*** Non-VLBA stations: Please review the CHECKLIST for non-VLBA stations. *** 990406 NRV Revised start/end dates to read April 15 and 16 (not 8 and 9) RDV14 (Astrometric/Geodetic VLBA-13) 1999 April 15 Notes prepared by Nancy Vandenberg, NVI/GSFC Schedule name: rdv14.skd Pointing files: rdv14crd.br, rdv14crd.fd, rdv14crd.hn, rdv14crd.kp, rdv14crd.la, rdv14crd.mk, rdv14crd.nl, rdv14crd.ov, rdv14crd.pt, rdv14crd.sc on aspen in directory /home/aspen6/astronomy/apr99/rdv14 PCFS file: rdv14.skd on cddisa in directory apr99 or via http://lupus.gsfc.nasa.gov/sess/1999/sesshtml/rdv14.html Nominal Start: 14:00 U.T. on April 15 (day 105) first observation at 13:30 U.T. on 1803+784 for Br-Fd-Gc-Hn- Kp-La-Nl-Ov-Pt-Sc-Wf first observation at 14:00 U.T. on 0552+398 for Hh-Mc-Ny-On- Ts-Wz first observation at 13:52 U.T. on NRAO512 for Mk-Kk Duration: 24 hours + 1 hour extra for Gc-Wf-Br-Fd-Hn-Kp-La-Nl-Ov-Pt-Sc Nominal Stop: 14:00 U.T. on April 16 (day 106) last observation at 13:49 U.T. on 0234+285 for Hh last observation at 13:53 U.T. on 1815-553 for Mc-Ny-On-Ts-Wz last observation at 13:56 U.T. on 1954-388 for Kk-Mk last observation at 14:11 U.T. on 1803+784 for Br-Fd-Gc-Hn- Kp-La-Nl-Ov-Pt-Sc-Wf Correlator: VLBA at Socorro Summary file for correlator: rdv14.sksum on aspen Stations: 19 Station Codes # of tapes # of obs Occupation Code Brewster B Br 2.3 (TT) 284 76149901 Fort Davis D Fd 2.3 (TT) 294 76139801 Gilcreek A Al 2.3 (TT) 252 40476601 HartRAO J Hh 2.0 (TT) 116 72326201 Hancock H Hn 2.3 (TT) 261 76185001 Kokee K Kk 2.2 (TT) 266 72983001 Kitt Peak L Kp 2.2 (TT) 287 76109401 Los Alamos M La 2.3 (TT) 294 76119601 Medicina C Mc 2.1 (TT) 203 72308801 Mauna Kea N Mk 2.2 (TT) 260 76175501 North Liberty O Nl 2.3 (TT) 288 76129701 Ny Alesund Q Ny 2.1 (TT) 220 73313301 Onsala T On 2.1 (TT) 209 72137701 Owens Valley R Ov 2.3 (TT) 278 76165401 Pie Town S Pt 2.3 (TT) 292 72348601 St. Croix E Sc 2.3 (TT) 251 76159001 Tsukuba U Ts 2.1 (TT) 201 73452301 Westford F Wf 2.3 (TT) 261 72097301 Wettzell V Wz 1.9 (TT) 176 72247801 Special notes for this session: - This experiment uses THIN TAPES ONLY at all stations. - The VLBA stations will use automatic tape allocation and automatic tape reversal. - Most VLBA stations record two initial fringe finding scans along with geodetic stations Fairbanks and Westford. These stations also record two final long scans. - This is the first participation by Tsukuba in a VLBA session. Their recording capabilities were verified with a fringe test last year. - GGAO and Green Bank will not participate in this session. - Wettzell will joint RDV14 at 17:08 after finishing intensive I99105. Purpose ======= This is the first of six bi-monthly coordinated astrometric/geodetic experiments in 1999 that use the full 10-station VLBA plus up to 10 geodetic stations currently 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 will perform repeated 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 small numbers of sources. While the quality of these results will be high, the observing and data reduction overhead required will be minimal because 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 out of the pool of ~400 Northern Hemisphere ICRF 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. Schedule ======== This is a new schedule generated by Marshall Eubanks using the 9706 version of the NASA sked program which handles continuous tape motion. All stations use thin tapes. "Requested" Sources in RD-V14 : Source name: J1241+6020 = 1239+606 Request from: Mike Garrett mag@nfra.nl Date: 11 March 1999 Previous RA, Dec: RA=12:41:29.59068 DEC=+60:20:41.3195 EPOCH='J2000' Expected flux: (~0.1Jy at 8.4GHz) from Ralph Gaume: 1315+346 = ICRF J131736.4+342515 RA= 13 17 36.494181 Dec= 34 25 15.93257 1338+381 = ICRF J134022.9+375443 RA= 13 40 22.951763 Dec= 37 54 43.83468 Yearly (Y), ROTATING & NEW (N) SOURCES FOR RD-V14 | 0039+230 | | 0212+735 | | 0319+121 | | 0434-188 | | 0528-250 | | 0711+356 | | 0836+710 | | 0954+658 | | 0955+326 | N | 1104-445 | | 1144+402 | | 1239+376 | Y | 1255-316 | Ga| 1315+346 OP326 | Ga| 1338+381 | | 1354-174 | N | 1417+385 | | 1458+718 3C309.1 | | 1600+335 | | 1744+557 NGC6454 | | 1923+210 | | 2134+004 2134+00 | Y | 2230+114 CTA102 | | 2252-090 2252-089 | | 2318+049 | With this session we continue rotating through the large list of candidate ICRF sources. The method was as follows: - Remove sources from the core list of 80 sources used last year. - Add up to 20 sources from the list of candidates that already have some NEOS or VLBA data available (rotating sources). - Add 3 sources from the list of candidates that have never been observed with the VLBA (new sources). The same criteria were used for generating this schedule as were used during the first year of these sessions. The criteria for sources to be mapped are a minimum of 3 scans and 135 observations. These criteria are relaxed for sources below -25 degrees declination. Most of the sources in this schedule meet the mapping criteria. The schedule was made using a combination of automatic selection plus manual scheduling to improve the coverage of the sources. Automatically scheduled scans were selected first on their improvement of sky coverage in the previous 1 hour, and then the best 60% were evaluated for the minor options: minimize idle time, minimize slewing time, and maximize the number of observations. An individual source was not observed more often than every 90 minutes. An early start of 30 seconds was used for the first scan on a tape pass. The minimum scan length was 40 seconds. Recording Mode and Frequencies: same as previous experiments ============================================================ The data will be recorded using 8 channels, 1:4 fan-out, 16 MHz sample rate, 1-bit sampling. This recording mode is designated 128-8-1. The correlator gets a speed-up factor of 2. The frequency sequence covers 490 MHz in 8 channels. 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 are available when observing with the VLBA stations, a wider spanned bandwidth is not advisable. With the 1:4 fanout at 16 MHz sample rate, all 32 tracks are recorded in one pass, so there will be 14 passes on a tape. These tables list the setup for the VLBA stations, the geodetic stations with VLBA back ends, and the geodetic stations with Mark IV back ends. These are the SAME frequencies used in all the standard RDV sessions. Geodetic stations: please read the special procedures in the next section! VLBA | Fairbanks | Kokee Chan Sky Tracks LO IF BBC | LO IF BBC #| LO IF BBC # 1 X 8405.99 2, 4, 6, 8 7900 B 505.99| 7600.1 A 805.89 3| 7600 A 805.99 3 2 X 8475.99 10,12,14,16 7900 B 575.99| 7600.1 A 875.89 4| 7600 A 875.99 4 3 X 8790.99 18,20,22,24 7900 B 890.99| 8080.0 C 710.99 5| 8100 C 690.99 5 4 X 8895.99 26,28,30,32 7900 B 995.99| 8080.0 C 815.99 6| 8100 C 795.99 6 5 S 2220.99 3, 5, 7, 9 2900 A 679.01| 1540.1 B 680.89 9| 1500 B 720.99 9 6 S 2240.99 11,13,15,17 2900 A 659.01| 1540.1 B 700.89 10| 1500 B 740.99 10 7 S 2330.99 19,21,23,25 2900 A 569.01| 1540.1 B 790.89 13| 1500 B 830.99 13 8 S 2360.99 27,29,31,33 2900 A 539.01| 1540.1 B 820.89 14| 1500 B 860.99 14 VLBA | Tsukuba Chan Sky Tracks LO IF BBC | LO IF BBC # 1 X 8405.99 2, 4, 6, 8 7900 B 505.99| 7680 A 725.99 3 2 X 8475.99 10,12,14,16 7900 B 575.99| 7680 A 795.99 4 3 X 8790.99 18,20,22,24 7900 B 890.99| 8080 A 710.99 5 4 X 8895.99 26,28,30,32 7900 B 995.99| 8080 A 815.99 6 5 S 2220.99 3, 5, 7, 9 2900 A 679.01| 1600 B 620.99 9 6 S 2240.99 11,13,15,17 2900 A 659.01| 1600 B 640.99 10 7 S 2330.99 19,21,23,25 2900 A 569.01| 1600 B 730.99 13 8 S 2360.99 27,29,31,33 2900 A 539.01| 1600 B 760.99 14 Onsala, Medicina, Wettzell VLBA | Westford, Ny Alesund 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 L 4 X 8895.99 26,28,30,32 7900 B 995.99| 8580.1 3 315.89 6 H 5 S 2220.99 3, 5, 7, 9 2900 A 679.01| 2020.0 2 200.99 9 L 6 S 2240.99 11,13,15,17 2900 A 659.01| 2020.0 2 220.99 10 L 7 S 2330.99 19,21,23,25 2900 A 569.01| 2020.0 2 310.99 13 H 8 S 2360.99 27,29,31,33 2900 A 539.01| 2020.0 2 340.99 14 H Procedures ========== With continuous tape motion, the tape starts moving and recording at the beginning of the first scan of a pass. The tape runs and records continuously thereafter to the end of the tape (EOT or BOT). A parity check is done after the tape reaches this point. The tape starts moving in the opposite direction at the early start time (30 seconds) before the next scan. There will be a variable length of time between tape passes. For the VLBA stations, there will normally be a long enough time gap between passes for playback. Special procedures for non-VLBA stations ======================================== The tape motion in this experiment is different from normal start&stop schedules. If you are new to continuous recording, please read this section carefully so that you know what to expect. At the time the antenna gets on source, you should see the "Data start" comment from the SNAP schedule. This is the signal that the VLBA correlator will use to determine when to start correlating this scan. At the time the antenna begins slewing to the next source, you will see the "Data stop" comment from the schedule. This is the signal the correlator will use to stop correlating that scan. There will be no "et" command at the end of a scan. The DRUDG listing has an extra column that lists the time that the tape will stop. Note the "Start Tape" and "Stop Tape" columns list times only when the tape will start or stop, otherwise the time is blanked out because the tape is moving. For each scan, the "Start Data" column will be the time when the antenna is expected to be on source. The "Stop Data" column is the time when the antenna starts slewing to the next source. After the setup procedure, the tape is started at the beginning of each pass and will continue to move, at record speed, until it reaches the end of the pass. There are no fast tape motions in this schedule. The tape is continuously recording from the initial "st" command at the start of the pass. There are no other "st" commands during a pass and there are no other setup procedures called. If you have to re-start the schedule for a problem or emergency, you will be able to do it either 1) at the beginning of a pass or 2) in the middle of a pass by entering the setup and start tape commands manually. The problem is that the heads cannot be positioned reliably when the tape is moving if there is recorded data on the tape. If the tape is moving the reproduce power level can cause cross-talk with the head positioner and give false indications of position. At the end of each pass a parity check is done. You will need procedures named "check2m1, check2m2" or "check2v1, check2v2". If you have not already done so for the first two sessions, please create these procedures as a copy of "check2c1, check2c2" and change the tracks to be "v0,v1,v2,v3". Check and adjust the timing of this procedure and then make sure it can complete in the 70 seconds that the schedule allows. If it cannot be completed, you could check the odd tracks in one direction and the even tracks in the other. Special procedures for Onsala, Medicina, Westford, Ny Alesund, Wettzell, HartRAO, Tsukuba ================================================================== These stations have Mark IV formatters. Use the procedures generated by DRUDG. These should be the same as the ones used in previous RDV sessions. This is a non-standard setup. There are 8 video converters used: 3, 4, 5, 6, 9, 10, 13, and 14. These were selected so that you will NOT have to change the standard geodetic IF patching. The 6 unused VCs 1, 2, 7, 8, 11, and 12 should be set to frequencies which do not occur in any of the passbands. Any value in the 100-200 MHz range is OK. The Mark IV formatters currently have no barrel roll capability, so please verify that your FORM command has no specification for barrel roll. The IF3 command in the procedure IFDSX assumes that VC3 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. If you have questions about the wiring, please contact Brian Corey at Haystack. Special procedures for Fairbanks, Kokee ======================================= These stations have VLBA back ends. Use the procedures generated by DRUDG. These procedures will be different from those used in previous RDV sessions. Starting with rdv13 different BBCs are used so that you do NOT have to swap IF inputs. 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. The unused BBCs 1,2,7,8,11,12 should be set to frequencies which do not occur in any of the passbands. Any value in the range 500-600 MHz is OK. The formatter should be set up to use barrel roll. Please verify that you are using the same barrel roll as you used in previous sessions correlated at the VLBA. 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. Make and check out parity check procedures. 2. Make .snp file and listings using DRUDG options 3 or 31 and 5. 3. Set up your system to monitor the clocks with the "gps-fmout" or "fmout-gps" commands. If you have questions or problems, 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 and pperley@nrao.edu on your ready message. 5. Send a "start" message soon after you have started recording. Copy analysts@nrao.edu and pperley@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 and pperley@nrao.edu on your message. 8. Transfer your log files to your normal log file data center. The directories for three possible servers are listed below: directory on cddisa: apr99 directory on vlbeer: apr99 directory on aspen: /home/aspen6/astronomy/apr99/rdv14 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 the log files. Correlation =========== This experiment will be correlated at the VLBA Correlator. Tapes should be shipped to Socorro as soon after the experiment as practical. Summary ======= The following listing is a summary of the observations in this schedule. SKED Summary from file ./rdv14.skd for experiment RDV14 (all scans with at least one subnet station) Average number of obs. per baseline per source (normalized by up-time) = 3.2 Min = .0 Max = 23.2 (Baseline Br-Fd on 0402-362) RMS = 3.0 Total time: 1491 minutes ( 24.9 hours). Key: Br=BR-VLBA Fd=FD-VLBA Gc=GILCREEK Hh=HARTRAO Hn=HN-VLBA Kk=KOKEE Kp=KP-VLBA La=LA-VLBA Mc=MEDICINA Mk=MK-VLBA Nl=NL-VLBA Ny=NYALES20 On=ONSALA60 Ov=OV-VLBA Pt=PIETOWN Sc=SC-VLBA Ts=TSUKUB32 Wf=WESTFORD Wz=WETTZELL Br Fd Gc Hh Hn Kk Kp La Mc Mk Nl Ny On Ov Pt Sc Ts Wf Wz Avg % obs. time: 60 58 66 28 61 64 56 58 43 53 59 60 63 58 59 55 42 71 53 56 % cal. time: 3 3 2 1 2 2 3 3 2 2 3 2 2 3 3 2 2 2 1 2 % slew time: 24 24 16 22 23 12 23 24 26 20 25 11 16 22 24 21 16 12 6 19 % idle time: 11 13 13 47 12 19 16 13 28 23 12 24 18 16 12 20 39 12 37 20 # of tapes : 2.3 2.3 2.3 2.0 2.3 2.2 2.3 2.3 2.1 2.2 2.3 2.1 2.1 2.3 2.3 2.3 2.1 2.3 1.9 total # scans: 284 294 252 116 261 266 287 294 203 260 288 220 209 278 292 251 201 261 176 247 # scans/hour : 11 11 10 4 10 10 11 11 8 10 11 8 8 11 11 10 8 10 7 10.3 Avg scan (sec): 190 178 236 219 209 217 176 177 189 185 183 247 270 186 182 196 187 245 274 207 # OF OBSERVATIONS BY BASELINE | Br Fd Gc Hh Hn Kk Kp La Mc Mk Nl Ny On Ov Pt Sc Ts Wf Wz StnTotal ------------------------------------------------------------------------------------------ Br|284 260 239 30 221 210 256 264 139 205 256 181 158 253 262 197 143 216 128 3254 Fd| 294 216 41 231 208 282 290 137 208 271 167 148 258 288 217 126 227 125 3161 Gc| 252 23 194 187 212 220 132 179 216 180 152 210 219 162 154 188 122 3680 Hh| 116 61 0 32 40 92 0 48 58 76 17 38 67 24 63 70 3449 Hn| 261 159 220 231 164 156 246 186 172 207 229 220 113 255 142 2900 Kk| 266 208 207 84 254 193 133 106 219 208 140 154 157 85 3662 Kp| 287 281 129 206 261 160 141 259 282 205 127 216 117 2940 La| 294 139 205 272 169 150 261 290 216 129 227 127 2918 Mc| 203 78 152 164 184 119 136 144 85 161 163 2790 Mk| 260 190 125 100 215 206 141 144 154 78 3242 Nl| 288 181 162 244 270 228 125 242 136 2600 Ny| 220 188 155 167 151 128 182 148 1404 On| 209 133 148 147 103 170 163 3227 Ov| 278 260 186 137 203 110 3105 Pt| 292 214 128 225 124 3144 Sc| 251 76 219 123 3203 Ts| 201 111 82 2571 Wf| 261 139 3093 Wz| 176 2773 Number of 2-station scans: 48 Number of 3-station scans: 37 Number of 4-station scans: 16 Number of 5-station scans: 13 Number of 6-station scans: 14 Number of 7-station scans: 14 Number of 8-station scans: 19 Number of 9-station scans: 24 Number of 10-station scans: 22 Number of 11-station scans: 22 Number of 12-station scans: 26 Number of 13-station scans: 28 Number of 14-station scans: 37 Number of 15-station scans: 36 Number of 16-station scans: 21 Number of 17-station scans: 39 Number of 18-station scans: 34 Number of 19-station scans: 0 Total # of scans, observations: 450 28558 Average baseline components for all observations Average XY = 4434. Average XZ = 3612. Average YZ = 3252. Average length = 4795.