rdv52 (Astrometric/Geodetic VLBA-52) 2005 August 24 Notes prepared by John Gipson, NVI/GSFC Revised: August 23, 2005 Schedule name: rdv52.skd Pointing files: rdv52crd.br, rdv52crd.fd, rdv52crd.hn, rdv52crd.kp, rdv52crd.la, rdv52crd.mk, rdv52crd.nl, rdv52crd.ov, rdv52crd.pt, rdv52crd.sc ftp://vlbiobs@aspen.nrao.edu/home/aspen6/astronomy/aug05/rdv52 Summary file for correlator: rdv52.sksum on aspen PCFS file: ftp://vlbigeo@cddisa.gsfc.nasa.gov/vlbigeo/aug05/rdv52.skd http://lupus.gsfc.nasa.gov/sess/2005/sesshtml/rdv52.html First observations: name yyddd-hhmmss Ap Br Fd Gc Hn Kp La Mk 0642+449 05236-180000| 300 300 300 300 300 300 300 300 | 1656+053 05236-180658| 300 | 0537-441 05236-180705| 300 | 0235+164 05236-180713| 300 300 | 0912+029 05236-180829| 300 300 300 300 | name yyddd-hhmmss Nl Gg Ov Pt Sc Tc Ts Wf 0642+449 05236-180000| 300 300 300 300 300 300 300 | 1656+053 05236-180658| 300 300 | 0537-441 05236-180705| 300 | 0235+164 05236-180713| 300 300 | 0912+029 05236-180829| 300 300 300 | Kokee and Wettzell start observing at 20:00:00, after the intensive. 0133+476 05236-200000| KK-Wetzell. Last Observations: name yyddd-hhmmss Ap Br Fd Gc Hn Kk Kp La Mk 0607-157 05237-173129| 135 66 229 73 76 109 | 1034-293 05237-173233| 40 52 | 0642+449 05237-173247| 40 | 0059+581 05237-174019| 300 300 300 300 300 300 300 300 300 | 1745+624 05237-174923| 300 300 300 300 300 300 300 | 3C371 05237-175445| 300 | 2209+236 05237-175606| 300 | 0434-188 05237-175616| 300 300 300 300 300 | name yyddd-hhmmss Nl Gg Ov Pt Sc Tc Ts Wf Wz 0607-157 05237-173129| 92 93 76 229 | 1034-293 05237-173233| 49 52 | 0642+449 05237-173247| 40 40 40| 0059+581 05237-174019|300 300 300 300 300 300 300| 1745+624 05237-174923|300 300 300 300 300 300 300 300| 3C371 05237-175445|300 300 300 | 2209+236 05237-175606| 300 300| 0434-188 05237-175616| 300 300 | ------------------------------------------------------------------- Key: Ap=ALGOPARK Br=BR-VLBA Fd=FD-VLBA Gc=GILCREEK Hn=HN-VLBA Kk=KOKEE Kp=KP-VLBA La=LA-VLBA Mk=MK-VLBA Nl=NL-VLBA Gg=ORION_5M Ov=OV-VLBA Pt=PIETOWN Sc=SC-VLBA Tc=TIGO Ts=TSUKUB32 Wf=WESTFORD Wz=WETTZELL Ap Br Fd Gc Hn Kk Kp La Mk Nl % obs. time: 36 75 74 66 75 65 73 73 65 74 % cal. time: 3 3 3 3 3 3 3 3 3 3 % slew time: 54 18 18 15 16 12 18 19 21 18 % idle time: 7 3 4 15 5 20 5 5 10 4 total # scans: 217 260 258 242 235 221 254 264 257 248 # scans/hour : 9.0 10.8 10.7 10.1 9.8 9.2 10.6 11.0 10.7 10.3 Avg scan (sec): 143 249 246 236 275 253 249 238 220 259 Total GBytes: 573 1167 1145 1047 1162 1020 1138 1130 1017 1155 Total GB(M5): 510 1037 1017 930 1033 907 1012 1004 904 1026 # of tapes : 2.1 2.4 2.4 2.6 2.4 2.0 2.4 2.4 2.4 2.4 tape (hhmm): 0510 0418 0418 0329 0418 0658 0418 0418 0421 0418 1628 1431 1431 1258 1431 0000 1431 1431 1431 1431 Gg Ov Pt Sc Tc Ts Wf Wz Avg % obs. time: 68 72 73 68 55 46 78 56 66 % cal. time: 2 3 3 2 1 3 2 2 3 % slew time: 5 18 19 15 3 12 8 5 17 % idle time: 23 6 4 13 41 39 10 36 14 total # scans: 201 257 265 207 85 253 190 154 226 # scans/hour : 8.4 10.7 11.0 8.6 3.5 10.5 7.9 6.4 9.4 Avg scan (sec): 295 244 238 284 556 156 356 314 266 Total GBytes: 1082 1127 1137 1059 865 725 1233 886 1037 Total GB(M5): 962 1002 1011 942 769 645 1096 788 922 # of tapes : 2.1 2.4 2.4 2.4 2.0 2.1 2.2 2.0 tape (hhmm): 0503 0418 0418 0418 0603 0519 0456 0728 1628 1431 1431 1431 0000 1652 1549 0000 Total number of tapes: 40.8 Total GBytes (M5) recorded: 16594.8 # OF OBSERVATIONS BY BASELINE | Ap Br Fd Gc Hn Kk Kp La Mk Nl Gg Ov Pt Sc Tc Ts Wf Wz StnTotal -------------------------------------------------------------------------------------- Ap|217 132 126 96 177 49 122 131 70 157 124 115 131 134 32 75 136 80 1887 Br| 260 197 168 143 113 199 210 143 191 127 215 211 105 33 124 105 63 2479 Fd| 258 125 139 104 233 239 132 191 122 206 248 127 57 89 106 54 2495 Gc| 242 105 108 131 137 119 125 101 143 133 68 14 166 84 88 1911 Hn| 235 56 138 148 76 179 134 130 144 161 39 74 173 105 2121 Kk| 221 115 109 207 87 60 127 112 39 34 133 44 29 1526 Kp| 254 242 141 190 116 220 246 113 51 93 103 53 2506 La| 264 135 203 128 222 255 122 52 98 112 60 2603 Mk| 257 111 75 156 141 55 40 152 57 26 1836 Nl| 248 132 181 198 145 45 88 133 82 2438 Gg| 201 116 124 100 33 70 122 61 1745 Ov| 257 220 102 44 112 96 49 2454 Pt| 265 119 52 98 109 58 2599 Sc| 207 59 39 134 79 1701 Tc| 85 2 42 18 647 Ts| 253 57 68 1538 Wf| 190 96 1709 Wz| 154 1069 Number of 2-station scans: 33 Number of 3-station scans: 121 Number of 4-station scans: 66 Number of 5-station scans: 43 Number of 6-station scans: 37 Number of 7-station scans: 35 Number of 8-station scans: 28 Number of 9-station scans: 25 Number of 10-station scans: 25 Number of 11-station scans: 37 Number of 12-station scans: 28 Number of 13-station scans: 26 Number of 14-station scans: 23 Number of 15-station scans: 19 Number of 16-station scans: 17 Number of 17-station scans: 2 Number of 18-station scans: 0 Total # of scans, observations: 565 17632 Special Notes for this session: - There was a problem with Wettzell in the original version of this schedule. The schedule was remade with Wettzell tagging along. This was done instead of regenerating the schedule because of the time constraints. - Most stations participate in two initial long (5-min) scans and a final 5-min scans. - GGAO was tagged along in the schedule - Wettzell and Kokee are absent from 18:30 to 20:30 because of the intensive. - IMPORTANT: Westford is scheduled as a Mark5 sessions. The synch time for the VLBA correlator using Mark5 is 25 seconds. Becuase of this, these stations will start taking data 25 seconds prior to the normal scan time. They will continue to take data between scans if the there is the gap is less than 25 seconds. - The fluxes use our most recent models. Two sources have no fluxes. These are assumed to have 0.3 Janskys over all baselines. Purpose ======= This is the 4th of six bi-monthly coordinated astrometric/geodetic experiments in 2005 that use the full 10-station VLBA plus up to 10 geodetic stations capable of recording VLBA modes. This year's series is a continuation of the highly successful RDV series begun 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 John Gipson using sked. In addition to the VLBA, the session also uses: Ap=ALGOPARK Gc=GILCREEK Hh=HARTRAO Gg=ORION_5M Ov=OV-VLBA Tc=TIGO Ts=Tsukuba Wz=WETTZELL SOURCE SELECTION There are a total of 100 sources in this session. 22 sources were chosen because they had not been observed recently in the RDVs. In addition there two requested source: 2250+194 Lebach. Observed regularly since RDV36 0358+040 Was requested by L. Petrov. This has been detected at K-band position, but has not been observed at X/S. The remaing 60 sources were chosen from the geodetic catalog to complement the sky distribution of the above sources. SCHEDULING ALGORITHMS This schedule also uses the "SRCEVN SQRT" mode. In the absense of any constraints, Sked will preferentially observe strong sources that have high visibility. This mode attempts to smooth out the number of observations per source. The VLBA stations routinely use automatic tape allocation and automatic tape reversal. Recording Mode and Frequencies: same as previous experiments ============================================================ The data will be recorded using the following setup: 8 channels 1:4 fan-out 16 MHz sample rate 1-bit sampling This recording mode is designated 128-8-1. The correlator speed-up factor is 2. The frequency sequence covers 500 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. With the 1:4 fanout at 16 MHz sample rate, all 32 tracks are recorded in one pass, so there will be 14 passes on a tape. Special note for sessions starting with RDV36: The S-band frequency sequence was increased by 7 MHz from RDV35. This was done to put the third S-band channel 7 MHz above the DARS band (2220-2245Mz.) 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 all the standard RDV sessions. Geodetic stations: please read the special procedures in the next section! VLBA Fairbanks Kokee Chan Sky Tracks LO IF BBC | LO IF BBC #| LO IF BBC # 1 X 8405.99 2, 4, 6, 8 7900 B 505.99| 7600.1 A 805.89 3|7600 A 805.99 3 2 X 8475.99 10,12,14,16 7900 B 575.99| 7600.1 A 875.89 4|7600 A 875.99 4 3 X 8790.99 18,20,22,24 7900 B 890.99| 8080.0 C 710.99 5|8100 C 690.99 5 4 X 8895.99 26,28,30,32 7900 B 995.99| 8080.0 C 815.99 6|8100 C 795.99 6 5 S 2232.99 3, 5, 7, 9 2900 A 667.01| 1540.1 B 692.89 9|1500 B 732.99 9 6 S 2262.99 11,13,15,17 2900 A 637.01| 1540.1 B 722.89 10|1500 B 762.99 10 7 S 2352.99 19,21,23,25 2900 A 547.01| 1540.1 B 812.89 13|1500 B 852.99 13 8 S 2372.99 27,29,31,33 2900 A 527.01| 1540.1 B 832.89 14|1500 B 872.99 14 VLBA | Tsukuba Chan Sky Tracks LO IF BBC | LO IF BBC # 1 X 8405.99 2, 4, 6, 8 7900 B 505.99| 7680 A 725.99 3 2 X 8475.99 10,12,14,16 7900 B 575.99| 7680 A 795.99 4 3 X 8790.99 18,20,22,24 7900 B 890.99| 8080 A 710.99 5 4 X 8895.99 26,28,30,32 7900 B 995.99| 8080 A 815.99 6 5 S 2232.99 3, 5, 7, 9 2900 A 667.01| 1600 B 632.99 9 6 S 2262.99 11,13,15,17 2900 A 637.01| 1600 B 662.99 10 7 S 2352.99 19,21,23,25 2900 A 547.01| 1600 B 752.99 13 8 S 2372.99 27,29,31,33 2900 A 527.01| 1600 B 772.99 14 Medicina, Wettzell, Matera, GGAO, TIGO VLBA | Westford, NOTO, HartRAO, Onsala Chan Sky Tracks LO IF BBC | LO IF VC VC# Patch 1 X 8405.99 2, 4, 6, 8 7900 B 505.99| 8080.0 1 325.99 3 H 2 X 8475.99 10,12,14,16 7900 B 575.99| 8080.0 1 395.99 4 H 3 X 8790.99 18,20,22,24 7900 B 890.99| 8580.1 3 210.89 5 L 4 X 8895.99 26,28,30,32 7900 B 995.99| 8580.1 3 315.89 6 H 5 S 2232.99 3, 5, 7, 9 2900 A 667.01| 2020.0 2 212.99 9 H 6 S 2262.99 11,13,15,17 2900 A 637.01| 2020.0 2 242.99 10 H 7 S 2352.99 19,21,23,25 2900 A 547.01| 2020.0 2 332.99 13 H 8 S 2372.99 27,29,31,33 2900 A 527.01| 2020.0 2 352.99 14 H Procedures ========== With continuous tape motion, the tape starts moving and recording at the beginning of the first scan of a pass. The tape runs and records continuously thereafter to the end of the tape (EOT or BOT). A parity check is done after the tape reaches this point. The tape starts moving in the opposite direction at the early start time (30 seconds) before the next scan. There will be a variable length of time between tape passes. For the VLBA stations, there will normally be a long enough time gap between passes for playback. Special procedures for non-VLBA stations ======================================== The tape motion in this experiment is different from normal start&stop schedules. At the time the antenna gets on source, you should see the command "data_valid=on" from the SNAP schedule. This is the signal that the VLBA correlator will use to determine when to start correlating this scan. At the time the antenna begins slewing to the next source, you will see the command "data_valid=off" from the schedule. This is the signal the correlator will use to stop correlating that scan. There will be no "et" command at the end of a scan. The DRUDG listing has a column that lists the time that the tape will stop. Note the "Start Tape" and "Stop Tape" columns list times only when the tape will start or stop, otherwise the time is blanked out because the tape is moving. For each scan, the "Start Data" column will be the time when the antenna is expected to be on source. The "Stop Data" column is the time when the antenna starts slewing to the next source. After the setup procedure, the tape is started at the beginning of each pass and will continue to move, at record speed, until it reaches the end of the pass. There are no fast tape motions in this schedule. The tape is continuously recording from the initial "st" command at the start of the pass. There are no other "st" commands during a pass and there are no other setup procedures called. If you have to re-start the schedule for a problem or emergency, you will be able to do it either 1) at the beginning of a pass or 2) in the middle of a pass by entering the setup and start tape commands manually. The problem is that the heads cannot be positioned reliably when the tape is moving if there is recorded data on the tape. If the tape is moving the reproduce power level can cause cross-talk with the head positioner and give false indications of position. Another problem is that the data disappears on tape while the formatter resets itself, thus largely eiliminating the benefits of continuous motion. At the end of each pass a parity check is done. You will need procedures named "checkf80" and "checkr80". Check and adjust the timing of this procedure and then make sure it can complete in the 100 seconds that the schedule allows. Special procedures for Medicina, Westford, Onsala, Wettzell, Tsukuba, Matera, GGAO, TIGO ================================================================== These stations have Mark IV formatters. Use the procedures generated by DRUDG. These must be generated for rdv52 because of the new S-band frequency sequence. Note that the patching for VC10 must be changed from L to H for this session. This is 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 Mark IV formatters now have barrel roll capability, so please verify that your FORM command has specification for barrel roll. 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 Kokee ================================================== These stations have VLBA back ends. Use the procedures generated by DRUDG. BBCs 3,4,5,6 are used at X-band with IFs A and C. BBCs 9,10,13,14 are used at S-band with IF B. The unused BBCs 1,2,7,8,11,12 should be set to frequencies which do not occur in any of the passbands. Any value in the range 500-600 MHz is OK. The formatter should be set up to use barrel roll. Please verify that you are using the same barrel roll as you used in previous sessions correlated at the VLBA. 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, or use the procedures from last session. Check out parity check procedures. 2. Make .snp file and listings using DRUDG options 3 and 5. 3. Set up your system to monitor the clocks with the "gps-fmout" or "fmout-gps" commands. If you have questions about this, please contact Ed Himwich as soon as possible. 4. Send a "ready" message an hour or so before the experiment to the ivs-ops mail list. Copy analysts@nrao.edu on your ready message. 5. Send a "start" message soon after you have started recording. Copy analysts@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 on your message. 8. Transfer your log files to your normal log file data center. The directories for three possible servers are listed below: directory on cddisa: aug05 directory on vlbeer: aug05 directory on aspen: /home/aspen6/astronomy/aug05/rdv52 NOTE: If you don't normally use aspen, you should not put your log file on that server. The VLBA correlator knows where to find your log files. Correlation =========== This experiment will be correlated at the VLBA Correlator. Tapes should be shipped to Socorro as soon after the experiment as practical.