RV103 (Astrometric/Geodetic VLBA-103) 2014 FEB 12 18:00 DOY 43 Notes prepared by David Gordon, Ed Himwich and John Gipson NVI/GSFC Special notes for this experiment ================================= The legacy system at the VLBA has been decommissioned. Therefore, this session will use the RDBE/DDC/Mark5C system at the VLBA sites for the first time. It will also use a new frequency sequence at ALL stations. The new X-band frequencies are: 8365.75, 8445.75, 8805.75, and 8925.75 MHz, and now span 560 MHz (previously 490 MHz). The new Sband frequencies are: 2232.75, 2262.75, 2352.75, and 2372.75 MHz. The ending in .75 MHz is necessary at the VLBA stations. Therefore it will not be possible to monitor phase cals using the 10 kHz filters. Ed Himwich will provide alternate instructions for monitoring phase cals. This session will record 8 8-MHz bandwidths and use 2-bit sampling, as in previous RDV's. The bit rate will be 256 Mbits/sec. The data will be correlated at the VLBA using the VLBA DiFX software correlator. There are 5 non-VLBA stations scheduled (HART15M, MATERA, NYALES20, ONSALA60, 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 scans on fairly strong sources with most antennas at the beginning, in the middle, and near the end of the schedule. All stations please try to be onsource and recording data for these scans. These scans are: Source Start DURATIONS me yyddd-hhmmss Br Fd Ht Hn Kp La Ma Mk Nl Ny On Ov Pt Sc Wz 3C418 14043-180000| 300 300 300 300 300 300 300 300 300 300 300 300 300 300| 0008-264 14043-180742| 300 300 300 300 300 300 300 | 0059+581 14044-024317| 200 200 200 200 200 200 200 200 200 200 200 200 200 200| 1849+670 14044-174622| 300 300 300 300 300 300 300 300 300 300 300 300 300 300| 0008-264 14044-175341| 300 300 300 300 300 300 300 300 | Purpose ======= This is the first of six coordinated astrometric/geodetic sessions in 2014 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 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: rv103.skd On ftp.aoc.nrao.edu (aspen): VLBA Pointing files: rv103crd.br rv103crd.fd rv103crd.hn rv103crd.kp rv103crd.la rv103crd.mk rv103crd.nl rv103crd.ov rv103crd.pt rv103crd.sc Summary file: rv103.sksum Sked file: rv103.skd Text file: rv103.txt Vex file: rv103.vex At IVS Data Center (ftp://cddisa.gsfc.nasa.gov/vlbi/ivsdata/aux/2014/rv103) Sked file: rv103.skd Text file: rv103.txt This experiment uses the 10 VLBA stations and 5 IVS stations. The IVS stations are: HART15M, MATERA, NYALES20, ONSALA60, and WETTZELL. Below is the sked summary: Key: Br=BR-VLBA Fd=FD-VLBA Ht=HART15M Hn=HN-VLBA Kp=KP-VLBA La=LA-VLBA Ma=MATERA Mk=MK-VLBA Nl=NL-VLBA Ny=NYALES20 On=ONSALA60 Ov=OV-VLBA Pt=PIETOWN Sc=SC-VLBA Wz=WETTZELL Br Fd Ht Hn Kp La Ma Mk Nl Ny On Ov Pt Sc Wz Avg % obs. time: 52 54 56 49 54 53 53 46 52 40 54 51 53 48 40 47 % cal. time: 4 4 3 4 4 4 4 3 4 3 4 4 4 4 4 4 % slew time: 26 25 16 26 25 24 28 22 25 18 20 25 24 26 12 22 % idle time: 18 17 24 20 16 18 14 28 19 38 21 20 17 21 43 28 total # scans: 340 345 293 336 343 346 337 284 343 289 307 334 346 319 345 306 # scans/hour : 14 14 12 14 14 14 14 12 14 12 13 14 14 13 14 13 Avg scan (sec): 131 134 166 126 136 132 136 140 130 118 152 131 133 129 101 124 # 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 TBytes: 1.6 1.7 1.7 1.5 1.7 1.6 1.7 1.4 1.6 1.2 1.7 1.6 1.7 1.5 1.2 1.5 Total TB(M5): 1.4 1.5 1.6 1.4 1.5 1.5 1.5 1.3 1.4 1.1 1.5 1.4 1.5 1.3 1.1 1.3 # OF OBSERVATIONS BY BASELINE | Br Fd Ht Hn Kp La Ma Mk Nl Ny On Ov Pt Sc Wz Total ------------------------------------------------------------------------------------------ Br| 249 22 216 260 268 43 231 248 92 51 271 267 159 45 2422 Fd| 50 215 318 319 39 212 274 55 42 276 325 205 39 2618 Ht| 66 33 39 264 0 56 130 201 10 40 95 240 1246 Hn| 200 219 78 144 267 98 88 187 214 235 89 2316 Kp| 320 26 229 261 52 30 298 325 184 26 2562 La| 35 220 282 58 38 285 338 200 35 2656 Ma| 14 56 185 260 19 35 81 297 1432 Mk| 185 56 22 251 221 121 21 1927 Nl| 79 61 239 277 224 58 2567 Ny| 213 55 56 70 194 1393 On| 22 38 76 258 1400 Ov| 288 152 23 2376 Pt| 196 35 2655 Sc| 85 2083 Wz| 1445 Number of 2-station scans: 53 Number of 3-station scans: 145 Number of 4-station scans: 135 Number of 5-station scans: 123 Number of 6-station scans: 50 Number of 7-station scans: 57 Number of 8-station scans: 77 Number of 9-station scans: 47 Number of 10-station scans: 98 Number of 11-station scans: 13 Number of 12-station scans: 8 Number of 13-station scans: 12 Number of 14-station scans: 7 Number of 15-station scans: 0 Total # of scans, observations: 825 15549 INTENSIVE BREAKS ================ There is an IVS INT01 Intensive session scheduled during RV103, so WETTZELL will drop out from 18:15-19:45. There will also be a USNO/NRAO UT1 Intensive session, scheduled to run at ~06:30 UTC (+/- 4 hrs), using Pietown and MK-VLBA, so these stations will drop out for about an hour. The exact time is unkown, so it is not scheduled in, but 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, 20 sources are from the astrometric monitoring list, 40 are from the geodetic monitoring list, and 28 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 560 MHz at X-band and 140 MHz at S-band using 4 channels in each band. At the VLBA, the X-band uses two LO's in order to fit in the VLBA 512 MHz passband. At the IVS stations, the X-band 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 and the Mark4 geodetic stations with Mark IV back ends. These are NEW frequencies being used for the first time in the RDV/RV sessions. MATERA, NYALES20, VLBA | ONSALA60, WETTZELL Chan Sky Tracks LO IF BBC | LO IF VC VC# Patch 1 X 8365.75 2, 4, 6, 8 7600 B 765.75| 8080.0 1 285.75 3 H 2 X 8445.75 10,12,14,16 7600 B 845.75| 8080.0 1 365.75 4 H 3 X 8805.75 18,20,22,24 9600 D 794.25| 8580.1 3 225.65 5 3(H) 4 X 8925.75 26,28,30,32 9600 D 674.25| 8580.1 3 345.65 6 3(H) 5 S 2232.75 3, 5, 7, 9 3100 A 867.25| 2020.0 2 212.75 9 L 6 S 2262.75 11,13,15,17 3100 A 837.25| 2020.0 2 242.75 10 H 7 S 2352.75 19,21,23,25 3100 A 747.25| 2020.0 2 332.75 13 H 8 S 2372.75 27,29,31,33 3100 A 727.25| 2020.0 2 352.75 14 H VLBA | HART15M Chan Sky Tracks LO IF BBC | LO IF VC VC# Input 1 X 8365.75 2, 4, 6, 8 7600 B 765.75| 8080.0 A 285.75 3 1 2 X 8445.75 10,12,14,16 7600 B 845.75| 8080.0 A 365.75 4 1 3 X 8805.75 18,20,22,24 9600 D 794.25| 8080.0 B 725.75 5 2 4 X 8925.75 26,28,30,32 9600 D 674.25| 8080.0 B 845.75 6 2 5 S 2232.75 3, 5, 7, 9 3100 A 867.25| 2020.0 C 212.75 9 1 6 S 2262.75 11,13,15,17 3100 A 837.25| 2020.0 C 242.75 10 1 7 S 2352.75 19,21,23,25 3100 A 747.25| 2020.0 C 332.75 11 1 8 S 2372.75 27,29,31,33 3100 A 727.25| 2020.0 C 352.75 12 1 Special operations for non-VLBA stations: ========================================= MATERA, NYALES20, ONSALA60, 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. HART15M This station has a DBBC rack. Please use the procedures generated by DRUDG. VCs 3 & 4 are used at X-band with IF A1. VCs 5 & 6 are used at X-band with IF B2. VCs 9, 10, 13 & 14 are used at S-band with IF C1. 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: feb14 directory on aspen: /astronomy/feb14/rv103 or /home/archive/e2e/archive/operations/VLBA/observe/feb14/rv103 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. Ny Alesund may use e-transfer and will need to coordinate this with Haystack Observatory. 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.