CORE-B309 (Continuous Observations of the Rotation of the Earth-B309) 1998 May 06 Notes prepared by Cynthia Thomas, NVI/GSFC Schedule name: CB309.SKD on CDDIS Nominal Start: 18:30 U.T. on May 06 (day 126) first observation at 18:30 U.T. on 4C39.25 for 65-GC-NT-GN-UR first observation at 18:30 U.T. on 1749+096 for KK-SH Duration: 24 hours Nominal Stop: 18:30 U.T. on May 07 (day 127) last observation at 18:21 U.T. on 0059+581 for 65 last observation at 18:29 U.T. on 0528+134 for GC last observation at 18:29 U.T. on 1741-038 for KK-SH-UR last observation at 18:32 U.T. on 0727-115 for NT-GN Correlator: Haystack **Frequency Sequence**: CDPSX - Standard CDP SX sequence. (360 MHz wide at X, 85 MHz wide at S) 1 letter 2 letter Station Code Code # of tapes # of obs Occupation Code DSS65 M 65 1 (TT) 250 16658501 Fairbanks A GC 1 (TT) 248 40476601 Kokee K KK 1 (TT) 224 72983001 Noto S NT 2 (HDT) 235 75478901 NRAO 20M N GN 1 (TT) 267 72484701 Seshan C SH 2 (HDT) 189 72336101 Urumqi U UR 2 (HDT) 215 73303201 Purpose ======= The purpose of the CORE-B sessions is to provide additional data for comparison of EOP measurements and to obtain long 48-hour data sets for geophysical studies. The analysis of CORE-A and CORE-B has concentrated on comparing the EOP results from these sessions with the NEOS sessions. Preliminary results of the comparisons show that, while the EOP results generally agree between different networks, there are systematic differences that are not fully understood. Because of these discrepancies, it was decided that an improved comparison could be made if the CORE-A, NEOS, and CORE-B could all be compared for the same day, making possible a 3-way comparison. Therefore we will run the CORE-B sessions on days adjacent to the CORE-A/NEOS days instead of on the alternate week. This plan will concentrate the observing days but it will provide more a robust data set for understanding the differences. Schedule ======== This is a new schedule generated by C. Thomas with the automatic mode of sked. The following are the characteristics of the schedule: 1) This schedule was optimized for sky coverage. 2) Only the observations in the previous two hours of the schedule were considered for the minor options. The best 60% 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 twenty minutes. 5) The minimum SNR limits for most baselines were set to 20 for X-band and 15 for S-band. 6) This schedule was made using 43 sources which helped improve the sky coverage. Station Information =================== 1) Fairbanks will record low density on thin tapes for this experiment because there are on three Mark IV drives at Haystack that can support high density thin tapes. 2) Yebes will not participate in this experiment because of formatter problems. 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 98Mar03 NEOS-A253 and the 98JAN27XA CORE-A028 experiments. Procedures ========== There are no special procedures for this experiment. Please use your standard SGP procedures. Correlation ========== This experiment will be correlated at the Haystack Correlator with all baselines being correlated. SKED Summary from file ./cb309.skd for experiment CB309 (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 I 8 16 2.0 0048-097I x x x x x I 5 18 2.3 0059+581Ix x x x x x x x x xx x x x xx x xxx I 20 333 18.0 0119+041I x x I 2 6 .6 0229+131I I 0 0 .0 CTA26 I x x x x x x x x xI 9 13 1.5 0454-234I x x x x x x x x x x x x x x x x I 16 26 4.5 0458-020I x x x x x x x x I 8 24 2.7 0528+134I x x x x xx x x x x x x x x x xx x x x xI 21 90 7.9 0552+398I x x x x x x xx xx xx xx xx x x x x x xx x x xI 26 251 16.9 0718+793I x I 1 3 .1 0727-115I x x x xx x x x x x xx x x x xx x I 19 49 7.0 0804+499I x x x x xx x x x x x x x x x x x x x xI 20 245 14.9 0823+033I x x xx x xx x xx x I 11 37 3.8 OJ287 I x x xx I 4 4 .3 0919-260I x x x I 3 3 .6 4C39.25 Ix x x x xx x x x x x x xx x x x xx x x x x I 23 207 14.0 OK290 I x x x I 3 5 .4 0955+476I x x I 2 20 1.2 1034-293I x I 1 1 .2 1044+719I x x x x x x x x x x x x I 12 240 11.7 1124-186I x x x xI 4 6 1.0 1128+385Ix x x I 3 19 1.3 1219+044Ix xxx xx x xx x I 10 36 3.6 1255-316I x x I 2 2 .5 1300+580I x x x I 3 18 1.0 1308+326I x x x x x x x I 7 15 1.0 1334-127I x x x x x x x x x xI 10 25 2.9 1351-018I I 0 0 .0 1357+769I x x x x x x x xx x I 10 210 10.0 1606+106I x x xx x x xxx x x x xx xI 15 58 5.4 1622-253I x xx xx x x x x x I 10 16 2.9 NRAO512 Ix x x x x xx x x x xx x x x x x x x xx x x x xx I 26 247 16.5 1739+522I x x x x x x x x x x x x x x x x x x x xI 20 277 16.5 1741-038I x x xx xx x xx x x x x x x x xx x x xxI 22 77 8.7 1749+096I x x x x x x xx x xx xx x x x I 16 67 6.2 1921-293I x x x x x x x x x x x x x xxI 15 23 4.5 1954-388I x x x x xI 5 5 1.3 1958-179I x x x x x x I 6 6 .9 2128-123I x x x x x xx x x I 9 19 2.6 2145+067I x x x x xx x x x xxx x xI 14 52 5.0 2234+282I x x I 2 9 .7 2255-282I x x x x I 4 4 .8 Total scans, obs: 427 2782 Average number of obs. per baseline per source (normalized by up-time) = 4.9 Min = .0 Max = 25.7 (Baseline Sh-Ur on 0552+398) RMS = 6.5 Total time: 1443 minutes ( 24.1 hours). Key: 65=DSS65 Gc=GILCREEK Kk=KOKEE Nt=NOTO Gn=NRAO20 Sh=SESHAN25 Ur=URUMQI 65 Gc Kk Nt Gn Sh Ur Avg % obs. time: 21 26 28 29 33 29 26 27 % cal. time: 2 2 2 2 3 2 2 2 % slew time: 41 19 12 37 15 39 26 27 % idle time: 34 51 57 30 48 29 43 42 # of tapes : .4 .8 .5 1.8 .6 1.8 1.7 total # scans: 250 248 224 235 267 189 215 232 # scans/hour : 10 10 9 9 11 7 8 9.7 Avg scan (sec): 74 91 108 106 107 132 107 103 # OF OBSERVATIONS BY BASELINE | 65 Gc Kk Nt Gn Sh Ur StnTotal ------------------------------------------ 65|250 138 76 220 168 93 136 853 Gc| 248 183 124 187 128 144 740 Kk| 224 64 163 112 102 927 Nt| 235 144 101 145 717 Gn| 267 80 103 827 Sh| 189 171 756 Ur| 215 744 Number of 2-station scans: 94 Number of 3-station scans: 130 Number of 4-station scans: 63 Number of 5-station scans: 72 Number of 6-station scans: 38 Number of 7-station scans: 30 Total # of scans, observations: 427 2782 Average baseline components for all observations Average XY = 6399. Average XZ = 4599. Average YZ = 4381. Average length = 6608.