RDV96 (Astrometric/Geodetic VLBA-96) 2012 DEC 05 18:00 DOY 340 Notes prepared by David Gordon, Ed Himwich and John Gipson 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 5 non-VLBA stations scheduled (HARTRAO, MATERA, NYALES20, 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 two long scans on fairly strong sources at the beginning of the schedule and two near 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 Hh Hn Kp La Ma Mk Nl Ny Ov Pt Sc Wf Wz 1803+784 12340-180000| 300 300 300 300 300 300 300 300 300 300 300 300 300 300| 2209+236 12340-180733| 300 300 300 300 300 300 300 300 300 300 300| 2059+034 12341-174621| 300 300 300 300 300 300 300 300 300 300 300 300| 1803+784 12341-175308| 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 sixth of six coordinated astrometric/geodetic sessions in 2012 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/astrometric VLBI programs of 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 and maintain 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 60-70 sources from the pool of geodetic, astrometric, and monitoring sources. About 30-40 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 will 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: rdv96.skd On ftp.aoc.nrao.edu (aspen): VLBA Pointing files: rdv96crd.br rdv96crd.fd rdv96crd.hn rdv96crd.kp rdv96crd.la rdv96crd.mk rdv96crd.nl rdv96crd.ov rdv96crd.pt rdv96crd.sc Summary file: rdv96.sksum Sked file: rdv96.skd Text file: rdv96.txt Vex file: rdv96.vex At IVS Data Center (ftp://cddisa.gsfc.nasa.gov/vlbi/ivsdata/aux/2012/rdv96) Sked file: rdv96.skd Text file: rdv96.txt This experiment uses the 10 VLBA stations and 5 IVS stations. The IVS stations are: HARTRAO, MATERA, NYALES20, WESTFORD and WETTZELL. Below is the sked summary: Key: Br=BR-VLBA Fd=FD-VLBA Hh=HARTRAO Hn=HN-VLBA Kp=KP-VLBA La=LA-VLBA Ma=MATERA Mk=MK-VLBA Nl=NL-VLBA Ny=NYALES20 Ov=OV-VLBA Pt=PIETOWN Sc=SC-VLBA Wf=WESTFORD Wz=WETTZELL Br Fd Hh Hn Kp La Ma Mk Nl Ny Ov Pt Sc Wf Wz Avg % obs. time: 49 50 44 44 50 50 46 40 47 40 47 51 45 38 33 45 % cal. time: 4 4 3 4 4 4 3 3 4 3 4 4 4 3 3 4 % slew time: 25 24 45 23 25 24 20 18 23 14 23 24 24 16 9 23 % idle time: 21 21 7 28 20 20 29 38 25 42 24 20 27 42 54 28 total # scans: 335 346 244 322 351 350 271 257 330 257 328 354 312 261 296 307 # scans/hour : 14 14 10 13 15 15 11 11 14 11 14 15 13 11 12 13 Avg scan (sec): 127 125 155 118 122 124 147 133 124 133 125 124 124 127 96 126 # 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: 1528 1558 1360 1368 1547 1567 1438 1232 1474 1234 1474 1576 1389 1191 1019 1397 Total GB(M5): 1358 1385 1209 1216 1375 1393 1278 1095 1310 1096 1310 1401 1234 1059 905 1242 # OF OBSERVATIONS BY BASELINE | Br Fd Hh Hn Kp La Ma Mk Nl Ny Ov Pt Sc Wf Wz StnTotal ------------------------------------------------------------------------------------- Br| 243 21 216 260 259 29 208 247 97 273 262 175 129 49 2468 Fd| 38 227 320 330 36 190 277 67 262 331 234 151 48 2754 Hh| 67 23 37 231 0 47 141 12 33 81 92 230 1053 Hn| 209 230 67 116 269 101 183 222 257 202 91 2457 Kp| 319 31 213 263 64 292 335 210 132 40 2711 La| 38 195 285 71 277 338 229 150 50 2808 Ma| 12 51 173 24 35 76 101 262 1166 Mk| 152 53 230 200 109 58 17 1753 Nl| 86 231 279 243 170 68 2668 Ny| 64 71 78 118 180 1364 Ov| 284 170 105 35 2442 Pt| 224 144 46 2804 Sc| 189 89 2364 Wf| 105 1846 Wz| 1310 Number of 2-station scans: 0 Number of 3-station scans: 144 Number of 4-station scans: 153 Number of 5-station scans: 48 Number of 6-station scans: 53 Number of 7-station scans: 51 Number of 8-station scans: 52 Number of 9-station scans: 42 Number of 10-station scans: 93 Number of 11-station scans: 36 Number of 12-station scans: 22 Number of 13-station scans: 9 Number of 14-station scans: 11 Number of 15-station scans: 0 Total # of scans, observations: 714 15984 INTENSIVE BREAKS ================ There is no INT01 Intensive session scheduled for DOY 340, so WETTZELL will not need to drop out. Hovever, there might be a USNO/NRAO UT1 Intensive session using PIETOWN and MK-VLBA. The timing for this is somewhat flexible - sometime between 15:00 and 23:00 UTC. Therefore, PT and MK may be taken out of RDV96 for an ~1.5-2.0 hr period sometime during that window on DOY 340 or 341. We will leave the timing 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 87 sources scheduled in this session. Among them, 30 sources are from the astrometric monitoring list, 30 are from the geodetic monitoring list, 9 are new requested sources and 18 are previously observed sources that have only a few observations or were observed in only one session. 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 ============================== 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 HARTRAO, MATERA, NYALES20, VLBA | WESTFORD, 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: ========================================= HARTRAO, MATERA, NYALES20, 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. 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: dec12 directory on aspen: /astronomy/dec12/rdv96 or /home/archive/e2e/archive/operations/VLBA/observe/dec12/rdv96 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 is practical. Socorro address for media shipping: 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. Therefore, 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.