antennas for your project will be sent with the data tape(s). NOTES: EF: Observed only LCP, no data in channel 2. ON: Weights drop to 80% periodically, no reason discovered. ALL: Spikes at 6GHz generally in both channels, sometimes pronounced at TR, may be RFI. MC: ok JB: ok TR: ok From analysts@aoc.nrao.edu Mon Jan 4 09:26:55 1999 Date: Mon, 21 Dec 1998 16:40:59 -0700 (MST) From: Data Analysts To: jive@RZMWS0.NFRA.NL Subject: EP023 PI Letter Dear PI, We have examined the data for project EP023 on 14 Nov. 1998. The contact person for this project was Chris Flatters. 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/nov98/ep023/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 J1800+3848, J2025+3343, J2202+4216, V645CYG, and ON2. 4. Cross-correlation bandpass plots were generated for all baselines to EF for scans on J1800+3848, J2025+3343, J2202+4216, V645CYG, and ON2. 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 EP023 can be found at: /home/aspen6/astronomy/nov98/ep023/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: 2720-2737 NOTES: JB: Weights start out bad (50%) with one dead channel, but improves around 9 UT. Noisy bandpass in autocorrelation plots. EF: Noisy bandpasses in autocorrelation plots. Weights are good. MC: Strange bandpasses in both BBCs. Complex bandpass calibration may be required. ON: RFI can be seen in both channels of the autocorrelation plots. TR: The LCP channel seems to be dead at Torun. Strong fringes are found in the RCP channel, so the polarization is not swapped. No fringes seen in the LCP channel. A little RFI evident near the bandpass edge in the autocorrelation plots. All stations: The rates in the delay/phase/rate plots all have a slope on correlated data tape #4. From analysts@aoc.nrao.edu Mon Jan 18 12:39:42 1999 Date: Wed, 13 Jan 1999 08:46:33 -0700 (MST) From: Data Analysts To: jive@RZMWS0.NFRA.NL Cc: agg@jb.man.ac.uk, foley@NFRA.NL, kb@astro.uni.torun.pl, p062gra@mpifr-bonn.mpg.de, trigilio@ira.noto.cnr.it, tventuri@astbo1.bo.cnr.it Subject: ED009-19NOV1998-CORR Dear PI, We have examined the data for project ED009 on 19 Nov. 1998. The contact person for this project was J. Hernstein. 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/nov98/ed009/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 EF 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 ED009 can be found at: /home/aspen6/astronomy/nov98/ed009/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: 9620-9623 NOTES: EF weights were slightly variable during the first five hours. JB field system was down until 15:05; weights were variable, down to 80% from 18:00 to about 19:30; MC weights were good throughout; present in the autocorrelation plots, in both channels, was a peculiar bandpass characteristic of elevated amplitudes through part of the spectrum. This characteristic was variable and intermittent through the plots. Effect on the data was not apparent. NT field system at wrong configuration until approximately 15:30; weights were good except at the beginning; TR weights good throughout, except 18:57-19:02 antenna off source WB weights were slightly variable, 90% to 100% during some forward passe From analysts@aoc.nrao.edu Wed Jan 20 12:50:09 1999 Date: Mon, 18 Jan 1999 15:42:26 -0700 (MST) From: Data Analysts To: agg@jb.man.ac.uk, apolatid@oso.chalmers.se, jive@RZMWS0.NFRA.NL, kb@astro, p062gra@mpifr-bonn.mpg.de, tventuri@astbo1.bo.cnr.it, uni.torun.pl@aoc.nrao.edu Dear PI, We have examined the data for project ED010 on 12 Nov. 1998. The contact person for this project was Jimmie Hernstein. 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/nov98/ed010/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 EF 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 ED010 can be found at: /home/aspen6/astronomy/nov98/ed010/jobs. These files provided the correlator with all ancillary data needed for VLBI, including: correlation parameters and telescopes correlated in the final production. The job numbers are: 2520-2521 NOTES: EF weights are good throughout; present in the autocorrelation plots are regular interval spikes that appear similar to pcal spikes JB playback is poor at the beginning to about 17:00, thereafter good; BBC 4 amplitude is approx. one quarter that of other BBC's; MC good weights throughout, excellent playback, no problems noted ON weights down approximately 10% from 17:30 to 19:00; 20% down from 23:30 to 01:00; other times good TR no data 17:30 to 17:47; all other times weights are good