RDV83 (Astrometric/Geodetic VLBA-83) 2010 NOV. 17 18:00 Day 321 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 4 non-VLBA stations (HARTRAO, HOBART26, NYALES20, and TSUKUB32) should see the "Special operations notes for non-VLBA stations" section below for special instructions. There is no Intensive session during RDV83. Therefore, no stations will need to drop out. There are no full network scans because of the wide distribution of stations. However, the schedule begins and ends with long, nearly full network scans, and long scans with HARTRAO and HOBART26, that are designed as fringe-finding scans. There are also a few nearly full network scans (without HARTRAO and HOBART26) in the schedule. These scans are: Source Start DURATIONS name yyddd-hhmmss Br Fd Hh Hn Ho Kp La Mk Nl Ny Ov Pt Sc Ts 1418+546 10321-180000| 300 300 300 300 300 300 300 300 300 300 300 300| 1124-186 10321-180800| 300 300 300 300 300 300 300 300 300| 2029+121 10321-181457| 300 300 300 300 300 300 300 300 | 1846+322 10321-232653| 105 116 109 115 115 117 106 126 115 116 126 74| 1803+784 10322-020124| 100 100 100 100 100 100 100 100 100 100 100 100| 3C418 10322-035026| 40 40 40 40 40 40 40 40 40 40 40 40| 2250+194 10322-043343| 155 271 297 269 267 264 279 323 268 270 323 180| 2358+189 10322-043953| 159 177 188 177 176 178 161 193 177 177 193 112| 2229+695 10322-045259| 40 40 40 40 40 40 40 40 40 40 40 40| 0059+581 10322-070829| 100 100 100 100 100 100 100 100 100 100 100 100| 0454+844 10322-112139| 209 291 299 293 255 445 240 445 268 272 480 480| 0738+491 10322-120443| 50 68 53 67 67 71 61 78 67 67 78 59| 0657+172 10322-120930| 100 100 100 100 100 100 100 100 100 100 100 100| 0743+277 10322-130456| 125 127 142 125 126 142 131 181 124 125 181 126| 0454+844 10322-153454| 207 279 305 282 245 465 246 433 260 261 480 480| 1040+244 10322-155856| 100 100 100 100 100 100 100 100 100 100 100 100| 1803+784 10322-174728| 300 300 300 300 300 300 300 300 300 300 300 300| 2029+121 10322-175352| 300 300 300 300 300 300 300 | 1040+244 10322-175532| 260 260 260 260 260 260| Additional Notes: - Two-bit sampling is used. - In this RDV, all stations will record on Mark5A, except Tsukuba. 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 fifth 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: rdv83.skd On ftp.aoc.nrao.edu (aspen): VLBA Pointing files: rdv83crd.br rdv83crd.fd rdv83crd.hn rdv83crd.kp rdv83crd.la rdv83crd.mk rdv83crd.nl rdv83crd.ov rdv83crd.pt rdv83crd.sc Summary file for correlator: rdv83.sksum Sked file: rdv83.skd Text file: rdv83.txt Vex file: rdv83.vex At IVS Data Center (ftp://cddisa.gsfc.nasa.gov/vlbi/ivsdata/aux/2010/rdv83) Sked file: rdv83.skd Text file: rdv83.txt This experiment uses the 10 VLBA stations and 4 IVS stations. The IVS stations are: HARTRAO, HOBART26,, NYALES20, and TSUKUB32. Below is the sked summary: Key: Br=BR-VLBA Fd=FD-VLBA Hh=HARTRAO Hn=HN-VLBA Ho=HOBART26 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 Ho Kp La Mk Nl Ny Ov Pt Sc Ts Avg % obs. time: 45 47 38 41 40 46 46 39 45 41 45 46 44 33 43 % cal. time: 4 4 3 4 3 4 4 3 4 3 4 4 4 3 4 % slew time: 24 26 52 26 37 26 26 24 26 18 25 26 27 15 27 % idle time: 26 22 7 28 20 23 23 33 25 37 25 23 24 48 26 total # scans: 331 359 221 353 230 352 359 294 359 284 339 359 343 299 320 # scans/hour : 14 15 9 15 10 15 15 12 15 12 14 15 14 12 13 Avg scan (sec): 117 114 149 101 149 113 110 115 107 125 114 112 110 95 115 # data tracks: 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 Total GBytes: 1751 1856 1423 1661 1485 1818 1815 1531 1776 1581 1756 1831 1727 1342 1668 Total GB(M5): 1556 1650 1265 1477 1320 1616 1614 1361 1579 1406 1561 1628 1536 1193 1483 # OF OBSERVATIONS BY BASELINE | Br Fd Hh Hn Ho Kp La Mk Nl Ny Ov Pt Sc Ts StnTotal -------------------------------------------------------------------------------- Br| 275 13 265 28 273 278 173 281 169 257 279 239 99 2629 Fd| 25 299 26 328 352 166 328 148 278 354 296 69 2944 Hh| 33 159 16 25 0 25 64 8 25 42 74 509 Hn| 11 275 301 136 324 166 229 298 304 72 2713 Ho| 33 27 63 18 29 38 27 9 112 580 Kp| 329 187 302 133 299 332 270 76 2853 La| 170 331 151 281 354 296 73 2968 Mk| 156 87 216 170 130 139 1793 Nl| 158 259 326 306 72 2886 Ny| 120 149 146 144 1664 Ov| 282 222 96 2585 Pt| 292 71 2959 Sc| 52 2604 Ts| 1149 Number of 2-station scans: 208 Number of 3-station scans: 152 Number of 4-station scans: 41 Number of 5-station scans: 21 Number of 6-station scans: 24 Number of 7-station scans: 31 Number of 8-station scans: 52 Number of 9-station scans: 80 Number of 10-station scans: 85 Number of 11-station scans: 62 Number of 12-station scans: 26 Number of 13-station scans: 0 Number of 14-station scans: 0 Total # of scans, observations: 782 15418 SOURCE SELECTION ================ There are a total of 88 sources scheduled in this session. Among them, 30 sources are from the astrometric monitoring list, 45 are from the geodetic monitoring list, and 2 are previously observed sources that have only a few observations. There are also 6 sources requested by Adam Deller being reobserved to improve their positions and maps. And there are 5 new sources requested by L. Petrov. The requested sources are observed in two scans each. The requested sources are: 0913+079 09 15 52.9682 +07 45 39.695 Deller/J0915+0745 1741-312 17 44 23.5783 -31 16 36.295 Deller/J1744-3116 1822-076 18 25 37.6095 -07 37 30.013 Deller/J1825-0737 1831-030 18 34 14.0746 -03 01 19.628 Deller/J1834-0301 1904+013 19 07 11.9961 +01 27 08.961 Deller/J1907+0127 1822-173 18 25 36.5323 -17 18 49.849 Deller/J1825-1718 0250-001 02 53 21.07 +00 06 01.6 Petrov/Angelaikis et al. 1009-321 10 11 56.20 -32 23 34.6 Petrov/Bright flat-spec 1218-341 12 21 01.79 -34 23 18.7 Petrov/LBA comparison 1441-058 14 43 41.05 -06 01 11.6 Petrov/Angelaikis et al. 2054-075 20 57 21.02 -07 19 40.5 Petrov/VLA calibrator 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 | TSUKUB32 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 | HartRAO, HOBART26, NYALES20 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, and Hobart26 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. 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. 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: nov10 directory on aspen: /astronomy/nov10/rdv83 or /home/archive/e2e/archive/operations/VLBA/observe/nov10/rdv83 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) to Socorro as soon after the experiment as practical. The TSUKUB32 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.