CORE-A072 (Continuous Observations of the Rotation of the Earth-A072) 1999 October 5 Notes prepared by Cynthia Thomas and Nancy Vandenberg,NVI/GSFC Schedule name: CA072.SKD on CDDISA Nominal Start: 18:00 U.T. on October 5 (day 278) first observation at 18:00 U.T. on 1749+096 for HH-MA-MC first observation at 18:00 U.T. on 4C39.25 for AP-GC-WF Nominal Stop: 18:00 U.T. on October 6 (day 279) last observation at 17:48 U.T. on 0003-066 for HH last observation at 17:58 U.T. on 1044+719 for AP-GC-MA-MC-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) 315 72828201 Fairbanks A GC 1 (TT) 255 40476601 HartRAO J HH 1 (TT) 173 72326201 Matera I MA 1 (TT) 306 72435701 Medicina B MC 3 (HDT) 337 72308801 Westford E WF 1 (TT) 341 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. Station Information =================== Matera was tagged along to this schedule file because the week prior to the experiment they are scheduled for a Mark IV upgrade. Therefore, Matera may not be able to participate in this experiment because the upgrade may not be completed. 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 | 64.46| UT1-TAI | 45% | | | | | | |Y-Wobble | 47.20| UT1-TAI | 48% | | | | | | |UT1-TAI | 2.51| Y-Wobble | 48% | | | | | | |UT1-TAI Rate| 5.84| ------- | 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 ==== ========== 99JUN15 CORE-A064 99JUN22 NEOS-A321 99JUN28 EUROPE-49 99JUN29 CORE-A065 99JUN29 NEOS-A322 99JUL06 NEOS-A323 99JUL13 NEOS-A324 99JUL19 IRIS-S140 99JUL20 NEOS-A325 99JUL27 NEOS-A326 99AUG03 NEOS-A327 99AUG10 NEOS-A328 99AUG17 NEOS-A329 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 ./ca072.skd for experiment CA072 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066Ixx x x x x x x x xx x x I 13 46 7.3 0048-097Ix x x x x x x I 7 25 4.0 0059+581I x x x x x x x x x x x x x xI 14 136 11.3 0106+013Ix x x x xx I 6 12 1.8 0119+115I x xx x xx xx x x x x I 12 60 7.7 0119+041Ix x x x x x x x x x I 10 35 5.0 0229+131Ix xx x I 4 12 1.8 0235+164I x x x x x x I 6 30 3.9 CTA26 I x x x x I 4 15 2.3 0402-362I xx x x I 4 10 4.6 0454-234I xx x x x x x x xxx xI 12 27 6.4 0458-020I x x x x x x x I 7 22 3.4 0528+134I x xx xx x xx x x xx x x x I 15 100 13.3 0552+398Ix xx xxx x x xx x xx xx x x x xx x x x x x xI 26 184 18.7 0556+238I x xx x x x x x x xx x x xx x x xI 18 84 9.5 0718+793I x x I 2 7 .6 0727-115I x x xx x x x xxxx x xx x I 15 51 8.2 0749+540I x x x x x x x x x x x x x xI 14 124 10.5 0804+499I x x x x x x x x x I 9 71 6.6 0805+410I x x I 2 6 .5 0823+033I x xxx x xx x x I 9 40 5.8 OJ287 I x x xx x x x x x x I 10 45 5.5 0919-260I xx x xx I 5 5 2.0 0920-397I I 0 0 .0 4C39.25 I x x x x x x xx x x xx x x x x xx xI 19 146 15.1 OK290 I x x x x I 4 15 1.6 0955+476I x x I 2 6 .6 1034-293I x x x x x I 5 13 3.3 1044+719Ix x x x x x x x x x x I 11 94 7.8 1053+815I x x x x x xI 6 56 4.7 1124-186I x x x x x xx x xx xxx x I 14 47 11.3 1128+385I x x xI 3 7 .6 1144-379I x x I 2 6 3.1 1219+044I I 0 0 .0 1255-316I x x I 2 2 .8 1300+580I I 0 0 .0 1313-333I I 0 0 .0 1334-127I x x I 2 2 .4 1351-018I xx xx x xx x x x xx x xx x x I 17 58 8.9 1357+769I x x x x x x I 6 48 4.0 1424-418I I 0 0 .0 1451-375I I 0 0 .0 1606+106I xx x x x xx xxx xx x x x x xx xxxI 21 86 11.6 1622-253I xx xx xx x x x x x x I 12 31 7.6 NRAO512 I x x x xx x x x x x xx x x xx x x I 18 139 14.4 1726+455I x x x xx x x x x I 9 58 5.8 1739+522I x x x x x x x x x x I 10 88 7.8 1741-038I xxx xx xx x x xx xx x x xxx xxI 20 87 13.4 1749+096I x xx x x I 5 39 5.4 1908-201I x x x x I 4 11 3.0 1921-293I x x x x x x x I 7 15 4.5 1954-388I x x x I 3 9 4.8 1958-179Ix x x x x xx x x I 9 24 5.3 2121+053Ix x x xxx x x x x xx x xx x I 16 79 11.3 2128-123Ix x xx x I 5 15 2.7 2145+067I x x x x x I 5 16 2.2 2234+282Ix x xx x x xx x x x xx x x x x x x I 19 115 13.1 2255-282I x x x x x xx I 7 15 4.4 Total scans, obs: 487 2474 Average number of obs. per baseline per source (normalized by up-time) = 5.8 Min = .0 Max = 29.3 (Baseline Ap-Wf on 1741-038) RMS = 6.7 Total time: 1440 minutes ( 24.0 hours). Key: Ap=ALGOPARK Gc=GILCREEK Hh=HARTRAO Ma=MATERA Mc=MEDICINA Wf=WESTFORD Ap Gc Hh Ma Mc Wf Avg % obs. time: 25 32 18 36 34 41 31 % cal. time: 3 2 2 3 3 3 3 % slew time: 55 15 30 15 34 13 27 % idle time: 15 49 48 43 27 40 37 # of tapes : 1.7 .6 .3 .6 2.1 .7 total # scans: 314 254 173 306 337 340 287 # scans/hour : 13 10 7 12 14 14 12.0 Avg scan (sec): 70 111 94 103 87 105 95 # OF OBSERVATIONS BY BASELINE | Ap Gc Hh Ma Mc Wf StnTotal -------------------------------------- Ap|314 210 41 147 166 309 873 Gc| 254 23 143 163 220 759 Hh| 173 159 170 55 448 Ma| 306 303 173 925 Mc| 337 192 994 Wf| 340 949 Number of 2-station scans: 68 Number of 3-station scans: 229 Number of 4-station scans: 64 Number of 5-station scans: 111 Number of 6-station scans: 15 Total # of scans, observations: 487 2474 Average baseline components for all observations Average XY = 4213. Average XZ = 3912. Average YZ = 3999. Average length = 5172.