CORE-3003 (Continuous Observations of the Rotation of the Earth-3003) 2000 September 20 Notes prepared by Nancy Vandenberg and Cynthia Thomas,NVI/GSFC Schedule name: sep00/c3003.skd on CDDISA Nominal Start: 18:30 U.T. on September 20 (day 264) first observation at 18:30 U.T. on 1357+769 Nominal Stop: 18:30 U.T. on Seotember 21 (day 265) last observation at 18:14 U.T. on OJ287 for GC-KK-WF last observation at 18:17 U.T. on 0119+115 for MA-NY-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) 322 40476601 Kokee K Kk 2 (TT) 274 72983001 Matera I Ma 2 (TT) 298 72435701 Ny Alesund N Ny 2 (TT) 313 73313301 Westford E Wf 2 (TT) 306 72097301 Wettzell V Wz 2 (TT) 344 72247801 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). There are three additional CORE-3s scheduled during October and November which also will provide at least 48 hours of continuous data. 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 C3003 with Fairbanks and Kokee in VLBA format with roll. Schedule ======== This schedule was made by C. Thomas using sked. Schedule setup parameters: Early start 20 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 105 seconds Average SNR 61.0 at X-band 34.3 at S-band Number of observations 2704 observations Average scans per station 538 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 ==== ========= 00FEB22 NEOS-A356 00FEB29 NEOS-A357 00MAR14 NEOS-A359 00MAR21 NEOS-A360 00MAR28 NEOS-A361 00APR04 NEOS-A362 00APR11 NEOS-A363 00APR25 NEOS-A365 00JUN06 NEOS-A371 Procedures ========== Please generate the procedures for this session using drudg. SKED Summary from file ./c3003.skd for experiment C3003 (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 x I 15 25 4.9 0048-097I x x x x x x x x I 8 14 2.8 0059+581I x x x x I 4 36 2.6 0106+013I x x x x x xx x x x x x x x x x x xI 18 56 8.4 0119+115I x x x x x x x x x x x x x x x xx x xx I 20 90 10.6 0119+041I x x x x x x x x x x I 10 24 3.4 0229+131I x x x x x x I 6 22 2.5 0235+164I x x x x x x x x x x x x x I 13 76 8.2 CTA26 I x x x x x I 5 16 2.1 0458-020I x x x x x x x x x x x x I 12 27 6.0 0528+134I x x x x x x x x x x x x x x x xI 16 69 7.8 0552+398I x x x x x x x xx x x x x xx x x x x x x x xI 23 210 17.8 0556+238I x x x x x xI 6 21 1.9 0718+793I x x x x x xI 6 22 1.5 0727-115I x x x x xx x x x x x x x xx x x I 17 23 6.5 0749+540I x x x x x x x x x x x x xx x x x x x xI 20 255 19.1 0804+499I x x x x x x I 6 71 5.6 0805+410I x I 1 6 .5 0823+033I xx x x x x x x x x x x x x x x x x x x I 20 62 9.0 OJ287 I x x x x x xx x x x x xx x x x xx x xI 20 101 10.4 0919-260I xx x x x I 5 5 2.0 0920-397I I 0 0 .0 4C39.25 I x x x x x x x x x x x x x x x x x x x x x x I 22 199 17.0 OK290 I x x x x x x x x x x I 10 23 2.2 0955+476I x x x x x x x x x x x x xI 13 131 10.3 1044+719I x x x x x x I 6 62 4.3 1053+815I x x I 2 20 1.3 1128+385I x x x I 3 30 2.6 1219+044I I 0 0 .0 1300+580Ix x x x x x x x I 8 77 5.8 1334-127I x x x x xx x x x x x x x x I 14 20 5.4 1351-018I x x x x x x x x x x x x xx x x x I 17 41 10.2 1357+769I x x x x x x x x x x I 10 150 10.0 1606+106I x x x x x x x x x x x x x x xx x x x x x x I 22 82 9.9 1622-253I x x x xx x x x xx I 10 12 4.4 NRAO512 Ix x x xx x x x x x xx x xx x x x I 18 147 12.3 1726+455I x x x x x x x x x x x I 11 94 7.5 1739+522Ix x x x x x x x x x x x I 12 113 8.6 1741-038Ix x x x x x x x x x xx x x x x x x x I 19 42 13.1 1749+096I x x x x xx x x I 8 34 4.2 1908-201I x x x x x x x x x I 9 13 4.4 1921-293I xx x x x I 5 5 2.2 1958-179I x x x xx x I 6 8 2.6 2121+053I x x x x x x x x x x x x x I 13 34 4.6 2128-123I x x x xx x x x xI 9 13 3.7 2134+00 I x x x x x x x x xI 9 9 1.3 2145+067Ix x x x x x x x x x x x x x x x I 16 57 7.7 2234+282I x x x x x x x x x x I 10 52 4.9 2255-282I x x x x xI 5 5 2.1 Total scans, obs: 538 2704 Average number of obs. per baseline per source (normalized by up-time) = 6.3 Min = .0 Max = 68.6 (Baseline Ny-Wz on 1741-038) RMS = 7.2 Total time: 1428 minutes ( 23.8 hours). Key: Gc=GILCREEK Kk=KOKEE Ma=MATERA Ny=NYALES20 Wf=WESTFORD Wz=WETTZELL Gc Kk Ma Ny Wf Wz Avg % obs. time: 28 43 37 35 44 38 37 % cal. time: 3 3 3 3 3 4 3 % slew time: 23 14 20 20 15 12 17 % idle time: 44 37 38 40 36 45 40 # of tapes : .9 1.2 1.1 1.1 1.3 1.1 total # scans: 322 274 298 313 306 344 309 # scans/hour : 13 11 12 13 12 14 12.9 Avg scan (sec): 75 137 106 96 125 95 105 # OF OBSERVATIONS BY BASELINE | Gc Kk Ma Ny Wf Wz StnTotal -------------------------------------- Gc|322 251 107 217 211 154 940 Kk| 274 47 150 178 86 712 Ma| 298 200 158 295 807 Ny| 313 207 245 1019 Wf| 306 198 952 Wz| 344 978 Number of 2-station scans: 156 Number of 3-station scans: 149 Number of 4-station scans: 106 Number of 5-station scans: 88 Number of 6-station scans: 39 Total # of scans, observations: 538 2704 Average baseline components for all observations Average XY = 4873. Average XZ = 4299. Average YZ = 3175. Average length = 5247.