CORE-B402 (Continuous Observations of the Rotation of the Earth-B402) 1999 March 24 Notes prepared by Cynthia Thomas and Nancy Vandenberg,NVI/GSFC Schedule name: CB402.SKD on CDDISA Nominal Start: 18:30 U.T. on March 24 (day 083) first observation at 18:30 U.T. on 1739+522 Nominal Stop: 18:30 U.T. on March 25 (day 084) last observation at 18:19 U.T. on 1053+815 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) 128 73323401 DSS15 D 15 1 (TT) 261 72318701 Fairbanks A GC 1 (TT) 282 40476601 Kokee K KK 1 (TT) 221 72983001 Medicina B MC 2 (HDT) 222 72308801 Ny Alesund N NY 1 (TT) 255 73313301 Westford E WF 2 (TT) 257 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 and Westford will record this experiment on thin tapes in low density. There are only 3 MKIV drives at Haystack, so Ny Alesund, DSS15, 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 | 79.56| UT1-TAI | 60% | | | | | | |Y-Wobble | 70.61| ------- | under 40% | | | | | | |UT1-TAI | 2.44| X-Wobble | 60% | | | | | | |UT1-TAI Rate| 4.78| ------- | 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 ==== ========== 98NOV17 NEOS-A290 98NOV17 CORE-A049 98NOV24 NEOS-A291 98DEC01 CORE-A050 98DEC08 NEOS-A293 98DEC15 NEOS-A294 98DEC15 CORE-A051 98DEC22 NEOS-A295 98DEC29 NEOS-A296 98DEC29 CORE-A052 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 ./cb402.skd for experiment CB402 (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 x x x x xx x x x xx xx x xx x x x x x x x I 23 368 20.1 0106+013I I 0 0 .0 0119+115Ix x xx x x xxxx xxxx xx xxx I 19 152 13.6 0229+131I x x I 2 4 .4 0235+164Ixx xxx x x x x xx x xxx x x x I 18 151 12.7 0458-020I xx x x x xx x x x xx xx I 14 56 6.6 0528+134Ix xxx x xx x x xxx x x x x x xx xxx xxI 24 158 13.7 0718+793I x x I 2 13 .6 0727-115I xx xx x x I 6 14 2.4 0749+540Ixx x x x x xx xx xx x x x x xx xx x x x x x I 25 386 22.4 0804+499I I 0 0 .0 0823+033I x x x x xx x xI 8 17 1.7 4C39.25 Ix xx xx xx xxxx x xx xx x xx x x x xx x xx xxx I 30 311 20.7 OK290 I x x x x x x x xI 8 20 1.6 0955+476I x x x xx x xx x x x x x x x x xI 17 194 12.0 1044+719I x x x x x x x x x x x x x x xI 15 285 13.8 1053+815I x x x x x x x x I 8 162 7.7 1144-379I I 0 0 .0 1219+044I xx xxx x xx x x I 10 57 5.7 1308+326Ix x x x x x xx I 8 30 2.2 1334-127I xx x x x x I 6 18 2.7 1357+769I x x x x x x x x x xI 10 204 9.7 1606+106I x xx xx xx x xxx x xxxx x x I 18 120 10.9 1739+522Ix x x x x x x x xx x xx x x x xx xx xx xx x xx I 27 400 23.6 1741-038I x xx x x x xx xxxx x x I 14 56 7.9 1749+096I xx x xx x x I 7 35 3.2 2121+053I x x x xx x xxx xxx x x x I 15 87 8.6 2128-123I x x x I 3 5 1.0 2134+00 I I 0 0 .0 2145+067I x x x x x x xI 7 26 2.5 2234+282Ix x x x xx I 6 39 3.0 Total scans, obs: 350 3368 Average number of obs. per baseline per source (normalized by up-time) = 7.1 Min = .0 Max = 34.3 (Baseline Ny-Wf on 1741-038) RMS = 8.4 Total time: 1430 minutes ( 23.8 hours). Key: Sm=CRIMEA 15=DSS15 Gc=GILCREEK Kk=KOKEE Mc=MEDICINA Ny=NYALES20 Wf=WESTFORD Sm 15 Gc Kk Mc Ny Wf Avg % obs. time: 20 22 28 35 28 31 36 29 % cal. time: 1 3 3 2 2 2 2 2 % slew time: 25 48 21 13 31 16 13 24 % idle time: 52 25 46 48 37 49 46 43 # of tapes : 1.3 .4 .8 .6 1.8 .5 1.1 total # scans: 128 261 282 221 222 255 257 232 # scans/hour : 5 10 11 9 9 10 10 9.7 Avg scan (sec): 140 74 85 138 109 104 121 110 # OF OBSERVATIONS BY BASELINE | Sm 15 Gc Kk Mc Ny Wf StnTotal ------------------------------------------ Sm|128 84 96 54 125 125 107 860 15| 261 234 197 151 178 220 817 Gc| 282 213 165 206 215 735 Kk| 221 101 144 162 951 Mc| 222 210 184 1159 Ny| 255 197 1216 Wf| 257 998 Number of 2-station scans: 31 Number of 3-station scans: 59 Number of 4-station scans: 79 Number of 5-station scans: 61 Number of 6-station scans: 74 Number of 7-station scans: 46 Total # of scans, observations: 350 3368 Average baseline components for all observations Average XY = 5365. Average XZ = 4443. Average YZ = 3622. Average length = 5696.