CORE-A067 (Continuous Observations of the Rotation of the Earth-A067) 1999 July 27 Notes prepared by Cynthia Thomas and Nancy Vandenberg,NVI/GSFC Schedule name: CA067.SKD on CDDISA Nominal Start: 18:00 U.T. on July 27 (day 208) first observation at 18:00 U.T. on 1622-253 for HH-MA-MC first observation at 18:00 U.T. on 4C39.25 for AP-GC-WF Nominal Stop: 18:00 U.T. on July 28 (day 209) last observation at 17:50 U.T. on 1606+106 for Hh last observation at 17:56 U.T. on 4C39.25 for AP-GC-MA-MC-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) 263 72828201 Fairbanks A GC 1 (TT) 193 40476601 HartRAO J HH 1 (TT) 135 72326201 Matera I MA 3 (HDT) 278 72435701 Medicina B MC 2 (HDT) 291 72308801 Westford E WF 1 (TT) 284 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 63 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 | 73.88| UT1-TAI | 46% | | | | | | |Y-Wobble | 47.73| UT1-TAI | 46% | | | | | | |UT1-TAI | 2.72| Y-Wobble | 46% | | | | | | |UT1-TAI Rate| 6.32| ------- | 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 ==== ========== 99APR06 NEOS-A310 99APR06 CORE-A059 99APR13 NEOS-A311 99APR19 IRIS-S137 99APR20 NEOS-A312 99APR20 CORE-A060 99APR26 EUROPE-48 99APR27 NEOS-A313 99MAY03 IRIS-S138 99MAY04 NEOS-A314 99MAY05 CORE-B403 99MAY11 NEOS-A315 99MAY18 NEOS-A316 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 ./ca067.skd for experiment CA067 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x x x x xx x I 7 22 3.8 0048-097Ix x x x x x xx x x I 10 50 8.0 0059+581I x x x x x x x x x x x x x x xI 15 142 11.8 0106+013Ix x x x x x x x x I 9 9 1.3 0119+115I x x xx x xx x I 8 42 5.4 0119+041I x x x x I 4 22 3.1 0229+131I x x x x I 4 18 2.3 0235+164I x x x xI 4 22 2.8 3C84 I x x x x x x x x x x x x x x xI 15 15 1.4 CTA26 I x x x I 3 9 1.4 0402-362I x x x I 3 5 2.1 0454-234I x x x xx x xx x xx I 11 37 9.4 0458-020I x x I 2 6 1.0 0528+134I x x x xx xx x x x x xx x x I 15 91 12.3 0552+398I x x x x xx x x x x x x x xx x I 16 137 14.5 0556+238I x x I 2 7 .8 0718+793I x x x x I 4 10 .8 0727-115I xx x x x x x x x xx x x x I 14 56 9.0 0749+540I x x x x x x x x x I 9 86 7.3 0804+499I x x x x x x x I 7 56 5.2 0805+410I x I 1 6 .5 0823+033I xx x x xx x x x x x I 11 44 6.4 OJ287 I I 0 0 .0 0919-260I xx x x x x x x x I 9 9 3.1 0920-397I x I 1 1 1.0 4C39.25 Ix x x x x x x x x x x x x xx x x xI 18 124 12.9 OK290 Ix x x x x x I 6 16 1.7 0955+476I x x I 2 6 .6 1034-293I x x x I 3 7 1.6 1044+719I x x x x x I 5 50 4.2 1053+815I x x I 2 20 1.7 1124-186I x x x x x x x x x x I 10 37 8.8 1128+385I x I 1 10 .9 1144-379I x x x I 3 5 2.2 1219+044Ix x x x x x x x x xxI 11 41 5.8 3C273B I x x x I 3 3 .4 1255-316I x xx x I 4 6 2.6 1300+580I I 0 0 .0 1313-333I x I 1 3 .7 1334-127Ix x x x I 4 14 2.5 1351-018I I 0 0 .0 1357+769I x x x x x I 5 46 3.8 1424-418I x I 1 1 .4 1451-375I x x I 2 2 1.7 1606+106Ix xx x x x x x x x x x I 12 49 6.6 1622-253I x x x xx x x I 7 22 5.1 NRAO512 I x x x x x x x x x x x x x x xx x x xI 19 147 15.2 3C345 I x I 1 1 .1 1726+455I x I 1 1 .1 1739+522I x x x x x x xx x x x x x x x x x x xI 19 167 14.7 1741-038I xx x x x x xx xxx x xx xx x xI 18 82 12.6 1749+096Ix x x x x x x I 7 45 6.4 1908-201I x x xx x x x I 7 13 3.1 1921-293I xx x x x I 5 15 3.7 1954-388Ix x x x I 4 8 3.8 1958-179I x x xx I 4 22 5.0 2121+053Ixx x x x x x x x x I 10 64 9.1 2128-123Ix x x x x x x I 7 22 3.9 2134+00 I x x xx I 4 4 .6 2145+067I x x x I 3 9 1.3 2234+282I x xx x x x x x xx x x I 12 87 9.9 3C454.3 Ix x x x x x x x x x x I 11 11 1.4 2255-282I x x x I 3 5 1.3 Total scans, obs: 419 2067 Average number of obs. per baseline per source (normalized by up-time) = 4.5 Min = .0 Max = 26.8 (Baseline Ma-Mc on 1741-038) RMS = 5.9 Total time: 1438 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: 21 29 20 45 27 47 32 % cal. time: 3 2 1 3 3 3 2 % slew time: 55 11 25 15 32 12 25 % idle time: 19 56 52 36 35 36 39 # of tapes : 1.4 .5 .3 2.7 1.7 .8 total # scans: 263 193 135 278 291 284 240 # scans/hour : 10 8 5 11 12 11 10.0 Avg scan (sec): 71 133 130 139 82 145 116 # OF OBSERVATIONS BY BASELINE | Ap Gc Hh Ma Mc Wf StnTotal -------------------------------------- Ap|263 167 43 129 145 259 587 Gc| 193 21 109 126 171 741 Hh| 135 130 123 60 635 Ma| 278 271 150 705 Mc| 291 163 699 Wf| 284 767 Number of 2-station scans: 107 Number of 3-station scans: 146 Number of 4-station scans: 52 Number of 5-station scans: 100 Number of 6-station scans: 14 Total # of scans, observations: 419 2067 Average baseline components for all observations Average XY = 4239. Average XZ = 3864. Average YZ = 4038. Average length = 5170.