RDV89 (Astrometric/Geodetic VLBA-89) 2011 OCT 12 18:00 DOY 285 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. There are 6 non-VLBA stations scheduled (FORTLEZA, HARTRAO, NYALES20, TSUKUB32, WESTFORD, and WETTZELL). These stations should see the "Special operations notes for non-VLBA stations" section below for special instructions. To facilitate fringe-finding, there are several long (300 second) scans on fairly strong sources at the beginning, in the middle, and at the end. All stations please try to be onsource and recording data for the first of these scans. These scans are: Source Start DURATIONS name yyddd-hhmmss Br Fd Ft Hh Hn Kp La Mk Nl Ny Ov Pt Sc Ts Wf Wz 1803+784 11285-180000| 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300| 1749+096 11285-180828| 300 300 300 300 300 300 300 300 300 300 300| 0212+735 11285-181515| 300 300 300 300 300 300 300 300 300 300 300 300 | 0212+735 11286-020130| 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300| 1928+738 11286-173720| 300 300 300 300 300 300 300 300 300 300 300 300 300 300| 1749+096 11286-174408| 300 300 300 300 300 300 300 300 300 300| 1803+784 11286-175053| 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300| Additional Notes: - Two-bit sampling is used. - In this RDV, all stations will record on Mark5A/B, except Tsukuba. Tsukuba will record on K5 and the data will be later transferred to Mark5A at Haystack Observatory. - The synch time for the VLBA DiFX correlator using Mark5 is only a few seconds. Because of this, the 'early' start has been reduced to 10 seconds. - The fluxes use our most recent models. Purpose ======= This is the fifth of six coordinated astrometric/geodetic experiments in 2011 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: rdv89.skd On ftp.aoc.nrao.edu (aspen): VLBA Pointing files: rdv89crd.br rdv89crd.fd rdv89crd.hn rdv89crd.kp rdv89crd.la rdv89crd.mk rdv89crd.nl rdv89crd.ov rdv89crd.pt rdv89crd.sc Summary file: rdv89.sksum Sked file: rdv89.skd Text file: rdv89.txt Vex file: rdv89.vex At IVS Data Center (ftp://cddisa.gsfc.nasa.gov/vlbi/ivsdata/aux/2011/rdv89) Sked file: rdv89.skd Text file: rdv89.txt This experiment uses the 10 VLBA stations and 6 IVS stations. The IVS stations are: FORTLEZA, HARTRAO, NYALES20, TSUKUB32, WESTFORD, and WETTZELL. Below is the sked summary: Key: Br=BR-VLBA Fd=FD-VLBA Ft=FORTLEZA Hh=HARTRAO Hn=HN-VLBA Kp=KP-VLBA La=LA-VLBA Mk=MK-VLBA Nl=NL-VLBA Ny=NYALES20 Ov=OV-VLBA Pt=PIETOWN Sc=SC-VLBA Ts=TSUKUB32 Wf=WESTFORD Wz=WETTZELL Br Fd Ft Hh Hn Kp La Mk Nl Ny Ov Pt Sc Ts Wf Wz Avg % obs. time: 48 50 55 51 48 49 50 42 49 50 46 50 45 32 50 47 48 % cal. time: 4 4 3 2 3 4 4 4 3 3 4 4 3 4 3 3 3 % slew time: 24 24 29 37 20 24 23 25 22 17 25 24 23 15 15 8 23 % idle time: 23 22 12 8 27 23 22 28 24 28 24 21 28 48 31 42 26 total # scans: 308 315 217 207 283 315 315 323 299 292 321 316 283 339 255 238 289 # scans/hour : 13 13 9 9 12 13 13 13 12 12 13 13 12 14 11 10 12 Avg scan (sec): 136 138 220 214 147 133 138 113 142 149 124 138 138 80 170 170 146 # 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: 1616 1673 1795 1668 1603 1627 1680 1424 1638 1667 1549 1678 1505 1103 1650 1540 1589 Total GB(M5): 1437 1487 1596 1483 1425 1446 1493 1266 1456 1482 1377 1492 1338 980 1467 1369 1412 # OF OBSERVATIONS BY BASELINE | Br Fd Ft Hh Hn Kp La Mk Nl Ny Ov Pt Sc Ts Wf Wz StnTotal ------------------------------------------------------------------------------------------ Br| 232 44 23 176 244 244 188 224 128 252 247 143 132 116 66 2459 Fd| 62 46 201 282 293 166 250 93 238 299 189 89 137 59 2636 Ft| 186 96 47 61 13 73 97 29 57 113 12 122 149 1161 Hh| 80 30 45 0 57 87 12 41 97 14 100 147 965 Hn| 185 207 106 238 129 161 201 226 70 193 103 2372 Kp| 287 188 240 89 270 295 167 99 120 47 2590 La| 173 261 102 249 307 184 89 141 64 2707 Mk| 146 80 223 177 95 210 53 22 1840 Nl| 113 212 256 207 87 163 79 2606 Ny| 94 101 99 158 150 163 1683 Ov| 253 137 139 96 44 2409 Pt| 180 92 138 60 2704 Sc| 54 163 99 2153 Ts| 68 64 1377 Wf| 125 1885 Wz| 1291 Number of 2-station scans: 189 Number of 3-station scans: 129 Number of 4-station scans: 68 Number of 5-station scans: 45 Number of 6-station scans: 45 Number of 7-station scans: 46 Number of 8-station scans: 54 Number of 9-station scans: 48 Number of 10-station scans: 62 Number of 11-station scans: 30 Number of 12-station scans: 32 Number of 13-station scans: 31 Number of 14-station scans: 9 Number of 15-station scans: 3 Number of 16-station scans: 0 Total # of scans, observations: 791 16419 INTENSIVE BREAKS ================ There are expected to be two 1-hr UT1 Intensive sessions during RDV89 using WETTZELL, PIETOWN, and MK-VLBA. WETTZELL will participate in the INT01 session I11285, and is not scheduled here from 285-1815 to 285-1945. PIETOWN and MK-VLBA are now also performing a daily UT1 measurement for the US Naval Observatory. The timing of this new VLBA UT1 Intensive is somewhat flexible - sometime between 15:00 and 23:00 UTC. Therefore, PT and MK will be taken out of RDV89 for an ~1.5-2.0 hr period, which could be either at or near the start, or near the end of the schedule, or possibly both. We will leave the time of this break to the discretion of the VLBA operators. From our standpoint, there is no particular period that is better or worse than another, and the loss of these two antennas for a short period should have only a minimal effect. SOURCE SELECTION ================ There are a total of 88 sources scheduled in this session. Among them, 28 sources are from the astrometric monitoring list, 41 are from the geodetic monitoring list, and 18 are previously observed sources that have only a few observations or were observed in only one session. There is also 1 new source requested by Y. Kovalev. The requested source is: 0829+089 08 31 54.10 +08 48 00.0 J0831+0848 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. The following 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 FORTLEA, NYALES20, HARTRAO, WESTFORD, VLBA | WETTZELL 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: ========================================= FORTLEZA, HARTRAO, Ny Alesund, Westford, and Wettzell: These stations have Mark IV or Mark 5 racks. Please use the procedures generated by DRUDG. VCs 3 & 4 are used at X-band with IF 1. VCs 5 & 6 are used at X-band with IF 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. Tsukuba32: This station uses K4-2 VCs and a K5 recorder. Please transfer data to Haystack in Mark IV format. 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 the 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: oct11 directory on aspen: /astronomy/oct11/rdv89 or /home/archive/e2e/archive/operations/VLBA/observe/oct11/rdv89 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 Tsukuba's) to Socorro as soon after the experiment as practical. The Tsukuba data should be e-transfered to Haystack in Mark IV format as soon after the experiment as is practical. Media should be shipped to: VLBA Array Operations Center National Radio Astronomy Observatory Attn: Juan Cordova 1003 Lopezville Road Socorro, NM 87801 U.S.A. Phone: 575-835-7000 Shipping and VLBA contact information is also given at: https://science.nrao.edu/facilities/vlba/contact/shipping_information. Please use one of the recommended shipping companies (FedEx, UPS, DHL, TNT). 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. If a station's media takes longer than this to arrive, correlation may be done without it. Therefore, all stations participating in the RDV sessions, please 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 and David.Gordon-1@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.