CORE-A027 (Continuous Observations of the Rotation of the Earth-A027) 1998 January 13 Notes prepared by Cynthia Thomas, NVI/GSFC Schedule name: CA027.SKD on CDDIS Nominal Start: 18:00 U.T. on January 13 (day 013) first observation at 18:00 U.T. on 0059+581 for AP-GC-MA-WF first observation at 18:00 U.T. on 0454-234 for HH-HO Duration: 24 hours Nominal Stop: 18:00 U.T. on January 14 (day 014) last observation at 17:58 U.T. on 2145+067 for AP-GC-WF last observation at 18:01 U.T. on 0454-234 for HH-HO-MA Correlator: Washington **Frequency Sequence**: CDP-WBCA - Modified CDP wide-band SX sequence. (720 MHz wide at X, 125 MHz wide at S), Shifted to avoid RFI at Matera 1 letter 2 letter Station Code Code # of tapes # of obs Occupation Code Algonquin G AP 2 (HDT) 318 72828201 Fairbanks A GC 1 (TT) 351 40476601 HartRAO J HH 3 (HDT) 234 72326201 Hobart H HO 2 (HDT) 185 72425901 Matera I MA 3 (HDT) 317 72435701 Westford E WF 1 (TT) 353 72097301 Purpose ======= The CORE-A sessions measure EOP simultaneously with NEOS, using an independent network of comparable or better precision. The purpose of the parallel sessions is to assess the true accuracy of VLBI results for EOP by comparing the measurements from the two networks. Note on Core-A 1998 results to date: As of early January 1998, 18 CORE-A sessions from 1997 have been completed and analyzed. The comparisons of the EOP results from these sessions with NEOS are quite encouraging. The levels of agreement for daily measurements are 125 micro-arcsec for X-pole, 105 micro-arcsec for Y-pole, and 7.4 microsec for UT1 and 20 microsec for LOD. The corresponding Chi-squares per degree of freedom are 1.2, 1.3, 2.2, and 2.4, respectively. The goals for EOP in the Mark IV era are 25 micro-arcsec for the pole components and 1 microsec for UT1. (No goal for LOD has been set.) We have a lot of work remaining, but these goals are not out of reach. Schedule ======== This is a new schedule generated by C. Thomas with the automatic mode of sked. The following are the characteristics of the schedule: 1) This schedule was optimized for sky coverage. 2) Only the observations in the previous hour of the schedule were considered for the minor options. The best 70% of the configurations were considered for minor options. 3) The "minor options" were set to select observations to maximize the total number of observations, to minimize the idle time between scans, and to minimize time between scans on the same source by twenty minutes. 5) The minimum SNR limits for most baselines were set to 20 for X-band and 15 for S-band. 6) This schedule was made using 59 sources which helped improve the sky coverage. 7) The source models were updated as of mid August 1997 by Dave Shaffer. Procedures ========== Please use the modified CDP Wide-band SX sequence, CDP-WBCA, for this experiment. Correlation ========== This experiment will be correlated at the Washington Correlator with all baselines being correlated. SKED Summary from file ./ca027.skd for experiment CA027 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066Ix x x x x x x x x xx xx xI 14 26 4.3 0048-097I x x x x x x x xxxx x x x xx x x x I 19 44 7.5 0059+581I x x x x x x xx x x x x x xx x x x x I 19 105 10.5 0104-408I x x x x xxx x x xx I 11 15 4.9 0106+013Ix x x x xx I 6 6 .9 0119+115I x x x x x x x xx xI 10 27 3.4 0119+041I x x xI 3 9 1.3 0208-512I x x x x x I 5 5 2.0 0229+131I x x x x xx I 6 10 1.4 0235+164I x x I 2 2 .3 CTA26 I xx x x x x x xI 8 14 2.2 0402-362I x xx x x x x x x I 9 11 3.6 0454-234I x x x xx x x xx xx x x I 15 23 4.4 0458-020I x xx x xx x x x xI 10 18 2.9 0528+134I xxx xx xx x x x x xxx x x x xx x x x xI 23 74 10.0 0537-441I x I 1 1 .3 0552+398I xx xx x x x x x x xx x x xx x xx x x x I 22 98 11.5 0556+238I x xx x x xx xxx x x x I 13 38 4.1 0637-752I x x x x x xx x x x x xI 12 12 4.9 0718+793I x x I 2 6 .6 0727-115I x x x x x x x x x x xx x xI 15 22 4.8 0749+540I x x x xx x x x xx x x x x x x xx I 18 93 9.4 0805+410I x x xx x x x x x x x x x x x xx I 17 61 5.9 0823+033I x x x x x x xx xx I 10 26 3.8 OJ287 I x x x I 3 5 .6 0920-397I x I 1 1 .3 4C39.25 Ix x x x x xx x x x x x x x x x x x I 18 82 8.4 OK290 I x x x x I 4 10 1.1 0955+476I x x x x x x x x x x x x x x xx x x xx xxI 22 86 10.0 1034-293I x x x x x xx xx x xI 11 15 2.7 1044+719Ix x x x x xx x x x x x x x x x x x I 18 90 9.0 1057-797Ix x x x x x x x x I 9 9 3.7 1124-186I x x x xx I 5 5 .9 1128+385I x x x x x x x x x x x x xx x xx x I 18 68 6.4 1144-379I x x xx x xxI 7 7 2.4 1219+044I x x I 2 2 .3 1308+326Ix x x x x x x x xx x x x x I 14 32 3.1 1313-333Ix xx x x x x x I 8 8 2.2 1334-127Ixxx x x x x x x x x x x xx I 15 19 3.8 1351-018I x x xxx I 5 15 2.4 1357+769Ix x x x x x x x x x x x x x x x I 16 84 8.4 1424-418Ixx x x xx x x I 8 8 2.7 1451-375I x x I 2 2 .7 1606+106I x x xx x x x xxx x xx xxxx xI 18 38 4.9 1610-771I x x x x x x x x x x x I 11 11 4.5 1622-253I x xx xx x x x x I 9 9 2.7 NRAO512 Ixx x x x x x x x xx x x xx xx x x x x I 21 101 11.8 1726+455Ix x x x x I 5 27 3.3 1739+522Ixx x xx x x x x x x x x x x x xx x x x I 21 103 10.9 1741-038I x xx xx xx x xx xx x x xxx x x xx xxx xxI 26 54 8.6 1749+096I xx x x xx x x x I 9 27 3.7 1815-553I x x x I 3 3 1.2 1954-388I x xxx x x xx x xx x I 12 12 4.0 2121+053I x x I 2 2 .3 2128-123I x xxx x x xx x x x I 11 15 2.6 2134+00 Ix x xx I 4 4 .6 2145+067I x x xx x x xx xx x x x x xxx x x xx I 22 51 7.0 2234+282I x x I 2 6 .6 2255-282I xxx x x x x I 7 11 3.0 Total scans, obs: 639 1768 Average number of obs. per baseline per source (normalized by up-time) = 3.6 Min = .0 Max = 28.6 (Baseline Gc-Ho on 0727-115) RMS = 6.0 Total time: 1443 minutes ( 24.1 hours). Key: Ap=ALGOPARK Gc=GILCREEK Hh=HARTRAO Ho=HOBART26 Ma=MATERA Wf=WESTFORD Ap Gc Hh Ho Ma Wf Avg % obs. time: 26 39 37 32 40 44 36 % cal. time: 3 4 2 2 3 4 3 % slew time: 53 20 37 26 18 13 28 % idle time: 17 35 21 39 37 38 31 # of tapes : 1.7 .7 2.3 2.0 2.4 .8 total # scans: 318 351 234 185 317 353 293 # scans/hour : 13 14 9 7 13 14 12.2 Avg scan (sec): 71 98 140 151 110 108 113 # OF OBSERVATIONS BY BASELINE | Ap Gc Hh Ho Ma Wf StnTotal -------------------------------------- Ap|318 245 25 3 160 307 595 Gc| 351 20 48 193 261 783 Hh| 234 130 117 35 329 Ho| 185 20 5 622 Ma| 317 199 831 Wf| 353 376 Number of 2-station scans: 316 Number of 3-station scans: 178 Number of 4-station scans: 133 Number of 5-station scans: 12 Number of 6-station scans: 0 Total # of scans, observations: 639 1768 Average baseline components for all observations Average XY = 4973. Average XZ = 4646. Average YZ = 3983. Average length = 5812.