CORE-A080 (Continuous Observations of the Rotation of the Earth-A080) 2000 January 25 Notes prepared by Cynthia Thomas and Dan MacMillan,NVI/GSFC Schedule name: CA080.SKD on CDDISA Nominal Start: 18:00 U.T. on January 25 (day 025) first observation at 18:00 U.T. on 0552+398 for HH-MA-TS first observation at 18:00 U.T. on 2121+053 for AP-GC-WF Nominal Stop: 18:00 U.T. on January 26 (day 026) last observation at 17:49 U.T. on 0552+398 for HH last observation at 17:51 U.T. on 0749+540 for AP-WF last observation at 17:57 U.T. on 4C39.25 for GC-MA-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) 278 72828201 Fairbanks A GC 1 (TT) 324 40476601 HartRAO J HH 1 (TT) 189 72326201 Matera I MA 1 (TT) 313 72435701 Tsukuba T TS 1 (TT) 293 73452301 Westford E WF 1 (TT) 287 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 | 52.83| UT1-TAI | under 40% | | | | | | |Y-Wobble | 45.58| UT1-TAI | under 40% | | | | | | |UT1-TAI | 1.98| Y-WOBBLE | 46% | | | | | | |UT1-TAI Rate| 3.71| ------- | 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 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 ./ca080.skd for experiment CA080 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x x xx x x xxx x xx x xx x I 16 24 4.0 0048-097I x xx x x xx x x x x I 11 27 4.1 0059+581I x x x x x x x x x x x I 11 106 8.9 0104-408I x x x I 3 3 1.0 0119+115Ix x xx x x xx xxxx x x x x xx x I 19 48 6.1 0119+041I x x x x xx x x x x x x x x x x I 16 24 3.4 0208-512I I 0 0 .0 0229+131I x x I 2 2 .3 0235+164Ix x x x x xx x x x I 10 32 4.1 CTA26 Ix x x x x x x x x x I 10 16 2.5 0402-362I x x x I 3 3 1.0 0454-234I x xxx x xx xx x xx x xx xx I 17 19 4.4 0458-020I xx x x x I 5 5 .8 0528+134Ix xx x xx x xx xx xxx x xx x x xx xx x xI 25 82 10.6 0537-441I I 0 0 .0 0552+398I x x x xx x x xx x x xx x xx xx xxxx x xx x xxI 28 174 17.8 0556+238I x x x x x x xx x xx xx x x x xI 17 25 2.6 0637-752I I 0 0 .0 0727-115Ix xx x xx xxx x xx x xx x x x xx xx x I 23 40 7.9 0749+540I x x x x x x x x x x x xI 12 112 9.7 0804+499I xx x x x x x xx x I 10 60 5.7 0805+410I I 0 0 .0 0823+033Ix x x xx xx x xx x x xx xx x x x xI 20 40 5.8 OJ287 I x xx x x x x xx x x x x I 13 37 4.2 0919-260I x xx xx I 5 5 2.0 0920-397I I 0 0 .0 4C39.25 I x xx x x x x x x x xx x x xx xx x xx x x xxI 25 149 15.2 OK290 I x x x x x xx x x x I 10 12 1.3 0955+476I x x x x x I 5 28 2.7 1034-293Ix x x x x x xI 7 7 1.3 1044+719I x x x x x x x x x x x x I 12 108 9.0 1053+815I I 0 0 .0 1057-797I I 0 0 .0 1104-445I I 0 0 .0 1124-186Ix x xx xx xxx xx x x x x x xx I 18 37 9.0 1128+385I x I 1 3 .2 1144-379Ix x x x x x I 6 6 2.0 1219+044Ix x x x x xx x xx x xxx xx x x xx x I 21 47 6.7 1255-316I xx x x I 4 4 2.6 1300+580I I 0 0 .0 1313-333I x I 1 1 .2 1334-127I x x x x x x xx I 8 10 3.1 1351-018Ix x x x x x x x x x I 10 18 2.8 1357+769I x x x x x xI 6 52 4.3 1424-418I x I 1 1 .3 1451-375I I 0 0 .0 1606+106Ix x x x x xx x x x xx xx xx x xx xx xx xI 24 59 7.8 1622-253I xx x x xx xx xxx x x x xx I 16 18 4.2 NRAO512 Ix xx x xx x x x x x x x xx x xx x xx x xx I 24 141 14.4 1726+455I x x x I 3 10 1.0 1739+522I x x I 2 12 1.1 1741-038I x x xxx xxxx xx x xx xxx xxx x xx xxx x I 27 67 10.7 1749+096I x x x x x I 5 24 3.4 1815-553I I 0 0 .0 1908-201I x x x x xx x xx x I 10 12 3.5 1954-388I x x x xx x x I 7 7 2.4 1958-179I I 0 0 .0 2052-474I I 0 0 .0 2121+053Ixx x xx x x x xx x x xx x x xxx xx x x xx x I 26 80 11.4 2128-123Ix x x x x x x x x xx I 11 15 4.2 2145+067I x x x x I 4 6 .8 2234+282I xxx x x x xx x x x x x I 13 46 5.3 2255-282I x x x x x x x I 7 9 2.7 Total scans, obs: 590 1873 Average number of obs. per baseline per source (normalized by up-time) = 4.5 Min = .0 Max = 30.1 (Baseline Ap-Wf on 1124-186) RMS = 6.4 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: 23 36 24 47 36 42 35 % cal. time: 3 3 2 3 3 3 3 % slew time: 56 24 39 19 10 12 26 % idle time: 16 35 34 30 50 41 34 # of tapes : 1.5 .6 .4 .8 .6 .7 total # scans: 278 324 189 313 293 287 280 # scans/hour : 11 13 7 13 12 11 11.7 Avg scan (sec): 72 96 111 129 107 128 107 # OF OBSERVATIONS BY BASELINE | Ap Gc Hh Ma Ts Wf StnTotal -------------------------------------- Ap|278 176 43 131 87 256 693 Gc| 324 25 124 226 170 721 Hh| 189 162 58 53 341 Ma| 313 123 153 693 Ts| 293 86 580 Wf| 287 718 Number of 2-station scans: 302 Number of 3-station scans: 130 Number of 4-station scans: 101 Number of 5-station scans: 56 Number of 6-station scans: 1 Total # of scans, observations: 590 1873 Average baseline components for all observations Average XY = 5409. Average XZ = 4640. Average YZ = 4655. Average length = 6258.