CORE-A050 (Continuous Observations of the Rotation of the Earth-A050) 1998 December 01 Notes prepared by Cynthia Thomas, NVI/GSFC Schedule name: CA050.SKD on CDDISA Nominal Start: 18:00 U.T. on December 01 (day 335) first observation at 18:00 U.T. on 2234+282 for AP-HH-MA-WF first observation at 18:00 U.T. on 0556+238 for GC-HO Nominal Stop: 18:00 U.T. on December 02 (day 336) last observation at 17:55 U.T. on 0104-408 for HH-HO-MA last observation at 17:56 U.T. on 1351-018 for AP-GC-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) 314 72828201 Fairbanks A GC 1 (TT) 327 40476601 HartRAO J HH 1 (TT) 221 72326201 Hobart H HO 2 (HDT) 166 72425901 Matera I MA 3 (HDT) 296 72435701 Westford E WF 1 (TT) 337 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 98AUG11 (CA042), 98AUG17 (EUROPE-44), and 98AUG25 (CORE-A043) experiments. Procedures ========== Please generate the procedures for this session using drudg. Correlation ========== This experiment will be correlated at the Washington Correlator with all baselines being correlated. SKED Summary from file ./ca050.skd for experiment CA050 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x x xI 3 7 1.3 0048-097Ix x x x xx x x x x I 10 19 3.3 0059+581Ixx x x x x x x x xx x x x x x x x x x x I 21 120 12.0 0104-408I x x xx xx x xx I 9 13 4.2 0106+013I x x x xI 4 4 .6 0119+115I x xx x x x xx x x x x x xI 14 32 4.1 0119+041I x x I 2 6 .9 0208-512I x x x x x xx I 7 7 2.9 0229+131I xx x x x x x x xx x x x I 13 21 2.8 0235+164I I 0 0 .0 CTA26 Ix x x I 3 7 1.1 0402-362I x xx x x xx x I 8 8 2.7 0454-234I xx x xxx xxx x xxx I 13 26 5.6 0458-020Ix x xx x x x I 7 15 2.4 0530-727I I 0 0 .0 0528+134Ixx x x xx x x x x xx x xxx x xx I 19 60 8.2 0537-441I I 0 0 .0 0552+398I x x x x x x x x x x x x x x xx xx x xxI 21 98 11.6 0556+238I x xx x x x x x I 8 28 3.0 0637-752Ix x x x x x x x x x I 10 10 4.1 0718+793I x x x x I 4 12 1.2 0727-115I x x xx xx x x x x x x xxxxxx xI 19 33 6.6 0749+540Ix x x x x x x x x x x x x xx x I 17 93 9.4 0804+499I x x x x x x x x I 8 33 3.7 0805+410I x x x x x I 5 16 1.6 0823+033I x x x x x x I 6 19 2.8 OJ287 I x x x x x I 5 5 .6 0919-260I x x x I 3 3 1.2 0920-397I x I 1 1 .3 4C39.25 I x x xx xx x x x x x xx x x x xx xx x I 21 93 9.3 OK290 I x x x x x xx x I 8 20 2.2 0955+476I xx x x x x x x x x xx x x xx x xI 18 74 8.6 1034-293Ix x x x x x x x xI 9 9 2.6 1044+719Ix x x x x x x x x x x x x x x x I 16 87 8.7 1053+815I x x I 2 6 .6 1057-797Ix x x x x x x x I 8 8 3.3 1104-445I I 0 0 .0 1124-186Ixxx x x x x x x I 9 13 2.6 1128+385Ix x x x x x x I 7 15 1.3 1144-379I x x xx x xI 6 8 2.6 1219+044I x x x I 3 10 1.4 1255-316I x x x I 3 3 1.9 1300+580I x x x x I 4 12 1.2 1308+326I x x x x x x x xx I 9 21 2.0 1313-333I x x xx x x x I 7 7 1.3 1334-127I x xx xx x x x x x x I 11 17 3.0 1351-018I x x x x I 4 8 1.3 1357+769I x x x x x x x x x x x x x x x x x x I 18 102 10.2 1424-418I x x x x x x I 6 6 2.0 1451-375I x x I 2 2 .7 1606+106I x xx xx x x x x x xxI 12 20 2.6 1610-771I x x x x x x x x I 8 8 3.3 1622-253I I 0 0 .0 NRAO512 I x xx x x x x x x x x x x x x x x xx I 20 91 10.5 1726+455I x x x x I 4 13 1.5 1739+522I x x xx xx x x x x x x x x x x x xx x x I 21 100 10.6 1741-038Ixx x x x xxx x x xxxx x x x x x x x I 21 50 8.0 1749+096I x xxx x x x x x x x x x x xx I 17 52 7.4 1815-553I x x I 2 2 .8 1908-201I xx x xx x xx x I 9 9 2.1 1921-293I xx x x x x xx xx x x xx x I 15 15 3.8 1954-388I x x x x x x x x I 8 8 2.7 1958-179I x x x x x x x I 7 9 1.9 2005-489I I 0 0 .0 2052-474I I 0 0 .0 2121+053I x x x x x xx x xI 9 23 3.2 2128-123I x xx x x xI 6 10 1.8 2134+00 I x x I 2 2 .3 2145+067I x x xx x x x xx x x xx xx x I 16 36 5.0 2234+282Ix x x x x x xI 7 23 2.6 2255-282I x xx xI 4 4 1.0 Total scans, obs: 599 1692 Average number of obs. per baseline per source (normalized by up-time) = 3.4 Min = .0 Max = 28.6 (Baseline Gc-Ho on 0727-115) RMS = 5.6 Total time: 1437 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 45 38 32 41 47 38 % cal. time: 3 3 2 1 3 3 3 % slew time: 53 18 42 23 17 12 28 % idle time: 16 31 15 41 37 35 29 # of tapes : 1.7 .8 .6 2.0 2.4 .8 total # scans: 314 327 221 166 296 337 276 # scans/hour : 13 13 9 6 12 14 11.5 Avg scan (sec): 71 120 151 169 120 122 125 # OF OBSERVATIONS BY BASELINE | Ap Gc Hh Ho Ma Wf StnTotal -------------------------------------- Ap|314 242 25 6 151 305 579 Gc| 327 15 42 175 252 762 Hh| 221 119 119 34 320 Ho| 166 22 5 595 Ma| 296 180 768 Wf| 337 360 Number of 2-station scans: 293 Number of 3-station scans: 159 Number of 4-station scans: 137 Number of 5-station scans: 10 Number of 6-station scans: 0 Total # of scans, observations: 599 1692 Average baseline components for all observations Average XY = 4895. Average XZ = 4602. Average YZ = 3963. Average length = 5749.