CORE-3025 (Continuous Observations of the Rotation of the Earth-3025) 2001 August 15 Notes prepared by Nancy Vandenberg and Cynthia Thomas,NVI/GSFC Schedule name: aug01/c3025.skd on CDDISA Nominal Start: 18:30 U.T. on August 15 (day 227) first observation at 18:30 U.T. on 2121+053 for HH-NY-WZ first observation at 18:30 U.T. on 0059+581 for GC-WF Nominal Stop: 18:30 U.T. on August 16 (day 228) last observation at 18:18 U.T. on 1357+769 for WF last observation at 18:20 U.T. on 1958-179 for HH last observation at 18:21 U.T. on 2234+282 for GC-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) 373 40476601 HartRAO J HH 1 (TT) 133 72326201 Ny Alesund N NY 2 (TT) 394 73313301 Westford E Wf 2 (TT) 372 72097301 Wettzell V Wz 2 (TT) 420 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 series 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 station with VLBA backends, Fairbanks, will use barrel roll during this session and record in VLBA (non-data replacement) format. Stations with Mark 4 formatters cannot barrel 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 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 106 seconds Median SNR 35.0 at X-band 25.0 at S-band Number of observations 1997 observations Average scans per station 338 scans Station Information =================== Tigo-Concepcion was scheduled to participate in this session. Unfortunately, Tigo-Conception will not be ready to observe until October. Parity ====== This schedule was made with a minimum scan time of less than the 55 seconds required for parity checks. As a result, some parity checks in the schedule may give bad results even though there is nothing wrong. The next release of the FS, 9.5, will correct this problem. In the meantime, please check when a parity check fails to see if the cause is a short scan. If the problem is presistent and occurs frequently at your station for a given schedule type, you may want to disable parity checks for specific experiments of that type. You can do this by creating empty "checkf80" and "checkr80" procedures (or "checkf135" and "checkr135" if you are using thick tape) in the EXPERIMENT procedure library for the effected experiment. If you do this, it is strongly recommend that you verify recorder performance before the experiment by recording some tape in both directions using the experiment set-up and check it with the appropriate parity check procedures. 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 ==== ========= 01MAR07 CORE-3011 01MAR19 IRIS-S160 01MAR21 CORE-3012 01MAR26 CONT-M1 01APR02 IRIS-S161 01APR04 CORE-3013 01APR18 CORE-3014 01MAY02 CORE-3015 01MAY24 IRIS-S162 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 $01AUG15ZZ -------------------------------------------------------------------| | | | Maximum | Correlating | | EOP | Formal | Correlation | Parameter | | Parameters | Errors | | | |------------+----------------+-------------+----------------------| | | | | | | X-Wobble | 62.7 muas | -0.10 | WETTZELL Z COMPONENT | | Y-Wobble | 50.4 muas | 0.10 | WETTZELL Z COMPONENT | | UT1-TAI | 2.3 musec | 0.14 | WETTZELL X COMPONENT | | UT1-Rate | 4.8 musec/d | -0.01 | WETTZELL Z COMPONENT | |------------|----------------|-------------|----------------------| Procedures ========== Please generate the procedures for this session using drudg. SKED Summary from file ./c3025.skd for experiment C3025 (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 xI 11 15 4.5 0048-097I x x x x x x xI 7 13 3.5 0059+581I x x x x x x x x x x x x x x x x x x x xI 20 115 16.4 0106+013I x x x x x x x x I 8 12 2.7 0119+115Ix x x x x x x x x x x I 11 32 5.6 0119+041I x x x xI 4 4 .9 0229+131I x x x x x x x x I 8 23 3.8 0235+164I x x x x x x x x x x x x x xx x x x xI 19 68 11.2 CTA26 Ix x x x x x x x x x I 10 14 4.9 0454-234I x x x x x x I 6 6 3.1 0458-020I x x x x x I 5 7 3.5 0528+134I x x x x x xx x x x x x x x x x x xx x x xI 22 53 8.1 0552+398I x x x x x x x x x x x x x x x x x x x x x x xI 23 125 17.7 0556+238Ix x x x x I 5 5 .7 0718+793I x x x x x x x I 7 42 6.0 0727-115I x x x x x x x x x I 9 15 4.0 0749+540I x x x x x x x x x x x x x I 13 78 11.1 0804+499I x x x x x x x x xI 9 51 7.5 0805+410I x x x x x x x x x x x x x x x x I 16 76 8.7 0823+033I x x x x x x x x x x x xx x x x I 16 24 5.6 OJ287 I I 0 0 .0 0919-260I I 0 0 .0 4C39.25 I x x x x x x x x x x x x x x x x xx x x xI 21 104 14.1 OK290 I I 0 0 .0 0955+476I x x x x x x x x x x x x x xI 14 81 12.1 1034-293I x x I 2 2 1.0 1044+719Ix x x x x x x x x x x x x x x x x x I 18 108 15.4 1053+815I x x x x x x I 6 36 5.1 1124-186I x x x x x x x I 7 9 4.8 1128+385I x x xx x x x x x x x x x x x x x x x x xI 21 96 11.7 1219+044Ix x x x x x xx x x x x I 12 24 5.3 1255-316I xx x I 3 3 1.5 1300+580Ix x x x x x x x x x x x x x x x xx x x xx I 22 132 18.9 1313-333I I 0 0 .0 1334-127I x x xx x x x x I 8 8 2.2 1351-018Ix x x x x x x x x I 9 9 5.1 1357+769Ix x x x x x x x x x x x x x xx x x I 18 108 15.4 1606+106Ix x xx x x x x x x x x x x x xI 16 45 8.2 1622-253I x x x x x x I 6 6 3.4 NRAO512 Ix x x x x x x x x x x x x x x xx x x x x I 21 93 10.0 1726+455I x x I 2 12 1.8 1739+522I x x x x x x x x x x x x x x x x x x I 18 105 15.1 1741-038Ix x xx x x x x x x I 10 10 2.4 1749+096Ix xx x x x x x x x x x xx x x x x I 18 60 11.7 1908-201I x x x xI 4 4 2.5 1921-293I x x x x I 4 4 2.0 1958-179I x x xx x x x x I 8 12 6.5 2121+053I x x x x x x x x x x xx x x I 14 38 8.3 2128-123I x x x I 3 3 .9 2134+00 I I 0 0 .0 2145+067I x x x x x x x x x I 9 26 5.4 2234+282I x x x x x x xx x x x x x x xx x x x x xI 21 79 10.6 2255-282I x x I 2 2 1.0 Total scans, obs: 546 1997 Average number of obs. per baseline per source (normalized by up-time) = 6.6 Min = .0 Max = 36.3 (Baseline Ny-Wz on 1351-018) RMS = 7.2 Total time: 1433 minutes ( 23.9 hours). Key: Gc=GILCREEK Hh=HARTRAO Ny=NYALES20 Wf=WESTFORD Wz=WETTZELL Gc Hh Ny Wf Wz Avg % obs. time: 37 22 42 47 49 39 % cal. time: 4 1 4 4 4 3 % slew time: 23 27 22 17 15 21 % idle time: 35 48 29 31 29 34 # of tapes : 1.0 .6 1.1 1.3 1.4 total # scans: 373 133 394 372 420 338 # scans/hour : 15 5 16 15 17 14.1 Avg scan (sec): 85 146 93 108 101 106 # OF OBSERVATIONS BY BASELINE | Gc Hh Ny Wf Wz StnTotal ---------------------------------- Gc|373 16 312 312 252 892 Hh| 133 58 40 128 242 Ny| 394 279 332 981 Wf| 372 268 899 Wz| 420 980 Number of 2-station scans: 185 Number of 3-station scans: 134 Number of 4-station scans: 215 Number of 5-station scans: 12 Total # of scans, observations: 546 1997 Average baseline components for all observations Average XY = 4658. Average XZ = 4178. Average YZ = 3871. Average length = 5432.