CORE-B308 (Continuous Observations of the Rotation of the Earth-B308) 1998 March 25 Notes prepared by Cynthia Thomas, NVI/GSFC Schedule name: CB308.SKD on CDDIS Nominal Start: 18:30 U.T. on March 25 (day 084) first observation at 18:30 U.T. on 1044+719 for GC-KK-NT-GN- SH-UR-YB first observation at 21:15 U.T. on 0059+581 for 15 Duration: 24 hours Nominal Stop: 18:30 U.T. on March 26 (day 085) last observation at 15:26 U.T. on 1606+106 for 15 last observation at 18:27 U.T. on 0458-020 for NT-GN-YB last observation at 18:32 U.T. on 1606+106 for GC-KK-SH-UR 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 DSS15 D 15 1 (TT) 176 72318701 Fairbanks A GC 1 (TT) 235 40476601 Kokee K KK 1 (TT) 205 72983001 Noto S NT 2 (HDT) 148 75478901 NRAO 20M N GN 1 (TT) 213 72484701 Seshan C SH 2 (HDT) 162 72336101 Urumqi U UR 2 (HDT) 174 73303201 Yebes Y YB 2 (HDT) 134 73333601 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. 7) The source models were updated as early March 1998 by Dave Shaffer. 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 ./cb308.skd for experiment CB308 (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 I 0 0 .0 0059+581I xx x x x x xx x x x x x x x x I 16 322 13.2 0119+041I x x x x x x x xI 8 31 2.3 0229+131I x x x x x x I 6 17 1.1 CTA26 I x x x I 3 9 .7 0454-234Ix x x x x x x x x x I 10 22 2.7 0458-020Ixx x x x x x xx x I 10 46 3.8 0528+134I x x x x x x x x x x x x x x xxI 16 100 6.7 0552+398I x x xx x x x x x x x x xx xx x x x xx x xI 23 267 13.5 0718+793I I 0 0 .0 0727-115I x x x x x xx x x x x x x x I 14 50 5.3 0804+499I x x x x x x x x x x x x x x xI 15 227 10.5 0823+033I x x xx x x x x x x x x I 12 64 4.8 OJ287 I I 0 0 .0 0919-260I x I 1 1 .1 4C39.25 I x x x x x x x x x x x x I 12 160 8.2 OK290 Ix x x I 3 12 .7 0955+476I x x x I 3 51 2.5 1034-293I x I 1 3 .4 1044+719Ix x x x x x x x x x x I 11 248 9.1 1124-186I I 0 0 .0 1128+385Ix x x x x x x x x I 9 105 5.5 1219+044I x x x x x xx x I 8 60 4.5 1255-316I I 0 0 .0 1300+580I x x x x I 4 24 1.0 1308+326I x x x x I 4 19 1.0 1334-127I x x x x x x x I 7 27 3.1 1351-018I I 0 0 .0 1357+769I x x x x x x x x x I 9 231 8.3 1606+106I x x x x xx xx x xx xx x x xx x I 18 112 7.7 1622-253I x x I 2 6 .8 NRAO512 I x xx x x x x x x x x x x x xx x x x x xI 21 233 11.8 1739+522I x x x x x x x x x x x x xx x xx x I 18 280 12.5 1741-038Ixx x x x x x x x x x x x x I 14 58 4.8 1749+096I x x x x x xx x I 8 42 3.0 1921-293I x x x x x x I 6 10 1.3 1954-388I x x I 2 2 .3 1958-179I x I 1 3 .3 2128-123I x x x x x xI 6 10 1.1 2145+067Ix x x xx x xx x x xx I 12 61 4.4 2234+282I x x x x I 4 29 1.6 2255-282I x x x I 3 3 .4 Total scans, obs: 320 2945 Average number of obs. per baseline per source (normalized by up-time) = 3.9 Min = .0 Max = 23.3 (Baseline Gc-Kk on 1606+106) RMS = 5.1 Total time: 1443 minutes ( 24.1 hours). Key: 15=DSS15 Gc=GILCREEK Kk=KOKEE Nt=NOTO Gn=NRAO20 Sh=SESHAN25 Ur=URUMQI Yb=YEBES 15 Gc Kk Nt Gn Sh Ur Yb Avg % obs. time: 19 28 33 22 37 31 28 23 28 % cal. time: 2 2 2 1 2 1 2 1 2 % slew time: 29 19 13 22 12 35 21 14 21 % idle time: 49 49 50 53 47 31 48 60 48 # of tapes : .3 .8 .6 1.4 .6 1.9 1.8 1.4 total # scans: 176 235 205 148 213 162 174 134 180 # scans/hour : 7 9 8 6 8 6 7 5 7.5 Avg scan (sec): 95 103 143 131 152 168 140 152 135 # OF OBSERVATIONS BY BASELINE | 15 Gc Kk Nt Gn Sh Ur Yb StnTotal ---------------------------------------------- 15|176 153 142 64 153 59 63 69 854 Gc| 235 180 105 176 116 126 108 744 Kk| 205 56 145 102 93 57 628 Nt| 148 104 82 111 119 718 Gn| 213 69 89 107 901 Sh| 162 144 63 725 Ur| 174 90 639 Yb| 134 681 Number of 2-station scans: 28 Number of 3-station scans: 67 Number of 4-station scans: 77 Number of 5-station scans: 56 Number of 6-station scans: 56 Number of 7-station scans: 22 Number of 8-station scans: 14 Total # of scans, observations: 320 2945 Average baseline components for all observations Average XY = 6249. Average XZ = 4398. Average YZ = 4377. Average length = 6475.