CORE-A078 (Continuous Observations of the Rotation of the Earth-A078) 1999 December 28 Notes prepared by Cynthia Thomas and Nancy Vandenberg,NVI/GSFC Schedule name: CA078.SKD on CDDISA Nominal Start: 18:00 U.T. on December 28 (day 362) first observation at 18:00 U.T. on 2234+282 Nominal Stop: 18:00 U.T. on December 29 (day 363) last observation at 17:52 U.T. on NRAO512 for MC last observation at 17:54 U.T. on 0402-362 for HH-MA last observation at 17:56 U.T. on 1606+106 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) 285 72828201 Fairbanks A GC 1 (TT) 213 40476601 HartRAO J HH 1 (TT) 173 72326201 Matera I MA 1 (TT) 324 72435701 Medicina B MC 2 (HDT) 325 72308801 Westford E WF 1 (TT) 302 72097301 Purpose ======= The purpose of CORE-A is to validate the CORE concept of measuring EOP continuously using different networks. Comparisons of the EOP results from simultaneous sessions in 1997 and 1998 have shown fairly good agreement, but there are some puzzling systematic differences. It is hoped that additional data to be obtained during 1999 will contribute to understanding this data set. The network for CORE-A includes Fairbanks, HartRAO, Algonquin, Westford, Matera, Medicina, Tsukuba, and Hobart. Tsukuba will begin to participate in CORE-A after April 1. This set of 8 stations includes two geographically paired stations: Algonquin/Westford and Matera/Medicina. For purposes of comparison with NEOS, we want to keep this network as constant as possible but we need to limit the network size to 6 stations. Whenever Tsukuba is available during non-network periods, we will drop Matera. Whenever Hobart is available we will drop Westford. Schedule ======== This is a new schedule generated by C. Thomas with the automatic mode of sked. Following are the characteristics of the CORE-A schedule file: 1) This schedule was optimized for sky coverage. 2) Only the observations in the previous 3 hours of the schedule were considered for the minor options. The best 50% 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 thirty minutes. 5) The minimum SNR limits for the baselines were set to 20 for X-band and 15 for S-band, with the exception of the HartRAO baselines. The minimum SNR limits for the HartRAO baselines were set to 15 for X-bannd and 12 for S-band. 6) This schedule was made using 58 sources which helped improve the sky coverage. Simulation Results ================== Simulated data from this schedule was used in a global solution to estimate the formal errors. The table below lists the formal errors for Earth orientation parameters. These results meet the simulation goals for the CORE-A network. Also shown in the table are the maximum correlations between the Earth orientation parameters and other parameters. The results from the 1998 CORE-A network showed very high (~70%) correlations between certain parameters and this was one of the motivations for re-design of the network. ____________________________________________ | | | | | | EOP |Formal| Other | | |Parameters |Errors|Parameters|Correlation| |____________|______|_________ |___________| | | | | | |X-Wobble | 70.41| UT1-TAI | 47% | | | | | | |Y-Wobble | 46.21| UT1-TAI | 48% | | | | | | |UT1-TAI | 2.65| Y-WOBBLE | 48% | | | | | | |UT1-TAI Rate| 5.20| ------- | under 40% | | | | | | ____________________________________________ 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 following databases: Date Experiment ==== ========== 99AUG16 EUROPE-50 99AUG17 NEOS-A329 99AUG24 CORE-A330 99AUG31 NEOS-A331 99SEP07 CORE-A070 99SEP07 NEOS-A332 99SEP14 NEOS-A333 99SEP20 IRIS-S142 99SEP21 CORE-A071 99SEP21 NEOS-A334 99SEP28 NEOS-A335 99OCT05 CORE-A072 99OCT05 NEOS-A336 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 ./ca078.skd for experiment CA078 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x x x xx xx xx x x x x x I 14 45 7.2 0048-097I x x x x x x x x I 8 35 5.7 0059+581I x x x x x x x xI 8 76 6.3 0106+013I x x x x x x x x x I 9 9 1.3 0119+115I x x x xx x x x xx x xI 12 56 7.1 0119+041Ix x x x x x x x x I 9 37 5.3 0229+131I x I 1 3 .4 0235+164I x x x x x x x x xx x x x I 13 60 7.9 CTA26 I x I 1 3 .5 0402-362I xx xx x I 5 11 5.0 0454-234Ixx x x xx x x xx x x I 12 34 8.7 0458-020I x x x xx xx xx I 9 26 4.1 0528+134I x xx x x xx x x x x x xI 13 81 10.8 0552+398Ixx x x x xx x x xx x x x x x x x x x x xx x xI 25 186 19.4 0556+238I x x x I 3 5 .6 0718+793I x x x x xI 5 9 .8 0727-115I xx xxx x xx x x x x x xxI 15 66 10.6 0749+540Ix x x x x x x xx x x x x I 13 126 10.6 0804+499I x x x x x x x x x I 9 68 6.3 0805+410I I 0 0 .0 0823+033Ixxxx x x x x x x xxx x x x x I 17 58 8.3 OJ287 Ix x x xx x x x xx x xx x x xx x x I 19 116 14.5 0919-260Ix x xx x x x x I 8 8 2.6 0920-397I xx I 2 2 2.0 4C39.25 Ix xx x xx x x xx x x xx x xx x xx xx I 22 157 16.4 OK290 I x x I 2 6 .7 0955+476I x x x I 3 19 1.8 1034-293I x x x x x xI 6 14 3.4 1044+719I x x x x x x x x I 8 76 6.3 1053+815I I 0 0 .0 1124-186Ix x x x xx x x x x x x xI 13 43 10.2 1128+385I x x I 2 4 .4 1144-379I x x I 2 2 .7 1219+044I xx x x x x x x xx xx x I 13 42 6.0 1255-316I I 0 0 .0 1300+580I I 0 0 .0 1313-333I x x I 2 4 1.7 1334-127I x x x x x x x I 7 16 2.8 1351-018I x x x x x I 5 13 2.0 1357+769I x x x x x x I 6 56 4.7 1424-418I x x I 2 2 .8 1451-375I x x x I 3 3 2.5 1606+106I x x x xx xx x x xxx xx x xxxx x x I 21 89 11.9 1622-253I xx xx xx x x x xx xx I 13 27 6.7 NRAO512 I xx x x x x x xx x x x x x x xx x x x I 20 147 14.9 1726+455I x x x xI 4 33 3.3 1739+522I x I 1 6 .5 1741-038I xx xxx x xx x x x x x xx x x x I 18 76 11.7 1749+096I x x x I 3 23 3.1 1908-201I I 0 0 .0 1921-293I I 0 0 .0 1954-388I x xx x I 4 8 3.9 1958-179I xxx xxxx x xx xxx xx xx I 17 47 10.8 2121+053I xx xxxx xxx x x xx xx xx x xI 19 98 14.0 2128-123I x x x I 3 10 1.8 2145+067I x x I 2 12 1.7 2234+282I x x x x xx xx xx x xx xx x x I 17 120 14.2 2255-282I x x x x x I 5 7 2.2 Total scans, obs: 473 2280 Average number of obs. per baseline per source (normalized by up-time) = 5.6 Min = .0 Max = 29.5 (Baseline Hh-Ma on 2121+053) RMS = 7.1 Total time: 1437 minutes ( 24.0 hours). Key: Ap=ALGOPARK Gc=GILCREEK Hh=HARTRAO Ma=MATERA Mc=MEDICINA Wf=WESTFORD Ap Gc Hh Ma Mc Wf Avg % obs. time: 23 27 22 44 29 43 32 % cal. time: 3 2 2 3 3 3 3 % slew time: 56 13 32 17 35 13 28 % idle time: 16 56 43 34 31 39 36 # of tapes : 1.5 .5 .4 .8 1.9 .8 total # scans: 285 213 173 324 325 302 270 # scans/hour : 11 8 7 13 13 12 11.3 Avg scan (sec): 71 113 110 119 78 125 102 # OF OBSERVATIONS BY BASELINE | Ap Gc Hh Ma Mc Wf StnTotal -------------------------------------- Ap|285 180 49 140 155 275 799 Gc| 213 24 117 128 185 634 Hh| 173 169 155 60 457 Ma| 324 309 162 897 Mc| 325 172 919 Wf| 302 854 Number of 2-station scans: 101 Number of 3-station scans: 203 Number of 4-station scans: 50 Number of 5-station scans: 103 Number of 6-station scans: 16 Total # of scans, observations: 473 2280 Average baseline components for all observations Average XY = 4144. Average XZ = 3907. Average YZ = 4091. Average length = 5181.