CORE-A075 (Continuous Observations of the Rotation of the Earth-A075) 1999 November 16 Notes prepared by Cynthia Thomas and Nancy Vandenberg,NVI/GSFC Schedule name: CA075.SKD on CDDISA Nominal Start: 18:00 U.T. on November 16 (day 320) first observation at 18:00 U.T. on 0119+041 for HH-MA-TS first observation at 18:00 U.T. on 1739+522 for AP-GC-WF Nominal Stop: 18:00 U.T. on November 17 (day 321) last observation at 17:58 U.T. on 1958-179 for AP-HH-MA-WF last observation at 17:59 U.T. on 0823+033 for GC-TS 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) 283 72828201 Fairbanks A GC 1 (TT) 313 40476601 HartRAO J HH 1 (TT) 182 72326201 Matera I MA 1 (TT) 300 72435701 Tsukuba T TS 1 (TT) 282 73452301 Westford E WF 1 (TT) 293 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 | 53.81| ------- | under 40% | | | | | | |Y-Wobble | 46.92| ------- | under 40% | | | | | | |UT1-TAI | 2.02| X-Wobble | 43% | | | | | | |UT1-TAI Rate| 4.35| ------- | 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 ./ca075.skd for experiment CA075 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x x x xx x x x x x x x xx x x I 16 28 4.8 0048-097I xx x x x xx x x xx xI 12 28 4.6 0059+581I I 0 0 .0 0106+013I x x x x x x xx xx x I 11 11 1.7 0119+115I x x x x x xx xx xx x xx xxx x x xx x xx x I 25 75 9.7 0119+041I x x xx x I 5 7 1.0 0229+131I I 0 0 .0 0235+164I x x x x I 4 15 1.8 CTA26 I x x x x x x x x xx xx I 12 18 2.8 0402-362Ix x x x xx I 6 6 2.0 0454-234Ix xx x x xx x xx xx xxx x xx I 18 27 6.6 0458-020I x x x x x xx x x xI 10 16 2.5 0528+134I xx xx xxx x x x xx x x xx x x xxxx xxI 24 64 8.2 0552+398I xx x x x x xx xx xx x xx x x x xx x x xx xx xI 27 170 17.2 0556+238I x x x xxxxx I 8 15 1.5 0718+793Ix x x x x x x I 7 9 .8 0727-115I x x xx x xx x x xx x x x xxx x x x x xxI 23 43 8.7 0749+540I x x xx x x x x I 8 76 6.6 0804+499Ix x x x x x x x x x xx x x x x I 16 108 10.3 0805+410I x x I 2 9 .8 0823+033Ixx xx x x x xx xxxxx x xx I 17 32 4.6 OJ287 I xx x x x x x xxx x x xx x x I 16 43 5.0 0919-260I xx x x I 4 4 1.6 0920-397I I 0 0 .0 4C39.25 I x xx x x x x x x x x x x xx x x x xxI 20 119 12.2 OK290 I x x x x x x x xxI 9 11 1.2 0955+476I x x x xI 4 25 2.5 1034-293I x x x x xx xx x I 9 9 2.0 1044+719I x x x x x x x x x I 9 82 6.8 1053+815I I 0 0 .0 1124-186Ixx x x xx xx xx x xx xx x x I 17 31 7.2 1128+385I x x x x I 4 19 1.7 1144-379I x xx x x x x x I 8 8 2.7 1219+044I x x x x x x xx x x x xx x x x I 16 31 4.4 1255-316I x x I 2 2 1.3 1300+580I I 0 0 .0 1313-333I I 0 0 .0 1334-127I x xx x x x x x I 8 10 3.2 1351-018I x x x xx x x x x x I 10 18 2.8 1357+769I x x x x x x x x I 8 80 6.7 1424-418I x I 1 1 .3 1451-375I I 0 0 .0 1606+106Ix xx x xx x x xx xx xx x x x x x x x x I 22 50 6.7 1622-253I x xx I 3 3 1.2 NRAO512 I x xx x x x xx x x x x x x x x x xx x xI 21 126 12.4 1726+455I x I 1 6 .6 1739+522Ix x x x x x x x x x x x x I 13 104 9.4 1741-038I xx x x xx x xx x xx x xx x x x xxx xxxI 24 59 9.4 1749+096I x x x x x x x I 7 36 4.9 1908-201I x xx x x xx x x xx x x xI 14 16 4.1 1921-293I x xx x x xx xxx xx xx I 14 14 3.3 1954-388I x xx x xx x I 7 7 2.4 1958-179I x x x x xx x xxI 9 21 4.9 2121+053Ixx x x x xxx x xxx x x x x I 16 31 4.3 2128-123I x x xx x x xxI 8 10 2.9 2145+067I x x x x x x x I 7 17 2.4 2234+282Ixx x xx xx xx x xx x x x x x I 17 52 5.8 2255-282I x x x x x x xI 7 9 3.2 Total scans, obs: 586 1811 Average number of obs. per baseline per source (normalized by up-time) = 4.3 Min = .0 Max = 38.1 (Baseline Gc-Ts on 0727-115) RMS = 5.9 Total time: 1440 minutes ( 24.0 hours). Key: Ap=ALGOPARK Gc=GILCREEK Hh=HARTRAO Ma=MATERA Ts=TSUKUB32 Wf=WESTFORD Ap Gc Hh Ma Ts Wf Avg % obs. time: 23 36 25 46 36 43 35 % cal. time: 3 3 2 3 3 3 3 % slew time: 55 21 37 17 24 12 28 % idle time: 17 38 35 32 35 40 33 # of tapes : 1.5 .7 .5 .8 .6 .8 total # scans: 283 313 182 300 282 293 275 # scans/hour : 11 13 7 12 11 12 11.5 Avg scan (sec): 72 101 120 133 113 128 111 # OF OBSERVATIONS BY BASELINE | Ap Gc Hh Ma Ts Wf StnTotal -------------------------------------- Ap|283 182 35 122 88 265 692 Gc| 313 19 118 213 170 702 Hh| 182 153 54 48 309 Ma| 300 117 145 655 Ts| 282 82 554 Wf| 293 710 Number of 2-station scans: 312 Number of 3-station scans: 123 Number of 4-station scans: 95 Number of 5-station scans: 56 Number of 6-station scans: 0 Total # of scans, observations: 586 1811 Average baseline components for all observations Average XY = 5329. Average XZ = 4545. Average YZ = 4551. Average length = 6140.