CORE-B209 (Continuous Observations of the Rotation of the Earth-B209) 1998 June 17 Notes prepared by Cynthia Thomas, NVI/GSFC Schedule name: CB209.SKD on CDDIS Nominal Start: 18:30 U.T. on June 17 (day 168) first observation at 18:30 U.T. on 4C39.25 for SM-FT-GC-MC-NY first observation at 18:30 U.T. on 0048-097 for 45-KA-KK Duration: 24 hours Nominal Stop: 18:30 U.T. on June 18 (day 169) last observation at 18:20 U.T. on 0552+398 for GC-KK last observation at 18:26 U.T. on 1958-179 for 45 last observation at 18:27 U.T. on 1144-379 for FT last observation at 18:31 U.T. on 1749+096 for SM-KA-MC-NY 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 Crimea C SM 2 (HDT) 163 73323401 DSS45 T 45 1 (TT) 230 16426001 Fortaleza F FT 2 (HDT) 146 72974801 Fairbanks A GC 1 (TT) 265 40476601 Kashima-26 Q KA 3 (HDT) 274 18567601 Kokee K KK 1 (TT) 294 72983001 Medicina B MC 3 (HDT) 311 72308801 Ny Alesund N NY 1 (TT) 265 73313301 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 45 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 =================== Fairbanks will record this experiment on thin tapes in low density. There are only 3 MKIV drives at Haystack, so Ny Alesund, DSS45, and Kokee will record on thin tapes in high density. 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 ./cb209.skd for experiment CB209 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066Ix x xx x xxx xx xx xx xxx xx x xI 21 31 2.5 0048-097I x x x x x x xxxx x I 11 41 3.6 0059+581I x x x x x x xx x x x xx x x x x I 17 242 14.1 0119+041Ixx xxx x xxx xx x x x xx x x xI 20 24 1.8 0229+131Ixx x x xx x x x x x x xx x xx xxx x I 21 103 7.5 CTA26 Ix x xx x xx xx x x x x xx x x I 17 23 1.8 0454-234Ix x xx xx xx x x xx x x x xx x x I 19 31 2.9 0458-020I x x x x x x x xx x x xI 12 37 3.0 0528+134I I 0 0 .0 0552+398I xx x x x x xx x x xx x x x x x x xx x x x xI 24 241 15.4 0718+793Ix x x x I 4 8 .4 0727-115Ix xx x x xx xxx x x xx xxx x xxxx x I 23 51 5.2 0804+499I x x x x x x x x x x x x x xx xI 16 163 9.6 0823+033I x xx x xxx x x xxx x xx I 16 24 1.8 OJ287 I x xx x xx xx x xxx x x I 14 14 .9 0919-260I xx I 2 2 .3 0920-397I I 0 0 .0 4C39.25 I xx x x xx x xx x x xx x xx x xx x x x xx x xI 26 287 18.9 OK290 Ixx x x x x x I 7 7 .4 0955+476I x x x I 3 18 .9 1034-293I xx x x x xx xx x x x I 12 16 1.4 1044+719I x x x x x x x xI 8 120 5.6 1124-186I x x xx x xx x xx x xx x x x I 16 30 2.7 1128+385I x x x x x I 5 25 1.2 1144-379I x xx x x xx x xx I 10 16 1.4 1219+044I x x x x x x xx x xx xx x xI 15 17 1.3 1255-316I x x I 2 2 .2 1300+580I x x I 2 16 .8 1308+326I x x x x x x x xx xx x x x x I 15 50 3.2 1334-127I x x x x x x x x x xxx xx xx xx xx x I 21 51 5.7 1351-018I xx x x x x I 6 6 .5 1357+769I x x x x I 4 60 2.7 1606+106I x xx xxx xx x xx xx xx x x x xI 19 100 7.3 1622-253I x x x x x x x x x xI 10 14 1.2 NRAO512 Ix x x x x x x xxx xx xx x x x x I 18 212 14.7 1739+522Ix x x x x x x xx x x x x x x x xx x x x I 21 261 16.1 1741-038Ixxxx x x x xx x xxx x xx xx x x x xx x xI 25 94 7.7 1749+096I x x x x x xx x xx I 11 74 5.5 1921-293Ixx xx x x xx xx x xx x x x x x x x x I 21 41 4.1 1954-388Ixx x xx x x xx x x x x x xxI 16 26 3.3 1958-179I x x x x x xx x x xx x xxx x x xx I 19 33 3.0 2128-123I x x xx I 4 4 .3 2145+067I x x x xx x xx xx xx xx xxx xx xx x xx xI 25 101 7.6 2234+282I x x xx x x x xx x x x x I 13 31 1.9 2255-282I x x xx x x xx x I 9 11 1.0 Total scans, obs: 600 2758 Average number of obs. per baseline per source (normalized by up-time) = 4.3 Min = .0 Max = 32.6 (Baseline 45-Ka on 2145+067) RMS = 7.0 Total time: 1442 minutes ( 24.0 hours). Key: Sm=CRIMEA 45=DSS45 Ft=FORTLEZA Gc=GILCREEK Ka=KASHIMA Kk=KOKEE Mc=MEDICINA Ny=NYALES20 Sm 45 Ft Gc Ka Kk Mc Ny Avg % obs. time: 30 26 30 31 44 47 36 32 35 % cal. time: 1 2 1 3 3 3 3 3 2 % slew time: 27 30 25 20 25 17 38 14 24 % idle time: 39 39 42 44 27 31 21 49 37 # of tapes : 1.8 .5 1.9 1.0 2.7 .8 2.2 .5 total # scans: 162 230 146 265 274 294 311 264 243 # scans/hour : 6 9 6 11 11 12 12 10 10.1 Avg scan (sec): 162 101 180 104 140 139 101 106 129 # OF OBSERVATIONS BY BASELINE | Sm 45 Ft Gc Ka Kk Mc Ny StnTotal ---------------------------------------------- Sm|162 32 64 87 75 49 146 110 647 45| 230 4 73 181 153 17 31 493 Ft| 146 47 9 39 119 54 542 Gc| 265 156 196 141 174 774 Ka| 274 185 87 120 646 Kk| 294 73 113 511 Mc| 311 223 928 Ny| 264 975 Number of 2-station scans: 257 Number of 3-station scans: 129 Number of 4-station scans: 88 Number of 5-station scans: 74 Number of 6-station scans: 41 Number of 7-station scans: 11 Number of 8-station scans: 0 Total # of scans, observations: 600 2758 Average baseline components for all observations Average XY = 5213. Average XZ = 5604. Average YZ = 4576. Average length = 6589.