CORE-A081 (Continuous Observations of the Rotation of the Earth-A081) 2000 February 8 Notes prepared by Cynthia Thomas and Dan MacMillan,NVI/GSFC Schedule name: CA081.SKD on CDDISA Nominal Start: 18:00 U.T. on February 8 (day 039) first observation at 18:00 U.T. on 0235+164 for AP-HH-MA first observation at 18:00 U.T. on 1749+096 for GC-TS-WF Nominal Stop: 18:00 U.T. on February 9 (day 040) last observation at 17:56 U.T. on 1741-038 for AP-WF last observation at 17:56 U.T. on 0528+134 for HH-MA last observation at 17:58 U.T. on 1606+106 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) 276 72828201 Fairbanks A GC 1 (TT) 329 40476601 HartRAO J HH 1 (TT) 192 72326201 Matera I MA 1 (TT) 307 72435701 Tsukuba T TS 1 (TT) 298 73452301 Westford E WF 1 (TT) 284 72097301 Purpose ======= Comparison of simultaneous CORE-A and NEOS sessions from 1997 to 1999 show that there are significant systematic differences between EOP estimates from the two networks. In addition, a bias can be seen between the CORE-A network of 1999, which replaced Hobart with Medicina, and the network for the previous two years. Further investigation is necessary to determine how to minimize this network sensitivity. Therefore, we plan to continue the CORE-A sessions in 2000 to provide more comparison data. The planned network for 12 of the sessions will be the 1998 network with Tsukuba replacing Westford, which will improve the formal uncertainties of polar motion estimates by a factor of 1.5-2.0. The remaining sessions will use Westford when Hobart is not available. 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 | 52.22| UT1-TAI | under 40% | | | | | | |Y-Wobble | 48.93| UT1-TAI | under 40% | | | | | | |UT1-TAI | 1.96|Tsukuba Y | 44% | | | | | | |UT1-TAI Rate| 3.72| ------- | 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 ==== ========== 99OCT04 CORE-B605 99OCT05 CORE-A072 99OCT05 NEOS-A336 99OCT11 EUROPE-51 99OCT12 NEOS-A337 99OCT19 NEOS-A338 99OCT26 NEOS-A339 99NOV02 CORE-A074 99NOV02 NEOS-A340 99NOV09 NEOS-A341 99NOV16 NEOS-A342 99NOV30 NEOS-A344 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 ./ca081.skd for experiment CA081 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x xx x x x xx xx xx x xx x xI 17 23 4.0 0048-097I x x x xx x x x xI 9 20 3.3 0059+581I x x x x x x x x xx x x x x x I 15 138 11.6 0104-408I x xx x x I 5 5 1.7 0119+115I xx x x xx xx x x x x x x xx x xI 18 53 6.7 0119+041I xx x x x x x x x x x x x x x xxI 17 34 4.8 0208-512I I 0 0 .0 0229+131I x x x x I 4 13 1.7 0235+164I x x x x x x xx x x x I 11 48 6.4 CTA26 I x x x x x x x x x I 9 17 2.7 0402-362I x I 1 1 .3 0454-234Ix x xxx x xx x x xx x x x x x I 17 24 6.2 0458-020Ixx x x xxx x x I 9 11 1.8 0528+134Ixx xx x xx x xxx xx xxx x x xx x x x x I 24 72 9.3 0537-441I I 0 0 .0 0552+398Ixx xx x xx x xx x x x x x xx x xx x x x xx x I 26 164 16.5 0556+238Ix x x x x xx x xx xx x x x x I 16 24 2.5 0637-752I I 0 0 .0 0727-115Ixx xx x x x x x x xx xx xx x x xx x xxxI 24 52 9.7 0749+540I x x x x x x x x x xx x x I 13 122 10.5 0804+499I x x x x x x x x x xI 10 62 5.9 0805+410I I 0 0 .0 0823+033Ix xx x xx xx xxx xxx xx x x xx xx I 22 40 5.8 OJ287 I x x x x x x x x x x x I 11 32 3.7 0919-260I x x I 2 2 .8 0920-397I I 0 0 .0 4C39.25 I xx x x x x x xx x x x x xxx x xxx x x xx xI 25 149 15.3 OK290 Ix x x xx xx x xx x x I 12 14 1.5 0955+476I x I 1 10 1.0 1034-293I xx x x x x x xxI 9 9 2.3 1044+719Ix x x x x x x x x x I 10 96 8.0 1053+815I I 0 0 .0 1057-797I I 0 0 .0 1104-445I I 0 0 .0 1124-186Ix xxx x x xxx x xx x xxI 15 21 4.6 1128+385I x x I 2 9 .8 1144-379Ix xx x x x xI 7 7 2.4 1219+044I x x x x x x x x xxx xx xxx xxx I 19 32 4.5 1255-316I x x xx I 4 4 2.1 1300+580I I 0 0 .0 1313-333I I 0 0 .0 1334-127I x x xx x x xx x x x I 11 13 4.3 1351-018I x x x x x x x x I 8 12 1.9 1357+769I x x x x x x I 6 56 4.7 1424-418I x I 1 1 .3 1451-375I I 0 0 .0 1606+106Ix xx xxx x x x x xx xx xx xx xxx x I 22 50 6.7 1622-253Ixx x x xx x xx xx x xx I 14 16 4.1 NRAO512 Ixx x x xx x xx x x x x x xx x x x xx xx I 23 129 12.9 1726+455I x I 1 6 .6 1739+522Ix x x x x x x x I 8 12 1.0 1741-038I xx x xxx x xxx x x x xx xx xx x xx xx I 24 64 10.2 1749+096I x x x x x xx x x x I 10 45 6.2 1815-553I I 0 0 .0 1908-201I xx x xx x xx I 8 10 2.8 1954-388I x x x xx x x I 7 7 2.4 1958-179I x x x x xx xx x x x I 11 13 2.8 2052-474I I 0 0 .0 2121+053Ixx xx x xx xx x xxx x x x xx x xx xxx x xxI 27 82 11.7 2128-123I I 0 0 .0 2145+067I x x x I 3 7 1.0 2234+282I x xx x x xx x x x x xx I 13 45 5.0 2255-282I x x x x x x x x I 8 10 3.1 Total scans, obs: 589 1886 Average number of obs. per baseline per source (normalized by up-time) = 4.5 Min = .0 Max = 38.6 (Baseline Gc-Ts on 1334-127) RMS = 6.2 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 37 24 46 36 43 35 % cal. time: 3 3 2 3 3 3 3 % slew time: 54 23 38 18 10 12 26 % idle time: 19 35 34 31 49 40 35 # of tapes : 1.5 .7 .4 .8 .6 .8 total # scans: 276 329 192 307 298 284 281 # scans/hour : 11 13 8 12 12 11 11.7 Avg scan (sec): 72 98 111 130 105 132 107 # OF OBSERVATIONS BY BASELINE | Ap Gc Hh Ma Ts Wf StnTotal -------------------------------------- Ap|276 187 40 126 94 248 695 Gc| 329 23 121 232 174 737 Hh| 192 164 56 56 339 Ma| 307 121 152 684 Ts| 298 92 595 Wf| 284 722 Number of 2-station scans: 302 Number of 3-station scans: 126 Number of 4-station scans: 101 Number of 5-station scans: 60 Number of 6-station scans: 0 Total # of scans, observations: 589 1886 Average baseline components for all observations Average XY = 5424. Average XZ = 4629. Average YZ = 4682. Average length = 6270.