IRIS-S163 (International Radio Interferometric Surveying - South) 2001 Jun. 04 Notes prepared by Arno Mueskens Geodetic Institute of the University of Bonn, Germany Nominal Start: 14:00 U.T. on Jun.04 (day 155) name yyddd-hhmmss Ft Gc Hh Wf Wz 0552+398 01155-140000| 60 190 230 230 60| Nominal Stop : 14:00 U.T. on Jun.05 (day 155) name yyddd-hhmmss Ft Gc Hh Wf Wz 0749+540 01156-134439| 390 390 120 100| 0537-441 01156-135444| 60 60 | 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 : 60 seconds. The most recent source flux models are included. SNR goals are 22 at X-band and 20 at S-band for all baselines. 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 A 10 SECOND EARLY TAPE START !! ---------------------------------------------- Wettzell, Westford, Fairbanks (Gilcreek) and HartRAO record at high (56kbpi) density (thin tape). Fortleza record on thick tapes (33kbpi) Appendix ======== SKED Summary from file is163.skd for experiment IS163 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x x xx x xx I 7 11 2.5 0048-097I x x x I 3 3 .8 0059+581I x x I 2 4 .5 0104-408I xxxx xxxxxx x x x x I 15 15 4.5 0106+013I xxx x xxxx xxx x xxxx I 16 31 6.7 0119+041I x x I 2 2 .4 0229+131I x x x x x xx xx x I 10 14 2.5 CTA26 I xxxxxxxxx x x xx x I 15 17 3.8 0402-362I x x x I 3 3 .9 0454-234I xx xx x I 5 9 2.7 0458-020I x x x xx I 5 5 1.2 0537-441I xxx xx xxx x x I 10 10 3.5 0552+398Ixxxx xxxxxxxxx xx xx xx xxxxx xxxx xxx xxxxx xxI 41 165 30.2 0637-752I x x I 2 2 .7 0718+793I x I 1 1 .1 0727-115I x xxx x xx x x xx xx I 13 39 8.3 0749+540Ixxxxxx xxxxxxxxxxxxxx xx xx xxx x x xx xxxx I 36 135 22.2 0804+499Ix x x xxx xx x x xx x xxx xxxI 20 46 6.0 0805+410I x x x x I 4 4 .4 0823+033I x x xx xx x xI 10 12 2.5 OJ287 Ixxxxxxx x xxx x x xxxx x I 19 45 8.5 0920-397I x I 1 1 .3 4C39.25 Ixxxxxx x xxxxxx xxxxx xxx xxx x xxxxxxxxI 33 128 22.8 OK290 I x x xx x xxx xxxxI 12 12 1.7 0955+476I x x xxx x xx x xxx x x x x x I 17 55 9.3 1034-293I x I 1 1 .3 1044+719I xx x x x x x x x x x x xI 13 35 4.4 1057-797I x x x I 3 3 1.1 1124-186I x xx x xxxx x x x I 11 24 7.2 1128+385I x xx x x I 5 5 .5 1144-379I x x x x x I 6 6 1.8 1334-127I xx x xx x I 6 6 1.4 1351-018I xxx x x I 5 5 1.2 1357+769I x x x x x x x x x I 9 25 3.1 1424-418Ixxxx xxxx xxxxxI 13 13 3.8 1606+106I x xxx xxx xx x x x I 13 21 3.9 1610-771I x x x x I 4 4 1.4 1622-253I xx x I 3 3 .9 NRAO512 Ix x xxxxx xx xxx xxxxxx xxx x xx xxxxI 29 59 6.8 1726+455I x xxx I 4 12 1.7 1739+522Ix x x x x xxxxxx x x xx x xxx xx x x xI 24 64 8.1 1741-038I x xxx x xxxx x xx xI 14 28 6.3 1749+096Ixxx xxx xxx xxxxx xxxx xx xx xI 23 81 17.0 1921-293I xxxxxxx xxxxx I 12 12 3.6 1954-388I xx x x I 4 4 1.2 1958-179I x x I 2 2 .6 2121+053I x x I 2 2 .4 2145+067Ixx x xxx x x xxxx xxx x x x I 18 24 5.0 2234+282I x xx xx x xx x x x I 11 19 2.6 2255-282I x x I 2 2 .6 Total scans, obs: 539 1229 Average number of obs. per baseline per source (normalized by up-time) = 4.1 Min = .0 Max = 42.9 (Baseline Hh-Wz on 0552+398) RMS = 8.0 Total time: 1435 minutes ( 23.9 hours). Key: Ft=FORTLEZA Gc=GILCREEK Hh=HARTRAO Wf=WESTFORD Wz=WETTZELL Ft Gc Hh Wf Wz Avg % obs. time: 37 49 31 58 50 45 % cal. time: 2 3 1 4 3 3 % slew time: 31 18 31 16 10 21 % idle time: 29 28 34 19 34 29 # of tapes : 2.1 .8 .5 .9 .8 total # scans: 195 340 153 373 320 276 # scans/hour : 8 14 6 15 13 11.5 Avg scan (sec): 163 124 179 136 136 147 # OF OBSERVATIONS BY BASELINE | Ft Gc Hh Wf Wz StnTotal ---------------------------------- Ft|195 62 103 118 87 370 Gc| 340 15 296 214 587 Hh| 153 29 92 239 Wf| 373 213 656 Wz| 320 606 Number of 2-station scans: 309 Number of 3-station scans: 168 Number of 4-station scans: 51 Number of 5-station scans: 11 Total # of scans, observations: 539 1229 Average baseline components for all observations Average XY = 5455. Average XZ = 5064. Average YZ = 5012. Average length = 6595.