CORE-3006 (Continuous Observations of the Rotation of the Earth-3006) 2000 December 13 Notes prepared by Nancy Vandenberg and Cynthia Thomas,NVI/GSFC Schedule name: dec00/c3006.skd on CDDISA Nominal Start: 18:30 U.T. on November 13 (day 348) first observation at 18:30 U.T. on 1357+769 Nominal Stop: 18:30 U.T. on November 14 (day 349) last observation at 00:22 U.T. on 1044+719 for SH last observation at 18:09 U.T. on 0749+540 for WF last observation at 18:14 U.T. on OJ287 for GC-KK last observation at 18:17 U.T. on 0119+115 for MA-ON-WZ Observing Mode: 2F (with barrel roll, see details below) Correlator: Haystack 1 letter 2 letter Station Code Code # of tapes # of obs Occupation Code Fairbanks A Gc 1 (TT) 354 40476601 Kokee K Kk 2 (TT) 297 72983001 Matera I Ma 2 (TT) 331 72435701 Onsala T On 2 (TT) 320 72137701 Westford E Wf 2 (TT) 304 72097301 Wettzell V Wz 2 (TT) 352 72247801 Seshan S Sh 1 (TT) 35 72336101 Purpose ======= The CORE-3 sessions mark the start of the regular CORE oberving program. These sessions will provide a monthly 72-hour continuous data set from July through December (CORE-1 + NEOS + CORE-3). 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 C3004 with Fairbanks and Kokee in VLBA format with roll. Wideband Test ============= Seshan has been tagged along to this session to test their wideband performance. Schedule ======== This schedule was made by C. Thomas using sked. Schedule setup parameters: Early start 10 sec (*) Minimum scan length 50 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 3 hours 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 Ny Alesund is used in the network instead of Onsala. Schedule characteristics: Average scan length 114 seconds Average SNR 59.3 at X-band 35.6 at S-band Number of observations 3021 observations Average scans per station 583 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 ==== ========= 00MAY02 NEOS-A366 00MAY08 IRIS-S150 00MAY09 NEOS-A367 00MAY10 CORE-B701 00MAY15 EUROPE-56 00MAY16 NEOS-A368 00MAY23 NEOS-A369 00MAY30 NEOS-A370 00JUN06 NEOS-A371 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-1 network. Also shown in the table are the maximum correlations between the Earth orientation parameters and other parameters. Simulation for experiment $00DEC13ZZ -------------------------------------------------------------------| | | | Maximum | Correlating | | EOP | Formal | Correlation | Parameter | | Parameters | Errors | | | |------------+----------------+-------------+----------------------| | | | | | | X-Wobble | 36.7 mas | 0.21 | KOKEE Z COMPONENT | | Y-Wobble | 29.9 mas | 0.15 | WETTZELL Z COMPONENT | | UT1-TAI | 1.4 musec | 0.17 | KOKEE Y COMPONENT | | UT1-Rate | 2.3 musec/d | 0.02 | WETTZELL X COMPONENT | |------------|----------------|-------------|----------------------| Procedures ========== Please generate the procedures for this session using drudg. SKED Summary from file ./c3006.skd for experiment C3006 (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 x x x x x x x x xx x x xI 19 58 6.9 0048-097I x x x x x x x x I 8 18 2.4 0059+581I x x x xx x x x x xx I 11 135 7.0 0106+013Ix x xx x x x x x x x x x x x x x xI 18 56 5.7 0119+115I xx x x x x x x x x x x x x x x x x x x I 20 79 6.9 0119+041I x x x x x x xx x x x x x x I 14 40 3.9 0229+131I x x x x x xx x I 8 22 1.9 0235+164I x x x x x x x x x xI 10 49 4.0 CTA26 I x x x x x x I 6 14 1.5 0458-020I x x x x xx x x x x xx x x x xI 16 52 5.7 0528+134I x x x x x x x x x x x x x x x x x x x xI 20 76 6.5 0552+398Ix x x x x xx x x x x x xx x x x x xx x x xx I 24 232 14.0 0556+238I x x x x I 4 6 .4 0718+793I x x x x x x x I 7 15 .7 0727-115I x x x xx x x x x x xx x xx xI 16 41 6.0 0749+540I x x x x x x x x x xx x x x x xx x x x xI 21 271 14.6 0804+499I x x x x x I 5 65 3.7 0805+410I x I 1 10 .6 0823+033I x xx x x x x x x x x x x x x x x xx xI 20 67 6.7 OJ287 Ix x x xx x x x x x x xx x x x I 16 26 2.0 0919-260Ix x x x x I 5 9 2.8 0920-397I I 0 0 .0 4C39.25 Ix x x x x x x x x x xx x x x x x x x x x x I 22 208 12.7 OK290 I x x x x x x x x x x x x x x x x xI 17 23 1.6 0955+476Ix x x x x x x x x x x x x x x x x I 17 196 11.2 1044+719Ix x x x x x x x x x x x x x I 14 152 7.5 1053+815I x x I 2 6 .3 1128+385I x I 1 10 .6 1219+044Ix x x x xx xx x x x x x x x x x x xx x x x I 23 79 7.8 1300+580I x x x x x x x xI 8 86 4.7 1334-127I x x x x x x x x x x x x x x x I 15 40 6.0 1351-018I x x x x x x x x x x x x x I 13 44 4.8 1357+769Ix x x x x x x x x x x I 11 183 8.7 1606+106I x x xx x xx x x x xx x x x x x x x xx x x x xI 25 103 9.3 1622-253I I 0 0 .0 NRAO512 I xx x xx x x x x x x x x x I 14 131 7.8 1726+455I xx xx x xx x I 8 15 .8 1739+522Ix x x x x x I 6 33 1.8 1741-038I xx x x x x x xx x x x x x x x x x x xI 20 63 7.1 1749+096I x xx x xx x I 7 31 2.8 1908-201I x xx x x x x x x x x x I 12 27 5.6 1921-293I x x x x I 4 4 1.1 1958-179I x x x x I 4 13 2.6 2121+053I x x x x x x x x x x x x x x x x x x xI 19 66 6.4 2128-123I x x x x x x x x x I 9 19 3.5 2134+00 I x x x x xx x x x x I 10 20 2.1 2145+067I x x x x x x x x x x I 10 42 4.0 2234+282Ix x x x x x x x x x x x x x x x x x I 18 81 5.7 2255-282I x x x x x I 5 5 1.4 Total scans, obs: 583 3021 Average number of obs. per baseline per source (normalized by up-time) = 4.9 Min = .0 Max = 30.9 (Baseline Gc-Kk on 2128-123) RMS = 6.7 Total time: 1428 minutes ( 23.8 hours). Key: Gc=GILCREEK Kk=KOKEE Ma=MATERA On=ONSALA60 Sh=SESHAN25 Wf=WESTFORD Wz=WETTZELL Gc Kk Ma On Sh Wf Wz Avg % obs. time: 34 45 44 44 6 46 37 36 % cal. time: 4 3 3 3 0 3 4 3 % slew time: 24 15 22 20 6 14 12 16 % idle time: 36 36 29 30 87 35 46 43 # of tapes : 1.0 1.2 1.2 1.2 .2 1.2 1.1 total # scans: 362 305 337 325 35 311 358 290 # scans/hour : 15 12 14 13 1 13 15 12.1 Avg scan (sec): 81 127 113 118 147 127 88 114 # OF OBSERVATIONS BY BASELINE | Gc Kk Ma On Sh Wf Wz StnTotal ------------------------------------------ Gc|362 288 134 152 34 222 155 985 Kk| 305 66 86 23 180 83 726 Ma| 337 297 21 182 336 1036 On| 325 19 194 312 1060 Sh| 35 17 22 136 Wf| 311 198 993 Wz| 358 1106 Number of 2-station scans: 152 Number of 3-station scans: 196 Number of 4-station scans: 96 Number of 5-station scans: 82 Number of 6-station scans: 52 Number of 7-station scans: 5 Total # of scans, observations: 583 3021 Average baseline components for all observations Average XY = 4662. Average XZ = 3959. Average YZ = 3042. Average length = 4971.