RDV16 (Astrometric/Geodetic VLBA-15) 1999 June 22 Notes prepared by Nancy Vandenberg, NVI/GSFC Schedule name: rdv16.skd Pointing files: rdv16crd.br, rdv16crd.fd, rdv16crd.hn, rdv16crd.kp, rdv16crd.la, rdv16crd.mk, rdv16crd.nl, rdv16crd.ov, rdv16crd.pt, rdv16crd.sc on aspen in directory /home/aspen6/astronomy/jun99/rdv16 PCFS file: rdv16.skd on cddisa in directory jun99 or via http://lupus.gsfc.nasa.gov/sess/1999/sesshtml/rdv16.html Nominal Start: 14:00 U.T. on June 21 (day 172) 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 4C39.25 for Hh-Mc-Ny-On first observation at 13:52 U.T. on 1739+522 for Mk-Kk-Ts first observation at 16:15 U.T. on 1101+384 for Wz 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 June 22 (day 173) last observation at 13:56 U.T. on 3C274 for Hh-Mc-On-Ny-Ts-Wz last observation at 13:57 U.T. on 0149+218 for Pt-Mk-Kk-Sc last observation at 14:06 U.T. on 1739+522 for Br-Fd-Gc-Hn- Kp-La-Nl-Ov-Wf Correlator: VLBA at Socorro Summary file for correlator: rdv16.sksum on aspen Stations: 19 Station Codes # of tapes # of obs Occupation Code Brewster B Br 2.3 (TT) 318 76149901 Fort Davis D Fd 2.3 (TT) 324 76139801 Gilcreek A Al 2.3 (TT) 296 40476601 HartRAO J Hh 2.1 (TT) 191 72326201 Hancock H Hn 2.3 (TT) 295 76185001 Kokee K Kk 2.2 (TT) 330 72983001 Kitt Peak L Kp 2.3 (TT) 330 76109401 Los Alamos M La 2.3 (TT) 327 76119601 Medicina C Mc 2.4 (TT) 247 72308801 Mauna Kea N Mk 2.2 (TT) 327 76175501 North Liberty O Nl 2.3 (TT) 308 76129701 Ny Alesund Q Ny 2.2 (TT) 265 73313301 Onsala T On 2.4 (TT) 251 72137701 Owens Valley R Ov 2.3 (TT) 327 76165401 Pie Town S Pt 2.3 (TT) 323 72348601 St. Croix E Sc 2.3 (TT) 290 76159001 Tsukuba U Ts 2.2 (TT) 281 73452301 Westford F Wf 2.3 (TT) 297 72097301 Wettzell V Wz 2.0 (TT) 228 72247801 Special notes for this session: - 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. - GGAO and Green Bank will not participate in this session. - Wettzell will do the intensive schedule I99172 which starts at 14:38. They will begin RDV16 at about 16:15 UT. Purpose ======= This is the next 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-V16 : none ! Yearly (Y), ROTATING & NEW (N) SOURCES FOR RD-V16 Y | 0111+021 | 0109+224 N | 0135-247 | 0149+218 | 0338-214 | 0454+844 | 0745+241 | 0833+585 | 1040+123 3C245 | 1302-102 | 1342+663 Y | 1418+546 | 1435+638 | 1504-166 | 1730-130 NRAO530 | 1732+389 N | 1734+363 | 1806+456 | 1958-179 | 2209+236 | 2325-150 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 experiment RDV15 ================================================================= 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, HartRAO 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. I think one problem > > would be that the data would disappear on tape while the formatter > > resets itself, thus largely eiliminating the benefits of continuous > > motion. 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, starting with RDV13. 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: jun99 directory on vlbeer: jun99 directory on aspen: /home/aspen6/astronomy/jun99/rdv16 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 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 ./rdv16.skd for experiment RDV16 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x x x x x xx xx x I 10 346 5.0 0014+813I x x x x x I 5 462 3.0 0048-097I x x x x x x I 6 262 4.1 0059+581I x x x x x xx x x x I 10 647 4.7 0104-408I x x x x x I 5 29 1.0 0109+224I x x x x x x x I 7 492 5.0 0111+021I x x x I 3 64 .8 0119+115I x x x x x I 5 77 .9 0119+041I x x x x I 4 149 1.8 0133+476I x x x x x x x x x I 9 780 6.4 0135-247I x x x I 3 102 2.0 0149+218I x x x x x x I 6 327 3.4 0201+113I x x x x I 4 164 1.9 0202+149Ix x x x x x I 6 241 2.6 0208-512I x x x I 3 8 .7 0229+131I x x x x x I 5 210 2.4 0234+285I x x x x x x I 6 435 4.2 0235+164I x x x x x x I 6 416 4.5 NGC1052 I x x x x x x I 6 144 2.1 CTA26 I x x x x x x x I 7 261 3.6 0338-214I x x x x x xI 7 229 4.3 0402-362I x x x xx x x I 7 83 3.0 3C120 I x xx x x x x I 7 210 2.6 0454-234I x x x x x x I 6 165 3.3 0458-020I x x x xx x I 6 217 2.9 0454+844I x x x x x I 5 520 3.3 0528+134I x x x x x xI 6 273 3.0 0537-441I x xx x I 4 80 3.9 0536+145I x x x x xI 5 212 2.4 0544+273Ix x x x x I 5 321 3.2 0552+398I x x x x x x x x x I 9 475 4.1 0600+177I x x x x x I 5 203 2.2 0610+260Ix x x x x I 5 236 2.4 0642+449Ix x x x x x x x I 8 479 4.0 0657+172I x x x x x x x I 7 378 4.0 0727-115I x x x x x x x x x I 9 208 3.1 0745+241I x x x x I 4 142 1.4 0804+499I x x x x x x x xI 8 548 4.4 0823+033I x x x x x x xI 7 167 2.1 0833+585I x x x x x I 5 221 1.6 OJ287 I x x x x x x x x x x xI 11 592 6.2 0919-260I x x x x x x x x I 8 177 3.8 0920-397I x x x x xI 5 82 3.0 4C39.25 I x x x x x xx x x x x x xI 13 605 5.5 0955+476I x x x x x x x x x x I 10 456 3.7 1034-293I x x x x I 4 143 3.4 3C245 I x x x I 3 114 1.3 1044+719Ix x x x x x x xx x x x I 12 837 5.6 1101+384I x x x x x x xI 7 324 3.0 1124-186I x x x x x x x x I 8 235 4.3 1128+385I x x x x xI 5 236 2.1 1144-379I x x x x x x I 6 63 2.0 1145-071I x x x x xx x I 7 202 3.0 1156+295I x x x x x x x I 7 315 3.0 3C274 I x x x x x x x x x I 10 400 4.5 1302-102I x x x x x x x I 7 217 3.2 1308+326I x x x x x x x x x I 9 501 4.7 1313-333I x x x x x x x I 7 131 3.2 1334-127I x x x x x x x x x x I 10 270 4.5 1342+663I x x x x x x I 6 581 4.0 1357+769I x x x x x x x I 7 501 3.2 OQ208 I x x x x x x x x x I 9 647 6.4 1418+546I x x x x x xI 6 420 3.3 1424-418I x x x I 3 50 2.0 1435+638I x x x x x I 5 282 1.9 1451-375I x x x x x x x I 7 71 1.9 1504-166I x x x x x x xI 7 189 3.3 1514-241I x x x x I 5 151 3.0 1606+106Ix x x x x x x x I 8 294 3.4 1611+343I x x x x x x x x xI 9 670 6.2 1622-253I x x x x x x I 6 131 2.7 NRAO512 I x x x x x x x xI 8 264 2.4 1726+455I x x x x x x xx x x I 10 358 3.1 NRAO530 Ix x x x x x x x x I 9 260 4.4 1732+389I x x x x x x I 6 256 2.2 1734+363I x x x x x I 5 200 1.8 1739+522I x x x x x x x x x x I 11 575 4.6 1741-038I x x x x x xI 6 230 3.5 1745+624I x x x x x xI 6 486 3.5 1749+096Ix x x x x x x x x I 9 410 4.8 1803+784I x x x x x x x x x x I 10 875 5.6 1806+456I x x x x x I 5 208 1.7 1815-553I x xx I 3 3 .3 1908-201I x x x x x x xx I 8 249 4.6 1921-293Ix x x x x x x I 7 65 1.4 1954-388I x x x x x x x I 7 72 2.4 1958-179I x x x x x x x I 7 194 3.5 2052-474I x x xx x x I 6 11 .5 2145+067Ix xx x x x x xx x I 11 489 5.9 VR422201I x x x x x x x x x x x x x I 13 856 7.3 2209+236I x x x x x x x x x x xI 11 758 7.7 2234+282I x x x x x x I 6 176 1.8 2243-123I x x x x x x x x xI 9 190 3.0 2325-150I x x x x x x I 6 148 2.5 Total scans, obs: 647 28203 Average number of obs. per baseline per source (normalized by up-time) = 3.4 Min = .0 Max = 23.6 (Baseline La-Pt on 0537-441) RMS = 3.0 Total time: 1481 minutes ( 24.7 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: 58 56 62 33 61 58 55 53 49 50 55 58 65 56 55 54 44 69 62 55 % cal. time: 3 3 3 2 3 3 3 3 2 3 3 2 2 3 3 3 3 3 2 3 % slew time: 27 27 21 33 24 15 27 27 28 25 26 14 16 27 27 23 24 15 7 23 % idle time: 10 12 13 30 10 21 13 14 19 20 14 23 14 12 13 17 28 11 27 17 # of tapes : 2.3 2.3 2.3 2.1 2.3 2.2 2.3 2.3 2.4 2.2 2.3 2.2 2.4 2.3 2.3 2.3 2.2 2.3 2.0 total # scans: 318 324 296 191 295 330 330 327 247 327 308 265 251 327 323 290 281 297 228 292 # scans/hour : 12 13 11 7 11 13 13 13 10 13 12 10 10 13 13 11 11 12 9 12.2 Avg scan (sec): 164 154 186 157 184 158 148 145 178 137 159 197 233 153 153 168 139 208 243 171 # 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|318 256 251 31 211 216 270 275 116 218 258 168 128 271 265 182 155 208 107 3174 Fd| 324 194 50 222 218 299 304 107 224 266 134 110 274 303 212 113 222 98 3042 Gc| 296 38 174 187 216 210 126 180 204 192 136 219 202 141 176 173 119 3830 Hh| 191 97 0 30 45 146 0 62 90 126 14 41 108 46 97 126 3422 Hn| 295 138 202 224 160 137 252 163 157 186 212 242 77 282 146 2854 Kk| 330 245 217 57 316 176 112 68 255 226 129 194 138 58 3745 Kp| 330 297 94 249 250 133 100 301 302 187 140 202 86 2778 La| 327 110 223 276 144 113 279 310 208 126 220 99 2847 Mc| 247 56 131 174 215 88 105 148 84 158 205 2666 Mk| 327 179 108 67 260 231 130 186 137 57 3280 Nl| 308 159 135 234 262 227 109 247 119 2649 Ny| 265 190 136 135 126 147 155 161 1631 On| 251 95 110 141 100 157 204 3072 Ov| 327 287 170 159 188 82 3228 Pt| 323 200 129 210 96 3035 Sc| 290 54 247 131 3031 Ts| 281 78 85 2528 Wf| 297 144 2873 Wz| 228 2721 Number of 2-station scans: 67 Number of 3-station scans: 51 Number of 4-station scans: 42 Number of 5-station scans: 49 Number of 6-station scans: 40 Number of 7-station scans: 50 Number of 8-station scans: 41 Number of 9-station scans: 44 Number of 10-station scans: 31 Number of 11-station scans: 36 Number of 12-station scans: 45 Number of 13-station scans: 34 Number of 14-station scans: 26 Number of 15-station scans: 31 Number of 16-station scans: 13 Number of 17-station scans: 30 Number of 18-station scans: 17 Number of 19-station scans: 0 Total # of scans, observations: 647 28203 Average baseline components for all observations Average XY = 4231. Average XZ = 3502. Average YZ = 3198. Average length = 4643.