CORE-A057 (Continuous Observations of the Rotation of the Earth-A057) 1999 March 9 Notes prepared by Cynthia Thomas and Nancy Vandenberg,NVI/GSFC Schedule name: CA057.SKD on CDDISA Nominal Start: 18:00 U.T. on March 9 (day 068) first observation at 18:00 U.T. on 0552+398 Nominal Stop: 18:00 U.T. on March 10 (day 069) last observation at 17:36 U.T. on 4C39.25 for HH last observation at 17:50 U.T. on 1053+815 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) 274 72828201 Fairbanks A GC 1 (TT) 215 40476601 HartRAO J HH 1 (TT) 141 72326201 Matera I MA 3 (HDT) 310 72435701 Medicina B MC 2 (HDT) 323 72308801 Westford E WF 1 (TT) 304 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. The characteristics of the CORE-A schedules have changed slightly because HartRAO is the only station in the southern hemisphere. Changes were made in order to increase the number of observations at HartRAO and to smooth out the distribution of observations over the sky. 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 | 67.76| UT1-TAI | 45% | | | | | | |Y-Wobble | 44.71| UT1-TAI | 52% | | | | | | |UT1-TAI | 2.39| Y-Wobble | 52% | | | | | | |UT1-TAI Rate| 5.33| ------- | 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 ==== ========== 98NOV17 NEOS-A290 98NOV17 CORE-A049 98NOV24 NEOS-A291 98DEC01 CORE-A050 98DEC08 NEOS-A293 98DEC15 NEOS-A294 98DEC15 CORE-A051 98DEC22 NEOS-A295 98DEC29 NEOS-A296 98DEC29 CORE-A052 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 ./ca057.skd for experiment CA057 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I I 0 0 .0 0048-097I x x x x xxx x x x xx I 12 59 9.5 0059+581Ix x x x x x x x x x x x x x x x x I 17 158 13.2 0106+013Ix x x x x x x x x x I 10 10 1.5 0119+115Ix x x x x xx xx x x I 11 56 7.1 0119+041I x x I 2 6 .9 0229+131Ix x I 2 6 .8 0235+164I x x x x x x x x xI 9 44 6.0 3C84 Ix x x x x x x x x x x x x x I 14 14 1.3 CTA26 I x x x x I 4 15 2.3 0402-362I x I 1 1 .3 0454-234Ix x xx x x x x xx x x xI 13 42 10.4 0458-020I xx x x x xI 6 19 3.0 0528+134I xx x x x x x x x x x x x I 13 80 10.7 0552+398Ixx x x x x x x x x x x x x x x x x x I 19 151 15.6 0556+238I x x x I 3 3 .3 0718+793I x x x I 3 5 .4 0727-115I x x x x x x x xx xx x xI 13 51 8.0 0749+540I x x x x x x x x x x x x I 12 116 9.8 0804+499I x x x x x x x I 7 49 4.6 0805+410I x x I 2 4 .3 0823+033I x x x x x x x x xx x I 11 34 4.9 OJ287 I x x x x x xx x x x xx x x I 14 90 11.4 0919-260I x x x x x x I 6 6 2.1 0920-397I I 0 0 .0 4C39.25 I x x x x x x x x x x x x xx x x xx x xI 20 157 16.4 OK290 I x x x I 3 7 .8 0955+476I x x x I 3 30 2.9 1034-293I x x x I 3 7 1.9 1044+719I x x x x x x x x x x x I 11 102 8.5 1053+815I x x x I 3 30 2.5 1124-186I x xx x x x xx xI 9 42 9.8 1128+385I x x I 2 6 .5 1144-379I x x x xI 4 10 4.9 1219+044I xx x x x x x x xI 9 30 4.3 3C273B Ix x x x x x I 6 6 .9 1255-316I x x I 2 2 .8 1300+580I I 0 0 .0 1313-333I I 0 0 .0 1334-127I x x x x I 4 9 1.6 1351-018I I 0 0 .0 1357+769I x x x x x I 5 50 4.2 1424-418I I 0 0 .0 1451-375I x I 1 1 .8 1606+106Ix x x xx x x xx x x I 11 53 7.0 1622-253I x x x xxx x x x x I 10 28 6.8 NRAO512 Ix x x xx xx xx x x x x x x x x x x x x I 21 167 17.4 3C345 I x x xI 3 3 .3 1726+455I I 0 0 .0 1739+522Ix x x x x x x x x x x x x x x x x x x x I 20 177 15.6 1741-038Ix x x xxx xx x x x x xx x I 15 68 10.4 1749+096Ix x x x xx x x I 8 48 6.8 1908-201I x x x I 3 3 .9 1921-293I x x x x x I 5 11 3.3 1954-388I xx x x I 4 8 3.8 1958-179I x x x x x I 5 19 4.7 2121+053I x xx xx x xx x xx x xx I 14 79 11.3 2128-123I x xx x x x x x I 8 18 3.1 2134+00 I I 0 0 .0 2145+067I x x x x x x I 6 24 3.4 2234+282I x x x x xx x x x x x x I 12 62 6.8 3C454.3 I x x x x x x x x x x x I 11 11 1.4 2255-282I x x x I 3 5 1.9 Total scans, obs: 448 2292 Average number of obs. per baseline per source (normalized by up-time) = 4.8 Min = .0 Max = 26.4 (Baseline Hh-Ma on NRAO512 ) RMS = 6.3 Total time: 1432 minutes ( 23.9 hours). Key: Ap=ALGOPARK Gc=GILCREEK Hh=HARTRAO Ma=MATERA Mc=MEDICINA Wf=WESTFORD Ap Gc Hh Ma Mc Wf Avg % obs. time: 22 30 19 42 30 45 31 % cal. time: 3 2 1 3 3 3 3 % slew time: 55 13 27 17 35 13 27 % idle time: 17 54 51 36 30 37 38 # of tapes : 1.5 .5 .3 2.5 1.9 .8 total # scans: 274 215 141 310 323 304 261 # scans/hour : 11 9 5 12 13 12 10.9 Avg scan (sec): 71 120 116 116 81 128 105 # OF OBSERVATIONS BY BASELINE | Ap Gc Hh Ma Mc Wf StnTotal -------------------------------------- Ap|274 178 44 145 161 270 645 Gc| 215 24 133 152 189 810 Hh| 141 137 129 65 702 Ma| 310 300 175 767 Mc| 323 190 801 Wf| 304 859 Number of 2-station scans: 117 Number of 3-station scans: 139 Number of 4-station scans: 58 Number of 5-station scans: 120 Number of 6-station scans: 14 Total # of scans, observations: 448 2292 Average baseline components for all observations Average XY = 4328. Average XZ = 3889. Average YZ = 4040. Average length = 5218.