IRIS-S159 (International Radio Interferometric Surveying - South) 2001 Feb. 12 Notes prepared by Arno Mueskens Geodetic Institute of the University of Bonn, Germany Nominal Start: 14:00 U.T. on Feb.12 (day 043) name yyddd-hhmmss Ft Gc Hh Ho Oh Wf Wz 4C39.25 01043-140000| 90 190 190| 1921-293 01043-140000| 90 90 | 2234+282 01043-141420| 774 774 420 220| 1749+096 01043-142845| 520 150 520 290 | Nominal Stop : 14:00 U.T. on Feb.13 (day 044) name yyddd-hhmmss Ft Gc Hh Ho Oh Wf Wz 1144-379 01044-133024| 390 390 | 0804+499 01044-134518| 90 90| 0402-362 01044-134653| 140 140 | 1954-388 01044-135125| 160 160 | 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 <35 microasec Y Wobble <19 microasec UT1-TAI < 2 microsec Nutation offset in longitude (Psi) <48 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 10 SECOND EARLY TAPE START !! -------------------------------------------- ID Station Tape length Density Ft FORTLEZA 8700feet (Thick) 33333. (Low ) Gc GILCREEK 17400feet (Thin ) 56250. (High) Hh HARTRAO 17400feet (Thin ) 56250. (High) Ho HOBART26 8700feet (Thick) 33333. (Low ) Oh OHIGGINS 17400feet (Thin ) 56250. (High) Wf WESTFORD 17400feet (Thin ) 56250. (High) Wz WETTZELL 17400feet (Thin ) 56250. (High) Appendix ======== SKED Summary from file is159.skd for experiment IS159 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I xxxx xxx x x xx xxx x xI 16 32 3.4 0048-097Ixx x x x x x x x I 10 12 1.0 0059+581I x x x I 3 5 .4 0104-408Ixxx xxxxxxxx xxxxx x xx x xI 22 36 3.8 0106+013Ixx xxx x xxx xxx xx xx xx I 18 26 2.7 0119+041I xx x x x x x x x x xI 11 11 1.1 0229+131Ix x xx x x xx xI 10 10 .9 CTA26 I xxxx x x x x xx I 10 18 1.9 0402-362Ix x xxx xx x xxxx x x x I 15 15 1.9 0454-234Ixxx x xxxxxx x xx xx xx x I 18 26 3.2 0458-020I xx x xxx x xx x I 11 11 1.3 0528+134I x x xxx x x xxI 9 19 1.7 0537-441I x x xxxxxxxxxxxxxxxxxxxxx x x x x x I 28 48 5.4 0552+398Ix xx xxxxx xxx xxx xxx xxx xx xx x x x x x xxI 33 110 11.6 0637-752I x x x x x x x x x I 9 16 1.6 0718+793I x x x I 3 3 .3 0727-115I xx xxxx xxxx x xx xx xxxxx x x x xxxI 27 58 6.9 0749+540I x x xxxx xx xx xxxxxxxxxx x xxxx x xxx x x xxI 33 131 15.0 0804+499I x x x xx xx x x xx x x I 13 27 2.4 0805+410I x xxxx x xx xx xx x x I 15 17 1.1 0823+033Ixxxxxx xx x x xxxxI 14 14 1.4 OJ287 I xxxx xx x xxx x x x I 15 58 5.2 0920-397I x I 1 1 .1 4C39.25 I x x xx xx xxxxxx x x xx x x x x I 21 98 10.2 OK290 I x x xx xx x x xxx I 11 11 .8 0955+476I x x xxxxx xxxxxx xxx x x x xxx I 22 76 8.7 1034-293I xx xx xx I 6 6 .8 1044+719I x x x x x x xx x I 9 23 1.9 1057-797I x x x x x x I 6 8 .7 1124-186I x x x xxxx xxx x I 11 17 2.0 1128+385I xxxx x x I 6 6 .3 1144-379I x x xx x x xx x x x x xx I 14 14 1.5 1255-316I x x I 2 2 .3 1300+580I x x I 2 2 .2 1308+326Ix xxxx x xI 7 7 .6 1334-127I x x x x xx I 6 6 1.1 1351-018I x x xxxxx x xI 9 9 1.0 1357+769I x x x x x x x x x x x x I 12 35 3.6 1424-418Ix x x x x xx x x xxxxxxxxxxx xx xI 24 40 4.3 1606+106I x xxxx xx xxx xxx x xxxxxx xx I 23 27 2.4 1610-771I x x x x x x x x x x I 10 16 1.5 1622-253Ix x x x xx xxx xI 11 15 1.9 NRAO512 Ixx xx x xxx xxxxx xx xx I 17 26 2.0 1726+455Ix x x x x xx xx xxx I 12 22 2.0 1739+522Ix x xx xxx x x x x x xxx xxx x xxx x x x I 25 67 5.7 1741-038I xxxx x x xx x xx xxxxx xxx I 22 44 4.5 1749+096I xxx xx xxxx xx xx x x x xx I 18 50 5.2 1815-553I I 0 0 .0 1921-293I x x xx x x xxxxxxxxxxxxx xxxx xxxxxI 30 30 3.6 1954-388I xxx xx x x xxxI 10 10 1.1 1958-179I xx xx xx x x x xx x xx I 14 24 3.0 2121+053I xx xxx x I 6 6 .6 2145+067Ixx x x x x xxx xxxx xx x x x xx I 22 34 3.3 2234+282I xx x x xx x x xxx xxI 14 21 1.7 2255-282Ixxx x xx x xx x I 10 10 1.2 Total scans, obs: 756 1466 Average number of obs. per baseline per source (normalized by up-time) = 2.5 Min = .0 Max = 35.5 (Baseline Ho-Oh on 0537-441) RMS = 5.7 Total time: 1434 minutes ( 23.9 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: 38 51 36 49 40 54 49 45 % cal. time: 2 4 1 2 1 4 3 3 % slew time: 29 20 32 32 8 16 10 21 % idle time: 30 23 28 15 49 23 36 29 # of tapes : 2.1 .8 .6 2.8 .6 .8 .8 total # scans: 194 360 172 247 153 379 324 261 # scans/hour : 8 15 7 10 6 15 13 10.9 Avg scan (sec): 169 122 183 171 229 124 131 161 # OF OBSERVATIONS BY BASELINE | Ft Gc Hh Ho Oh Wf Wz StnTotal ------------------------------------------ Ft|194 59 54 8 17 149 90 377 Gc| 360 11 50 1 257 203 581 Hh| 172 72 26 23 85 271 Ho| 247 144 3 11 288 Oh| 153 3 0 191 Wf| 379 200 635 Wz| 324 589 Number of 2-station scans: 511 Number of 3-station scans: 177 Number of 4-station scans: 64 Number of 5-station scans: 4 Number of 6-station scans: 0 Number of 7-station scans: 0 Total # of scans, observations: 756 1466 Average baseline components for all observations Average XY = 5740. Average XZ = 5705. Average YZ = 5088. Average length = 7029.