RDV87 (Astrometric/Geodetic VLBA-87) 2011 JUNE 28 17:30 DOY 179 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 9 non-VLBA stations scheduled (FORTLEZA, HARTRAO, KOKEE, MEDICINA, NYALES20, SESHAN25, TSUKUB32, WESTFORD, and WETTZELL). These stations should see the "Special operations notes for non-VLBA stations" section below for special instructions. The VLBA DiFX correlator is expected to have only 16 playback units. If all 19 stations participate as scheduled, it will be necessary to limit scans to no more than 16 stations. This will be done by pairing stations together in the two bays of one playback unit, and editing the vex file to remove one of the two stations, when necessary. The pairs would be: 1) Kokee and Hartrao; 2) Fortleza and Tsukuba; and SC-VLBA and Seshan. With the wide distribution of stations, it is not possible to get all the stations in a single scan. However, the schedule has two long (300 second) scans each at the beginning and near the end which contain all the stations. These are designed to facilitate fringe finding at the VLBA correlator. All stations please try to be onsource and recording data for the first scans. There are also a few long scans in the middle with most of the stations that could also be used as fringe finders. These scans are: Source Start DURATIONS name yyddd-hhmmss Br Fd Ft Hh Hn Kk Kp La Mc Mk Nl Ny Ov Pt Sc Sh Ts Wf Wz 0345+460 11179-173000| 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300| 0912+029 11179-174101| 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300| 1357+769 11179-174847| 130 154 157 459 148 139 382 172 147 413 138 143 212 443 84 459 273| 0716+714 11179-195019| 45 45 45 45 45 45 45 45 45 45 45 45 45 45 45 45 45| 0613+570 11179-214016| 480 480 480 480 480 480 480 480 480 480 480 480 480 480 395 480 480| 1300+580 11179-231456| 220 203 480 170 480 215 205 480 365 184 472 224 207 170 277 480 480| 1357+769 11180-034808| 100 112 128 379 107 106 373 100 115 379 102 107 160 364 70 379 253| 1508+572 11180-042137| 480 480 480 480 480 480 480 480 480 480 480 480 480 480 480 480 480| 3C371 11180-043814| 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300| 2229+695 11180-075105| 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300| 2000+472 11180-083653| 124 100 480 83 480 110 99 360 190 88 306 125 110 85 180 283 387| 3C371 11180-110221| 200 200 200 200 200 200 200 200 200 200 200 200 200 200 200 200 200| 2229+695 11180-134435| 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300| 0716+714 11180-171413| 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300 300| 0925-203 11180-172221| 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 third 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: rdv87.skd On ftp.aoc.nrao.edu (aspen): VLBA Pointing files: rdv87crd.br rdv87crd.fd rdv87crd.hn rdv87crd.kp rdv87crd.la rdv87crd.mk rdv87crd.nl rdv87crd.ov rdv87crd.pt rdv87crd.sc Summary file: rdv87.sksum Sked file: rdv87.skd Text file: rdv87.txt Vex file: rdv87.vex At IVS Data Center (ftp://cddisa.gsfc.nasa.gov/vlbi/ivsdata/aux/2011/rdv87) Sked file: rdv87.skd Text file: rdv87.txt This experiment uses the 10 VLBA stations and 9 IVS stations. The IVS stations are: FORTLEZA, HARTRAO, KOKEE, MEDICINA, NYALES20, SESHAN25, TSUKUB32, WESTFORD and WETTZELL. Below is the sked summary: Key: Br=BR-VLBA Fd=FD-VLBA Ft=FORTLEZA Hh=HARTRAO Hn=HN-VLBA Kk=KOKEE Kp=KP-VLBA La=LA-VLBA Mc=MEDICINA Mk=MK-VLBA Nl=NL-VLBA Ny=NYALES20 Ov=OV-VLBA Pt=PIETOWN Sc=SC-VLBA Sh=SESHAN25 Ts=TSUKUB32 Wf=WESTFORD Wz=WETTZELL Br Fd Ft Hh Hn Kk Kp La Mc Mk Nl Ny Ov Pt Sc Sh Ts Wf Wz Avg % obs. time: 56 57 45 34 53 49 56 57 48 53 55 50 55 57 52 44 37 55 45 50 % cal. time: 3 3 2 2 3 3 3 3 3 3 3 3 3 3 3 4 4 3 3 3 % slew time: 21 20 31 40 20 16 19 21 28 23 20 14 21 20 20 28 16 12 8 21 % idle time: 19 19 21 24 23 31 20 18 20 20 21 32 20 18 24 24 41 30 44 25 total # scans: 269 271 189 192 272 266 272 274 247 292 265 237 274 273 256 305 360 237 244 262 # scans/hour : 11 11 8 8 11 11 11 11 10 12 11 10 11 11 11 13 15 10 10 11 Avg scan (sec): 181 181 205 151 168 160 179 180 169 155 180 183 175 181 175 125 89 199 158 167 # data tracks: 16 16 16 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 16 16 16 Total GBytes: 1853 1865 1460 1113 1745 1628 1848 1870 1594 1739 1816 1644 1821 1874 1707 1479 1285 1786 1476 1663 Total GB(M5): 1647 1658 1298 989 1551 1447 1643 1663 1417 1546 1615 1461 1618 1666 1517 1314 1143 1588 1312 1479 # OF OBSERVATIONS BY BASELINE | Br Fd Ft Hh Hn Kk Kp La Mc Mk Nl Ny Ov Pt Sc Sh Ts Wf Wz StnTotal --------------------------------------------------------------------------------------------------------- Br| 205 56 16 169 110 217 217 65 165 200 81 233 216 158 49 81 113 64 2415 Fd| 73 30 188 92 243 252 73 150 219 77 216 254 187 37 65 129 70 2560 Ft| 94 90 30 62 73 79 24 82 69 50 72 100 13 11 112 73 1163 Hh| 44 0 20 28 118 0 35 66 10 28 42 58 48 47 108 792 Hn| 48 168 188 91 92 221 98 155 183 223 35 52 175 90 2310 Kk| 105 93 27 218 68 60 124 93 45 96 131 71 30 1441 Kp| 245 64 161 203 68 239 251 166 38 67 118 60 2495 La| 75 148 226 78 222 267 183 39 69 132 70 2605 Mc| 25 79 158 55 73 81 93 79 102 217 1554 Mk| 120 46 183 148 95 81 133 59 27 1875 Nl| 87 191 221 205 40 62 150 76 2485 Ny| 66 77 82 99 108 116 157 1593 Ov| 223 150 44 79 107 52 2399 Pt| 181 38 67 131 69 2592 Sc| 25 42 151 77 2193 Sh| 275 39 89 1188 Ts| 47 78 1494 Wf| 98 1897 Wz| 1505 Number of 2-station scans: 280 Number of 3-station scans: 139 Number of 4-station scans: 125 Number of 5-station scans: 64 Number of 6-station scans: 47 Number of 7-station scans: 33 Number of 8-station scans: 27 Number of 9-station scans: 33 Number of 10-station scans: 54 Number of 11-station scans: 22 Number of 12-station scans: 21 Number of 13-station scans: 25 Number of 14-station scans: 19 Number of 15-station scans: 13 Number of 16-station scans: 8 Number of 17-station scans: 10 Number of 18-station scans: 3 Number of 19-station scans: 0 Total # of scans, observations: 923 18278 SOURCE SELECTION ================ There are a total of 90 sources scheduled in this session. Among them, 30 sources are from the astrometric monitoring list, 42 are from the geodetic monitoring list, and 12 are previously observed sources that have only a few observations. There are also 6 new sources requested by Y. Kovalev. The requested sources are: 0200+304 02 03 45.3561 +30 41 29.109 J0203+3041 0200+30A 02 03 44.2709 +30 42 37.798 J0203+3042 2016-053 20 18 57.74 -05 09 28.0 J2018-0509 2151-118 21 53 49.00 -11 36 28.0 J2153-1136 2337-123 23 39 47.00 -12 06 45.7 J2339-1206 0124-086 01 27 16.31 -08 21 29.7 J0127-0821 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 | 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 | 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 | SESHAN25 Chan Sky Tracks LO IF BBC | LO IF BBC # 1 X 8405.99 2, 4, 6, 8 7900 B 505.99| 9100 A 694.01 3 2 X 8475.99 10,12,14,16 7900 B 575.99| 9100 A 624.01 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| 1600 B 632.99 9 6 S 2262.99 11,13,15,17 2900 A 637.01| 1600 B 662.99 10 7 S 2352.99 19,21,23,25 2900 A 547.01| 1600 B 752.99 13 8 S 2372.99 27,29,31,33 2900 A 527.01| 1600 B 772.99 14 FORTLEA, NYALES20, HARTRAO, WESTFORD, VLBA | WETTZELL, MEDICNIA 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: ========================================= Kokee, Seshan These stations have VLBA4 back ends. 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. FORTLEZA, HARTRAO, Medicina, Ny Alesund, Westford, Wettzell: These stations have Mark IV 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: These stations use 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: jun11 directory on aspen: /astronomy/jun11/rdv87 or /home/archive/e2e/archive/operations/VLBA/observe/jun11/rdv87 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) to Socorro as soon after the experiment as practical. The Tsukuba data should be e-transfered to Haystack as soon after the experiment as is 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.