CORE-A070 (Continuous Observations of the Rotation of the Earth-A070) 1999 September 7 Notes prepared by Cynthia Thomas and Nancy Vandenberg,NVI/GSFC Schedule name: CA070.SKD on CDDISA Nominal Start: 18:00 U.T. on September 7 (day 250) first observation at 18:00 U.T. on NRAO512 Nominal Stop: 18:00 U.T. on September 8 (day 251) last observation at 17:55 U.T. on 1741-038 for HH-MA-MC last observation at 17:56 U.T. on 0823+033 for AP-GC-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) 277 72828201 Fairbanks A GC 1 (TT) 212 40476601 HartRAO J HH 1 (TT) 159 72326201 Matera I MA 3 (HDT) 308 72435701 Medicina B MC 2 (HDT) 309 72308801 Westford E WF 1 (TT) 296 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 | 72.63| UT1-TAI | 52% | | | | | | |Y-Wobble | 49.17| UT1-TAI | 53% | | | | | | |UT1-TAI | 2.86| Y-Wobble | 53% | | | | | | |UT1-TAI Rate| 7.10| ------- | 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 ==== ========== 99JUN01 CORE-A063 99JUN01 NEOS-A318 99JUN08 NEOS-A319 99JUN15 CORE-A064 99JUN22 NEOS-A321 99JUN29 CORE-A065 99JUN29 NEOS-A322 99JUL06 NEOS-A323 99JUL13 NEOS-A324 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 ./ca070.skd for experiment CA070 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x xx x x x x x x x xI 11 28 4.5 0048-097I x xx x x x x I 7 45 7.2 0059+581I x x x x x x xI 7 62 5.2 0106+013Ix x x xxx x xx x x x I 12 12 1.7 0119+115I x x x xx x x x xx x I 11 63 8.0 0119+041I x x I 2 6 .9 0229+131I x x I 2 6 .9 0235+164Ix x xx x xx x xxI 10 49 6.7 CTA26 I x x x x x I 5 13 2.1 0402-362I x x x x I 4 10 4.6 0454-234I xx xx x x xx x x x x x I 13 39 9.6 0458-020I I 0 0 .0 0528+134I x x x x x xx xx xx xx x x I 15 88 11.6 0552+398Ix x xx x xx x xx x x xx x x x x x x x x I 22 172 17.8 0556+238I x I 1 3 .3 0718+793I x x x I 3 3 .3 0727-115I x x xx x x xxx x x x x x x I 15 59 9.5 0749+540I x x x I 3 30 2.5 0804+499Ix x x x x x x x x x x x x x x I 15 122 11.4 0805+410I x x I 2 6 .5 0823+033I x x xx x x xx xx xxx x I 14 42 6.1 OJ287 I xx xx x x xx x x x x x x x x I 16 93 11.9 0919-260I xx x x xx x x x x x I 11 11 3.6 0920-397I x x I 2 2 2.0 4C39.25 I x x x x x xx x x xx x x x x x x I 17 134 13.8 OK290 I x x x x I 4 19 2.2 0955+476I x x I 2 16 1.5 1034-293I x x x x I 4 8 2.1 1044+719I x x x x x x x x I 8 72 6.0 1053+815I I 0 0 .0 1124-186I x x xx x x xx x xx xx x I 14 50 11.9 1128+385I x x x x I 4 12 1.0 1144-379I x x x I 3 3 1.0 1219+044I x x x xx x x xx x x xx x I 14 48 6.8 1255-316I x I 1 1 .6 1300+580I x I 1 3 .3 1313-333I x x x I 3 5 2.6 1334-127I x x xx x I 5 5 .9 1351-018Ix x x x x x I 6 21 3.3 1357+769I x x x x x x I 6 56 4.7 1424-418I x I 1 1 .4 1451-375I x x I 2 2 1.7 1606+106I xx xx xx x x xx x x xI 13 56 7.5 1622-253Ix x x xx x x x x x I 10 22 5.5 NRAO512 I x x xx x x x x x x x xx xx x x x x xI 20 146 14.2 1726+455I x I 1 6 .6 1739+522I x x x x x xx x x x x x x xI 14 124 10.9 1741-038Ix xx x x x xx xx xxx xx xx x xI 19 89 13.7 1749+096I x xxx x xxx I 8 55 7.8 1908-201I xx x x x x x xx I 9 24 6.1 1921-293I x x x x x x xx I 8 18 4.9 1954-388I x x I 2 6 3.2 1958-179Ix x xx x x x I 7 13 3.2 2121+053Ix x xx x x x xx x x x x xx x xx I 18 97 13.8 2128-123I x x x xx x x I 7 12 2.1 2145+067I x x I 2 9 1.2 2234+282Ix xx x xx x x x x x x x xx I 15 98 11.1 2255-282I x x x x x I 5 7 2.6 Total scans, obs: 456 2202 Average number of obs. per baseline per source (normalized by up-time) = 5.4 Min = .0 Max = 29.3 (Baseline Ma-Mc on 1741-038) RMS = 6.7 Total time: 1437 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: 23 29 21 44 28 45 32 % cal. time: 3 2 1 3 3 3 3 % slew time: 55 13 29 16 32 13 26 % idle time: 17 54 46 35 35 38 38 # of tapes : 1.5 .5 .4 2.6 1.8 .8 total # scans: 277 212 159 308 309 296 260 # scans/hour : 11 8 6 12 12 12 10.8 Avg scan (sec): 72 121 116 123 78 132 107 # OF OBSERVATIONS BY BASELINE | Ap Gc Hh Ma Mc Wf StnTotal -------------------------------------- Ap|277 176 50 134 145 269 774 Gc| 212 21 121 129 184 631 Hh| 159 154 144 62 431 Ma| 308 296 155 860 Mc| 309 162 876 Wf| 296 832 Number of 2-station scans: 107 Number of 3-station scans: 185 Number of 4-station scans: 40 Number of 5-station scans: 112 Number of 6-station scans: 12 Total # of scans, observations: 456 2202 Average baseline components for all observations Average XY = 4178. Average XZ = 3912. Average YZ = 4065. Average length = 5182.