CORE-A074 (Continuous Observations of the Rotation of the Earth-A074) 1999 November 2 Notes prepared by Cynthia Thomas and Nancy Vandenberg,NVI/GSFC Schedule name: CA074.SKD on CDDISA Nominal Start: 18:00 U.T. on November 2 (day 306) first observation at 18:00 U.T. on 0119+041 for HH-MA-MC-WF first observation at 18:00 U.T. on 4C39.25 for AP-GC Nominal Stop: 18:00 U.T. on November 3 (day 307) last observation at 17:51 U.T. on 1606+106 for GC last observation at 17:58 U.T. on 1749+096 for AP-HH-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) 290 72828201 Fairbanks A GC 1 (TT) 216 40476601 HartRAO J HH 1 (TT) 174 72326201 Matera I MA 1 (TT) 322 72435701 Medicina B MC 2 (HDT) 326 72308801 Westford E WF 1 (TT) 303 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 | 73.76| UT1-TAI | 55% | | | | | | |Y-Wobble | 47.04| UT1-TAI | 51% | | | | | | |UT1-TAI | 3.06| X-Wobble | 55% | | | | | | |UT1-TAI Rate| 6.83| ------- | 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 ==== ========== 99JUL19 IRIS-S140 99JUL20 NEOS-A325 99JUL27 NEOS-A326 99AUG03 NEOS-A327 99AUG09 IRIS-S141 99AUG10 NEOS-A328 99AUG17 NEOS-A329 99AUG31 NEOS-A331 99SEP07 NEOS-A332 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 ./ca074.skd for experiment CA074 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I xx x x x x xx x x xI 11 35 5.5 0048-097I x x x xx x x x x I 9 40 6.5 0059+581I I 0 0 .0 0106+013I xx x xx x x x x xxx xx I 14 14 2.0 0119+115I xxx x xx xx x x x x x xI 14 67 8.6 0119+041I x x x I 3 12 1.7 0229+131I x x x I 3 7 1.0 0235+164I x x x x x x x xI 8 59 7.9 CTA26 I xx x x x x x x I 8 30 4.5 0402-362I x x xI 3 7 3.2 0454-234Ix x x x xx x x x xxx x I 13 41 9.9 0458-020I x x xx x I 5 18 2.9 0528+134I x x xx x x x x x x xx x x x I 15 86 11.4 0552+398I xx xx xx x x x xx x xx x xx x x x x x xx xxI 26 189 19.5 0556+238I xx x x xx x I 7 35 3.8 0718+793Ix x x x x I 5 7 .6 0727-115Ixxx x xx xxx x xx x x x x I 16 73 11.6 0749+540Ix x x x x x x x x x x I 11 102 8.6 0804+499I x x x x x x x x I 8 59 5.5 0805+410I I 0 0 .0 0823+033Ixx x xx x x xx xxx xx x x x x I 18 46 6.6 OJ287 I x xx x x x x xx x x x x x xI 15 91 11.7 0919-260I xxx xx x x x x x I 10 10 3.1 0920-397I x I 1 1 1.0 4C39.25 I x x xx xx x xx x x x xx x x xx x x xxI 22 172 17.7 OK290 I x x x I 3 7 .8 0955+476I x x xx x I 5 24 2.3 1034-293I x x x x I 4 10 2.9 1044+719Ix x x x x x x x x I 9 86 7.2 1053+815I I 0 0 .0 1124-186I xx x x x x x x x xx x I 12 39 9.2 1128+385I x x x I 3 9 .8 1144-379I x x x x I 4 6 2.6 1219+044I xx x x xx x x x x x x x x I 14 43 6.1 1255-316I x x x x I 4 4 2.1 1300+580I I 0 0 .0 1313-333I x I 1 3 .7 1334-127I I 0 0 .0 1351-018I x x x x x x x x I 8 27 4.2 1357+769I x x x x x x x I 7 66 5.5 1424-418I x I 1 1 .4 1451-375I x I 1 1 .8 1606+106Ix x x x x x xx x xx xxx x I 15 70 9.3 1622-253I xx x x x x x x x x I 10 22 5.5 NRAO512 Ix x x x x xxx x xx x x x x x xx x I 19 152 15.9 1726+455I x x x I 3 23 2.3 1739+522Ix x x x x x x x x x I 10 92 8.1 1741-038Ixx xx xx xx xx x xx x xx x I 17 73 11.2 1749+096I x xxx xx x xx I 9 58 8.0 1908-201I x xx x x x x x x I 9 20 5.0 1921-293I x x x x x x x xI 8 14 4.2 1954-388I x x x x I 4 10 5.1 1958-179I x x x xx x x xxI 9 31 7.1 2121+053I x xx x x x x x I 8 32 4.5 2128-123I x x x x x x xI 7 9 1.6 2145+067I x x x xx x x x x x x x I 12 45 6.3 2234+282I x x x x x x x x x x x xx I 13 83 9.9 2255-282I x xx x x x I 6 8 3.0 Total scans, obs: 480 2269 Average number of obs. per baseline per source (normalized by up-time) = 5.6 Min = .0 Max = 31.9 (Baseline Ma-Mc on 0727-115) RMS = 6.7 Total time: 1439 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 30 24 46 29 46 33 % cal. time: 3 2 2 3 3 3 3 % slew time: 54 13 32 16 33 12 27 % idle time: 18 53 41 33 33 37 36 # of tapes : 1.5 .5 .5 .8 1.9 .8 total # scans: 290 216 174 322 326 303 271 # scans/hour : 12 9 7 13 13 12 11.3 Avg scan (sec): 71 122 121 124 78 133 108 # OF OBSERVATIONS BY BASELINE | Ap Gc Hh Ma Mc Wf StnTotal -------------------------------------- Ap|290 186 49 135 153 283 806 Gc| 216 24 112 124 190 636 Hh| 174 170 157 60 460 Ma| 322 306 154 877 Mc| 326 166 906 Wf| 303 853 Number of 2-station scans: 108 Number of 3-station scans: 206 Number of 4-station scans: 48 Number of 5-station scans: 103 Number of 6-station scans: 15 Total # of scans, observations: 480 2269 Average baseline components for all observations Average XY = 4101. Average XZ = 3897. Average YZ = 4072. Average length = 5150.