CORE-B401 (Continuous Observations of the Rotation of the Earth-B401) 1999 January 13 Notes prepared by Cynthia Thomas and Nancy Vandenberg,NVI/GSFC Schedule name: CB401.SKD on CDDISA Nominal Start: 18:30 U.T. on January 13 (day 013) first observation at 18:30 U.T. on 0119+115 for SM-MC-WF first observation at 18:30 U.T. on 1128+385 for GC-KK-NY Nominal Stop: 18:30 U.T. on January 14 (day 014) last observation at 18:27 U.T. on 0235+164 for SM-MC-NY-WF last observation at 18:27 U.T. on 1308+326 for GC-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) 126 73323401 Fairbanks A GC 1 (TT) 227 40476601 Kokee K KK 1 (TT) 164 72983001 Medicina B MC 2 (HDT) 213 72308801 Ny Alesund N NY 1 (TT) 233 73313301 Westford E WF 1 (TT) 209 72097301 Purpose ======= The purpose of the CORE-B sessions is to obtain EOP data on days adjacent to the main NEOS/CORE-A and CORE-3 sessions and thus extend the span of continuous data. The secondary purpose of CORE-B is to provide observing sessions during which the stations can demonstrate their performance and their ability to participate in future regular CORE sessions. During the first half of the year CORE-B is observed on Wednesdays starting at 18:30 UT, following a NEOS session. Beginning on July 1 CORE-B is observed on Thursdays starting at 19:00 UT, following the CORE-3 sessions. The CORE-B networks are numbered 4, 5, and 6 to distinguish them from the networks used in 1998. Schedule ======== This is a new schedule generated by C. Thomas with the automatic mode of sked. The characteristics of the CORE-B schedules have changed slightly. Changes were made to smooth out the distribution of observations over the sky. Following are the characteristics of the CORE-B schedule file: 1) This schedule was optimized for sky coverage. 2) Only the observations in the previous 2 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 thirty minutes. 5) The minimum SNR limits for the baselines were set to 20 for X-band and 15 for S-band. 6) This schedule was made using 42 sources which helped improve the sky coverage. Station Information =================== Fairbanks will record this experiment on thin tapes in low density. There are only 3 MKIV drives at Haystack, so Ny Alesund, Westford, and Kokee will record on thin tapes in high density. Simulation Results ================== Simulated data from this schedule was used in a global solution to estimate the formal errors. The table below lists the formal errors for Earth orientation parameters. These results meet the simulation goals for the CORE-B network. Also shown in the table are the maximum correlations between the Earth orientation parameters and other parameters. ____________________________________________ | | | | | | EOP |Formal| Other | | |Parameters |Errors|Parameters|Correlation| |____________|______|_________ |___________| | | | | | |X-Wobble | 96.86| UT1-TAI | 57% | | | | | | |Y-Wobble | 80.71| ------- | under 40% | | | | | | |UT1-TAI | 2.84| X-Wobble | 57% | | | | | | |UT1-TAI Rate| 6.15| ------- | under 40% | | | | | | ____________________________________________ 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 following databases: Date Experiment ==== ========== 98SEP22 CORE-A045 98SEP29 NEOS-A283 98OCT06 NEOS-A284 98OCT06 CORE-A046 98OCT20 NEOS-A286 98OCT20 CORE-A047 98NOV03 NEOS-A288 Procedures ========== Please generate the procedures for this session using drudg. Correlation ========== This experiment will be correlated at the Haystack Correlator with all baselines being correlated. SKED Summary from file ./cb401.skd for experiment CB401 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066Ixx x I 3 9 1.8 0048-097I x x x I 3 3 .6 0059+581I x x xx x x x x x x x x x x xx x x I 18 225 17.2 0106+013I x I 1 1 .1 0119+115Ix x x x x x x x xx xI 11 59 7.1 0119+041I x x x x x I 5 15 2.1 0229+131I I 0 0 .0 0235+164I x x x x x x x x xx x x I 12 64 7.3 CTA26 I x x x x I 4 13 2.6 0458-020I x x x I 3 5 .8 0528+134Ix x xx x x x x x x x x x x x xI 16 82 9.8 0556+238I I 0 0 .0 0718+793I x x x I 3 12 .8 0727-115Ixx x x x I 5 11 2.5 0749+540I x x x x x x x x x x x x x x x x x x I 18 195 15.4 0804+499I x x x I 3 35 3.0 0805+410I x x x x x x x I 7 58 4.9 0823+033I x x I 2 2 .3 OJ287 I x x x x xx x x x x x x x I 13 66 6.7 4C39.25 I x x x x x x x x x x x x x x x xI 16 121 11.0 OK290 I x x I 2 4 .4 0955+476Ix x x I 3 31 2.6 1044+719I x x x x x x x xx x x I 11 130 8.9 1053+815I x x x x xI 5 50 3.3 1128+385I x x x x x x x x x x I 10 70 6.0 1144-379I x I 1 1 .8 1219+044I x x x x x I 5 27 3.8 1300+580I x x x I 3 30 2.3 1308+326I x x x x x x I 6 16 1.5 1334-127I xx x x x I 5 7 2.0 1351-018I x x x x I 4 6 1.0 1357+769I x x x x x x x x x I 9 135 9.0 1606+106I x x x x x I 5 19 2.3 1726+455I x x x x x x x x x x x xI 12 77 6.0 1739+522Ix x x x x x x x x x x xx x x xx I 17 195 15.7 1741-038I x x xx x x x xx x x xI 12 36 10.1 1749+096I x x xx x x x xx x x xx xx x xI 17 71 9.1 2121+053I x x I 2 4 .5 2128-123I x I 1 1 .7 2134+00 I x I 1 1 .2 2145+067I x x x x x x x x xx xI 11 42 5.7 2234+282I x x x x x x xx I 8 30 2.9 Total scans, obs: 293 1959 Average number of obs. per baseline per source (normalized by up-time) = 4.6 Min = .0 Max = 68.6 (Baseline Ny-Wf on 1741-038) RMS = 6.1 Total time: 1438 minutes ( 24.0 hours). Key: Sm=CRIMEA Gc=GILCREEK Kk=KOKEE Mc=MEDICINA Ny=NYALES20 Wf=WESTFORD Sm Gc Kk Mc Ny Wf Avg % obs. time: 27 31 39 31 42 50 36 % cal. time: 1 2 1 2 2 2 2 % slew time: 25 16 8 30 14 11 18 % idle time: 45 48 50 35 40 35 42 # of tapes : 1.7 .9 .6 2.0 .7 .8 total # scans: 126 227 164 213 233 209 195 # scans/hour : 5 9 6 8 9 8 8.1 Avg scan (sec): 186 120 205 126 156 208 166 # OF OBSERVATIONS BY BASELINE | Sm Gc Kk Mc Ny Wf StnTotal -------------------------------------- Sm|126 69 38 124 109 86 488 Gc| 227 163 148 186 174 584 Kk| 164 84 124 119 691 Mc| 213 192 166 608 Ny| 233 177 769 Wf| 209 778 Number of 2-station scans: 31 Number of 3-station scans: 76 Number of 4-station scans: 80 Number of 5-station scans: 74 Number of 6-station scans: 32 Total # of scans, observations: 293 1959 Average baseline components for all observations Average XY = 5322. Average XZ = 4491. Average YZ = 3503. Average length = 5667.