rdv53 (Astrometric/Geodetic VLBA-52) 2005 September 29 Notes prepared by John Gipson, NVI/GSFC Schedule name: rdv53.skd Pointing files: rdv53crd.br, rdv53crd.fd, rdv53crd.hn, rdv53crd.kp, rdv53crd.la, rdv53crd.mk, rdv53crd.nl, rdv53crd.ov, rdv53crd.pt, rdv53crd.sc ftp://vlbiobs@aspen.nrao.edu/home/aspen6/astronomy/sep05/rdv53 Summary file for correlator: rdv53.sksum on aspen PCFS file: ftp://vlbigeo@cddisa.gsfc.nasa.gov/vlbigeo/sep05/rdv53.skd http://lupus.gsfc.nasa.gov/sess/2005/sesshtml/rdv53.html In addition to the VLBA, the session also uses: Ap=ALGOPARK Gc=GILCREEK Gg=ORION_5M KK=Kokee On=Onsala Tc=TIGO Ws=Westford Wz=WETTZELL First observations: name yyddd-hhmmss Ap Br Fd Gc Hn Kp La Mk 0642+449 05271-180000| 300 300 300 300 300 300 300 300| 1749+096 05271-180000| | 1958-179 05271-180644| | OJ287 05271-180849| 300 300 300 300 300 300 300 300| name yyddd-hhmmss 0642+449 05271-180000 Nl On Gg Ov Pt Sc Tc Wf 1749+096 05271-180000 300 300 300 300 300 300 1958-179 05271-180644 300 300 OJ287 05271-180849 700 700 Wettzell and Kokee don't observe until after the intensive is done. Wettzell's first observation is: 2356+385 05271-200019 Kokee's is: 0153+744 05271-200021 The last observations: name yyddd-hhmmss Ap Br Fd Gc Hn Kk Kp La Mk 1749+096 05272-174119| 0642+449 05272-174625| 300 300 300 300 300 300 300 300 300 OJ287 05272-175514| 300 300 300 300 300 300 300 300 300 name yyddd-hhmmss Nl On Gg Ov Pt Sc Tc Wf Wz 1749+096 05272-174119| 700 109 700 700| 0642+449 05272-174625| 300 300 300 300 300 | OJ287 05272-175514| 300 300 300 300 300 300 | SUMMARY OF OBSERVATIONS Total time: 1440 minutes ( 24.0 hours). 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 On=ONSALA60 Gg=ORION_5M Ov=OV-VLBA Pt=PIETOWN Sc=SC-VLBA Tc=TIGO Wf=WESTFORD Wz=WETTZELL Ap Br Fd Gc Hn Kk Kp La Mk Nl % obs. time: 44 77 75 70 80 67 74 76 70 78 % cal. time: 2 3 3 3 3 2 3 3 2 3 % slew time: 49 17 17 15 14 9 18 17 16 16 % idle time: 4 3 5 11 3 22 4 3 11 3 total # scans: 199 222 225 219 219 162 234 231 190 222 # scans/hour : 8.3 9.2 9.4 9.1 9.1 6.8 9.8 9.6 7.9 9.2 Avg scan (sec): 192 300 287 278 314 355 274 284 318 303 Total GBytes: 687 1199 1161 1112 1239 1050 1156 1182 1089 1209 Total GB(M5): 611 1065 1032 988 1102 934 1027 1050 968 1075 # of tapes : 0.1 2.4 2.4 2.6 2.4 2.0 2.4 2.4 2.4 2.4 tape change: 0000 0422 0422 0333 0422 0702 0422 0422 0422 0422 0000 1428 1428 1254 1428 0000 1428 1428 1435 1428 On Gg Ov Pt Sc Tc Wf Wz Avg % obs. time: 67 84 74 76 73 55 87 59 71 % cal. time: 2 2 3 3 2 1 2 2 2 % slew time: 11 6 18 18 14 3 8 5 16 % idle time: 19 7 4 3 10 40 2 33 11 total # scans: 152 188 229 234 208 86 169 150 196 # scans/hour : 6.3 7.8 9.5 9.8 8.7 3.6 7.0 6.2 8.2 Avg scan (sec): 378 387 278 280 303 555 447 338 325 Total GBytes: 1051 1311 1147 1182 1137 874 1359 927 1115 Total GB(M5): 934 1165 1020 1051 1010 777 1208 824 991 # of tapes : 2.1 0.1 2.4 2.4 2.4 2.1 0.1 1.9 tape change: 0519 0000 0422 0422 0422 0537 0000 0659 1722 0000 1428 1428 1428 1741 0000 0000 Total number of tapes: 34.4 Total GBytes (M5) recorded: 17843.0 # OF OBSERVATIONS BY BASELINE | Ap Br Fd Gc Hn Kk Kp La Mk Nl On Gg Ov Pt Sc Tc Wf Wz StnTotal -------------------------------------------------------------------------------------- Ap|199 132 135 101 176 52 128 144 69 164 63 120 121 141 136 26 122 67 1897 Br| 222 164 155 135 94 169 173 118 169 72 103 184 176 101 25 109 70 2149 Fd| 225 114 141 82 207 211 107 181 55 117 175 215 131 45 114 56 2250 Gc| 219 101 110 125 119 122 123 88 92 143 121 68 10 83 78 1753 Hn| 219 50 135 147 65 176 87 136 125 146 161 36 151 89 2057 Kk| 162 93 82 153 71 30 54 112 86 36 28 49 24 1206 Kp| 234 207 117 174 55 119 193 216 120 47 109 51 2265 La| 231 108 189 61 120 180 224 129 40 119 61 2314 Mk| 190 91 34 64 137 110 45 35 54 22 1451 Nl| 222 71 126 163 188 143 32 140 74 2275 On| 152 64 59 61 72 16 78 129 1095 Gg| 188 109 118 122 46 128 62 1700 Ov| 229 187 102 37 99 54 2180 Pt| 234 130 43 118 58 2338 Sc| 208 59 121 80 1756 Tc| 86 38 17 580 Wf| 169 74 1706 Wz| 150 1066 Number of 2-station scans: 32 Number of 3-station scans: 90 Number of 4-station scans: 50 Number of 5-station scans: 35 Number of 6-station scans: 30 Number of 7-station scans: 32 Number of 8-station scans: 23 Number of 9-station scans: 20 Number of 10-station scans: 23 Number of 11-station scans: 27 Number of 12-station scans: 22 Number of 13-station scans: 23 Number of 14-station scans: 27 Number of 15-station scans: 20 Number of 16-station scans: 14 Number of 17-station scans: 2 Number of 18-station scans: 2 Total # of scans, observations: 472 16019 Special Notes for this session: - IMPORTANT. In this RDV 3 stations will record on Mark5. These stations are Algopark, GGAO, and Westford. For these stations we will make the snap and proc files at GSFC. These will be placed on cddisa and should be picked up the stations. - IMPORTANT: The synch time for the VLBA correlator using Mark5 is 25 seconds. Becausese of this, stations recording with Mark5 disks 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. - 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 18:00 to 20:00 because of the intensive. - 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 5th 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. SOURCE SELECTION There are a total of 100 sources in this session. 30 sources were chosen because they had not been observed recently in the RDVs. In addition there three requested source: 2250+194 Lebach. Observed regularly since RDV36 L. Petrov requested: 1600+43A J1601+431A 16 01 40.443903 +43 16 47.75672 2115-305 J2118-3019 21 18 10.597707 -30 19 11.60633 These sources have been observed in standard geodetic sessions, but have never been observed with the VLBA. The remaing 67 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. 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 rdv53 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: sep05 directory on vlbeer: sep05 directory on aspen: /home/aspen6/astronomy/sep05/rdv53 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.