IRIS-S132 (International Radio Interferometric Surveying - South) 1998 Nov.02 Notes prepared by Arno Mueskens Geodetic Institute of the University of Bonn, Germany Schedule name: is132.skd on CDDISA [Nov98] Nominal Start: 12:00 U.T. on Nov.02 (day 306) name yyddd-hhmmss Ft Gc Hh Wf Wz 4C39.25 98306-120001| 70 70 70 70| 1741-038 98306-120717| 70 70 70| Nominal Stop : 12:00 U.T. on Nov.03 (day 307) name yyddd-hhmmss Ft Gc Hh Wf Wz 1057-797 98307-114828| 470 470 | 0955+476 98307-120046| 270 270 250 230| 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. With the addition of Fairbanks this network produced excellent EOP results. This network with long noth-south and east-west baselines as well as the wideband capability provides a good EOP determination even with the inclusion of the O'Higgins antenna. 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 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 : 70 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 25. 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, . local 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 25 min 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. FREQUENCY SEQUENCE: The NEOS-wideband RF band frequency sequence ------------------ is used for this experiment. THIS SCHEDULE HAS A 10 SECOND EARLY TAPE START: ----------------------------------------------- To gain synchronization time at the correlator. WESTFORD and FAIRBANKS RECORDING ON THIN TAPES --------------------------------------------- Westford and Fairbanks (Gilcreek) record this session at high (56kbpi) density. Correlation =========== This experiment will be processed at Bonn in one correlation pass with all baselines to be correlated. An extra correlation report will be sent after completion. Appendix ======== SKED Summary from file is132.skd for experiment IS132 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x x x x I 4 4 1.1 0048-097I x x x I 3 3 .8 0059+581Ix xxx x xxx xx xxxx xx x xx x xxx xx xxx x x x I 31 122 21.1 0104-408Ixx x x x x x xI 8 8 2.4 0119+115I x x x x xx x x x x x x x I 13 19 3.6 0119+041I xxx x I 4 6 1.2 0208-512I x I 1 1 .3 0229+131I xxx x x I 5 5 1.0 0402-362Ixxx xxx x x xxI 10 10 3.0 0454-234I xx x x x x x xxI 9 25 7.7 0458-020I x x xx x x x x I 8 8 1.9 0528+134Ix xxx x xxxx xxxxxxxxxxx xx x xx I 25 84 17.2 0552+398Ixxxxx xxx xxxxxx xxxxxx xxxxx xx x xxx xxxx I 35 160 29.1 0637-752I x x x x I 4 4 1.4 0727-115Ixxx x xx x x xx xx x xI 14 30 6.3 0749+540Ixxx x xx xxx xx xx xx x x xxxxx xxxxx xx xx I 31 87 10.9 0804+499Ixx x xx x x x x x I 10 26 3.4 0805+410I x x x x x xx xx x xx x x x x xI 17 33 3.7 0823+033I x x x x xxx I 7 9 1.9 4C39.25 I x xx xxxxxxxxxx xxxx xxx xx x x x x xx xI 29 158 29.6 OK290 I x x x xx I 5 5 .7 0955+476Ixx xxx xx xx x xx xx x xx xx xxxxxx xx x xI 29 102 18.7 1044+719Ix x x x x x x x x x xx x x xx xx x x x x xI 23 86 15.9 1057-797I x I 1 1 .4 1124-186I x x I 2 2 .6 1128+385I x x xxxx x x x I 9 9 1.0 1144-379I x I 1 1 .3 1308+326I x x x x xxx x xxx x x x I 14 16 2.2 1351-018I x xx I 3 3 .8 1357+769I x x x x x x x xx x x xI 12 37 5.7 1424-418I xx x x I 4 4 1.2 1606+106I xx xxxxx x xx x x xxx x xxx xxI 22 22 4.5 1610-771I x x x I 3 3 1.1 NRAO512 Ix xxx x x x xx xx xx xxxx xxxx xx xxxx xxI 29 132 23.8 1726+455Ix x x x x xx x x xx xx x x xxxxxI 20 46 6.3 1739+522Ixxxx xxxxx xx x xxx xx xxx xx xx xx xxxx xxxxx xI 36 144 25.2 1741-038I xxxx xxxx xxx xxxx x xxx xx xxI 23 66 14.4 1749+096I x x I 2 4 .7 1921-293I xx xx x xx xx x x xI 12 22 6.5 1954-388I x xxxxx xx xxx xx xI 14 14 4.1 1958-179I xx x xx I 5 5 1.5 2128-123I x xxx x I 5 5 1.0 2145+067I x xx xx x x x x xxx xxI 15 25 5.1 2234+282I x xx I 3 5 .7 2255-282I x x x xI 4 8 2.4 Total scans, obs: 564 1569 Average number of obs. per baseline per source (normalized by up-time) = 5.2 Min = .0 Max = 40.5 (Baseline Ft-Wf on 0552+398) RMS = 9.7 Total time: 1445 minutes ( 24.1 hours). Key: Ft=FORTLEZA Gc=GILCREEK Hh=HARTRAO Wf=WESTFORD Wz=WETTZELL Ft Gc Hh Wf Wz Avg % obs. time: 43 50 28 55 46 44 % cal. time: 2 4 1 4 4 3 % slew time: 31 21 23 18 14 21 % idle time: 22 23 46 21 34 29 # of tapes : 2.5 .8 1.6 .9 2.5 total # scans: 216 390 158 420 372 311 # scans/hour : 8 16 6 17 15 13.0 Avg scan (sec): 173 112 154 114 107 132 # OF OBSERVATIONS BY BASELINE | Ft Gc Hh Wf Wz StnTotal ---------------------------------- Ft|216 104 99 157 126 604 Gc| 390 31 352 275 335 Hh| 158 43 110 718 Wf| 420 272 781 Wz| 372 700 Number of 2-station scans: 266 Number of 3-station scans: 187 Number of 4-station scans: 92 Number of 5-station scans: 19 Total # of scans, observations: 564 1569 Average baseline components for all observations Average XY = 5514. Average XZ = 5261. Average YZ = 5081. Average length = 6717.