CORE-3015 (Continuous Observations of the Rotation of the Earth-3015) 2001 May 2 Notes prepared by Nancy Vandenberg and Cynthia Thomas,NVI/GSFC Schedule name: may01/c3015.skd on CDDISA Nominal Start: 18:30 U.T. on May 2 (day 122) first observation at 18:30 U.T. on 1357+769 Nominal Stop: 18:30 U.T. on May 3 (day 123) last observation at 18:15 U.T. on CTA26 for GC-KK-WF last observation at 18:15 U.T. on 0919-260 for MC-ON-WZ Observing Mode: 2F (with barrel roll, see details below) Correlator: Bonn 1 letter 2 letter Station Code Code # of tapes # of obs Occupation Code Fairbanks A Gc 1 (TT) 327 40476601 Kokee K Kk 2 (TT) 268 72983001 Medicina B Mc 1 (TT) 362 72308801 Onsala T On 2 (TT) 299 72137701 Westford E Wf 2 (TT) 298 72097301 Wettzell V Wz 2 (TT) 345 72247801 Purpose ======= The CORE-3 sessions marked the start of the regular CORE oberving program. These sessions will provide a bi-weekly 48-hour continuous data set from January through July (NEOS + CORE-3) and a weekly 48-hour continuous data set from July through December. The CORE-3 sessions will be recorded in a Mark 4 mode which requires that the participating stations have Mark 4 capability. Observing Mode ============== This is the first CORE series that uses a "Mark 4" style observing mode. The mode for CORE-3 uses fan-out and records on all 32 tracks to achieve a data rate of 128 Mb/s, more than twice that of the standard geodetic Mode C which is 56 Mb/s. CORE Mode "2F" (twice the standard mode C, fanned out) ----------------------------------------------------------------- Number of frequencies 14 (standard wide-band frequency sequence modified to avoid RFI at Matera) Number of channels 16 (14 USB + 2 LSB) Channel bandwidth 4.0 MHz Sample rate 8 Mb/s Bits per sample 1 Total data rate 128 Mb/s Data rate on tape 4 Mb/s/track Fan-out 1:2 Tape speed 80 ips Tracks per pass 32 Passes per tape 14 Barrel roll yes (*) Track frame format Mark4 and VLBA (*) The 16 recorded channels are comprised of the standard 14-channel USB frequency sequence plus the LSB channels of the first and last frequencies at X-band. The two outer X-band LSB channels give extra sensitivity. They also slightly narrow the peak of the delay resolution function, resulting in better group delay precision. *The stations with VLBA backends, Fairbanks and Kokee, will use barrel roll during this session and record in VLBA (non-data replacement) format. Stations with Mark 4 formatters cannot barrel roll. Schedule ======== This schedule was made by C. Thomas using sked. Schedule setup parameters: Early start 10 sec Minimum scan length 30 sec Maximum scan length 600 sec Minimum SNR 20 at X-band, margin of 5 15 at S-band, margin of 3 Automatic scheduling setup: optimize for uniform sky coverage at all stations, maximize the number of observations, minimize slewing time, minimize time between scans, consider the top 50% of ranked scans for selection, consider the last 1 hour of scans for sky coverage calculations, minimum 50 min between scans on the same source. The characteristics of the generated schedule are listed below. These will vary slightly for each schedule that is generated. The characteristics also will change when Matera and Ny Alesund are used in the network instead of Medicina and Onsala. Schedule characteristics: Average scan length 108 seconds Average SNR 58.6 at X-band 31.2 at S-band Number of observations 2794 observations Average scans per station 316 scans Parity ====== This schedule was made with a minimum scan time of less than the 55 seconds required for parity checks. As a result, some parity checks in the schedule may give bad results even though there is nothing wrong. The next release of the FS, 9.5, will correct this problem. In the meantime, please check when a parity check fails to see if the cause is a short scan. If the problem is presistent and occurs frequently at your station for a given schedule type, you may want to disable parity checks for specific experiments of that type. You can do this by creating empty "checkf80" and "checkr80" procedures (or "checkf135" and "checkr135" if you are using thick tape) in the EXPERIMENT procedure library for the effected experiment. If you do this, it is strongly recommend that you verify recorder performance before the experiment by recording some tape in both directions using the experiment set-up and check it with the appropriate parity check procedures. Flux Information ================ Program snranal compares the measured performance of a session with respect to the predicted. The program calculates an empirical flux density for each source. In order to account for changes in the flux catalog since the last update based on source modeling, the fluxes in the flux catalog for the sources in the current source catalog were adjused using the following databases: Date Session ==== ========= 00NOV14 NEOS-A394 00NOV28 NEOS-A396 00DEC12 NEOS-A398 01JAN08 IRIS-S158 01JAN16 NEOS-A403 01JAN23 NEOS-A404 01JAN30 NEOS-A405 01FEB06 NEOS-A406 01FEB13 NEOS-A407 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-3 network. Also shown in the table are the maximum correlations between the Earth orientation parameters and other parameters. Simulation for experiment $01MAY02ZZ -------------------------------------------------------------------| | | | Maximum | Correlating | | EOP | Formal | Correlation | Parameter | | Parameters | Errors | | | |------------+----------------+-------------+----------------------| | | | | | | X-Wobble | 47.9 mas | -0.06 | WETTZELL Z COMPONENT | | Y-Wobble | 37.9 mas | 0.31 | MEDICINA Y COMPONENT | | UT1-TAI | 1.9 musec | 0.15 | MEDICINA Z COMPONENT | | UT1-Rate | 3.0 musec/d | 0.11 | MEDICINA Y COMPONENT | |------------|----------------|-------------|----------------------| Procedures ========== Please generate the procedures for this session using drudg. Sources ======= Sources 0229+131 and 0235+164 are less than 15 degrees from the Sun. So, thoses sources were not observed during this session. SKED Summary from file ./c3015.skd for experiment C3015 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x x x x xx x x x x x x x xx x x xx x I 20 55 9.4 0048-097I I 0 0 .0 0059+581I x x x x x I 5 46 3.3 0106+013I x x x x x x x x x x x x x xI 14 47 6.8 0119+115I x x x x x x x x x x x x x x x x x x I 18 75 9.2 0119+041I x I 1 1 .1 0229+131I I 0 0 .0 0235+164I I 0 0 .0 CTA26 I x x x x x x x x x x x x x x x x x xxI 19 59 9.0 0454-234I x x x x x x x x x I 9 17 6.0 0458-020I x x x x x x x x x x x x x x x x x I 17 43 6.7 0528+134I x x x x x x x x x x x x x x x xx x x x x xI 22 86 10.3 0552+398I x x x x x x x x x x x x x x x x x x x x x xI 22 208 17.5 0556+238I x x I 2 7 .7 0718+793Ix x x x x x x x I 8 10 .7 0727-115I x x xx x x x x x x x xx x x x x I 17 45 9.3 0749+540I x x x x x x x x x x x I 11 145 10.8 0804+499I x x x x x x x x I 8 100 7.7 0805+410Ix x x x x I 5 40 3.3 0823+033I x x x x x x x x x x x x x x x x x x xI 19 64 9.0 OJ287 I x x x x x x x x x x x x x x x x x x xI 19 82 8.9 0919-260I x x x x x x I 6 10 4.9 4C39.25 I x x x x x x x x x x x x x x x x xI 17 163 13.9 OK290 I x x x x x x x x x x x I 11 19 1.8 0955+476I x x x x x x x x x x I 10 111 8.8 1044+719I x x x x x x x x x x x I 11 100 6.8 1053+815I I 0 0 .0 1124-186I x x x x x x x x x x x xI 12 30 9.3 1128+385I x x x x x x x I 7 77 6.6 1219+044I x x x x x x x x x x x x x I 13 32 4.4 1255-316I x x x x I 4 4 2.2 1300+580Ix x x x x x x x x x I 10 92 7.0 1313-333I I 0 0 .0 1334-127I x x x x xx x x x x xx x I 13 36 7.1 1351-018I x x x x x x x x x x xx I 12 29 4.5 1357+769I x x x x x x x x x x x x x x x x x x x I 19 285 19.0 1606+106I x x xx x x x x x xx x x x x x x x xx xI 21 84 10.6 1622-253I x x x x x x x x xI 9 17 6.9 NRAO512 I x x x x x x xI 7 46 3.9 1726+455I x x x I 3 31 2.6 1739+522I x x x x x x x x x x xI 11 116 8.3 1741-038I x x x x x x x x x x x x x x x x x xI 18 54 8.6 1749+096I x x x x xx x x x x x x x xx x x x x I 19 75 9.5 1908-201I x x x x x x xx xI 9 17 5.2 1921-293I x x x I 3 3 1.5 1958-179I x x x x x I 5 14 4.1 2121+053I x x x x x x x x x x xx I 12 34 4.6 2128-123I x x x x x x x x x I 9 19 4.9 2134+00 I x x x x x x x x I 8 22 3.2 2145+067I x x x x x x x x x x x I 11 49 6.5 2234+282Ix x x x xx x x x x x x x x x x x x I 18 90 8.7 2255-282I x x x x x I 5 5 2.3 Total scans, obs: 549 2794 Average number of obs. per baseline per source (normalized by up-time) = 6.3 Min = .0 Max = 30.9 (Baseline Gc-Kk on 2128-123) RMS = 6.7 Total time: 1426 minutes ( 23.8 hours). Key: Gc=GILCREEK Kk=KOKEE Mc=MEDICINA On=ONSALA60 Wf=WESTFORD Wz=WETTZELL Gc Kk Mc On Wf Wz Avg % obs. time: 33 40 26 45 49 39 39 % cal. time: 3 3 4 3 3 4 3 % slew time: 24 15 38 18 14 10 20 % idle time: 38 40 30 32 32 45 36 # of tapes : .9 1.1 .8 1.2 1.4 1.1 total # scans: 327 268 362 299 298 345 316 # scans/hour : 13 11 15 12 12 14 13.2 Avg scan (sec): 87 129 63 131 143 98 108 # OF OBSERVATIONS BY BASELINE | Gc Kk Mc On Wf Wz StnTotal -------------------------------------- Gc|327 243 165 142 204 153 907 Kk| 268 81 82 170 87 663 Mc| 362 283 196 339 1064 On| 299 173 289 969 Wf| 298 187 930 Wz| 345 1055 Number of 2-station scans: 150 Number of 3-station scans: 182 Number of 4-station scans: 88 Number of 5-station scans: 73 Number of 6-station scans: 56 Total # of scans, observations: 549 2794 Average baseline components for all observations Average XY = 4492. Average XZ = 3890. Average YZ = 2748. Average length = 4760.