CORE-A083 (Continuous Observations of the Rotation of the Earth-A083) 2000 April 18 Notes prepared by Cynthia Thomas and Dan MacMillan,NVI/GSFC Schedule name: CA083.SKD on CDDISA Nominal Start: 18:00 U.T. on April 18 (day 109) first observation at 18:00 U.T. on 1357+769 for AP-GC-MA-TS first observation at 18:00 U.T. on 0637-752 for HO-HH Nominal Stop: 18:00 U.T. on April 19 (day 110) last observation at 17:48 U.T. on 0003-066 for AP-GC last observation at 17:48 U.T. on 1219+044 for HH-MA last observation at 17:51 U.T. on 1958-179 for HO-TS 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) 336 40476601 HartRAO J HH 1 (TT) 201 72326201 Hobart H HO 2 (HDT) 241 72425901 Matera I MA 1 (TT) 262 72435701 Tsukuba T TS 1 (TT) 397 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 | 35.04| ------- | under 40% | | | | | | |Y-Wobble | 38.14|Tsukuba Z | 49% | | | | | | |UT1-TAI | 2.19|Tsukuba Y | 42% | | | | | | |UT1-TAI Rate| 4.34| ------- | 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 ==== ========== 99NOV02 CORE-A074 99NOV02 NEOS-A340 99NOV09 NEOS-A341 99NOV16 NEOS-A342 99NOV30 NEOS-A344 99DEC14 NEOS-A346 99DEC21 NEOS-A347 99DEC28 NEOS-A348 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 ./ca083.skd for experiment CA083 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #O BS #Obs/bl 0003-066Ixxx xxxx xx xx x xxx x x x xx x xxx x I 25 42 6.7 0048-097Ix x x x x x xx I 8 23 4.3 0059+581I x x x x xx x x x xx x xx x x I 16 36 3.6 0104-408Ix xx xx xx x xx xx x x x x I 16 20 6.0 0119+115I I 0 0 .0 0119+041I I 0 0 .0 0208-512I I 0 0 .0 0229+131I I 0 0 .0 0235+164I I 0 0 .0 CTA26 Ix x xxx xxx xxx xx xx x x x x x x I 21 21 3.3 0402-362I x x x I 3 3 .8 0454-234I xx xx xxx xx xx x x xx x x x x I 19 23 4.1 0458-020I xx x x x x x x xI 9 25 4.0 0528+134Ix xx xxxx xxxx xx x xx x xx x x xx x xI 25 41 5.1 0537-441I xx xx x x x xx xx x I 12 14 4.1 0552+398I xx xxx xx xxx xx x xx x xx x xx x x xx xI 26 95 11.0 0556+238Ix x x x x x xx x xx x x x x xx x xI 19 23 2.5 0637-752I x x x x x I 5 5 2.0 0727-115I xx x xx x xx xxx xxxx xx xx x x I 21 27 5.0 0749+540I x x xx x x x x x x x x x x x xI 16 75 7.6 0804+499I x x xx x I 5 21 2.3 0805+410I x I 1 3 .3 0823+033I xx x xx xxxx xxx x xx xxx x xx xI 22 26 3.8 OJ287 I x x xx x x x x x x x I 11 17 2.3 0919-260I I 0 0 .0 0920-397I I 0 0 .0 4C39.25 I x x x x xxx x xx xx x x x x xx xI 19 64 7.9 OK290 Ixx x x xx xx xx xx xx x xx I 17 17 1.9 0955+476I x x x x x x x x x I 9 40 4.7 1034-293I x xx xx xxx x x x xx I 13 13 2.0 1044+719I x x x x x x x x x x xI 11 43 4.3 1053+815I x I 1 6 .6 1057-797I x x x x I 4 4 1.6 1104-445I x I 1 1 .3 1124-186Ix xxx xx xxx x xxxx xx xxx xxx xxx xx I 27 44 8.4 1128+385I x x xx x x x I 7 21 1.8 1144-379I x x xxxx xx x x x x x xx x I 16 22 6.6 1219+044Ix xx x xx xxx xxx xx xxx xxx xxxxx x xxx x I 30 86 12.7 1255-316I I 0 0 .0 1300+580I x x x x xx x x x x I 10 24 2.4 1313-333I I 0 0 .0 1334-127I x x x x xx x x I 8 12 3.2 1351-018I xx x x x xx xxx I 10 10 1.6 1357+769I x x x x x x x I 7 39 3.9 1424-418I x x x x I 4 6 1.8 1451-375I x x x I 3 3 .9 1606+106Ix x xx x x xxx x x xx xxx xx x x xx xxI 24 58 8.0 1622-253Ix xx xx x x x x xx xx x x x x x x xI 20 24 4.5 NRAO512 Ix x x x x xx xx xx x x x x I 15 41 4.1 1726+455I x x x xx x I 6 8 .9 1739+522I x x x x x x I 6 10 1.1 1741-038I x x x x x x x xxx xx xx x x xx x x xxI 22 26 4.3 1749+096I x x x xx x x x xxx I 11 40 5.8 1815-553I x x I 2 2 .8 1908-201I x x x x x xx x xI 9 9 1.5 1954-388I x xx x x xx xx xx xI 12 12 3.3 1958-179Ix xx x xxxx x x x x x x x x xI 17 31 6.2 2052-474I x x I 2 2 .5 2121+053Ixx xxx xxx xx xx x x xxx xx xx xx xx xxx xxxI 31 82 12.0 2128-123I x xx I 3 3 1.6 2145+067I xx x x I 4 6 .8 2234+282Ix x xxx x x x x x x xx x x x x xx xx I 21 51 5.5 2255-282I x x I 2 2 .6 Total scans, obs: 684 1402 Average number of obs. per baseline per source (normalized by up-time) = 3.5 Min = .0 Max = 36.2 (Baseline Ho-Ts on 1219+044) RMS = 5.8 Total time: 1432 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: 25 39 34 28 41 43 35 % cal. time: 3 3 2 2 3 4 3 % slew time: 51 22 40 32 19 19 31 % idle time: 20 34 22 35 36 32 30 # of tapes : 1.5 .7 .6 1.7 .7 .8 total # scans: 260 336 201 241 262 397 282 # scans/hour : 10 14 8 10 10 16 11.8 Avg scan (sec): 82 99 146 101 136 93 109 # OF OBSERVATIONS BY BASELINE | Ap Gc Hh Ho Ma Ts StnTotal -------------------------------------- Ap|260 204 30 13 109 103 459 Gc| 336 11 45 91 230 581 Hh| 201 74 143 45 303 Ho| 241 23 191 346 Ma| 262 90 456 Ts| 397 659 Number of 2-station scans: 415 Number of 3-station scans: 209 Number of 4-station scans: 60 Number of 5-station scans: 0 Number of 6-station scans: 0 Total # of scans, observations: 684 1402 Average baseline components for all observations Average XY = 5319. Average XZ = 6128. Average YZ = 5648. Average length = 7463.