CORE-B109 (Continuous Observations of the Rotation of the Earth-B109) 1998 May 20 Notes prepared by Cynthia Thomas, NVI/GSFC Schedule name: CB109.SKD on CDDIS Nominal Start: 18:30 U.T. on May 20 (day 140) first observation at 18:30 U.T. on 1044+719 for AP-FT-GC-KA- ON-WZ-YK first observation at 19:30 U.T. on 0454-234 for 15 Duration: 24 hours Nominal Stop: 18:30 U.T. on May 21 (day 141) last observation at 18:13 U.T. on 0528+134 for FT last observation at 18:25 U.T. on 0718+793 for 15 last observation at 18:30 U.T. on 1357+769 for AP-YK-GC-KA- ON-WZ 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 Algonquin G AP 2 (HDT) 268 72828201 Yellowknife X YK 2 (HDT) 215 72965101 DSS15 D 15 1 (TT) 274 72318701 Fortaleza F FT 2 (HDT) 135 72974801 Fairbanks A GC 1 (TT) 297 40476601 Kashima-26 Q KA 3 (HDT) 201 18567601 Onsala T ON 3 (HDT) 231 72137701 Wettzell V WZ 3 (HDT) 281 72247801 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 50 sources which helped improve the sky coverage. 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. Station Information =================== Yellowknife has been tagged along to this schedule because of their equipment problems. 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 ./cb109.skd for experiment CB109 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x x x xx x x x I 8 36 3.4 0048-097I x x x x x x x x I 8 31 3.0 0059+581I x x x x x x x x x x x x x x x x x xI 18 339 13.9 0106+013I xxxx xx xxx xx xx x xx I 16 20 1.6 0119+115I x x x x xx x x x x xx xxI 14 41 2.8 0119+041I x xx x I 4 23 1.8 0229+131I x x x I 3 17 1.1 0235+164I x x x x x I 5 9 .6 CTA26 I x xx x x x x x x x x x x xI 14 30 2.5 0454-234Ix x x x x x x I 7 9 1.5 0458-020Ix xx x x x x I 7 25 2.1 0528+134Ix x x x xxxxx x x x x xx x x I 18 101 6.8 0552+398Ix x x x xx x xx x x xxx xx x x x x x xx x xI 25 365 17.3 0556+238I x x x x x I 5 35 2.1 0718+793I x x x x x x x x x x x I 11 48 1.7 0727-115I x x x x xx x x x x xx x x xxx x I 18 63 6.7 0749+540Ix x x x x x x x x x x x x x x x x x x I 19 336 13.4 0804+499I I 0 0 .0 0805+410I x x x x x x x I 7 55 2.5 0823+033Ixx x x x x x x x x I 10 37 2.8 OJ287 I x x x x x x x x I 8 23 1.4 0919-260I x x x I 3 3 .7 4C39.25 I x x xx xx x xx x x x x x xx x x x x xI 21 321 15.5 OK290 I x x xx x x x x x I 9 40 2.3 0955+476I x I 1 15 .7 1044+719Ix x x x x x x x x x I 10 157 6.2 1053+815I I 0 0 .0 1124-186I x xx x xx I 6 18 2.7 1128+385Ix xx x I 4 36 1.7 1219+044I x x xx x x x xx x x xI 12 51 3.9 1300+580I x x x I 3 26 1.0 1308+326I x x x x x xx x x x xI 11 47 2.4 1334-127I x xx x x x x x x xxx xx I 14 48 4.8 1351-018I x x x x x I 5 14 1.2 1357+769I x x x x x x I 6 85 3.0 1606+106I x x x x x xx x x x xx xx xx I 16 111 7.7 1622-253Ix x xx x x I 6 6 .9 NRAO512 I x x x x x x x x x x x x x x I 14 185 8.9 1726+455I I 0 0 .0 1739+522I x x x x x x x x x x x x x x x x x x x xI 20 347 15.2 1741-038I x xx x x x x x x x xx x x x xx xxx xI 21 91 7.8 1749+096I x xx x x x xxxx I 10 57 4.0 1908-201I x x x xx xI 6 20 3.4 1958-179I x x I 2 4 .4 2121+053I xx x x xx x I 7 39 2.9 2128-123I x xx x x x x x x x x x I 12 32 3.8 2134+00 I x xx xxx xxx xxx x xI 14 14 1.1 2145+067I x xx x x x x x x x x x I 12 83 6.0 2234+282I xx x x x x I 6 27 1.5 2255-282I x x x I 3 7 1.6 Total scans, obs: 479 3527 Average number of obs. per baseline per source (normalized by up-time) = 4.1 Min = .0 Max = 34.6 (Baseline On-Wz on 0106+013) RMS = 5.8 Total time: 1441 minutes ( 24.0 hours). Key: Ap=ALGOPARK Yk=ARIES_9M 15=DSS15 Ft=FORTLEZA Gc=GILCREEK Ka=KASHIMA On=ONSALA60 Wz=WETTZELL Ap Yk 15 Ft Gc Ka On Wz Avg % obs. time: 22 32 27 27 33 36 37 37 31 % cal. time: 3 2 3 1 3 2 2 3 2 % slew time: 54 25 34 24 18 19 18 11 25 % idle time: 19 39 35 46 44 41 41 47 39 # of tapes : 1.5 2.0 .5 1.7 .6 2.2 2.2 2.3 total # scans: 268 215 274 135 297 201 231 281 237 # scans/hour : 11 8 11 5 12 8 9 11 9.9 Avg scan (sec): 73 131 86 176 97 156 140 114 121 # OF OBSERVATIONS BY BASELINE | Ap Yk 15 Ft Gc Ka On Wz StnTotal ---------------------------------------------- Ap|268 176 217 97 201 90 113 139 1034 Yk| 215 180 65 184 95 96 103 908 15| 274 83 224 116 100 111 841 Ft| 135 58 13 73 90 875 Gc| 297 169 135 146 923 Ka| 201 118 119 793 On| 231 216 687 Wz| 281 993 Number of 2-station scans: 128 Number of 3-station scans: 92 Number of 4-station scans: 94 Number of 5-station scans: 55 Number of 6-station scans: 56 Number of 7-station scans: 49 Number of 8-station scans: 5 Total # of scans, observations: 479 3527 Average baseline components for all observations Average XY = 5060. Average XZ = 4142. Average YZ = 3807. Average length = 5510.