CORE-B208 (Continuous Observations of the Rotation of the Earth-B208) 1998 April 22 Notes prepared by Cynthia Thomas, NVI/GSFC Schedule name: CB208.SKD on CDDIS Nominal Start: 18:30 U.T. on April 22 (day 112) first observation at 18:30 U.T. on 4C39.25 for SM-FT-GC-MC-NY first observation at 18:30 U.T. on 1606+106 for KA-KK Duration: 24 hours Nominal Stop: 18:30 U.T. on April 23 (day 113) last observation at 18:24 U.T. on NRAO512 for SM-NY last observation at 18:28 U.T. on 1034-293 for FT-MC last observation at 18:29 U.T. on 0003-066 for GC last observation at 18:31 U.T. on 1954-388 for KA-KK 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) 166 73323401 Fortaleza F FT 2 (HDT) 134 72974801 Fairbanks A GC 1 (TT) 291 40476601 Kashima-26 Q KA 3 (HDT) 265 18567601 Kokee K KK 1 (TT) 295 72983001 Medicina B MC 3 (HDT) 300 72308801 Ny Alesund N NY 1 (TT) 259 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. 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 ./cb208.skd for experiment CB208 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x x x xxx xxxx x x xxxx x xx xxI 21 31 3.9 0048-097I x x x x x x I 6 12 1.5 0059+581Ixx x x x x x x x x x x x x x x xx x I 19 273 16.8 0119+041I I 0 0 .0 0229+131I I 0 0 .0 CTA26 I x x x x xx x x x x xx xxx I 15 19 2.1 0454-234I xxx xx x x x xx x xx I 13 13 2.0 0458-020Ixxxx x x x x x x x I 11 25 2.8 0528+134I xxx x xx xx x x x x xxx x x x xI 19 65 5.7 0552+398Ix x xx xxx x x xx x xx xx x x x x x x xx xI 25 217 15.1 0718+793I x x x x I 4 10 .5 0727-115Ixx xx x x x x xx x x xx x xx x xx x xI 22 38 6.4 0804+499Ixx x x x x x x x x x x x xx x x x I 18 197 12.1 0823+033I xx x x x xxx x xx xx x I 14 22 2.2 OJ287 I x xx x xx xx xx x I 11 11 .9 0919-260I x I 1 1 .2 0920-397I x I 1 1 .3 4C39.25 Ix x x x x x x x xx xx xxx x xx x xx x xI 23 239 17.5 OK290 I xx x xx x x x x xxI 11 11 .8 0955+476I x I 1 10 .6 1034-293I xx x x x I 5 5 .6 1044+719I x x x x x x x x x x x I 11 160 8.1 1124-186I x x x x x x xx xI 9 9 1.3 1128+385I x x x x xI 5 18 1.1 1144-379I x x x x I 4 4 .7 1219+044Ix x x xx x x x xx xx x x x xx xxx I 20 37 3.7 1255-316I x x I 2 2 .4 1300+580I x x x x x I 5 39 2.1 1308+326I x x x x x x x xx xx x x I 13 37 2.5 1334-127I x x x xx xx xx xx x x x xxxxI 18 32 5.8 1351-018I I 0 0 .0 1357+769Ix x x x x x I 6 90 4.3 1606+106I x x x x x xxx x xx xxxx xx I 18 63 5.7 1622-253I x xx x x xx x I 8 8 1.3 NRAO512 I x xx x x x x x x x xx x xx xx x x x I 20 192 13.8 1739+522Ix x x xx x x x x xx x xx xx xx x x x x I 22 280 18.3 1741-038I xxx x x xx x x x x x x xx xxx x x x xx xI 24 66 7.5 1749+096I x x x xx xxx x I 9 53 5.0 1921-293I x x x x x x x xx x xx x x I 14 20 3.5 1954-388I x x x x x x xx I 9 9 2.1 1958-179I x xx x x x x x x x xx I 12 12 1.8 2128-123I x x x xx xx I 7 13 3.0 2145+067I x x x x x xx xx xx xx x x xx xx x x xxI 24 73 7.0 2234+282I x x x x xx x xxx x x x xI 14 51 3.6 2255-282I x xx x xx xI 7 7 1.3 Total scans, obs: 521 2475 Average number of obs. per baseline per source (normalized by up-time) = 4.5 Min = .0 Max = 30.6 (Baseline Gc-Kk on 0003-066) RMS = 7.1 Total time: 1442 minutes ( 24.0 hours). Key: Sm=CRIMEA Ft=FORTLEZA Gc=GILCREEK Ka=KASHIMA Kk=KOKEE Mc=MEDICINA Ny=NYALES20 Sm Ft Gc Ka Kk Mc Ny Avg % obs. time: 32 29 35 44 47 35 32 36 % cal. time: 1 1 3 3 3 3 2 2 % slew time: 28 23 21 24 16 37 15 23 % idle time: 36 46 39 27 31 23 48 36 # of tapes : 2.0 1.8 .6 2.6 .8 2.2 .6 total # scans: 166 134 291 265 295 300 259 244 # scans/hour : 6 5 12 11 12 12 10 10.2 Avg scan (sec): 171 187 105 145 140 102 109 137 # OF OBSERVATIONS BY BASELINE | Sm Ft Gc Ka Kk Mc Ny StnTotal ------------------------------------------ Sm|166 59 99 92 52 153 118 531 Ft| 134 49 12 42 108 54 610 Gc| 291 188 218 157 190 703 Ka| 265 218 106 134 672 Kk| 295 84 120 521 Mc| 300 222 1029 Ny| 259 884 Number of 2-station scans: 219 Number of 3-station scans: 125 Number of 4-station scans: 48 Number of 5-station scans: 72 Number of 6-station scans: 54 Number of 7-station scans: 3 Total # of scans, observations: 521 2475 Average baseline components for all observations Average XY = 5573. Average XZ = 5088. Average YZ = 3764. Average length = 6152.