CORE-3004 (Continuous Observations of the Rotation of the Earth-3004) 2000 October 18 Notes prepared by Nancy Vandenberg and Cynthia Thomas,NVI/GSFC Schedule name: oct00/c3004.skd on CDDISA Nominal Start: 18:30 U.T. on October 18 (day 292) first observation at 18:30 U.T. on 0749+540 Nominal Stop: 18:30 U.T. on October 19 (day 293) last observation at 18:02 U.T. on 1044+719 for KK last observation at 18:11 U.T. on 1739+522 for GC-WF last observation at 18:19 U.T. on 2145+067 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) 333 40476601 Kokee K Kk 2 (TT) 287 72983001 Matera I Ma 2 (TT) 277 72435701 Onsala T On 2 (TT) 272 72137701 Westford E Wf 2 (TT) 280 72097301 Wettzell V Wz 2 (TT) 316 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). 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. 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 130 seconds Average SNR 56.6 at X-band 34.9 at S-band Number of observations 2432 observations Average scans per station 294 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 ==== ========= 00APR04 NEOS-A362 00APR11 NEOS-A363 00APR18 NEOS-A364 00APR18 CORE-A083 00APR24 IRIS-S149 00APR25 NEOS-A365 00MAY02 NEOS-A366 00JUN06 NEOS-A371 Procedures ========== Please generate the procedures for this session using drudg. SKED Summary from file ./c3004.skd for experiment C3004 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066Ix x xx x xx x x x x x x x x x x I 17 51 8.5 0048-097Ix x x x x x x I 7 20 3.6 0059+581I x x I 2 16 1.1 0106+013I x x xx x x x xx x x x x x x x x xI 18 61 8.8 0119+115Ix x x x x x x x xx x x x x x x x x x x xx x I 23 87 10.7 0119+041I x x x x x x x I 7 17 2.3 0229+131I x x x I 3 14 1.7 0235+164I x x x x x x x x x x x x x x x I 15 78 9.0 CTA26 I x x x x x I 5 13 1.9 0458-020Ix x x x x x x xx x x x I 12 39 6.0 0528+134Ix x x x x x x x x x x x x x x x x I 17 57 6.9 0552+398Ix x x x x x x x x x x x x x x x x x x x x x I 22 192 16.2 0556+238I x x x xx x x x x I 9 11 1.1 0718+793I x x x x x x x x I 8 12 .8 0727-115Ix x x xx x xx x xx x x x x x I 16 41 7.9 0749+540Ix x x x x x x x x x x x x x x x x x x I 19 240 17.9 0804+499I x x x x x I 5 61 4.9 0805+410I x I 1 3 .3 0823+033I x x x x x x x x x x x x x x x x x x I 18 59 8.3 OJ287 I x x x x x x x x x x xx x x xI 15 23 2.4 0919-260I x x x x x x I 6 12 5.9 0920-397I I 0 0 .0 4C39.25 Ix x x x x x x x x x x x x x x x x xx x x I 21 189 16.0 OK290 I x x x x x x x x x x x x x x x I 15 26 2.6 0955+476I x x x x x x x x x x x I 11 111 8.8 1044+719I x x x x x x x x x x xI 11 100 6.9 1053+815I x x I 2 12 .8 1128+385I x x x I 3 19 1.7 1219+044Ix x x x xx x x x x x x x x x x x x x x I 20 64 8.8 1300+580I x x x x x x x x x x x xI 12 67 5.1 1334-127I I 0 0 .0 1351-018I I 0 0 .0 1357+769I x x x x x x x x x x xI 11 160 10.7 1606+106Ix x x x x x x x x xx x x x x x x x xx x x I 22 73 9.2 1622-253I xx x x x x I 6 8 2.9 NRAO512 I x x x x x x x x x I 9 66 5.3 1726+455Ix x x x x x x x x x x x I 12 20 1.5 1739+522I x x xx x x x x I 8 24 1.8 1741-038Ix x x x x x x xx x x x x x x x x x I 18 51 8.1 1749+096Ix x x x x x x x x x x x I 12 52 6.6 1908-201Ix x x x xx x x x x x I 11 28 8.8 1921-293I x x x I 3 3 1.3 1958-179I x x x x x xI 6 12 3.3 2121+053I x x x x x x x x xx x x x x xI 15 45 6.0 2128-123I x x x x x x x x x I 9 19 4.8 2134+00 I x x x x x x x x xI 9 17 2.4 2145+067I x x x x x x x x x x x x x x I 14 57 7.5 2234+282Ix x x x x x x x x xx x x x x x x x x x x I 21 97 9.6 2255-282I x xx x x I 5 5 2.1 Total scans, obs: 531 2432 Average number of obs. per baseline per source (normalized by up-time) = 5.6 Min = .0 Max = 30.9 (Baseline Gc-Kk on 2128-123) RMS = 6.6 Total time: 1430 minutes ( 23.8 hours). Key: Gc=GILCREEK Kk=KOKEE Ma=MATERA On=ONSALA60 Wf=WESTFORD Wz=WETTZELL Gc Kk Ma On Wf Wz Avg % obs. time: 36 47 49 45 49 38 44 % cal. time: 3 3 3 3 3 3 3 % slew time: 22 14 19 17 13 11 16 % idle time: 37 34 28 33 33 46 35 # of tapes : 1.0 1.2 1.4 1.2 1.3 1.1 total # scans: 333 287 277 272 280 316 294 # scans/hour : 13 12 11 11 11 13 12.3 Avg scan (sec): 94 140 151 142 152 105 130 # OF OBSERVATIONS BY BASELINE | Gc Kk Ma On Wf Wz StnTotal -------------------------------------- Gc|333 269 100 126 201 137 833 Kk| 287 48 71 170 74 632 Ma| 277 244 136 275 803 On| 272 153 258 852 Wf| 280 170 830 Wz| 316 914 Number of 2-station scans: 153 Number of 3-station scans: 187 Number of 4-station scans: 93 Number of 5-station scans: 62 Number of 6-station scans: 36 Total # of scans, observations: 531 2432 Average baseline components for all observations Average XY = 4521. Average XZ = 3957. Average YZ = 2906. Average length = 4850.