RDV79 (Astrometric/Geodetic VLBA-79) 2010 June 23 18:00 Day 174 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 2 previous 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 6 non-VLBA stations with Mark IV and VLBA4 racks (Hobart, Kokee, Matera, Ny Alesund, Tsukuba, and Zelenchenskya) should see the "Special operations notes for non-VLBA stations" section below for special instructions. There are no full network scans, since Hobart is observing. However, the schedule has nearly full network scans at the beginning and end that can be used for 'fringe finding' at all stations except Hobart. Fringe finding scans with Hobart occur right after the start and shortly before the end. These scans are: Source Start DURATIONS name yyddd-hhmmss Br Fd Hn Ho Kk Kp La Ma Mk Nl Ny Ov Pt Sc Ts Zc 1053+815 10174-180000| 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300| 0237-027 10174-180808| 300 300 300 300 300 300 300 300 300 300 300 300 300 | 0400-319 10175-174413| 200 200 200 200 200 200 200 200 200 200 200 | 1053+815 10175-175635| 200 200 200 200 200 200 200 200 200 200 200 200 200 200 200| Additional Notes: - Two-bit sampling is used. - In this RDV, all stations will record on Mark5A, except Tsukuba and Zelenchenskaya. The K5 Tsukuba data will be later transferred to Mark5A. Zelenchenskaya is expected to be Mark5B. - 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 first of six bi-monthly 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: rdv79.skd On ftp.aoc.nrao.edu (aspen): VLBA Pointing files: rdv79crd.br rdv79crd.fd rdv79crd.hn rdv79crd.kp rdv79crd.la rdv79crd.mk rdv79crd.nl rdv79crd.ov rdv79crd.pt rdv79crd.sc Summary file for correlator: rdv79.sksum Sked file: rdv79.skd Text file: rdv79.txt Vex file: rdv79.vex At IVS Data Center (ftp://cddisa.gsfc.nasa.gov/vlbi/ivsdata/aux/2010/rdv79) Sked file: rdv79.skd Text file: rdv79.txt This experiment uses the 10 VLBA stations and 6 IVS stations. The IVS stations are: HOBART26, KOKEE, MATERA, NYALES20, TSUKUB32, and ZELENCHK. Below is the sked summary: Total time: 1440 minutes ( 24.0 hours). Key: Br=BR-VLBA Fd=FD-VLBA Hn=HN-VLBA Ho=HOBART26 Kk=KOKEE Kp=KP-VLBA La=LA-VLBA Ma=MATERA Mk=MK-VLBA Nl=NL-VLBA Ny=NYALES20 Ov=OV-VLBA Pt=PIETOWN Sc=SC-VLBA Ts=TSUKUB32 Zc=ZELENCHK Br Fd Hn Ho Kk Kp La Ma Mk Nl Ny Ov Pt Sc Ts Zc Avg % obs. time: 50 53 48 28 41 52 53 47 41 51 48 52 53 50 31 30 46 % cal. time: 4 4 4 3 4 4 4 3 4 4 3 4 4 4 4 4 4 % slew time: 24 24 24 25 18 23 24 27 27 24 18 24 23 25 17 47 25 % idle time: 22 18 23 43 36 20 19 22 27 20 29 20 19 21 46 18 26 total # scans: 321 321 325 233 303 322 324 298 351 323 295 321 322 326 353 320 316 # scans/hour : 13 13 14 10 13 13 14 12 15 13 12 13 13 14 15 13 13 Avg scan (sec): 135 144 127 105 117 141 141 136 101 136 141 139 142 132 76 81 123 # data tracks: 16 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 16 Total GBytes: 1907 2005 1834 1133 1602 1980 1992 1785 1660 1929 1813 1953 1993 1897 1352 1283 1757 Total GB(M5): 1695 1782 1630 1007 1424 1760 1771 1586 1476 1715 1611 1736 1772 1686 1202 1140 1562 # OF OBSERVATIONS BY BASELINE | Br Fd Hn Ho Kk Kp La Ma Mk Nl Ny Ov Pt Sc Ts Zc StnTotal ------------------------------------------------------------------------------------------ Br| 245 243 41 146 253 253 120 188 260 146 259 256 215 114 101 2840 Fd| 263 44 126 294 311 116 177 293 121 269 311 262 79 82 2993 Hn| 10 100 248 269 136 140 285 147 228 265 276 83 108 2801 Ho| 124 51 43 21 137 35 23 55 44 29 151 46 854 Kk| 144 125 52 260 121 89 156 127 97 165 59 1891 Kp| 291 106 195 278 117 295 295 240 90 74 2971 La| 122 178 304 128 269 316 265 86 93 3053 Ma| 44 123 209 96 120 138 105 228 1736 Mk| 167 84 209 177 142 177 52 2327 Nl| 133 257 298 272 85 97 3008 Ny| 111 124 126 146 213 1917 Ov| 273 216 101 69 2863 Pt| 260 83 88 3037 Sc| 60 104 2702 Ts| 149 1674 Zc| 1563 Number of 2-station scans: 174 Number of 3-station scans: 146 Number of 4-station scans: 122 Number of 5-station scans: 44 Number of 6-station scans: 32 Number of 7-station scans: 25 Number of 8-station scans: 31 Number of 9-station scans: 38 Number of 10-station scans: 53 Number of 11-station scans: 69 Number of 12-station scans: 46 Number of 13-station scans: 30 Number of 14-station scans: 14 Number of 15-station scans: 12 Number of 16-station scans: 0 Total # of scans, observations: 836 19115 SOURCE SELECTION ================ There are a total of 90 sources scheduled in this session. Among them, 30 sources are from the astrometric monitoring list and 45 are from the geodetic monitoring list. There are also 7 ICRF2 sources with only a few observations and poorly determined ICRF2 positions, and 8 new sources requested by L. Petrov and C. Phillips. These 15 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 8 requested sources are: 0616-244 J0618-2426 06 18 22.66 -24 26 38.9 0753-425 J0755-4239 07 55 23.19 -42 39 58.6 0902-350 J0904-3514 09 04 42.34 -35 14 23.8 1755+626 J1755+6236 17 55 48.4397 +62 36 44.119 2136-251 J2139-2454 21 39 13.25 -24 54 15.0 2204-007 J2206-0031 22 06 43.29 -00 31 03.0 2227-445 J2230-4416 22 30 56.44 -44 16 29.9 2317-372 J2319-3656 23 19 53.65 -36 56 29.0 SCHEDULING ALGORITHMS ===================== This schedule uses the "SRCEVN SQRT" mode of Sked. 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. 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 VLBA back ends, and the geodetic stations with Mark IV back ends. These are the SAME frequencies used in all the standard RDV sessions. 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 | 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 | Hobart26, NyAlesund, Matera 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 VLBA | Zelenchenskaya Chan Sky Tracks LO IF BBC | LO IF BBC # 1 X 8405.99 2, 4, 6, 8 7900 B 505.99| 7600.0 A 805.99 1 2 X 8475.99 10,12,14,16 7900 B 575.99| 7600.0 A 875.99 2 3 X 8790.99 18,20,22,24 7900 B 890.99| 8080.0 C 710.99 3 4 X 8895.99 26,28,30,32 7900 B 995.99| 8080.0 C 815.99 4 5 S 2232.99 3, 5, 7, 9 2900 A 667.01| 1540.1 B 692.89 9 6 S 2262.99 11,13,15,17 2900 A 637.01| 1540.1 B 722.89 10 7 S 2352.99 19,21,23,25 2900 A 547.01| 1540.1 B 812.89 13 8 S 2372.99 27,29,31,33 2900 A 527.01| 1540.1 B 832.89 14 Special operations for non-VLBA stations: ========================================= Hobart26, Ny Alesund, and Matera: 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. Zelenchenskya: This station has a VLBA5 back end with its own (non-VSI4) sampler in the equivalent configuration of the VSI4 "geo" mode and uses a Mark 5B recorder. Use the procedures generated by DRUDG with the following exceptions: (1) use option 11 to select equipment VLBA5 rack and Mark5B recorder before generating the output files and (2) in the .prc file comment out the "vsi4=..." command from the set-up procedure in the and add whatever commands are needed (if any) to configure your sampler for the "geo" mode. BBCs 1, 2, 3, & 4 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. 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 cddisa.gsfc.nasa.gov/ivsincoming directory on vlbeer: jun10 directory on aspen: /astronomy/jun10/rdv79 or /home/archive/e2e/archive/operations/VLBA/observe/jun10/rdv79 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 to Socorro as soon after the experiment as practical.