CORE-A084 (Continuous Observations of the Rotation of the Earth-A084) 2000 June 27 Notes prepared by Cynthia Thomas and Dan MacMillan,NVI/GSFC Schedule name: CA084.SKD on CDDISA Nominal Start: 18:00 U.T. on June 27 (day 179) first observation at 18:00 U.T. on 1749+096 for HH-HO-TS first observation at 18:00 U.T. on 4C39.25 for AP-GC-MA Nominal Stop: 18:00 U.T. on June 28 (day 180) last observation at 17:45 U.T. on 2145+067 for GC last observation at 17:48 U.T. on 1749+096 for HH-HO-TS last observation at 17:55 U.T. on 0823+033 for AP-MA Correlator: Haystack **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) 260 72828201 Fairbanks A GC 1 (TT) 332 40476601 HartRAO J HH 1 (TT) 190 72326201 Hobart H HO 2 (HDT) 242 72425901 Matera I MA 1 (TT) 262 72435701 Tsukuba T TS 1 (TT) 398 73452301 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 10 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. Westford participated in the other three sessions since Hobart was 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. 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 | 36.24| ------- | under 40% | | | | | | |Y-Wobble | 39.18|Tsukuba Z | 48% | | | | | | |UT1-TAI | 2.28|Tsukuba Y | 43% | | | | | | |UT1-TAI Rate| 4.91| ------- | 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 ==== ========== 00FEB01 NEOS-A353 00FEB08 NEOS-A354 00FEB08 CORE-A081 00FEB22 NEOS-A356 00FEB29 NEOS-A357 00MAR14 NEOS-A359 00MAR21 NEOS-A360 00MAR28 NEOS-A361 00APR04 NEOS-A362 00APR11 NEOS-A363 Procedures ========== Please generate the procedures for this session using drudg. Correlation ========== This experiment will be correlated at the Haystack Correlator with all baselines being correlated. SKED Summary from file ./ca084.skd for experiment CA084 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I xxx x x x x x x xx x x xx x x xxx xx x xI 24 40 6.4 0048-097I x x x x x x xx x I 9 21 4.1 0059+581I x x x x x x x x xx x x x x x I 15 37 3.7 0104-408I x xx x x xx xx x xx xxI 14 20 6.0 0119+115I x x xx x x x x x x x x xx x x x x xxx x I 22 43 5.8 0119+041Ix xx x xx x x x xx I 11 15 2.3 0208-512I I 0 0 .0 0229+131I x xx I 3 3 .4 0235+164Ix x x x x x x x x I 9 36 4.7 CTA26 Ix x x xx x x x x x x x x x x x I 16 16 2.5 0402-362I xx I 2 2 .7 0454-234Ix xxx x x x x xx x xxx x xxxxx I 20 24 4.3 0458-020I x x x x x xxx x x I 10 21 3.4 0528+134I xx x x x x xx xx x x xx x xx x x xI 20 36 4.7 0537-441Ixx x xxx x xx x x xx I 13 15 4.4 0552+398Ixx xx x xx xx xx x x x x x xx x x x xx x I 24 94 10.8 0556+238I I 0 0 .0 0637-752I x x x x x I 5 5 2.0 0727-115I xx x xxxx x x xx xxx x x x xx I 19 21 3.1 0749+540Ix x x xx x x x x x x x x x x x x x x x I 20 102 10.3 0804+499I x I 1 3 .3 0805+410I x x x I 3 12 1.2 0823+033Ixx xxxxx x xxx x xxxx x xxx xI 21 25 3.6 OJ287 I xx x x x x xx x x x x x xxx xI 17 29 3.7 0919-260I I 0 0 .0 0920-397I I 0 0 .0 4C39.25 I x xx x xx xx xx x x x x x xx x x xxI 21 70 8.6 OK290 I x x x x x x x x x xI 10 10 1.1 0955+476I x xx x x x x x x I 9 34 3.9 1034-293I xx x x xxx xx x xxx xxx I 16 16 2.6 1044+719I x x x x x x x x x xI 10 37 3.7 1053+815I x I 1 6 .6 1057-797I x x x I 3 3 1.2 1104-445I I 0 0 .0 1124-186I x x xx xxx xxxx x xx x xx xxx xxx xx I 25 40 7.6 1128+385I x I 1 3 .3 1144-379I x xx xx x xx x x x xx x x I 15 17 5.1 1219+044I xxx x x xx xx xx xxx x xx x x xx x x xxxI 26 66 9.8 1255-316I I 0 0 .0 1300+580I x x x x x x x x xI 9 19 1.9 1313-333I I 0 0 .0 1334-127I x x x x I 4 4 .7 1351-018I x x x x x x x x xx I 10 10 1.6 1357+769Ix x x x x x x x I 8 48 4.8 1424-418I x x x xx x I 6 10 3.0 1451-375I xx x x I 4 4 1.1 1606+106I xx x xx xxx xx xx xxx xx x xx xx x xx I 25 50 6.9 1622-253Ix x xxx xx xxx x xx x xxx x I 18 18 3.0 NRAO512 I xx x x x x xx x x x x x I 13 40 4.0 1726+455I x x x x x I 5 5 .6 1739+522Ix x x x xx x x x I 9 35 3.7 1741-038I x x x x x x xx xx xxxxx xx x x xx x I 22 24 3.9 1749+096I x x x xx x xx xxx xI 12 39 5.7 1815-553I x xI 2 2 .8 1908-201I x xx x x x xxx xx x I 12 12 2.0 1954-388Ixx xx x xx xx x x I 11 11 3.0 1958-179I x xxx x x x x xx xx x x x I 15 24 4.4 2052-474I x x x I 3 3 .8 2121+053Ix x x x x x xx x x x x I 12 20 2.9 2128-123I x x x I 3 3 1.1 2145+067Ix x x xx x x x x xx xxx xxx xxxx I 21 45 6.4 2234+282I x xx xx x xx x x x xx x x xx x x I 19 37 3.7 2255-282I xx xxI 4 4 1.3 Total scans, obs: 682 1389 Average number of obs. per baseline per source (normalized by up-time) = 3.4 Min = .0 Max = 32.1 (Baseline Ho-Ts on 1606+106) RMS = 5.5 Total time: 1436 minutes ( 23.9 hours). Key: Ap=ALGOPARK Gc=GILCREEK Hh=HARTRAO Ho=HOBART26 Ma=MATERA Ts=TSUKUB32 Ap Gc Hh Ho Ma Ts Avg % obs. time: 23 37 37 30 46 43 36 % cal. time: 3 3 2 2 3 4 3 % slew time: 53 21 37 32 18 19 30 % idle time: 19 36 23 34 31 32 29 # of tapes : 1.5 .7 .6 1.9 .8 .8 total # scans: 260 332 190 242 262 398 280 # scans/hour : 10 13 7 10 10 16 11.7 Avg scan (sec): 79 98 168 107 152 93 116 # OF OBSERVATIONS BY BASELINE | Ap Gc Hh Ho Ma Ts StnTotal -------------------------------------- Ap|260 210 27 13 113 112 475 Gc| 332 7 47 92 229 585 Hh| 190 61 143 33 271 Ho| 242 19 197 337 Ma| 262 86 453 Ts| 398 657 Number of 2-station scans: 427 Number of 3-station scans: 192 Number of 4-station scans: 61 Number of 5-station scans: 2 Number of 6-station scans: 0 Total # of scans, observations: 682 1389 Average baseline components for all observations Average XY = 5222. Average XZ = 6003. Average YZ = 5679. Average length = 7382.