IRIS-S156 (International Radio Interferometric Surveying - South) 2000 Nov.13 Notes prepared by Arno Mueskens Geodetic Institute of the University of Bonn, Germany Nominal Start: 14:00 U.T. on Nov.13 day 318) name yyddd-hhmmss Ft Gc Hh Tg Wf Wz 1749+096 00318-140000| 150 90 150 100 150| 0749+540 00318-140355| 90 90 90| Nominal Stop : 14:00 U.T. on Nov.14 (day 319) name yyddd-hhmmss Ft Gc Hh Tg Wf Wz 2145+067 00319-134830| 90 90 90| 1741-038 00319-135048| 90 90 90 90| 1958-179 00319-135421| 590 360 590| Duration: 24 hours Correlator: BONN MK4 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 25 at X-band and 25 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 NONE!! SECOND EARLY TAPE START ------------------------------------------------ Wettzell, Westford, Fairbanks and HartRAO record at high (56kbpi) density (thin tape). Fortaleza record on thick tapes (33kbpi) TIGO will participate for testing equipment. Appendix ======== SKED Summary from file is156.skd for experiment IS156 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x x xxx x xxxxx x xx I 15 64 9.3 0048-097I xx x x x I 5 20 2.9 0059+581I x x I 2 7 .6 0104-408I xx xxxxxxxx xxxI 13 13 3.0 0106+013Ixx x x xxxx xxxxx x I 14 45 6.4 0119+041I x xx x x I 5 5 .7 0229+131Ix x x x xxx I 7 14 1.6 CTA26 I x x xx xx xx I 8 16 2.4 0402-362Ix xx xx I 5 5 1.1 0454-234Ix x x x I 4 18 3.8 0458-020I x x x x x x I 6 10 1.5 0528+134I xxxxx xxxxxx I 11 36 4.2 0537-441Ix xxx xxx xx xI 10 10 2.6 0552+398I xxxxxxx xxx xxx xxxx xx xxx xx x xx xxx x xxI 33 245 28.5 0637-752I x x x I 3 3 .8 0718+793I x x I 2 6 .5 0727-115Ix xxx x xxxxx x xxx x xI 16 85 12.5 0749+540Ix xxx x xxx x xx xx xxxx xxxxxxxxxxxxxxxxxxxx xxI 39 256 27.5 0804+499Ix xx x x xx x x xx xxx x x xxI 18 88 7.5 0805+410I x xx x xx x x I 8 22 1.7 0823+033I x xxxx xxx x x x I 11 28 3.9 OJ287 Ixx xx x x xxx xx x x x xxxx x I 21 117 14.8 0920-397I x I 1 1 .2 4C39.25 I x xx xx xxxxx xxxxxxxx xxx x x xx xxxxx xxI 32 235 27.1 OK290 I x x xx xx xx x x I 10 12 1.1 0955+476I x x x x x x x xx xx xxxx x xx I 18 101 11.2 1034-293I x I 1 3 .8 1044+719Ix x x xx x x xx x x x x x x xI 16 83 6.9 1057-797I x I 1 1 .3 1124-186I x xx x x x xx I 8 45 9.5 1128+385I xx x x x x I 6 14 1.1 1144-379I x xx I 3 3 .7 1255-316I x I 1 3 .9 1334-127I xx I 2 6 .9 1351-018I xx xx x x I 6 6 1.0 1357+769I x x x x x x x x x x x x xI 13 80 8.5 1424-418I xx xxx xxxx x I 10 10 2.3 1606+106I x x x xxxx xx x xx I 13 35 4.3 1610-771I x x x x I 4 4 1.1 1622-253I x x x xx I 5 20 4.6 NRAO512 Ix xx xxx x xx xx xx x I 15 40 3.0 1726+455I xx x x xxx xxx I 11 43 4.2 1739+522Ix xx xxx x x xxx xx x x xx x x xxxxxxx xI 27 132 11.1 1741-038I x xx xxx xxx xxx x I 13 62 9.1 1749+096I x x x xx xxx x xxx xxx I 15 104 14.7 1921-293I x xxx x x I 6 6 1.1 1954-388I x xx I 3 3 .7 1958-179I x x x x I 4 8 1.6 2121+053I xx x I 3 3 .4 2145+067Ixx x x xx xxxxx x xx I 14 33 4.6 2234+282I x xx x xx x x x I 9 19 1.7 2255-282I x xxxx x x I 7 9 1.7 Total scans, obs: 533 2237 Average number of obs. per baseline per source (normalized by up-time) = 5.1 Min = .0 Max = 39.0 (Baseline Gc-Wf on 0749+540) RMS = 8.4 Total time: 1444 minutes ( 24.1 hours). Key: Ft=FORTLEZA Gc=GILCREEK Hh=HARTRAO Tg=TIGOWTZL Wf=WESTFORD Wz=WETTZELL Ft Gc Hh Tg Wf Wz Avg % obs. time: 42 50 34 55 58 54 49 % cal. time: 2 3 1 3 4 3 3 % slew time: 27 16 31 9 15 11 18 % idle time: 27 28 32 31 21 29 28 # of tapes : 2.4 .8 .5 .7 .8 .8 total # scans: 217 333 163 300 369 328 285 # scans/hour : 9 13 6 12 15 13 11.9 Avg scan (sec): 171 132 181 159 138 144 154 # OF OBSERVATIONS BY BASELINE | Ft Gc Hh Tg Wf Wz StnTotal -------------------------------------- Ft|217 68 121 113 132 121 555 Gc| 333 18 204 291 218 799 Hh| 163 94 40 101 374 Tg| 300 211 279 901 Wf| 369 226 900 Wz| 328 945 Number of 2-station scans: 198 Number of 3-station scans: 121 Number of 4-station scans: 131 Number of 5-station scans: 71 Number of 6-station scans: 12 Total # of scans, observations: 533 2237 Average baseline components for all observations Average XY = 4782. Average XZ = 4470. Average YZ = 4521. Average length = 5873.