CORE-3008 (Continuous Observations of the Rotation of the Earth-3008) 2001 January 24 Notes prepared by Nancy Vandenberg and Cynthia Thomas,NVI/GSFC Schedule name: jan01.c3008.skd on CDDISA Nominal Start: 18:30 U.T. on January 24 (day 024) first observation at 18:30 U.T. on 1739+522 Nominal Stop: 18:30 U.T. on January 25 (day 025) last observation at 18:17 U.T. on 2121+053 for GC-KK-WF last observation at 18:17 U.T. on 0528+134 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) 348 40476601 Kokee K Kk 2 (TT) 287 72983001 Medicina B Mc 1 (TT) 372 72308801 Onsala T On 2 (TT) 326 72137701 Westford E Wf 2 (TT) 313 72097301 Wettzell V Wz 1 (TT) 364 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 session 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 (see below). Stations with Mark 4 formatters cannot barrel roll. (*) Special Instructions for Fairbanks and Kokee ================================================ Fairbanks and Kokee have VLBA backends, which can record in either VLBA ("v" or NDR=non-data replacement) or Mark4 ("m" or DR=data replacement) format. The VLBA formatters also have barrel roll capability. Only the VLBA format with barrel roll was tested in the CORRT test schedule. Therefore it was decided to record C3007 with Fairbanks and Kokee in VLBA format with 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 (*) It is anticipated that the time required at the correlator to synchronize tapes will decrease to just a few seconds. When that capability is available, the value of early start will be lowered. 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 99 seconds Average SNR 60.5 at X-band 35.3 at S-band Number of observations 2993 observations Average scans per station 335 scans 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 ==== ========= 00OCT03 NEOS-A388 00OCT10 NEOS-A389 00OCT24 NEOS-A391 00OCT31 NEOS-A392 00NOV14 NEOS-A394 00NOV28 NEOS-A396 00DEC12 NEOS-A398 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 $01JAN24ZZ -------------------------------------------------------------------| | | | Maximum | Correlating | | EOP | Formal | Correlation | Parameter | | Parameters | Errors | | | |------------+----------------+-------------+----------------------| | | | | | | X-Wobble | 43.8 mas | -0.07 | WETTZELL Z COMPONENT | | Y-Wobble | 35.3 mas | 0.31 | MEDICINA Y COMPONENT | | UT1-TAI | 1.8 musec | 0.20 | MEDICINA Z COMPONENT | | UT1-Rate | 2.5 musec/d | 0.05 | MEDICINA Y COMPONENT | |------------|----------------|-------------|----------------------| Procedures ========== Please generate the procedures for this session using drudg. SKED Summary from file ./c3008.skd for experiment C3008 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x x x x x x xx x x x x x x x I 15 39 6.7 0048-097I x x x x x I 5 16 3.0 0059+581I x x x x x x x x x x I 10 121 8.7 0106+013I x x x x x x x x x x x x x I 13 36 5.2 0119+115I xx x x x x x x x x x x x x x x I 16 65 8.0 0119+041I x x xI 3 5 .7 0229+131I x x x x I 4 16 2.0 0235+164Ix x xx x x x x x x x x x x x x x x I 18 90 10.3 CTA26 I xx x xx x x x x x x x x x x x x x x x I 20 63 9.6 0454-234I x x x x x x x x x I 9 19 6.9 0458-020I x x x x x x x x x x x x xx x x xI 17 55 8.4 0528+134I x x x x x x x x x x x xx x x x x x x x x xI 22 82 9.8 0552+398Ix x x x x x x x x x x x x x x x xx x x x I 21 202 16.9 0556+238I x x x I 3 5 .5 0718+793I x x x x x x x x x I 9 9 .6 0727-115I x x x x x x x x x x x x x x x x x I 17 42 8.7 0749+540Ix x x x x x x x x x I 10 121 8.9 0804+499I x x x x x x x I 7 95 7.4 0805+410I x x x x x x I 6 57 4.6 0823+033I x x x x x x x x x x x x x x xx x xx x I 20 65 9.1 OJ287 I x x x x x x x x x xx xI 12 38 4.1 0919-260I xx x x x x I 6 10 4.8 4C39.25 I x x x x x x x x x x x x x x x x x I 17 162 13.7 OK290 I x x x x x x x x x I 9 16 1.5 0955+476I x x x x x x x xI 8 81 6.4 1044+719I x x x x x x x x x x x x x x I 14 140 9.6 1053+815I I 0 0 .0 1124-186I x x x x x x x x x x xI 11 29 9.0 1128+385I x x x x x x x x x x x x x x x x x x I 18 165 14.1 1219+044I x x x x x x x x x x x xI 12 28 3.9 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 1334-127Ix x x x x x x x x x x x x x I 14 36 7.1 1351-018I x x x x xx x x x xx x x x xx x xI 18 59 9.1 1357+769Ix x x x x x x x x x x x x x x x x x x x I 20 300 20.0 1606+106I x x x x xx x x x x x x xx x x xx x x x x xI 23 88 11.1 1622-253I x x x x x x x I 7 15 6.4 NRAO512 Ix x x x x I 5 27 2.2 1726+455I x x x I 3 35 2.8 1739+522I x x x x x x x x x x I 10 125 9.2 1741-038I x xx x x x x x x x x x x x x x x x I 18 51 8.1 1749+096I x x x x x x x x x x x x x x x x x x x xI 20 78 9.9 1908-201I x x x x x x x x x x I 10 25 8.0 1921-293I x x x I 3 3 1.5 1958-179I I 0 0 .0 2121+053Ixx x x x x x x x x x x x I 13 41 5.5 2128-123Ix x x x x x x x x x x I 11 23 5.5 2134+00 I x x x x I 4 12 1.7 2145+067I x x x x x x x x x x x I 11 36 4.8 2234+282I x x x x x x x x x x x x x x x xI 16 67 6.5 2255-282I x x x x I 4 4 1.9 Total scans, obs: 576 2993 Average number of obs. per baseline per source (normalized by up-time) = 6.6 Min = .0 Max = 30.0 (Baseline Gc-Kk on 2128-123) RMS = 6.8 Total time: 1428 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: 32 40 24 47 47 36 38 % cal. time: 4 3 4 3 3 4 3 % slew time: 24 15 39 20 14 11 21 % idle time: 39 40 31 28 33 47 36 # of tapes : .9 1.1 .7 1.3 1.3 1.0 total # scans: 348 287 372 326 313 364 335 # scans/hour : 14 12 15 13 13 15 14.0 Avg scan (sec): 79 120 56 123 131 86 99 # OF OBSERVATIONS BY BASELINE | Gc Kk Mc On Wf Wz StnTotal -------------------------------------- Gc|348 261 170 160 218 162 971 Kk| 287 85 96 185 95 722 Mc| 372 305 201 354 1115 On| 326 188 314 1063 Wf| 313 199 991 Wz| 364 1124 Number of 2-station scans: 151 Number of 3-station scans: 194 Number of 4-station scans: 95 Number of 5-station scans: 70 Number of 6-station scans: 66 Total # of scans, observations: 576 2993 Average baseline components for all observations Average XY = 4505. Average XZ = 3911. Average YZ = 2747. Average length = 4774.