CORE-A045 (Continuous Observations of the Rotation of the Earth-A045) 1998 September 22 Notes prepared by Cynthia Thomas, NVI/GSFC Schedule name: CA045.SKD on CDDISA Nominal Start: 18:00 U.T. on September 22 (day 265) first observation at 18:00 U.T. on 1044+719 for AP-GC-MA-WF first observation at 18:00 U.T. on 1610-771 for HH-HO Duration: 24 hours Nominal Stop: 18:00 U.T. on September 23 (day 266) last observation at 17:56 U.T. on 0229+131 for GC-HO last observation at 18:01 U.T. on 1741-038 for AP-HH-MA-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) 328 72828201 Fairbanks A GC 1 (TT) 327 40476601 HartRAO J HH 3 (HDT) 233 72326201 Hobart H HO 3 (HDT) 168 72425901 Matera I MA 3 (HDT) 313 72435701 Westford E WF 1 (TT) 354 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. Flux Information ================ Several years ago John Gipson wrote a program called snranal which compares the measured performance of an experiment with respect to the predicted. One of the things this program calculates is an empirical flux density for each source. Recently J. Gipson compared the fluxes generated by this program with those from more careful modeling. The agreement is generally good (~15%) for those sources which have been observed more than 20 times. In order to account for changes in the flux catalog since the last update, J. Gipson adjusted the fluxes in the flux catalog for the sources in the current source catalog using the 98Mar03 NEOS-A253 and the 98JAN27XA CORE-A028 experiments. 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 ./ca045.skd for experiment CA045 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I xxx x x x I 6 10 1.7 0048-097Ix x x x x x x x x xx x x xxx I 16 35 5.8 0059+581I x x x x x x x x x x x xx x x x x xI 18 102 10.2 0104-408Ixx x xx x xx xx x I 11 15 4.9 0106+013I x x x x x x x I 7 7 1.1 0119+115I x x xx x x x x xx I 10 35 4.5 0119+041I x x I 2 6 .9 0208-512I xx x x xx x I 7 7 2.9 0229+131I x xx x xx x x x I 9 18 2.3 0235+164I I 0 0 .0 CTA26 I x x x xx x x I 7 15 2.4 0402-362Ix x xx xx xx x xx I 11 15 4.9 0454-234I x x xx xx x x x x x xxI 13 19 3.8 0458-020I x x x x x x x x x x x I 11 15 2.4 0530-727I I 0 0 .0 0528+134Ix xx xxx x x x x xxx x x x xI 17 49 6.5 0537-441I x I 1 1 .3 0552+398Ix x x x x xx x xx x xx x x x xx x xxI 21 85 9.4 0556+238I x x I 2 4 .4 0637-752I x x x x x x x x xI 9 9 3.7 0718+793I x x xI 3 9 .9 0727-115Ix xx xx x x x xx x x x x xx xI 17 30 6.0 0749+540I x x x x x x x x x xx x x xx x x x xI 19 103 10.4 0804+499I x x x x xI 5 20 2.2 0805+410I x x x x x x x x x x x x x x xI 15 50 4.8 0823+033I x x x x xx x x I 8 20 2.9 OJ287 I x x I 2 2 .2 0919-260I x x x x I 4 4 1.6 0920-397I I 0 0 .0 4C39.25 I xx xx xx x xx xx x x x x x x x I 18 92 10.9 OK290 I x x x x x xx I 7 11 1.2 0955+476I xx x xx x x x x x x x x x x x x x I 18 66 7.6 1034-293I xx x x I 4 4 1.4 1044+719I x x x x x x x x x x x x x x x x x x I 18 99 9.9 1053+815I I 0 0 .0 1057-797I x x x x x x x I 7 7 2.9 1104-445I I 0 0 .0 1124-186I xx x x x x x xx I 9 9 2.0 1128+385I x x x x x x x I 7 13 1.1 1144-379I xx xx x xx x I 8 8 2.7 1219+044I I 0 0 .0 1255-316I x x I 2 2 1.3 1300+580I x I 1 3 .3 1308+326I xx xx x x xx x x xx x x x x xI 17 37 3.6 1313-333I x x x xx x x x I 8 8 2.2 1334-127I xx xxx xxx x x x x x x xxx x I 18 22 3.6 1351-018I x x x x xI 5 9 1.4 1357+769I x x x x x x x x x x x x x x x I 15 81 8.1 1424-418I x xx x x x I 6 6 2.0 1451-375I x I 1 1 .3 1606+106Ix x xxx x x x x x x xx x x x x x I 18 45 5.9 1610-771I x x x x x x I 6 6 2.5 1622-253I x x x xx xx x x I 9 9 2.6 NRAO512 Ixx xx x x x x x x x x x x x x xx x I 19 89 10.5 1726+455I x xx x x x x I 7 25 3.0 1739+522Ixx x xx xx x x xx x x x x xxx x x x I 21 104 11.0 1741-038Ix xx xx xxx xx x xx xx x xxx x xx x x x I 26 65 10.3 1749+096Ixx x xx x xx x xx x x x x xxx x I 19 62 8.6 1815-553I x x x I 3 3 1.2 1908-201Ix xx x x x xx x x x I 11 11 2.8 1921-293Ix xx x x xx xxx x x xx xx x I 17 17 4.4 1954-388I x x x xx x x xx xx I 11 11 3.7 1958-179Ix x x x x I 5 5 1.0 2005-489I I 0 0 .0 2052-474I I 0 0 .0 2121+053I x I 1 1 .1 2128-123Ix x x xx x xxxx x x I 12 16 2.7 2134+00 I x xx x x xI 6 6 .9 2145+067I x x xx xx xx x x xx xx x xx x I 18 32 4.4 2234+282I x x x x I 4 10 1.0 2255-282I xx x x xx I 6 12 3.7 Total scans, obs: 639 1692 Average number of obs. per baseline per source (normalized by up-time) = 3.5 Min = .0 Max = 28.4 (Baseline Gc-Ho on 0727-115) RMS = 5.9 Total time: 1442 minutes ( 24.0 hours). Key: Ap=ALGOPARK Gc=GILCREEK Hh=HARTRAO Ho=HOBART26 Ma=MATERA Wf=WESTFORD Ap Gc Hh Ho Ma Wf Avg % obs. time: 26 41 39 33 40 43 37 % cal. time: 3 3 2 1 3 4 3 % slew time: 55 19 44 23 18 13 29 % idle time: 13 35 12 41 37 39 30 # of tapes : 1.8 .7 2.4 2.0 2.5 .8 total # scans: 328 327 233 168 313 354 287 # scans/hour : 13 13 9 6 13 14 12.0 Avg scan (sec): 70 108 146 170 112 105 118 # OF OBSERVATIONS BY BASELINE | Ap Gc Hh Ho Ma Wf StnTotal -------------------------------------- Ap|328 229 26 4 152 316 575 Gc| 327 17 43 182 239 762 Hh| 233 122 125 31 303 Ho| 168 17 4 611 Ma| 313 185 771 Wf| 354 362 Number of 2-station scans: 346 Number of 3-station scans: 152 Number of 4-station scans: 130 Number of 5-station scans: 11 Number of 6-station scans: 0 Total # of scans, observations: 639 1692 Average baseline components for all observations Average XY = 4866. Average XZ = 4587. Average YZ = 3938. Average length = 5727.