CORE-A076 (Continuous Observations of the Rotation of the Earth-A076) 1999 November 30 Notes prepared by Cynthia Thomas and Nancy Vandenberg,NVI/GSFC Schedule name: CA076.SKD on CDDISA Nominal Start: 18:00 U.T. on November 30 (day 334) first observation at 18:00 U.T. on 1749+096 for AP-GC-MA-WF first observation at 18:00 U.T. on 0454-234 for HH-TS Nominal Stop: 18:00 U.T. on December 1 (day 335) last observation at 17:46 U.T. on 0556_238 for GC-TS last observation at 17:56 U.T. on 1958-179 for AP-HH-MA-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) 279 72828201 Fairbanks A GC 1 (TT) 308 40476601 HartRAO J HH 1 (TT) 181 72326201 Matera I MA 1 (TT) 305 72435701 Tsukuba T TS 1 (TT) 273 73452301 Westford E WF 1 (TT) 289 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 | 55.32| ------- | under 40% | | | | | | |Y-Wobble | 47.53| ------- | under 40% | | | | | | |UT1-TAI | 2.02| X-Wobble | 44% | | | | | | |UT1-TAI Rate| 4.21| ------- | 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 ./ca076.skd for experiment CA076 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x x x x x x x x x xx x xx x x I 16 24 4.0 0048-097I x x x x x x x x x x x x I 12 33 5.6 0059+581I x I 1 10 .8 0106+013I x x x x x I 5 5 .8 0119+115Ix x x x x x x x xx x x xx xx xx I 18 48 6.1 0119+041I x x x x xxx x I 8 12 1.7 0229+131I x x I 2 7 .9 0235+164Ix x x x x x x xx I 9 33 4.3 CTA26 Ix x x x x x xx xx xxx x I 14 22 3.4 0402-362I x x x x xI 5 5 1.7 0454-234I xx xx xx xx x x xx xx x xx xI 18 27 6.8 0458-020I x x x xx x x x I 8 12 2.0 0528+134I xx x xxx xx x x x x xxx x x x x x x xI 22 65 8.3 0552+398I x x x xx x x x xx xx x x xx x x xx x xx xxI 25 153 15.5 0556+238I x x x x xx xxx x x x x I 13 21 2.3 0718+793I x x x x x x I 6 6 .5 0727-115Ix xx x xx xx x x x xx xxx x x xx x xI 22 43 8.7 0749+540I x x x x x x x x xI 9 90 7.8 0804+499I x x x x x x x x x x x x x I 13 78 7.4 0805+410I I 0 0 .0 0823+033I x xx x x xx x xx xx xx xx x xI 18 35 5.1 OJ287 Ix x x x x x x x xx xx I 12 40 4.9 0919-260I x x xx x I 5 5 2.0 0920-397I I 0 0 .0 4C39.25 Ixx x xx xx x x xx x xx xx x x x x x x x x I 24 147 15.1 OK290 I x x x x x x xx x I 9 11 1.1 0955+476I x x x I 3 19 1.9 1034-293I x x x x x x x x I 8 8 1.8 1044+719I x x x x x x x x I 8 76 6.3 1053+815I I 0 0 .0 1124-186I xxx x x xxx x x x x xx x I 15 24 5.5 1128+385I I 0 0 .0 1144-379I x x x I 3 3 1.0 1219+044I x xx x x x x xx xx x x x xx x xx x I 20 47 6.7 1255-316I x x x xx I 5 5 2.3 1300+580I I 0 0 .0 1313-333I I 0 0 .0 1334-127I x x x xx x x x x xx I 11 15 4.0 1351-018I x x x x x x x x x x x I 11 19 2.9 1357+769I x x x x x x x xI 8 72 6.0 1424-418I I 0 0 .0 1451-375I I 0 0 .0 1606+106I xx xxxx x xx xx xx x xx x xx x xI 21 47 6.2 1622-253I I 0 0 .0 NRAO512 I xx xx x x x x x x x x xx x x x x x x xx xI 23 142 14.4 1726+455I x I 1 6 .6 1739+522I x x x x x x x x x x I 10 77 7.0 1741-038Ix x xxx x xx x xxx xx x x x x x x x xx xx xI 26 64 10.2 1749+096I x x x xx x x x x x xI 11 47 6.4 1908-201I x xx xx xx x x x xx xx x x I 16 18 4.6 1921-293I x x xx xx xx x xx xx x x x I 16 16 4.4 1954-388I x x x x x I 5 5 1.7 1958-179Ix x x x x x I 6 15 3.5 2121+053I x x x xx xxx x x x xx x xI 15 32 4.5 2128-123I x x xx xx x xI 8 8 3.0 2145+067I xxx x x x xxx x x x I 12 28 3.9 2234+282I x x xx x xx x xx x xx x I 14 54 6.3 2255-282Ix x x x x x x xx I 9 11 3.5 Total scans, obs: 579 1790 Average number of obs. per baseline per source (normalized by up-time) = 4.4 Min = .0 Max = 38.1 (Baseline Gc-Ts on 0727-115) RMS = 6.0 Total time: 1438 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: 22 35 27 48 35 43 35 % cal. time: 3 3 2 3 3 3 3 % slew time: 55 21 34 17 23 13 27 % idle time: 18 39 35 30 37 39 33 # of tapes : 1.5 .6 .5 .8 .6 .8 total # scans: 279 308 181 305 273 289 272 # scans/hour : 11 12 7 12 11 12 11.4 Avg scan (sec): 71 99 131 136 111 130 113 # OF OBSERVATIONS BY BASELINE | Ap Gc Hh Ma Ts Wf StnTotal -------------------------------------- Ap|279 170 42 123 80 261 676 Gc| 308 23 113 213 161 680 Hh| 181 162 49 52 328 Ma| 305 113 150 661 Ts| 273 78 533 Wf| 289 702 Number of 2-station scans: 305 Number of 3-station scans: 124 Number of 4-station scans: 98 Number of 5-station scans: 51 Number of 6-station scans: 1 Total # of scans, observations: 579 1790 Average baseline components for all observations Average XY = 5307. Average XZ = 4571. Average YZ = 4621. Average length = 6172.