IRIS-S147 (International Radio Interferometric Surveying - South) 2000 Feb. 14 Notes prepared by Arno Mueskens Geodetic Institute of the University of Bonn, Germany Nominal Start: 14:00 U.T. on Feb.14 (day 045) name yyddd-hhmmss Ft Gc Hh Ho Oh Wf Wz 1044+719 00045-140001| 90 90 90| 0104-408 00045-140011| 110 110 90 | 0528+134 00045-140607| 230 230 90| Nominal Stop : 14:00 U.T. on Feb.15 (day 046) name yyddd-hhmmss Ft Gc Hh Ho Oh Wf Wz 1144-379 00046-133045| 560 560 | 1921-293 00046-134611| 90 90 | 0454-234 00046-134714| 90 90 | 1044+719 00046-135813| 90 90 90| Duration: 24 hours Correlator: BONN Purpose ======= The purpose of the IRIS-S sessions is to continue the series of measurements for the determination of earth rotation parameters. IRIS-S experiments are set up to provide all earth orientation parameters (UT1, polar motion, and nutation), baseline components and positions of extragalactic radio sources. SInce a long period this network produced excellent EOP results and with the long north-south and east-west baselines as well as the wideband capability provides a good EOP determination. Network ======= The standard configuration of the monthly observed IRIS-S (South) experiments consists of four stations. One station in the United States(Westford,Ma), one station in South Africa (Hartebeesthoek), one radio telescope in Europe (Wettzell,Germany) and one radio telescope in South America (Fortaleza,Brasil). Since January 1997 the network is augmented by station Fairbanks(Alaska). During the O'Higgins occupations two more stations of the southern hemispere are added to this network. With O'Higgins (Antartika) and Hobart (Tasmania) we will have seven participate station in this network. Schedule ======== This schedule was generated by (auto)-SKED using the NEOS-WB frequency setup, using variable scan lengths with a minimum of : 90 seconds. The most recent source flux models are included. SNR goals are 20 at X-band and 15 at S-band for all baselines. On all baselines with Fortaleza the SNR goal for the X-band is 23. The predicted SNRs used include a 30 ps noise contribution added in quadrature, which is a typical magnitude for the reweight constants applied in SOLVE solutions. The schedule is generated for the estimation of all five (seven) earth orientation parameters, clock offsets and clock rates for all participating stations except the reference station and atmo- sphere parameters for all participating stations. It was optimized for three earth orientation parameters (polar motion, UT1). Other optimization features enabled for this experiment : - the covariance analysis during schedule generation considers the previous 24 hours of observations, - minor SKED optimization parameters . maximum number of observations, . minimum time, . sky coverage, were optimized over the best ( in a covariance sense ) 75% of the possible observations, this produces a somewhat more even sky distribution, - observations were weighted by their expected SNRs, - 30 ps noise contribution added, - mimimum time between observations of the same radio source was set to 20 min - using 59 source for improving the sky covorage Simulation Results ================== Simulation results of this schedule was used in a global solution estimate the formel errors for Earth orientation parameters. X Wobble <40 microasec Y Wobble <20 microasec UT1-TAI < 2 microsec Nutation offset in longitude (Psi) <50 microasec Nutation offset in obliquity (Eps) <20 microasec Procedures ========== NO PREPASS TIME: There is no time allowed in the schedule for prepassing tapes. Therefore all tapes needed for this experiment must be pre-checked before the start of this experiment. Please generate the procedures for this session using drudg. FREQUENCY SEQUENCE: The NEOS-wideband RF band frequency sequence ------------------ is used for this experiment. THIS SCHEDULE HAS NONE!! SECOND EARLY TAPE START ------------------------------------------------ Wettzell, Westford, Fairbanks (Gilcreek) and HartRAO record at high (56kbpi) density (thin tape). Hobart and O'Higgins record on thick tapes (33kbpi) Appendix ======== SKED Summary from file is147.skd for experiment IS147 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x x xxI 4 4 .5 0048-097Ix x x x x x xxx x I 10 10 .8 0059+581I x I 1 1 .1 0104-408I xx xxxxx xxx xxx x xx x xx xxx xx xI 25 31 3.4 0119+041Ix x x xx x xxI 8 10 1.0 0229+131Ix x x x xx xx x xx x x xI 14 16 1.5 CTA26 Ixxxxxxx x xxxx x xI 14 14 1.6 0402-362I x x xxx x x x xx xxxx xx xxxxxx x I 24 26 3.1 0454-234I xx xxxx xx xxxx I 13 17 2.0 0458-020I x x x x x xx xx xI 10 10 1.1 0528+134Ixx xxxxxx x xx xxxxxx xx I 20 61 6.0 0537-441I x I 1 1 .1 0552+398Ixx xxxxxxxxxxxxxxx x x xxxxxxx x xxxxxx x x xxI 38 145 16.2 0637-752I x x x x xx x I 7 9 .8 0718+793I x x I 2 2 .2 0727-115I x x xx x xxxx x x xxxx xx x x xI 21 56 6.3 0749+540I xxxxxxx xxxxxxxxxxxxxxxxxxxxxxxx xx xx x xxxI 41 165 18.7 0804+499I x x xxxx xxxxxxxx x xxxx xxxxxx xx x x I 30 96 10.4 0805+410I x xx x xxx xx xxxx x x x xx x x I 21 31 2.1 0823+033Ix xx xx xx I 7 7 .7 OJ287 I x xx x xx xx xxx xxxx I 15 19 1.8 0920-397I x xx I 3 3 .4 4C39.25 Ixx x x xxxxxxxx x xx x x xxx xxx x xxxxx xxI 32 150 15.8 OK290 I xx xxxxx x x xx I 12 12 .9 0955+476I x xx x xx x xxxxx xxx x I 18 40 3.6 1034-293I x x x x x x I 6 6 .8 1044+719I xx x x xx x xxx xx xxx xx x xx xx x I 23 75 7.3 1057-797I x x x x x x I 6 6 .5 1124-186Ix x x x x x xx xI 9 19 2.4 1128+385I x x x x xxxxx x x I 11 13 .8 1144-379I x x x x x x x xx x I 10 12 1.3 1300+580I x I 1 1 .1 1308+326Ixx x xxxx x I 8 8 .8 1334-127I xx xx x I 5 5 .5 1351-018I xx xx x x x I 7 7 .8 1357+769I x x x x x x x x x x x x x x x x I 16 60 8.3 1424-418I xx xx x xxx x xxxx xx I 16 16 1.9 1606+106I xx x xxx x x xx xxxxx x x x I 18 22 2.1 1610-771I x x x x x x x x x I 9 11 .9 1622-253Ixxx x x xx x xxx x x xI 15 21 2.7 NRAO512 I x x xxx x xxxxxxx xx x I 16 47 4.8 1726+455I xx x x x x xxx xxxxx xx x I 17 33 3.0 1739+522I x x xxxxx xxx xxxxx x x I 17 49 4.2 1741-038I x x xxxx x x x x xx x x xxxx x x xxx I 25 104 11.1 1749+096I x x x x x x x x xxx x x x xI 16 54 5.8 1921-293I xxxxxx xx xx xxxxx xxxxxx xxxxxxxxxxx I 35 55 6.6 1954-388Ixxxxxxx x x x x x x xxxxx xxxxxxxxxxxx I 32 50 5.5 1958-179I xxxxx x xx xx x x xx xxxx x xxxx I 23 41 5.4 2121+053I x x x xx I 5 5 .5 2145+067Ix xx xx x x xx x xx xx x xx xxxI 21 27 2.7 2234+282I xx x x x x I 6 6 .5 2255-282Ixxxxxx x x x xxxx xx I 15 19 2.3 Total scans, obs: 779 1708 Average number of obs. per baseline per source (normalized by up-time) = 3.0 Min = .0 Max = 41.0 (Baseline Gc-Wf on 0749+540) RMS = 6.8 Total time: 1439 minutes ( 24.0 hours). Key: Ft=FORTLEZA Gc=GILCREEK Hh=HARTRAO Ho=HOBART26 Oh=OHIGGINS Wf=WESTFORD Wz=WETTZELL Ft Gc Hh Ho Oh Wf Wz Avg % obs. time: 39 54 37 51 43 56 55 48 % cal. time: 2 4 2 2 1 4 4 3 % slew time: 27 19 38 27 8 15 11 21 % idle time: 31 20 21 18 46 23 28 27 # of tapes : 2.0 .8 .5 2.9 2.5 .8 .8 total # scans: 200 400 205 226 151 391 385 279 # scans/hour : 8 16 8 9 6 16 16 11.7 Avg scan (sec): 168 118 159 196 248 125 124 162 # OF OBSERVATIONS BY BASELINE | Ft Gc Hh Ho Oh Wf Wz StnTotal ------------------------------------------ Ft|200 76 80 8 29 140 105 438 Gc| 400 17 41 6 295 261 696 Hh| 205 70 29 33 109 338 Ho| 226 123 5 8 255 Oh| 151 23 11 221 Wf| 391 239 735 Wz| 385 733 Number of 2-station scans: 489 Number of 3-station scans: 199 Number of 4-station scans: 72 Number of 5-station scans: 19 Number of 6-station scans: 0 Number of 7-station scans: 0 Total # of scans, observations: 779 1708 Average baseline components for all observations Average XY = 5680. Average XZ = 5735. Average YZ = 5212. Average length = 7084.