IRIS-S133 (International Radio Interferometric Surveying - South) 1998 Dec.07 Notes prepared by Arno Mueskens Geodetic Institute of the University of Bonn, Germany Schedule name: is133.skd on CDDISA [Dec98] Nominal Start: 12:00 U.T. on Dec.07 (day 341) name yyddd-hhmmss Ft Gc Hh Wf Wz 1739+522 98341-120001| 150 150 130 90| NRAO512 98341-120424| 390 230 390 270 230| Nominal Stop : 12:00 U.T. on Dec.08 (day 342) name yyddd-hhmmss Ft Gc Hh Wf Wz 1741-038 98342-115704| 70 70 70| 0749+540 98342-115940| 70 80 80| 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, FAIRBANKS AND HARTRAO RECORDING ON THIN TAPES --------------------------------------------- Westford, Fairbanks (Gilcreek) and HartRAO 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 is133.skd for experiment IS133 (all scans with at least one subnet station) SOURCE |0 6 12 18 | #SCANS #OBS #Obs/bl 0003-066I xx xx x x I 6 6 1.7 0048-097I x x x x x x I 6 21 4.7 0059+581I xxx xxx xxxx xxxxx x xx x x xxx xx x xx xxxI 31 133 24.1 0104-408Ix x xx x x xx x I 9 9 2.7 0119+115I x x xx I 4 8 1.4 0119+041I x x x I 3 5 1.0 0208-512I xx x I 3 3 1.0 0229+131I x xx x x xx I 7 9 1.7 CTA26 I x I 1 1 .3 0402-362I x x x xx xx I 7 9 2.7 0454-234I xx x x x I 5 19 5.9 0458-020I x xx x x x I 6 6 1.5 0528+134Ix xx xx xxx xxx x x x x x x x xx xI 21 82 17.1 0552+398Ix xxxxx xx xxxxx xx x x x xx xx x xxx xxI 28 143 26.1 0637-752I x x x I 3 3 1.1 0727-115I x x x x x xx x xI 9 21 4.4 0749+540Ix xx xx x xxxx x xxx xxx xxx xxx xx xx xx xxxI 32 95 12.4 0804+499I x x xx x x x x x x x x I 12 34 4.5 0805+410I xxx x xxx xx xx x x x x x I 16 32 3.6 0823+033I x x x x x I 5 5 1.0 4C39.25 Ix xx xxxxx xx xx xxx xx x x x x xx x xI 25 131 24.4 OK290 I x x I 2 2 .3 0955+476I xxx xx xxx xxx x x xx xxxxxx xxxxx xx xI 29 102 18.8 1044+719Ixx xx x xx x x xx x x x x x x x x x I 20 74 13.6 1057-797I x I 1 1 .4 1124-186I x I 1 1 .3 1128+385Ix x xxxx x x x x xxI 12 21 3.2 1144-379I x xx I 3 3 .9 1308+326I x x xx xx x xx I 9 13 1.8 1334-127I x x I 2 4 .9 1351-018I x x x x I 4 4 1.0 1357+769Ix x x x x x x x xx x x x I 13 43 7.4 1424-418I xx xxx x I 6 6 1.8 1606+106I xx x x x x xx xxxx xx I 14 14 2.8 1610-771I x x I 2 2 .7 NRAO512 I x x x x xx xxx xxxx xxx xxxx xx xx xx xI 27 124 22.6 1726+455Ix x x xx xx x x x xx xxxxx xxI 19 52 7.9 1739+522I xx xx xx xx xxxxxxx xxxxx xxx xxxxx x xxxxx xI 35 147 26.3 1741-038I xxx xx xxx xxxxx x xx x x x I 19 58 12.7 1749+096I x xx x I 4 8 1.5 1921-293I x x xx x x x x I 8 16 4.7 1954-388I xxxxxx x x I 8 8 2.4 1958-179I x x x I 3 3 .9 2121+053I x I 1 1 .2 2128-123I xxx xx I 5 5 1.1 2145+067I x xx xx x I 6 12 2.4 2234+282I x x x xx I 5 13 1.8 2255-282I x x xI 3 7 2.1 Total scans, obs: 500 1519 Average number of obs. per baseline per source (normalized by up-time) = 5.1 Min = .0 Max = 37.6 (Baseline Ft-Gc on 1739+522) RMS = 9.1 Total time: 1440 minutes ( 24.0 hours). Key: Ft=FORTLEZA Gc=GILCREEK Hh=HARTRAO Wf=WESTFORD Wz=WETTZELL Ft Gc Hh Wf Wz Avg % obs. time: 46 51 29 54 47 45 % cal. time: 2 4 1 4 4 3 % slew time: 29 19 28 15 13 21 % idle time: 21 25 40 25 35 29 # of tapes : 2.7 .8 .5 .8 2.5 total # scans: 199 365 139 381 348 286 # scans/hour : 8 15 5 15 14 11.9 Avg scan (sec): 201 121 182 124 118 149 # OF OBSERVATIONS BY BASELINE | Ft Gc Hh Wf Wz StnTotal ---------------------------------- Ft|199 106 100 141 128 608 Gc| 365 27 332 274 322 Hh| 139 48 89 662 Wf| 381 274 761 Wz| 348 685 Number of 2-station scans: 204 Number of 3-station scans: 179 Number of 4-station scans: 98 Number of 5-station scans: 19 Total # of scans, observations: 500 1519 Average baseline components for all observations Average XY = 5596. Average XZ = 5230. Average YZ = 5083. Average length = 6736.