************************************************************************** **** Remember to use your own data center for log files. Non-VLBA **** **** stations do not put log files on aspen any more. **** ************************************************************************** RDV10 (Astrometric/Geodetic VLBA-08) 1998 August 10 Notes prepared by Nancy Vandenberg, NVI/GSFC Schedule name: RDV10.skd Pointing files: rdv10crd.br, rdv10crd.fd, rdv10crd.hn, rdv10crd.kp, rdv10crd.la, rdv10crd.mk, rdv10crd.nl, rdv10crd.ov, rdv10crd.pt, rdv10crd.sc on aspen in directory /home/aspen6/astronomy/aug98/rdv10 PCFS file: rdv10.skd on cddisa in directory aug98 or via http://lupus.gsfc.nasa.gov/sess/sesshtml/rdv10.html Nominal Start: 14:00 U.T. on August 10 (day 222) first observation at 13:35 U.T. on 1803+784 for Gg-Gc-Wf-Nl- Hn-Kp-La-Ov-Pt-Br-Fd-Sc first observation at 14:00 U.T. on 0059+581 for Kk-Mc-Mk-Ny-On first observation at 17:01 U.T. on 0454-234 for Gn Duration: 24 hours + 1 hour extra for Gc-Gg-Wf-Nl-Br-Fd-Sc-Ov-Pt-Hn-Kp-La Nominal Stop: 14:00 U.T. on August 11 (day 223) last observation at 13:33 U.T. on VR422201 for Gn last observation at 14:02 U.T. on OQ208 for Mc-On-Ny last observation at 14:03 U.T. on 0420-014 for Kk-Kp-Mk-Ov last observation at 14:21 U.T. on 1044+791 for Br-Fd-Gc-Hn- La-Nl-Gg-Pt-Wf Correlator: VLBA at Socorro Summary file for correlator: rdv10.sksum on aspen Stations: 18 Station Codes # of tapes # of obs Occupation Code Brewster B Br 2.3 (TT) 282 76149901 Fort Davis D Fd 2.3 (TT) 290 76139801 Gilcreek A Al 2.3 (TT) 250 40476601 Hancock H Hn 2.3 (TT) 268 76185001 Kokee K Kk 2.1 (TT) 256 72983001 Kitt Peak L Kp 2.3 (TT) 289 76109401 Los Alamos M La 2.3 (TT) 291 76119601 Medicina C Mc 2.1 (TT) 212 72308801 Mauna Kea N Mk 2.1 (TT) 256 76175501 North Liberty O Nl 2.3 (TT) 285 76129701 Green Bank 20m P Gn 2.0 (TT) 238 72484701 Ny Alesund Q Ny 2.2 (TT) 238 73313301 Onsala T On 2.2 (TT) 225 72137701 GGAO (MV3) Z Gg 2.3 (TT) 248 71085301 Owens Valley R Ov 2.2 (TT) 277 76165401 Pie Town S Pt 2.3 (TT) 290 72348601 St. Croix E Sc 2.3 (TT) 251 76159001 Westford F Wf 2.3 (TT) 265 72097301 Special notes on tape usage: - This experiment uses THIN TAPES ONLY at all stations. - The VLBA stations will use dynamic tape allocation for this experiment. - Gn will record the intensive and then join the experiment at 1700 UT. They will change tape between 0200-0300 UT and then run unattended for the night shift. All tape changes occur during normal site working hours. - Most VLBA stations record the two initial MV3 fringe finding scans along with Fairbanks and Westford. These stations also record two final long scans. Purpose ======= This is the fourth of six bi-monthly coordinated astrometric/geodetic experiments in 1998 that use the full 10-station VLBA plus the 8 geodetic stations currently capable of recording VLBA modes. This year's series is a continuation of the highly successful series 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 RDV10: There were no requested sources for this session. 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). Yearly (Y), ROTATING & NEW (N) SOURCES FOR RDV10: | 0007+171 | | 0046+316 NGC0262 | Y| 0111+021 | | 0221+067 | | 0420-014 | | 0707+476 | | 0839+187 | Y| 1004+141 | | 1022+194 | | 1038+064 | | 1146+596 NGC3894 | | 1221+809 | | 1338+381 | | 1413+135 | | 1510-089 | | 1557+032 | | 1738+476 | | 1746+470 | | 2017+745 2017+743 | Y| 2136+141 | | 2210-257 | | 2319+272 | 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. Due to its low sensitivity, MV3 was not included directly into the schedule because the necessarily longer scan lengths would have compromised the experiment results. Instead, after the schedule was made, MV3 was tagged along to the schedule. In the tagalong mode, MV3 observes with the longest scan duration of all the stations participating in each scan, to maximize SNR. MV3 will make fringes on about 2/3 of the observations in which it participates. This amount of data will allow a good determination of MV3's position in the reference frame. 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 the first two RDV0x sessions. Geodetic stations: please read the special procedures in the next section! VLBA | Fairbanks | Kokee, GB 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 B 805.89| 7600 B 805.99 2 X 8475.99 10,12,14,16 7900 B 575.99| 7600.1 B 875.89| 7600 B 875.99 3 X 8790.99 18,20,22,24 7900 B 890.99| 8080.0 C 710.99| 8100 C 690.99 4 X 8895.99 26,28,30,32 7900 B 995.99| 8080.0 C 815.99| 8100 C 795.99 5 S 2220.99 3, 5, 7, 9 2900 A 679.01| 1540.1 A 680.89| 1500 A 720.99 6 S 2240.99 11,13,15,17 2900 A 659.01| 1540.1 A 700.89| 1500 A 740.99 7 S 2330.99 19,21,23,25 2900 A 569.01| 1540.1 A 790.89| 1500 A 830.99 8 S 2360.99 27,29,31,33 2900 A 539.01| 1540.1 A 820.89| 1500 A 860.99 Onsala, Medicina, VLBA | Westford, MV3, 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 will be different from normal start&stop schedules. 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, MV3, Ny Alesund ================================================================== Onsala, Medicina, Westford, MV3, and Ny Alesund have Mark IV formatters. You can use the same procedures as for the previous RDV0x sessions. You can also have DRUDG generate the procedures. Please verify your procedures against this writeup. Remember 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, Green Bank =================================================== Fairbanks, Kokee, and Green Bank have VLBA back ends. You can use the same procedures generated for the previous sessions. You can also have DRUDG generate them for you. You must swap your IF inputs so that BBCs 1-8 have the inputs shown in the table above. The unused BBCs 9-14 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, per Ed Himwich's messages. If you have questions or problems, please contact Ed as soon as possible. 4. Send a "ready" message an hour or so before the experiment to the ops mail list. Copy analysts@nrao.edu and pperley@nrao.edu on the 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 the message. 8. *NEW PROCEDURE* Transfer your log files ONLY to your normal log file data center. The directories for three possible servers are listed below: directory on cddisa: aug98 directory on astbo1: aug98 directory on aspen: /home/aspen6/astronomy/aug98/rdv10 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 ./rdv10.skd for experiment RDV10 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x x x x x x I 6 402 6.5 0007+171I x x x x x x x I 7 665 7.9 0014+813I x x x x x x x x x I 9 1096 7.2 NGC0262 I x I 1 36 .4 0048-097Ix x x x I 4 173 2.9 0059+581I x x x x x x x x x x I 11 1249 9.3 0104-408I x x x I 3 30 1.5 0119+115I x x x x x I 5 547 6.9 0119+041I x I 1 66 .9 0133+476I x x x x x x x x I 8 815 6.9 0111+021I x x I 2 150 2.1 0201+113I x x I 2 9 .1 0202+149I x x x I 3 228 2.7 0208-512I I 0 0 .0 0221+067I x x x x I 4 230 3.1 0229+131I x x I 2 39 .5 0234+285I x x x x xx x x I 8 573 6.1 NGC1052 I x x x I 3 172 3.3 CTA26 I x x x I 3 95 1.5 0402-362I x x I 2 16 .4 0420-014I x x x x x I 6 354 5.2 3C120 I x x x I 3 186 2.5 0454-234I x x x x x x I 6 236 5.4 0458-020I x x x I 3 103 1.5 0528+134I x x x x x x x I 7 594 7.3 0537-441I x xx x I 4 6 .3 0552+398I x x x x xx x x x I 9 877 8.2 0642+449I x x x x x x x x I 8 769 6.8 0707+476I x x x xI 4 406 3.5 0727-115I x x x x x x I 6 178 3.0 0804+499I x x x x x x I 6 291 2.5 0823+033I x x x x x I 5 299 4.1 0839+187I x x I 2 160 1.8 OJ287 I x x x x x x x x I 8 716 8.2 0919-260I x x x x x I 5 138 3.5 0920-397I x x I 2 22 .9 4C39.25 Ix x x x x x x I 7 609 5.8 0955+476I x x x x x x x xx x I 10 641 5.4 1004+141I x xI 2 111 1.4 1022+194I x x x x x I 5 401 4.7 1034-293I x x x I 3 134 3.6 1038+064I x x x I 3 109 1.5 1044+719Ix x x x x x x x xx x I 12 1152 7.8 1055+018I x x x x x I 5 325 4.6 1101+384I x x I 2 76 .7 1124-186I x x x x I 4 126 2.6 1128+385I x x x x I 4 377 3.6 1144-379I x x I 2 58 2.3 1145-071I x x x I 3 184 3.0 NGC3894 Ix x I 2 231 1.7 1156+295I x x x I 3 208 2.2 1221+809I x x x x x I 5 731 4.8 3C274 Ix x x x x x I 6 376 4.7 1308+326I x x x x xx x x xI 9 632 6.5 1313-333Ix x x x x I 5 204 6.5 1334-127I x x x x xI 5 242 4.1 1338+381I x x x I 3 63 .6 1357+769I x x x x x x x xI 8 932 6.1 OQ208 I x x x I 3 136 1.4 1413+135I x x x x x x I 6 491 6.1 1424-418I x x I 2 24 1.1 1451-375I x I 1 21 .6 1510-089I x x x x x x x I 7 141 2.9 1514-241I x x x xI 4 182 4.1 1557+032I x xI 2 126 1.7 1606+106I x x x x x x x I 7 532 6.8 1611+343Ix x x x x x xxI 8 645 6.5 1622-253I x x x I 3 117 2.8 NRAO512 I xxx x x x x x x xI 10 596 5.6 1738+476Ix x x x x x I 6 765 6.6 1739+522Ix x x x x xx x I 8 470 3.8 1741-038I x x x x x xI 6 405 6.2 1745+624I x x x x I 4 545 3.9 1746+470I x x I 2 136 1.1 1749+096I x x x x x I 5 411 5.3 1803+784I x x x xx x x x x xI 10 834 5.5 1815-553I x x I 2 2 .4 1908-201I x x x xI 4 212 4.5 1921-293I x x I 2 99 2.8 1954-388I x x x I 3 77 3.0 2017+743I x x x x I 4 435 2.9 2052-474I x I 1 1 .1 2136+141I xx x x I 4 354 4.3 2145+067I x x x x x x xI 7 430 5.8 VR422201I x x x x x x x x x xI 10 993 9.1 2210-257I x x x x x I 5 161 3.8 2234+282I x x x x I 4 320 3.4 2243-123I x x x x x x I 6 252 4.3 2319+272I x x x x I 4 451 4.8 Total scans, obs: 426 30212 Average number of obs. per baseline per source (normalized by up-time) = 4.0 Min = .0 Max = 19.6 (Baseline Gc-Kk on 1510-089) RMS = 3.2 Total time: 1496 minutes ( 24.9 hours). Key: Br=BR-VLBA Fd=FD-VLBA Gc=GILCREEK Hn=HN-VLBA Kk=KOKEE Kp=KP-VLBA La=LA-VLBA Mc=MEDICINA Mk=MK-VLBA Nl=NL-VLBA Gn=NRAO20 Ny=NYALES20 On=ONSALA60 Gg=ORION_5M Ov=OV-VLBA Pt=PIETOWN Sc=SC-VLBA Wf=WESTFORD Br Fd Gc Hn Kk Kp La Mc Mk Nl Gn Ny On Gg Ov Pt Sc Wf Avg % obs. time: 61 57 65 60 60 55 57 41 51 60 55 62 62 67 58 56 54 71 59 % cal. time: 3 3 2 2 2 3 3 2 2 3 2 2 2 2 3 3 2 2 2 % slew time: 25 26 16 24 13 26 26 23 20 26 13 11 15 9 24 26 21 13 20 % idle time: 9 12 14 11 23 15 13 32 25 9 28 23 19 20 13 13 20 12 17 # of tapes : 2.3 2.3 2.3 2.3 2.1 2.3 2.3 2.1 2.1 2.3 2.0 2.2 2.2 3.3 2.2 2.3 2.3 2.3 total # scans: 282 290 250 268 256 289 291 212 256 285 234 238 225 248 277 290 251 265 261 # scans/hour : 11 11 10 10 10 11 11 8 10 11 9 9 9 9 11 11 10 10 10.9 Avg scan (sec): 197 177 234 203 211 171 177 177 178 191 213 235 249 244 190 175 196 241 203 # OF OBSERVATIONS BY BASELINE | Br Fd Gc Hn Kk Kp La Mc Mk Nl Gn Ny On Gg Ov Pt Sc Wf StnTotal -------------------------------------------------------------------------------------- Br|282 269 222 248 190 262 275 140 199 271 206 184 155 206 258 272 220 233 3467 Fd| 290 212 251 191 276 285 137 199 275 215 175 153 210 257 283 228 239 3304 Gc| 250 201 185 208 216 130 182 212 159 185 146 180 209 213 170 190 3592 Hn| 268 164 239 253 152 171 260 210 180 161 212 227 250 234 248 3631 Kk| 256 204 194 83 243 184 147 146 109 154 206 196 145 170 3576 Kp| 289 277 131 210 264 209 172 147 203 265 277 214 229 3539 La| 291 140 202 278 213 179 155 210 262 288 228 240 3386 Mc| 212 83 145 125 173 191 130 121 139 143 144 3172 Mk| 256 192 150 139 102 154 214 202 148 168 3632 Nl| 285 218 183 158 214 252 275 234 244 3062 Gn| 234 154 135 180 191 212 197 204 3337 Ny| 238 190 163 165 178 158 177 3549 On| 225 145 139 156 148 169 3029 Gg| 248 194 209 194 221 3497 Ov| 277 262 203 217 3080 Pt| 290 227 239 2871 Sc| 251 227 3415 Wf| 265 3285 Number of 2-station scans: 40 Number of 3-station scans: 36 Number of 4-station scans: 21 Number of 5-station scans: 15 Number of 6-station scans: 6 Number of 7-station scans: 14 Number of 8-station scans: 6 Number of 9-station scans: 18 Number of 10-station scans: 15 Number of 11-station scans: 15 Number of 12-station scans: 17 Number of 13-station scans: 27 Number of 14-station scans: 33 Number of 15-station scans: 40 Number of 16-station scans: 48 Number of 17-station scans: 34 Number of 18-station scans: 41 Total # of scans, observations: 426 30212 Average baseline components for all observations Average XY = 3783. Average XZ = 3256. Average YZ = 2495. Average length = 4055.