RDV82 (Astrometric/Geodetic VLBA-82) 2010 Oct. 13 17:30 Day 286 Notes prepared by David Gordon, John Gipson, and Ed Himwich, NVI/GSFC Special notes for this experiment ================================= This session will use 2-bit sampling again, as in the last few RDV's. Frequencies and channel bandwidths (8 MHz) are the same as in previous RDV's. The bit rate will be 256 Mbits/sec. The 8 MHz, 2-bit sampling is preferable to 16 MHz, 1-bit sampling because the 16 MHz filters are not very good at the non-VLBA stations. The data will be correlated at the VLBA using the DiFX software correlator. The 5 non-VLBA stations (HARTRAO, Kashima, Kokee, Ny Alesund, and Tsukuba) should see the "Special operations notes for non-VLBA stations" section below for special instructions. Kokee and Ny Alesund will drop out of the RDV82 session at ~18:15 UT to observe the daily UT1 Intensive and will resume RDV82 at ~19:45 UT. With HARTRAO in this schedule, there can be no full network scans. However, there are nearly full network scans without HARTRAO and large scans with HARTRAO at the beginning and near the end of the schedule that can be used for fringe finding. There are also several nearly full network scans scattered throughout the schedule. These scans are: Source Start DURATIONS name yyddd-hhmmss Br Fd Hh Hn Kb Kk Kp La Mk Nl Ny Ov Pt Sc Ts 0716+714 10286-173000| 300 300 300 300 300 300 300 300 300 300 300 300 300 300| 1754+155 10286-173709| 300 300 300 300 300 300 300 300 | 1623+578 10286-202029| 188 340 379 409 480 342 337 480 194 480 340 338 480 342| 1520+437 10286-213508| 72 72 78 79 141 72 72 61 73 141 65 72 81 46| 0014+813 10287-001944| 200 200 200 200 200 200 200 200 200 200 200 200 200 200| 0059+581 10287-040312| 200 200 200 200 200 200 200 200 200 200 200 200 200 200| 1053+815 10287-082323| 200 200 200 200 200 200 200 200 200 200 200 200 200 200| 0716+714 10287-123239| 200 200 200 200 200 200 200 200 200 200 200 200 200 200| 1617+229 10287-171544| 300 300 300 300 300 300 300 300 300 300 300 | 1053+815 10287-172225| 300 300 300 300 300 300 300 300 300 300 300 300 300 300| Additional Notes: - Two-bit sampling is used. - In this RDV, all stations will record on Mark5A, except Kashima and Tsukuba. Kashima and Tsukuba will record on K5 and the data will be later transferred to Mark5A. - The synch time for the VLBA correlator using Mark5 is ~25 seconds. Because of this, stations will start taking data 30 seconds prior to the normal scan time. They will continue to take data between scans if there is a gap of less than 30 seconds. - The fluxes use our most recent models. Purpose ======= This is the fourth of six coordinated astrometric/geodetic experiments in 2010 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 and Bordeaux Observatory will perform 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 a small number of sources. While the quality of these results will be high, the observing and data reduction overhead required will be minimal because a small number of 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 from the pool of geodetic, astrometric, and monitoring 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. A small number of poorly observed and/or new requested sources may also be included to obtain or improve their positions. Schedule information ==================== This is a new schedule generated by David Gordon at GSFC using sked. Schedule file name: rdv82.skd On ftp.aoc.nrao.edu (aspen): VLBA Pointing files: rdv82crd.br rdv82crd.fd rdv82crd.hn rdv82crd.kp rdv82crd.la rdv82crd.mk rdv82crd.nl rdv82crd.ov rdv82crd.pt rdv82crd.sc Summary file for correlator: rdv82.sksum Sked file: rdv82.skd Text file: rdv82.txt Vex file: rdv82.vex At IVS Data Center (ftp://cddisa.gsfc.nasa.gov/vlbi/ivsdata/aux/2010/rdv82) Sked file: rdv82.skd Text file: rdv82.txt This experiment uses the 10 VLBA stations and 5 IVS stations. The IVS stations are: HARTRAO, KASHIM34, KOKEE, NYALES20, and TSUKUB32. Below is the sked summary: Key: Br=BR-VLBA Fd=FD-VLBA Hh=HARTRAO Hn=HN-VLBA Kb=KASHIM34 Kk=KOKEE Kp=KP-VLBA La=LA-VLBA Mk=MK-VLBA Nl=NL-VLBA Ny=NYALES20 Ov=OV-VLBA Pt=PIETOWN Sc=SC-VLBA Ts=TSUKUB32 Br Fd Hh Hn Kb Kk Kp La Mk Nl Ny Ov Pt Sc Ts Avg % obs. time: 41 43 36 38 36 36 43 43 40 40 37 43 43 39 32 39 % cal. time: 4 4 3 4 4 4 4 4 4 4 3 4 4 4 4 4 % slew time: 25 24 51 23 35 18 26 25 28 24 15 28 25 22 15 26 % idle time: 29 28 10 34 24 42 26 28 27 31 43 24 27 34 48 31 total # scans: 341 332 287 323 339 308 341 340 354 327 283 348 340 319 362 329 # scans/hour : 14 14 12 13 14 13 14 14 15 14 12 15 14 13 15 14 Avg scan (sec): 105 113 107 102 93 101 109 108 98 107 114 107 109 106 75 103 # data tracks: 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 # Mk5 tracks: 16 16 16 16 16 16 16 16 16 16 16 16 16 16 16 Total GBytes: 1656 1703 1415 1533 1495 1448 1707 1690 1628 1611 1472 1722 1702 1559 1372 1581 Total GB(M5): 1472 1514 1257 1363 1329 1287 1517 1502 1447 1432 1308 1531 1513 1386 1219 1405 # OF OBSERVATIONS BY BASELINE | Br Fd Hh Hn Kb Kk Kp La Mk Nl Ny Ov Pt Sc Ts StnTotal ------------------------------------------------------------------------------------- Br| 247 66 209 103 122 246 260 165 241 129 244 258 168 116 2574 Fd| 96 228 54 103 294 317 149 275 103 240 320 217 69 2712 Hh| 142 82 0 72 92 0 113 161 36 90 176 87 1213 Hn| 41 61 209 237 92 267 150 166 233 257 53 2345 Kb| 158 75 58 157 50 106 110 58 24 324 1400 Kk| 133 108 281 83 44 176 111 44 156 1580 Kp| 305 181 257 94 280 309 191 90 2736 La| 155 289 109 251 336 215 72 2804 Mk| 124 37 233 157 78 175 1984 Nl| 125 215 285 240 62 2626 Ny| 77 107 124 106 1472 Ov| 252 147 124 2551 Pt| 213 72 2801 Sc| 33 2127 Ts| 1539 Number of 2-station scans: 171 Number of 3-station scans: 151 Number of 4-station scans: 136 Number of 5-station scans: 65 Number of 6-station scans: 40 Number of 7-station scans: 36 Number of 8-station scans: 53 Number of 9-station scans: 56 Number of 10-station scans: 78 Number of 11-station scans: 61 Number of 12-station scans: 16 Number of 13-station scans: 7 Number of 14-station scans: 9 Number of 15-station scans: 0 Total # of scans, observations: 879 16232 SOURCE SELECTION ================ There are a total of 92 sources scheduled in this session. Among them, 30 sources are from the astrometric monitoring list and 46 are from the geodetic monitoring list. There are also 9 previously observed sources that have only a few observations and 7 new sources requested by L. Petrov. The requested sources are observed in two scans each at the VLBA sites, with the goal of accurately determining their coordinates. They are not optimized for imaging. The requested sources are: 0809+483 08 13 36.07 +48 13 01.9 0951+699 09 55 51.88 +69 40 46.1 1832+687 18 32 35.52 +68 48 07.2 0045-255 00 47 33.13 -25 17 17.1 1304-318 13 07 15.21 -32 07 57.9 1320-407 13 23 40.82 -41 01 23.3 1510-319 15 13 21.68 -32 09 29.6 SCHEDULING ALGORITHMS ===================== This schedule uses the "SRCEVN SQRT" mode of Sked. In the absence 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. RECORDING MODE and FREQUENCIES ============================== NOTE: THERE ARE SOME CHANGES FROM PREVIOUS EXPERIMENTS FOR 2-BIT SAMPLING. The data will be recorded using the following setup: 8 channels 1:2 fan-out 16 MHz sample rate 2-bit sampling This recording mode is designated 256-8(RDV). There is no correlator speed-up factor. The frequency sequence covers 490 MHz at X-band and 140 MHz at S-band using 4 channels in each band. 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 total 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 K5 back ends, and the geodetic stations with Mark IV back ends. These are the SAME frequencies used in all the standard RDV sessions. VLBA | Kashima34 M B Chan Sky Tracks LO IF BBC | LO IF BBC # # 1 X 8405.99 2, 4, 6, 8 7900 B 505.99| 7580 1 825.99 3 7 2 X 8475.99 10,12,14,16 7900 B 575.99| 7580 1 895.99 4 8 3 X 8790.99 18,20,22,24 7900 B 890.99| 8080 3 710.99 5 1 4 X 8895.99 26,28,30,32 7900 B 995.99| 8080 3 815.99 6 2 5 S 2232.99 3, 5, 7, 9 2900 A 667.01| 1520 2 712.99 9 15 6 S 2262.99 11,13,15,17 2900 A 637.01| 1520 2 742.99 10 16 7 S 2352.99 19,21,23,25 2900 A 547.01| 1520 2 832.99 13 11 8 S 2372.99 27,29,31,33 2900 A 527.01| 1520 2 852.99 14 12 M#: Main recording channel number B#: Backup recording channel number VLBA | Tsukuba Chan Sky Tracks LO IF BBC | LO IF BBC # 1 X 8405.99 2, 4, 6, 8 7900 B 505.99| 7680 1 725.99 3 2 X 8475.99 10,12,14,16 7900 B 575.99| 7680 1 795.99 4 3 X 8790.99 18,20,22,24 7900 B 890.99| 8080 3 710.99 5 4 X 8895.99 26,28,30,32 7900 B 995.99| 8080 3 815.99 6 5 S 2232.99 3, 5, 7, 9 2900 A 667.01| 1600 2 632.99 9 6 S 2262.99 11,13,15,17 2900 A 637.01| 1600 2 662.99 10 7 S 2352.99 19,21,23,25 2900 A 547.01| 1600 2 752.99 13 8 S 2372.99 27,29,31,33 2900 A 527.01| 1600 2 772.99 14 VLBA | Kokee Chan Sky Tracks LO IF BBC | LO IF BBC # 1 X 8405.99 2, 4, 6, 8 7900 B 505.99| 7600 A 805.99 3 2 X 8475.99 10,12,14,16 7900 B 575.99| 7600 A 875.99 4 3 X 8790.99 18,20,22,24 7900 B 890.99| 8100 C 690.99 5 4 X 8895.99 26,28,30,32 7900 B 995.99| 8100 C 795.99 6 5 S 2232.99 3, 5, 7, 9 2900 A 667.01| 1500 B 732.99 9 6 S 2262.99 11,13,15,17 2900 A 637.01| 1500 B 762.99 10 7 S 2352.99 19,21,23,25 2900 A 547.01| 1500 B 852.99 13 8 S 2372.99 27,29,31,33 2900 A 527.01| 1500 B 872.99 14 VLBA | HartRAO, Ny Alesund 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 3(H) 4 X 8895.99 26,28,30,32 7900 B 995.99| 8580.1 3 315.89 6 3(H) 5 S 2232.99 3, 5, 7, 9 2900 A 667.01| 2020.0 2 212.99 9 L 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 Special operations for non-VLBA stations: ========================================= HartRAO, Ny Alesund These stations have Mark IV racks. Please use the procedures generated by DRUDG. VCs 3, 4, 5, & 6 are used at X-band with IFs 1 and 3. VCs 9, 10, 13, & 14 are used at S-band with IF B. The IF3 command in the procedure IFDSX assumes that VC3 and VC10 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. The standard wiring is described in "help=if3". If you have questions about the wiring, please contact Brian Corey at Haystack. Kokee: This station has a VLBA4 back end. 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. Tsukuba: This station uses a K4-2 VC and K5 recorder. Use the procedures generated by DRUDG. Be sure to set your rack type to K4-2, not K4-2/M4, if that change has not already been made. Please note you will need to comment out the incorrect VC commands in VCSX8 after the comment about these converters being present, but not used. This will be corrected in a future DRUDG release. The tpicd commands should be benign and do not need to be commented out unless they cause a problem. If you wish to record back-up channels, please add appropriate valo=..., va=... vblo=... and vb=... commands in the VCSX8 procedure. We assume the same back-up VCs would work for Tsukuba as are specified for Kashima34 (above). Kashima34: This station uses K4-2 VCs and a K5 recorder. Use the procedures generated by DRUDG. Be sure to set your rack type to K4-2, not K4-2/M4, if that change has not already been made. Please note you will need to comment out the incorrect VC commands in the VCSX8 procedure after the comment about these converters being present, but not used. This will be corrected in a future DRUDG release. Please also set the attenuation and detector appropriately in the va=.. and vb=... commands. The tpicd commands in SX8M12A should be benign and do not need to be commented out unless they cause a problem. If you wish to record back-up channels, please add appropriate valo=..., va=... vblo=... and vb=... commands in the VCSX8 procedure. 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 the .snp file with DRUDG. 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. 7. Transfer your log files to your normal log file data center. The directories for three possible servers are listed below: ftp cddisin.gsfc.nasa.gov/ivsincoming directory on vlbeer: oct10 directory on aspen: /astronomy/oct10/rdv82 or /home/archive/e2e/archive/operations/VLBA/observe/oct10/rdv82 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 on the VLBA-DiFX software correlator. Disks should be shipped (except TSUKUB32 and KASHIM34) to Socorro as soon after the experiment as practical. The TSUKUB32 and KASHIM34 data should be e-transfered to Haystack as soon after the experiment as practical. The VLBA needs to process the session at their correlator as soon as possible, because of limited media. They prefer to have the data within one week of the observation, but in no case later than two weeks after the observation. So, we are asking all stations, participating in the RDV sessions, to ship your media to the VLBA the same day the session ends or the next business day (just like the R1/R4 media is shipped). If you know that there is going to be a problem sending your media to the VLBA the same day the session ends or the next business day, please let us (ivscc@ivscc.gsfc.nasa.gov) know as soon as possible so that we, along with the VLBA, can determine the best course of action. If you have any questions or comments, please let us know.