Dear PI, We have examined the data for project RD000 on 21 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/rd000/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 0234+285, CTA26, 0528+134, 0552+398, OJ287, 4C39.25, OQ208 and 1803+784. 4. Cross-correlation bandpass plots were generated for all baselines to HN for scans on 0234+285, CTA26, 0528+134, 0552+398, OJ287, 4C39.25, OQ208 and 1803+784. 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 RD000 can be found at: /home/aspen6/astronomy/jun99/rd000/jobs. These files provided the correlator with all ancillary data needed for VLBI, including: correlation parameters and telescopes correlated in the final production. The job numbers are: 9020-9051 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: All Stations: RFI in channel 6 at S-band (13 cm). BR: OK FD: OK GC: Late start at site at 14:00 - 15:45 UT. HH: Weak on track #3 at 00:20-1:10 UT; weights at 90%. Stalled at 1:10-2:50 UT; no data. HN: OK KK: OK KP: RFI in all channels at S-band (13 cm). LA: Poor fringing and low pcal amplitudes in channel 7. MC: Severe RFI in all channels at S-band (13 cm). MK: OK NL: OK NY: In and out of sync at 13:45 - 14:00 UT. Some RFI in channel 5 of autocorrelation plots. ON: In and out of sync at ~17:00 - 22:00 UT. In SEARCH at 10:00 - 11:05 UT; the track was offset +168 microns for this tape pass compared to the normal offsets of the other passes. Weights are near 50% at 11:05 - 11:50 UT; a playback problem. In SEARCH again at 11:50 - 12:05 UT. Some poor fringing seen in channels 1 and 5 on tape 2 in the cross-correlation plots. OV: OK PT: RFI in channels 7 and 8 (13 cm) in autocorrelation plots. SC: OK TS: Weights near 0% at 1:00 - 2:00 UT; otherwise weights look good the rest of the run. WF: OK WZ: Out for intensive at 14:00 - 16:00 UT. Variable weights at 4:48 - 6:52 UT; weights vary between 75% - 95%.