CORE-A028 (Continuous Observations of the Rotation of the Earth-A028) 1998 January 27 Notes prepared by Cynthia Thomas, NVI/GSFC Schedule name: CA028.SKD on CDDIS Nominal Start: 18:00 U.T. on January 27 (day 027) first observation at 18:00 U.T. on 0119+115 for AP-MA-WF first observation at 18:00 U.T. on 0552+398 for GC-HH Duration: 24 hours Nominal Stop: 18:00 U.T. on January 28 (day 028) last observation at 17:59 U.T. on 0552+398 for GC-HH-MA last observation at 18:01 U.T. on 2134+00 for AP-WF 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) 319 72828201 Fairbanks A GC 1 (TT) 322 40476601 HartRAO J HH 2 (HDT) 151 72326201 Matera I MA 3 (HDT) 343 72435701 Westford E WF 1 (TT) 357 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. Hobart is not available to participate in this experiment because of a prior commitment they had to participate in another experiment. 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 ./ca028.skd for experiment CA028 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x x xx xx x x x xx x I 12 18 4.3 0048-097I x x x x x x I 6 13 3.0 0059+581I xx x x xxx x xx x x x x x x x x x x I 20 108 13.5 0104-408I x x x x x I 5 5 3.4 0106+013I x x xx x x xI 7 7 1.6 0119+115I xx x x x xxxx xI 10 37 7.1 0119+041I I 0 0 .0 0208-512I I 0 0 .0 0229+131I x x x x x x xI 7 13 2.6 0235+164I x I 1 1 .2 CTA26 Ixx x x x x I 6 12 2.9 0402-362I xx xx xx x I 7 7 4.8 0454-234I x x xx xx x x I 8 13 4.9 0458-020I x x I 2 2 .4 0530-727I I 0 0 .0 0528+134I xx x xx xx x x x xx x xxxxx x xxI 21 71 14.2 0537-441I I 0 0 .0 0552+398Ixx xx x x x x x x x x x x xx xx x xx x x I 24 112 17.3 0556+238Ix x xx xx x x x x x x xI 13 47 8.0 0637-752I I 0 0 .0 0718+793I x I 1 3 .4 0727-115Ix x x xxxxx xx x I 11 16 3.7 0749+540Ix x x x x x x x x x x x x x x x x x I 18 105 13.3 0804+499I I 0 0 .0 0805+410I x x x xx x x x x x x x x x x x x xI 18 67 8.4 0823+033I x x x x x x I 7 24 5.2 OJ287 I x x I 2 2 .4 0919-260I x x I 2 2 1.3 0920-397I I 0 0 .0 4C39.25 I x x x x x x x x x x x x xx xx x xx x I 20 86 13.6 OK290 I xx x x x x xx I 8 20 3.2 0955+476Ix x x x x x x x x x x x x x x x x xx x I 20 82 11.9 1034-293I x x x x x xI 6 6 1.7 1044+719Ix x x x x x x x x x x x x x x x xx x x I 20 93 11.6 1053+815I I 0 0 .0 1057-797I I 0 0 .0 1104-445I I 0 0 .0 1124-186I x x x I 3 3 1.2 1128+385I x x xx x xx x x x x x xx xx x x x I 19 85 12.4 1144-379I x x x I 3 3 2.0 1219+044I xx xx x I 5 15 3.2 1255-316I I 0 0 .0 1300+580I I 0 0 .0 1308+326I x x x x x x x xx x x x I 12 32 4.8 1313-333I x I 1 1 1.4 1334-127I x x x x x x I 6 8 2.1 1351-018I x x x I 3 7 1.7 1357+769I x x x x x x x x x x x x x x x x x x I 18 99 12.4 1424-418I x x x I 3 3 2.0 1451-375I x I 1 1 .7 1606+106I x x xx x x x x x x x x xxx I 15 38 7.6 1610-771I I 0 0 .0 1622-253I x x x x I 4 4 2.3 NRAO512 Ix x x x xx x x x x x x x x x x x x x I 19 97 14.9 1726+455I x x x x x x I 6 22 3.3 1739+522Ix x xx x xx x x x x x x x x x x x x x x I 21 111 14.7 1741-038I x x x xx xxx x xx x x x xxxx I 18 49 11.6 1749+096I x x x x x xx x x I 9 36 7.2 1815-553I I 0 0 .0 1908-201I x x xx x x xx x x I 10 10 3.9 1921-293I xx xx x x x x x x I 11 11 4.6 1954-388I x x x x x I 5 5 3.4 1958-179I I 0 0 .0 2005-489I I 0 0 .0 2052-474I I 0 0 .0 2121+053I I 0 0 .0 2128-123I I 0 0 .0 2134+00 I x x x I 3 3 .7 2145+067I x x x xx xxx x x xx x xxx x I 18 45 9.4 2234+282I x x x I 3 9 1.4 2255-282I x x x I 3 3 1.3 Total scans, obs: 501 1672 Average number of obs. per baseline per source (normalized by up-time) = 4.9 Min = .0 Max = 29.7 (Baseline Hh-Ma on 0552+398) RMS = 6.9 Total time: 1443 minutes ( 24.1 hours). Key: Ap=ALGOPARK Gc=GILCREEK Hh=HARTRAO Ma=MATERA Wf=WESTFORD Ap Gc Hh Ma Wf Avg % obs. time: 26 36 21 42 44 34 % cal. time: 3 3 1 3 4 3 % slew time: 56 16 28 20 14 27 % idle time: 14 43 47 33 36 35 # of tapes : 1.7 .6 1.4 2.5 .8 total # scans: 319 322 151 343 357 298 # scans/hour : 13 13 6 14 14 12.4 Avg scan (sec): 71 97 125 107 108 101 # OF OBSERVATIONS BY BASELINE | Ap Gc Hh Ma Wf StnTotal ---------------------------------- Ap|319 255 32 167 315 882 Gc| 322 27 207 280 596 Hh| 151 147 39 445 Ma| 343 203 752 Wf| 357 669 Number of 2-station scans: 185 Number of 3-station scans: 159 Number of 4-station scans: 140 Number of 5-station scans: 17 Total # of scans, observations: 501 1672 Average baseline components for all observations Average XY = 4590. Average XZ = 4092. Average YZ = 3981. Average length = 5358.