Modifications: 980924 nrv Modified to add tape speed to mode table. 980927 nrv Removed references to barrel roll. Added barrel roll to mode table. 980928 nrv Add Gg to list of stations starting at 13:30. ************************************************************************** **** This session has a DIFFERENT SETUP from other RDV sessions. **** **** Non-VLBA stations please read the "Recording Mode" section. **** ************************************************************************** RDV11 (Astrometric/Geodetic VLBA-11) 1998 October 1 Notes prepared by Nancy Vandenberg, NVI/GSFC Schedule name: rdv11.skd Pointing files: rdv11crd.br, rdv11crd.fd, rdv11crd.hn, rdv11crd.kp, rdv11crd.la, rdv11crd.mk, rdv11crd.nl, rdv11crd.ov, rdv11crd.pt, rdv11crd.sc on aspen in directory /home/aspen6/astronomy/oct98/rdv11 PCFS file: rdv11.skd on cddisa in directory oct98 or via http://lupus.gsfc.nasa.gov/sess/sesshtml/rdv11.html Nominal Start: 14:00 U.T. on October 1 (day 274) first observation at 13:30 U.T. on 1803+784 for Br-Fd-Gc-Hn Kp-La-Mk-Nl-Ov-Pt-Sc-Wf-Gg first observation at 14:00 U.T. on 0955+476 for Kk-Mc-Ny-On first observation at 18:04 U.T. on 1145-071 for Gn Duration: 24 hours + 1 hour extra for Gc-Gg-Wf-Nl-Br-Fd-Sc-Ov-Pt-Hn-Kp-La Nominal Stop: 14:00 U.T. on October 2 (day 275) last observation at 14:01 U.T. on 4C39.25 for Br-Fd-Gc-Hn Kk-Kp-La-Mc-Mk-Nl-Ny-On-Ov-Pt-Sc-Wf last observation at 14:21 U.T. on 1044+791 for Br-Fd-Gc-Hn- La-Nl-Gg-Pt-Wf Correlator: VLBA (first), following which a subset will be processed at WACO Summary file for correlator: rdv11.sksum on aspen Stations: 18 Station Codes # of tapes # of obs Occupation Code Brewster B Br 0.5 (TT) 265 76149901 Fort Davis D Fd 0.5 (TT) 283 76139801 Gilcreek A Al 0.6 (TT) 242 40476601 Hancock H Hn 0.6 (TT) 250 76185001 Kokee K Kk 0.7 (TT) 262 72983001 Kitt Peak L Kp 0.5 (TT) 276 76109401 Los Alamos M La 0.5 (TT) 278 76119601 Medicina C Mc 0.4 (TT) 211 72308801 Mauna Kea N Mk 0.6 (TT) 267 76175501 North Liberty O Nl 0.5 (TT) 272 76129701 Green Bank 20m P Gn 0.5 (TT) 224 72484701 Ny Alesund Q Ny 0.5 (TT) 226 73313301 Onsala T On 0.7 (TT) 224 72137701 GGAO (MV3) Z Gg 0.7 (TT) 225 71085301 Owens Valley R Ov 0.7 (TT) 269 76165401 Pie Town S Pt 0.7 (TT) 283 72348601 St. Croix E Sc 0.7 (TT) 253 76159001 Westford F Wf 0.8 (TT) 256 72097301 Special notes on tape usage: - This experiment uses THIN TAPES ONLY at all stations. - All stations use less than one tape. - The VLBA stations will NOT use dynamic tape allocation for this session. - Tape motion will be the usual START&STOP (NOT continuous). - Gn will record the intensive and then join the experiment at 1800 UT. - Most VLBA stations record the two initial MV3 fringe finding scans along with Fairbanks and Westford. These stations also record two final long scans. Purpose ======= This is the fifth of six bi-monthly coordinated astrometric/geodetic experiments in 1998 that use the full 10-station VLBA plus the 8 geodetic stations currently capable of recording VLBA modes. This year's series is a continuation of the highly successful series in 1997. These experiments are being coordinated by the geodetic VLBI programs of three agencies: USNO, NASA, and NRAO. The experiments have been designed so that the same data set may be used by each agency for its particular goals. USNO will perform repeated imaging and correction for source structure. These sources will establish a set of core reference sources with known structure and precisely known positions. These data will provide the basis for evaluating the long term stability of the radio reference frame and the ultimate accuracy of wide angle astrometric measurements of extragalactic radio sources using VLBI. NASA will analyze this data to determine a high accuracy terrestrial reference frame. The data will incorporate the VLBA stations into the VLBI reference frame through the inclusion of other geodetic stations for which we have long histories. The data will also produce the most accurate Earth rotation results ever produced. We will use these data to make accurate absolute measurements of UT1. NRAO will use these sessions to provide a service to users who require high quality positions for small numbers of sources. While the quality of these results will be high, the observing and data reduction overhead required will be minimal because such sources can be incorporated into a session of the regular geodetic observations, instead of requiring special observations. Sources for this series of experiments will be selected using the proposed approach. For each experiment we will select a set of 70-80 sources out of the pool of ~400 Northern Hemisphere ICRF sources. About 40-50 of these will remain the same from experiment to experiment and will be chosen to optimize the goals of the three groups. Schedule ======== This is a new schedule generated by Marshall Eubanks using the 9809 version of the NASA sked program. "Requested" Sources in RD-V11 : NONE Yearly (Y), ROTATING & NEW (N) SOURCES FOR RD-V11 | 0106+013 | | 0440+345 | | 0521-365 | | 0814+425 | | 0954+658 | | 1038+528 1038+52A | Y | 1219+044 | | 1222+037 | Y | 1300+580 | | 1354+195 | | 1508+572 | | 1633+382 1633+38 | | 1807+698 3C371 | | 1937-101 | | 2007+777 | | 2253+417 | Due to the on-going attempts to check out and debug the VLBA correlator and the AIPS data processing system, this session will be recorded in a mode which can also be correlated using a MARK III-A correlator. In view of this, the schedule was intended to be somewhat conservative. No "New" sources were observed, and only 16 well-observed sources from the larger VLBA + NEOS source list were included in the source rotation. The same criteria were used for generating this schedule as were used during the first year of these sessions. The criteria for sources to be mapped are a minimum of 3 scans and 135 observations. These criteria are relaxed for sources below -25 degrees declination. Most of the sources in this schedule meet the mapping criteria. The schedule was made using a combination of automatic selection plus manual scheduling to improve the coverage of the sources. Automatically scheduled scans were selected first on their improvement of sky coverage in the previous 1 hour, and then the best 60% were evaluated for the minor options: minimize idle time, minimize slewing time, and maximize the number of observations. An individual source was not observed more often than every 90 minutes. All scans have an early start of 30 seconds. The minimum scan length was 40 seconds. Due to its low sensitivity, MV3 was not included directly into the schedule because the necessarily longer scan lengths would have compromised the experiment results. Instead, after the schedule was made, MV3 was tagged along to the schedule. In the tagalong mode, MV3 observes with the longest scan duration of all the stations participating in each scan, to maximize SNR. MV3 will make fringes on about 2/3 of the observations in which it participates. This amount of data will allow a good determination of MV3's position in the reference frame. ** NEW ** Recording Mode and Frequencies ** NEW ** ============================================================ This session will be processed at both Socorro and Washington to compare outputs from the two correlators. The purpose of the comparison is to address questions about the ultimate precision of the results. In order for data to be processed at both the VLBA and the Mark IIIA correlators, we have to use a compatible recording mode. The data will be recorded as shown below. There is no VLBA correlator speedup. The recording mode is essentially a double-speed 8-channel Mode E. Number of channels 8 Sample rate 8 MHz Video bandwidth 4 MHz Sampling 1-bit Fan-out none Number of tape passes per head position 4 Total number of tape passes 56 Tape speed 160 ips Barrel roll none This recording mode has been agreed to by both correlators and test tapes have been recorded and checked out at Socorro and at Washington. The frequency sequence covers 490 MHz in 8 channels. This span fits in one VLBA receiver passband but it uses both the high and low parts of the geodetic receivers. Because only 8 channels are available when observing with the VLBA stations, a wider spanned bandwidth is not advisable. These tables list the setup for the VLBA stations, the geodetic stations with VLBA back ends, and the geodetic stations with Mark IV back ends. These are the SAME frequencies used in previons RDV sessions. Geodetic stations: please read the special procedures in the next section! VLBA | Fairbanks | Kokee, GB Chan Sky LO IF BBC | LO IF BBC | LO IF BBC 1 X 8405.99 7900 B 505.99| 7600.1 B 805.89| 7600 B 805.99 2 X 8475.99 7900 B 575.99| 7600.1 B 875.89| 7600 B 875.99 3 X 8790.99 7900 B 890.99| 8080.0 C 710.99| 8100 C 690.99 4 X 8895.99 7900 B 995.99| 8080.0 C 815.99| 8100 C 795.99 5 S 2220.99 2900 A 679.01| 1540.1 A 680.89| 1500 A 720.99 6 S 2240.99 2900 A 659.01| 1540.1 A 700.89| 1500 A 740.99 7 S 2330.99 2900 A 569.01| 1540.1 A 790.89| 1500 A 830.99 8 S 2360.99 2900 A 539.01| 1540.1 A 820.89| 1500 A 860.99 Onsala, Medicina, VLBA | Westford, MV3, Ny Alesund Chan Sky LO IF BBC | LO IF VC VC# Patch 1 X 8405.99 7900 B 505.99| 8080.0 1 325.99 3 H 2 X 8475.99 7900 B 575.99| 8080.0 1 395.99 4 H 3 X 8790.99 7900 B 890.99| 8580.1 3 210.89 5 L 4 X 8895.99 7900 B 995.99| 8580.1 3 315.89 6 H 5 S 2220.99 2900 A 679.01| 2020.0 2 200.99 9 L 6 S 2240.99 2900 A 659.01| 2020.0 2 220.99 10 L 7 S 2330.99 2900 A 569.01| 2020.0 2 310.99 13 H 8 S 2360.99 2900 A 539.01| 2020.0 2 340.99 14 H Procedures ========== This session will be recorded sith START&STOP tape motion. A parity check is done after the first scan of each pass. The tape will start moving 30 seconds before the nominal start of the scan. Procedures for Non-VLBA Stations ================================ You must use drudg to generate the procedures for this session. Do NOT use the procedures from previous RDV sessions. Please take the time to check out these procedures since we have not used this recording mode for RDV sessions. There are only 8 tracks recorded per tape pass, and a different group is recorded in each of 4 subpasses per head position. Parity check procedures named check2m1/2 are invoked in the SNAP file. You can use parity check procedures that check all tracks and ignore the errors found for tracks that were not recorded. Special procedures for Onsala, Medicina, Westford, MV3, Ny Alesund ================================================================== Onsala, Medicina, Westford, MV3, and Ny Alesund have Mark IV formatters. This is still a non-standard setup. There are 8 video converters used: 3, 4, 5, 6, 9, 10, 13, and 14. These were selected so that you will NOT have to change the standard geodetic IF patching. The 6 unused VCs 1, 2, 7, 8, 11, and 12 should be set to frequencies which do not occur in any of the passbands. Any value in the 100-200 MHz range is OK. The IF3 command in the procedure IFDSX assumes that VC3 will be patched to High. Please verify that the switches for your IF3 module are wired this way, and if they are not please edit the IF3 command to change the switches. If you have questions about the wiring, please contact Brian Corey at Haystack. Special procedures for Fairbanks, Kokee, Green Bank =================================================== Fairbanks, Kokee, and Green Bank have VLBA back ends. You must swap your IF inputs so that BBCs 1-8 have the inputs shown in the table above. The unused BBCs 9-14 should be set to frequencies which do not occur in any of the passbands. Any value in the range 500-600 MHz is OK. CHECKLIST for non-VLBA stations =============================== Please follow the checklist below to ensure you have done all the necessary steps for this experiment: 1. Make .prc file with DRUDG and check them out. Check out parity check procedures. 2. Make .snp file and listings using DRUDG options 3 or 31 and 5. 3. Set up your system to monitor the clocks with the "gps-fmout" or "fmout-gps" commands, per Ed Himwich's messages. If you have questions or problems, please contact Ed as soon as possible. 4. Send a "ready" message an hour or so before the experiment to the ops mail list. Copy analysts@nrao.edu and pperley@nrao.edu on the message. 5. Send a "start" message soon after you have started recording. Copy analysts@nrao.edu and pperley@nrao.edu on the message. 6. At the end of the experiment, send a "finish" message summarizing how the experiment was conducted. Copy analysts@nrao.edu and pperley@nrao.edu on the message. 8. Transfer your log files ONLY to your normal log file data center. The directories for three possible servers are listed below: directory on cddisa: aug98 directory on astbo1: vlbi_arch/aug98 directory on aspen: /home/aspen6/astronomy/aug98/RDV11 Correlation =========== This experiment will be correlated initially at the VLBA Correlator. Tapes should be shipped to Socorro as soon after the experiment as practical. After correlation is finished at Socorro the tapes will all be shipped to the Washington Correlator, c/o Kerry Kingham. Summary ======= The following listing is a summary of the observations in this schedule. SKED Summary from file ../schedules/rdv11a.skd for experiment RDV11 (all scans with at least one subnet station) Average number of obs. per baseline per source (normalized by up-time) = 3.9 Min = .0 Max = 24.0 (Baseline Hn-Kp on 1451-375) RMS = 3.1 Total time: 1501 minutes ( 25.0 hours). Key: Br=BR-VLBA Fd=FD-VLBA Gc=GILCREEK Hn=HN-VLBA Kk=KOKEE Kp=KP-VLBA La=LA-VLBA Mc=MEDICINA Mk=MK-VLBA Nl=NL-VLBA Gn=NRAO20 Ny=NYALES20 On=ONSALA60 Gg=ORION_5M Ov=OV-VLBA Pt=PIETOWN Sc=SC-VLBA Wf=WESTFORD Br Fd Gc Hn Kk Kp La Mc Mk Nl Gn Ny On Gg Ov Pt Sc Wf Avg % obs. time: 30 31 35 28 43 31 30 20 33 29 29 32 46 44 30 31 29 50 33 % cal. time: 2 3 2 2 2 3 3 2 2 3 2 2 2 2 2 3 2 2 2 % slew time: 23 24 16 21 15 24 24 25 23 23 12 12 16 8 23 24 21 12 19 % idle time: 43 40 45 47 38 40 41 52 39 44 55 52 34 44 43 41 45 33 43 # of tapes : .5 .5 .6 1.5 .7 .5 .5 .4 .6 .5 .5 2.5 .7 .7 .5 .5 .5 .8 total # scans: 265 283 242 250 262 276 278 211 267 272 224 226 224 225 269 283 253 256 253 # scans/hour : 10 11 9 9 10 11 11 8 10 10 8 9 8 8 10 11 10 10 10.6 Avg scan (sec): 102 99 130 101 149 103 100 86 114 96 119 130 185 180 101 98 106 179 120 # OF OBSERVATIONS BY BASELINE | Br Fd Gc Hn Kk Kp La Mc Mk Nl Gn Ny On Gg Ov Pt Sc Wf StnTotal -------------------------------------------------------------------------------------- Br|265 238 209 216 171 233 248 122 184 243 177 154 124 160 238 245 193 199 3039 Fd| 283 183 218 177 262 262 116 192 252 196 140 121 172 244 269 223 215 2905 Gc| 242 187 155 184 193 130 166 192 144 168 132 143 186 189 151 172 3180 Hn| 250 133 207 225 137 146 231 192 154 129 177 199 223 207 218 3246 Kk| 262 183 169 74 246 161 125 114 99 125 188 175 130 143 3167 Kp| 276 255 111 198 242 184 138 115 159 251 263 207 204 3117 La| 278 125 186 257 197 151 123 171 247 271 214 210 2972 Mc| 211 75 128 108 162 175 116 104 121 127 127 2768 Mk| 267 175 136 111 91 124 206 192 137 148 3263 Nl| 272 198 149 128 178 233 261 216 220 2767 Gn| 224 122 101 144 176 195 181 179 2994 Ny| 226 182 135 132 146 129 149 3188 On| 224 134 110 123 121 137 2707 Gg| 225 153 171 172 188 3108 Ov| 269 252 190 192 2731 Pt| 283 216 215 2531 Sc| 253 208 3009 Wf| 256 2860 Number of 2-station scans: 68 Number of 3-station scans: 46 Number of 4-station scans: 38 Number of 5-station scans: 19 Number of 6-station scans: 18 Number of 7-station scans: 15 Number of 8-station scans: 14 Number of 9-station scans: 21 Number of 10-station scans: 18 Number of 11-station scans: 24 Number of 12-station scans: 21 Number of 13-station scans: 25 Number of 14-station scans: 30 Number of 15-station scans: 32 Number of 16-station scans: 35 Number of 17-station scans: 30 Number of 18-station scans: 30 Total # of scans, observations: 484 26783 Average baseline components for all observations Average XY = 3726. Average XZ = 3224. Average YZ = 2443. Average length = 3996.