CORE-1015 (Continuous Observations of the Rotation of the Earth-1015) 2001 August 20 Notes prepared by Cynthia Thomas and Nancy Vandenberg,NVI/GSFC Session code: C1015 Schedule file: aug01/c1015.skd on CDDISA Nominal Start: 17:30 U.T. on August 20 (day 232) first observation at 17:30 U.T. on 2145+067 for HH-SH-TS first observation at 17:30 U.T. on 4C39.25 for GC-MA-WF Nominal Stop: 17:30 U.T. on August 21 (day 233) last observation at 17:13 U.T. on 0955+476 for MA last observation at 17:15 U.T. on 1124-186 for HH-WF last observation at 17:23 U.T. on 0235+164 for GC-SH-TS Correlator: Haystack Observing Mode: 4F (with barrel roll, see details below) 1 letter 2 letter Station Code Code # of tapes # of obs Occupation Code Fairbanks A GC 2 (TT) 487 40476601 HartRAO J HH 1 (TT) 203 72326201 Matera I MA 2 (TT) 453 72435701 Seshan C SH 2 (TT) 309 72336101 Tsukuba T TS 2 (TT) 531 73452301 Westford E WF 2 (TT) 416 72097301 Purpose ======= The CORE-1 sessions provide a monthly 72 hour continuous data set (CORE-1 + NEOS + CORE-3). These sessions will help reach CORE's goal of continuous data. The CORE-1 sessions will be recorded in a Mark 4 mode which requires that the participating stations have Mark 4 capability. Observing Mode ============== CORE Mode "4F" (four times the standard mode C, fanned out) ----------------------------------------------------------------- Number of frequencies 14 Frequency sequence X-band standard wide-band frequency sequence modified to avoid RFI at Matera S-band NEW sequence to avoid overlapping channels at the high end Number of channels 16 (14 USB + 2 LSB) Channel bandwidth 8.0 MHz Sample rate 16 Mb/s Bits per sample 1 Total data rate 256 Mb/s Data rate on tape 8 Mb/s/track Fan-out 1:2 Tape speed 160 ips Tracks per pass 32 Passes per tape 14 Barrel roll yes for Fairbanks (*) Track frame format Mark4 and VLBA (*) The 16 recorded channels are comprised of a 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. This session uses a NEW S-BAND FREQUENCY SEQUENCE, generated by Dave Shaffer. Because of the 8 MHz channel bandwidth, the standard S-band sequence had some overlapping channels. This sequence avoids the overlap and tries to avoid the direct-broadcast satellite band of 2320-2345 MHz. (*) Fairbanks, which has a VLBA backend, 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 200 sec* Minimum SNR 20 at X-band 15 at S-band * The maximum scan length was reduced from 600 seconds to 200 seconds so that more scans would be scheduled using less tapes. The CORE-1 sessions were planned with the stations utilizing no more than two (2) tapes per session. When the recording mode was changed from "2F" to "4F", the tape usage at Matera and Westford changed from 2 tapes to 3 tapes. There are not enough tapes in the tape pool to accomodate 3 tapes at 2 stations for the CORE-1 sessions. 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 40 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. Schedule characteristics: Average scan length 57 seconds Median SNR 40.0 at X-band 30.0 at S-band Number of observations 2344 observations Average scans per station 399 scans 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-1 network. Also shown in the table are the maximum correlations between the Earth orientation parameters and other parameters. Simulation for experiment $01AUG20ZZ -------------------------------------------------------------------| | | | Maximum | Correlating | | EOP | Formal | Correlation | Parameter | | Parameters | Errors | | | |------------+----------------+-------------+----------------------| | | | | | | X-Wobble | 35.3 muas | -0.01 | WESTFORD Z COMPONENT | | Y-Wobble | 32.2 muas | 0.30 | SESHAN25 Z COMPONENT | | UT1-TAI | 1.4 musec | 0.11 | GILCREEK Y COMPONENT | | UT1-Rate | 2.5 musec/d | 0.07 | SESHAN25 X COMPONENT | |------------|----------------|-------------|----------------------| Procedures ========== Please generate the procedures for this session using drudg. SKED Summary from file ./c1015.skd for experiment C1015 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066Ix x xx xx xx xx xx xx x x x x x x I 20 32 5.7 0048-097Ix x x x x x x xx x x x x I 13 30 4.4 0059+581Ix x x x x x x x x x x x x x x x x x I 18 105 9.6 0104-408Ix x x x x x xx x x x x I 12 14 3.7 0106+013I x xx xx xx xxx x xx xx x x x xxx x x x xx I 26 48 7.0 0119+115Ix x x x x xx x x x xx x x x x x x I 18 47 5.9 0119+041I x x I 2 2 .3 0229+131Ixx x x x x x x x x x I 11 17 2.1 0235+164I x x xx xx x x x x x x x x xx x x x I 19 63 8.0 CTA26 I x xx xx x x x x x xx xx xx x xx xx xx x xxI 26 40 6.2 0402-362I x x x x x x x xx x I 10 10 2.6 0454-234I x x x xx x x x x xx x x x I 14 16 3.7 0458-020I x x x x x x x xx x x xxI 13 13 2.1 0528+134Ixx xx x x xx x x x x xx xx xx xx xx xx x x x I 27 57 7.0 0552+398I x x x x xx x x x x x x x xx xx x x x x x x xI 24 147 15.5 0556+238I x x x x x x x x x x x x xx x xx x I 18 18 1.7 0718+793Ix x x x x x x x x x x x x x x x x x x x I 20 26 2.4 0727-115Ixx x x x xx x x xx xx x x x x I 17 44 9.4 0749+540I x x x x x x x x x xx x x x x xI 16 48 4.6 0804+499I x x x x xx x x I 8 36 3.7 0805+410I x x x x x x x x x x x xx x I 14 43 3.4 0823+033I x xx xx x xx x xx x x x xx x x xx xx x x xI 25 39 5.5 OJ287 I xx x x x x x xxx x x xx x x x x x x x xx xx xI 26 66 7.8 0919-260Ix x x x x I 5 5 1.4 0920-397Ix x x x I 4 4 1.4 4C39.25 Ix x x x x xx x x x x x x xx x x xx x I 20 117 12.1 OK290 I I 0 0 .0 0955+476Ix x x xx x x x xx x x x xx I 15 87 9.4 1034-293I x xx x x x x x I 8 8 2.0 1044+719I x x x x x x x x x x x x x x x xI 16 67 6.1 1053+815I x x x x x x x I 7 42 3.8 1124-186I x x xx x x x x xx xx xx x x x I 17 28 6.4 1128+385Ix x x x x x x x x x x x x x x x x x x xx I 21 78 6.6 1144-379I x xx x x x x xx x x x x I 13 13 3.2 1219+044Ixx x x x xx x x x x x x xx xx xx xx xx x I 24 40 5.6 1255-316I x x x x x x x x x x I 10 10 2.4 1300+580Ix x x x x x x x x x x x x x x x x x x x I 20 122 11.4 1313-333I I 0 0 .0 1334-127I x x xx x xx x x x x x xx xx xx x I 19 34 8.0 1351-018Ix x x xx x x xx x x x x x x I 15 17 2.7 1357+769I x x x x x x x x x x x x x x x x x x xI 19 190 17.3 1424-418I x x x x x I 5 5 1.4 1451-375I x x x x x I 5 5 1.4 1606+106I x x xx x xx x x x x x x x x xx xxx xx xx x xxI 27 68 8.8 1622-253I x x x xx x x xx x x x xx x I 15 15 3.8 NRAO512 I xx x x x x x x xx x x x x x xI 16 49 3.9 1726+455I x x x x I 4 18 1.9 1739+522I x x x x x x x x x x x I 11 30 2.9 1741-038I xx x xx xx xx x xx xx x x x xxx x xxx x xxI 27 48 7.6 1749+096I xx x xx x xx x x xx xx x x x x xx x xx x xI 25 74 9.9 1908-201I x x xx x x xx x x x xxI 13 13 3.3 1921-293I xx x xx x x x x x x x I 12 12 3.1 1954-388I x x x x x x x x I 8 8 2.2 1958-179I x x x x xx x xx x xx xI 13 25 5.6 2121+053Ixx x x xx xx x x x xx xx x x x x x x x xx x I 25 66 9.2 2128-123I x x x xxx x x xx x x xx xI 15 15 4.0 2134+00 I x x x I 3 3 .4 2145+067I x x x x x x x x I 8 18 2.5 2234+282Ix x x x x xx x x x x x x x x x xx x I 19 40 4.0 2255-282I x x x xx x xx x I 9 9 2.6 Total scans, obs: 890 2344 Average number of obs. per baseline per source (normalized by up-time) = 5.2 Min = .0 Max = 30.9 (Baseline Gc-Ts on 2128-123) RMS = 6.5 Total time: 1434 minutes ( 23.9 hours). Key: Gc=GILCREEK Hh=HARTRAO Ma=MATERA Sh=SESHAN25 Ts=TSUKUB32 Wf=WESTFORD Gc Hh Ma Sh Ts Wf Avg % obs. time: 27 17 34 17 26 32 26 % cal. time: 5 2 5 3 6 4 4 % slew time: 31 38 31 50 23 19 32 % idle time: 35 41 28 27 43 42 36 # of tapes : 1.6 1.0 1.9 1.1 1.6 1.9 total # scans: 487 203 453 309 531 416 399 # scans/hour : 20 8 18 12 22 17 16.7 Avg scan (sec): 48 72 64 49 43 67 57 # OF OBSERVATIONS BY BASELINE | Gc Hh Ma Sh Ts Wf StnTotal -------------------------------------- Gc|487 11 190 148 343 309 1001 Hh| 203 179 51 43 50 334 Ma| 453 78 185 247 879 Sh| 309 292 46 615 Ts| 531 172 1035 Wf| 416 824 Number of 2-station scans: 451 Number of 3-station scans: 294 Number of 4-station scans: 111 Number of 5-station scans: 33 Number of 6-station scans: 1 Total # of scans, observations: 890 2344 Average baseline components for all observations Average XY = 5810. Average XZ = 4728. Average YZ = 4749. Average length = 6541.