CORE-3007 (Continuous Observations of the Rotation of the Earth-3007) 2001 January 10 Notes prepared by Nancy Vandenberg and Cynthia Thomas,NVI/GSFC Schedule name: jan01.c3007.skd on CDDISA Nominal Start: 18:30 U.T. on January 10 (day 010) first observation at 18:30 U.T. on 1739+522 Nominal Stop: 18:30 U.T. on January 11 (day 011) last observation at 18:14 U.T. on 0119+041 for ON-WF last observation at 18:16 U.T. on 0454-234 for MC-WZ last observation at 18:17 U.T. on OK290 for GC-KK 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) 352 40476601 Kokee K Kk 2 (TT) 283 72983001 Medicina B Mc 1 (TT) 365 72308801 Onsala T On 2 (TT) 321 72137701 Westford E Wf 2 (TT) 314 72097301 Wettzell V Wz 2 (TT) 349 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 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 Matera and Ny Alesund are used in the network instead of Medicina and Onsala. Schedule characteristics: Average scan length 102 seconds Average SNR 62.6 at X-band 32.9 at S-band Number of observations 3013 observations Average scans per station 330 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-3 network. Also shown in the table are the maximum correlations between the Earth orientation parameters and other parameters. Simulation for experiment $01JAN10ZB -------------------------------------------------------------------| | | | Maximum | Correlating | | EOP | Formal | Correlation | Parameter | | Parameters | Errors | | | |------------+----------------+-------------+----------------------| | | | | | | X-Wobble | 43.2 mas | -0.07 | WETTZELL Z COMPONENT | | Y-Wobble | 36.5 mas | 0.30 | MEDICINA Y COMPONENT | | UT1-TAI | 1.7 musec | 0.17 | MEDICINA Z COMPONENT | | UT1-Rate | 2.3 musec/d | 0.03 | MEDICINA X COMPONENT | |------------|----------------|-------------|----------------------| Procedures ========== Please generate the procedures for this session using drudg. SKED Summary from file ./c3007.skd for experiment C3007 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066Ix x x x x x x x x x x x xx x x x x I 18 58 9.8 0048-097I x x x x x x x I 7 18 3.4 0059+581I x x x x x x x x x x x I 11 127 9.1 0106+013Ix x x xx x x x x x x I 11 38 5.5 0119+115I x x x x x x x x x x x x x x x xI 16 68 8.3 0119+041I x x x x I 4 11 1.5 0229+131I x x x x x x x x x x I 10 37 4.4 0235+164Ix x x x x x x x x x I 10 44 5.0 CTA26 I x x xx x x x x I 8 16 2.5 0454-234I x x xx x x x xI 8 16 5.7 0458-020I x x x x x x x x x x x x x x x x x xI 18 54 8.3 0528+134I x x x x x x x x x x x x x x x x x x x xI 20 75 9.0 0552+398I x xx x x x x x x x x x x x x x x x x x x xI 22 204 17.1 0556+238I x x x x x I 5 9 .9 0718+793I x x x x x x x x x x x x x xI 14 50 3.3 0727-115I x x x x x x x x x x x x x x x I 15 38 7.5 0749+540I x x x x x x x x x x xx x x x xI 16 201 14.8 0804+499I x x x x I 4 60 4.8 0805+410I x x x x I 4 29 2.2 0823+033Ix x x x x x x x x x x x x x x x x x I 18 65 9.1 OJ287 I x x x x x x x x x x x x x I 13 33 3.5 0919-260I x x x x x I 5 9 4.5 4C39.25 I x x x x x x x x x x x x x x x x x I 17 162 13.8 OK290 I x x x x x x x x x x x x xI 13 24 2.3 0955+476Ix x x x x x x x I 8 91 7.3 1044+719I x x x x x x x x x x x x I 12 146 10.0 1053+815I I 0 0 .0 1124-186Ix x x x x x x x x x xI 11 29 9.1 1128+385I x x x x x x x x x x x x I 12 119 10.2 1219+044I x x x x x x x x x x x x x x x x x x x xI 20 72 9.9 1255-316I x x x x x I 5 5 2.5 1300+580I x x x x x x x I 7 62 4.7 1313-333I I 0 0 .0 1334-127I x x x x x x x x x x x x x I 13 38 6.8 1351-018I x x x x x x x x x x xx x x I 14 36 5.6 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 x x x x x x x x x x x x x x x x xI 21 82 10.3 1622-253I x x x x x x x x xx I 10 18 7.2 NRAO512 I x x x x x x x x x x x x x I 13 129 10.7 1726+455I x x x x I 4 11 .9 1739+522I x x x x x x x I 7 70 5.3 1741-038I x x x x x x xx x x x x x x x x x xI 18 54 8.6 1749+096Ix x x x x x x x x x x x x x x x x x x I 19 77 9.8 1908-201I I 0 0 .0 1921-293I I 0 0 .0 1958-179I I 0 0 .0 2121+053I x x x x x x x x x x x xx x x x x I 17 68 9.1 2128-123I x x x x x x x x x x x I 11 23 5.6 2134+00 I x x I 2 6 .9 2145+067I x x x x x x x xI 8 33 4.4 2234+282I x x x x x x x x x x x x x x x x x xI 18 94 9.1 2255-282I x x x x I 4 4 1.9 Total scans, obs: 561 3013 Average number of obs. per baseline per source (normalized by up-time) = 6.6 Min = .0 Max = 30.9 (Baseline Gc-Kk on 2128-123) RMS = 6.6 Total time: 1427 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 28 46 47 37 39 % cal. time: 4 3 4 3 3 4 3 % slew time: 24 14 36 19 14 10 20 % idle time: 37 41 30 30 34 48 37 # of tapes : .9 1.1 .9 1.3 1.3 1.1 total # scans: 352 283 365 321 314 349 330 # scans/hour : 14 11 15 13 13 14 13.8 Avg scan (sec): 82 121 67 124 129 91 102 # OF OBSERVATIONS BY BASELINE | Gc Kk Mc On Wf Wz StnTotal -------------------------------------- Gc|352 260 180 164 221 166 991 Kk| 283 89 101 180 96 726 Mc| 365 299 210 340 1118 On| 321 198 307 1069 Wf| 314 202 1011 Wz| 349 1111 Number of 2-station scans: 146 Number of 3-station scans: 178 Number of 4-station scans: 98 Number of 5-station scans: 68 Number of 6-station scans: 71 Total # of scans, observations: 561 3013 Average baseline components for all observations Average XY = 4576. Average XZ = 3958. Average YZ = 2788. Average length = 4844.