IRIS-S129 (International Radio Interferometric Surveying - South) 1998 Aug 24 Notes prepared by Arno Mueskens Geodetic Institute of the University of Bonn, Germany Schedule name: is129.skd on CDDISA [aug98] Nominal Start: 12:00 U.T. on Aug.24 (day 194) name yyddd-hhmmss Ft Gc Hh Wf Wz 4C39.25 98236-120001| 70 80 80 70 70| Nominal Stop : 12:00 U.T. on Aug.25 (day 195) name yyddd-hhmmss Ft Gc Hh Wf Wz 4C39.25 98237-115959| 70 80 80 70 70| 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) will 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 is129.skd for experiment IRS129 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I x xx xx x x I 7 7 1.9 0048-097I x x x x xxI 6 18 3.8 0059+581I x x x x x x x xx x x x x x x x x x xI 19 71 12.1 0104-408I x x xx x x x xx xI 10 10 3.0 0119+115I x xx x x x xx x xx xx xxx x I 17 23 4.4 0119+041I x x xx x x x I 7 7 1.4 0208-512I x x x x I 4 4 1.4 0229+131I xx x x I 4 4 .8 CTA26 I x x x xx x I 6 6 1.5 0402-362I x x x x x x x x x x I 10 12 3.6 0454-234I x x xx xx xx x x I 10 32 9.8 0458-020I x x x xx x x x x x I 10 10 2.3 0528+134I xx x xx xxx xx xx xx xxx x xxx xx x I 24 88 18.4 0552+398Ix x xx xx xx xx x xx x xx x x x x xx x xx xx x I 28 119 21.9 0637-752I x x x x I 4 4 1.4 0718+793I x I 1 1 .1 0727-115I xx xx xx x x xx xx xx x x I 16 42 8.9 0749+540Ix x x x x x x x x x x x x x x x x x x x I 20 61 8.1 0804+499I x x I 2 2 .3 0805+410I xx x x x x x x x xx x xx x x x x I 18 34 3.8 0823+033I xx x xx x xxx I 9 9 1.9 OJ287 I x I 1 1 .1 4C39.25 I x x x x x xxx x x x xI 12 67 13.0 OK290 I x I 1 1 .2 0955+476Ix x x x x x x x x x I 10 30 5.0 1034-293I x x I 2 6 1.8 1044+719I x x x x x x x xx x x x xI 13 51 9.8 1057-797I x I 1 1 .4 1128+385Ix x x x x x x x xI 9 9 1.0 1144-379I x x x x x I 5 5 1.5 1255-316I xx I 2 2 .6 1300+580I x x I 2 2 .3 1308+326I x x xx x x x x xx x xx xx I 15 21 3.0 1334-127I x x x xx x x I 7 13 2.9 1351-018Ixx x x xxx x xx I 10 10 2.4 1357+769I x x x x x x x x x I 9 28 4.5 1424-418I xx x x xx x x x I 9 9 2.7 1606+106I xx xxx xx xxx xx x xx x x xx x xxxI 23 36 7.2 1610-771I x x x I 3 3 1.1 1622-253I x x I 2 2 .8 NRAO512 Ix x xx x xx x xx x x x x x xxx x xx x xx x x xI 27 111 20.1 1726+455I x x x I 3 9 1.2 1739+522Ix x x x x x x x x x x x x x x x x x x x x I 21 91 16.5 1741-038Ix x xx x xx x xx xx x xx xxx xI 19 60 13.1 1749+096I xI 1 3 .6 1921-293I xx x xx x x xx x x x I 12 22 6.5 1954-388Ix x xx x x xx x x xI 11 11 3.2 1958-179I x x x x I 4 4 1.2 2121+053I x x I 2 2 .4 2128-123I x x xx x I 5 5 1.2 2145+067Ix x x xx x xx x x xx xx xx x x I 18 34 7.1 2234+282I x x x x x x x xx x x x xxI 14 22 3.1 2255-282I x xx x I 4 8 2.4 Total scans, obs: 509 1243 Average number of obs. per baseline per source (normalized by up-time) = 4.4 Min = .0 Max = 33.6 (Baseline Hh-Wz on 0528+134) RMS = 7.1 Total time: 1441 minutes ( 24.0 hours). Key: Ft=FORTLEZA Gc=GILCREEK Hh=HARTRAO Wf=WESTFORD Wz=WETTZELL Ft Gc Hh Wf Wz Avg % obs. time: 43 40 31 54 44 42 % cal. time: 2 3 1 4 3 3 % slew time: 33 19 24 18 13 22 % idle time: 20 36 41 22 39 32 # of tapes : 2.4 .6 1.9 .8 2.4 total # scans: 208 286 165 362 311 266 # scans/hour : 8 11 6 15 12 11.1 Avg scan (sec): 180 121 167 129 122 143 # OF OBSERVATIONS BY BASELINE | Ft Gc Hh Wf Wz StnTotal ---------------------------------- Ft|208 65 111 139 111 463 Gc| 286 21 253 176 270 Hh| 165 45 109 612 Wf| 362 213 598 Wz| 311 543 Number of 2-station scans: 288 Number of 3-station scans: 141 Number of 4-station scans: 67 Number of 5-station scans: 13 Total # of scans, observations: 509 1243 Average baseline components for all observations Average XY = 5407. Average XZ = 5171. Average YZ = 5323. Average length = 6747.