CORE-A071 (Continuous Observations of the Rotation of the Earth-A071) 1999 September 21 Notes prepared by Cynthia Thomas and Nancy Vandenberg,NVI/GSFC Schedule name: CA071.SKD on CDDISA Nominal Start: 18:00 U.T. on September 21 (day 264) first observation at 18:00 U.T. on 1128+385 for GC-MA-WF first observation at 18:00 U.T. on 0048-097 for HH-HO Nominal Stop: 18:00 U.T. on September 22 (day 265) last observation at 17:51 U.T. on 4C39.25 for WF last observation at 17:54 U.T. on 0229+131 for GC-HO last observation at 17:54 U.T. on 1958-179 for HH-MA 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 Fairbanks A GC 1 (TT) 311 40476601 HartRAO J HH 1 (TT) 202 72326201 Hobart H HO 2 (HDT) 154 72425901 Matera I MA 3 (HDT) 294 72435701 Westford E WF 1 (TT) 306 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 =================== Algonquin will not participate in this experiment because Algonquin is scheduled to participate in an experiment for calibrating the W-Sensor on GPS satellites. 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 | 64.43|Hart-Hobrt| 75% | | | | | | |Y-Wobble | 50.34|--------- | under 40% | | | | | | |UT1-TAI | 2.77|Hart-Hobrt| 43% | | | | | | |UT1-TAI Rate| 7.27| ------- | 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 ./ca071.skd for experiment CA071 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066Ix x x x xxx xx x xxx xx I 15 15 3.7 0048-097I x x xx x x xx x I 9 13 3.5 0059+581I x x x x x x xI 7 21 4.2 0106+013I I 0 0 .0 0119+115Ixxx x xx x xx x xxx x I 14 18 3.3 0119+041I x x x xx xx x I 8 8 1.7 0229+131I x x I 2 2 .4 0235+164I x x xxx x xxxx xx x x xI 15 17 3.1 CTA26 I xx xxx x I 6 6 1.5 0402-362I x x x x x xx xxI 9 9 3.1 0454-234I xx x x x x x xxx xI 11 17 5.8 0458-020I x xx xxx xx x I 9 9 2.2 0528+134I x xx x x x xxxxxx xx xx x x I 18 36 7.3 0552+398I x x x xx x xx x xxxx x x x xxx xxx x x x xx x I 28 73 14.2 0556+238I x x x xxx I 6 6 .9 0718+793I I 0 0 .0 0727-115I xx xx xx x xx xx xx x x xxx xI 19 29 9.1 0749+540I x x x x x x xx x I 9 27 5.5 0804+499I x x x x x x x x x x x x x x x I 15 33 7.0 0805+410I x I 1 1 .1 0823+033I x xx x x xxx xxxxx xxx I 16 16 3.4 OJ287 Ixx xx xx x x x xx xx xxx xx xx xxx I 23 27 4.5 0919-260I I 0 0 .0 0920-397I x I 1 1 .3 4C39.25 I x x xxx x x x xxx xx x xx xx x xx x x xx x I 26 71 13.9 OK290 I x xx x x xx I 7 7 1.0 0955+476I x x x x I 4 10 2.2 1034-293I x x x x x xx x x I 9 9 3.3 1044+719I x x x x x xI 6 18 3.6 1053+815I I 0 0 .0 1124-186I x xx x x xxx x x x xx x xx I 16 28 9.7 1128+385I x xx x x I 5 7 .8 1144-379I x xx x x x I 6 6 2.0 1219+044I I 0 0 .0 1255-316I x I 1 1 .3 1300+580I I 0 0 .0 1313-333I I 0 0 .0 1334-127I x x xx x x I 6 6 1.4 1351-018Ix x x xx xx x x xx x x xxx xx I 18 18 4.3 1357+769I x x x x x x x x xI 9 27 5.4 1424-418I x x x I 3 3 1.0 1451-375I I 0 0 .0 1606+106I xx x xx x xx xx xx xx xx xxxI 19 19 3.5 1622-253I x xx x xx xxx xx x I 12 12 4.1 NRAO512 I xx x xx x x x xx xx x x xx xx x xI 20 32 4.5 1726+455I x x I 2 4 .9 1739+522I x x x x xx x xx x x x x x x xI 16 42 8.8 1741-038I xx x xxx xx xx x xxx x xx xxx x xxx xx xI 27 47 11.0 1749+096I x xxx x xx x x xxx xx I 14 34 7.4 1908-201I x x x x xx x I 7 7 2.9 1921-293I x x x x x x x x x I 9 9 3.3 1954-388I x xx xx x x x x I 9 9 3.1 1958-179I x xx x x xx x I 8 10 3.3 2121+053Ix x x xx xx x x x xx x x x x xx xx x x I 22 36 7.7 2128-123I x I 1 1 .2 2145+067Ix x x x x x x x I 8 12 2.5 2234+282Ix x x x xx xxx x xx x I 13 24 3.8 2255-282I x x x x x I 5 5 1.6 Total scans, obs: 549 898 Average number of obs. per baseline per source (normalized by up-time) = 3.5 Min = .0 Max = 38.1 (Baseline Gc-Ho on 0727-115) RMS = 5.9 Total time: 1437 minutes ( 24.0 hours). Key: Gc=GILCREEK Hh=HARTRAO Ho=HOBART26 Ma=MATERA Wf=WESTFORD Gc Hh Ho Ma Wf Avg % obs. time: 46 31 29 47 48 40 % cal. time: 3 2 1 3 3 2 % slew time: 22 40 23 19 14 24 % idle time: 27 26 44 29 33 32 # of tapes : .8 .5 1.8 2.8 .8 total # scans: 311 202 154 294 306 253 # scans/hour : 12 8 6 12 12 10.6 Avg scan (sec): 128 133 166 140 137 140 # OF OBSERVATIONS BY BASELINE | Gc Hh Ho Ma Wf StnTotal ---------------------------------- Gc|311 15 67 128 225 435 Hh| 202 78 135 45 273 Ho| 154 19 10 174 Ma| 294 176 458 Wf| 306 456 Number of 2-station scans: 391 Number of 3-station scans: 147 Number of 4-station scans: 11 Number of 5-station scans: 0 Total # of scans, observations: 549 898 Average baseline components for all observations Average XY = 5711. Average XZ = 6197. Average YZ = 5414. Average length = 7456.