BULLETIN B 120 31 January 1998 Contents described in the Explanatory Supplement, mailed with Bulletin B121 1 - EARTH ORIENTATION PARAMETERS (IERS evaluation). The values in this section are samplings of section 2 given at five-day intervals. Date MJD x y UT1R-UTC UT1R-TAI dPsi dEpsilon 1997/98 " " s s 0.001" 0.001" (0h UTC) Final Bulletin B values. DEC 2 50784 .17317 .22148 .267344 -30.732656 -42.7 -5.3 DEC 7 50789 .16400 .21202 .259298 -30.740702 -41.0 -4.2 DEC 12 50794 .15414 .20349 .250031 -30.749969 -42.1 -4.1 DEC 17 50799 .14116 .19416 .241201 -30.758799 -41.5 -4.4 DEC 22 50804 .12969 .18819 .232940 -30.767060 -41.0 -4.1 DEC 27 50809 .11551 .17987 .224586 -30.775414 -42.2 -4.5 JAN 1 50814 .10262 .17459 .217169 -30.782831 -40.9 -4.3 JAN 6 50819 .09053 .17171 .209267 -30.790733 -40.6 -4.1 Preliminary extension, to be updated weekly in Bulletin A and monthly in Bulletin B. JAN 11 50824 .07634 .16848 .201096 -30.798904 -41.6 -4.3 JAN 16 50829 .06050 .16752 .192603 -30.807397 -40.9 -3.9 JAN 21 50834 .04499 .16828 .183910 -30.816090 -41.4 -4.7 JAN 26 50839 .02869 .16757 .174652 -30.825348 -40.1 -5.4 JAN 31 50844 .01511 .16780 .164946 -30.835054 -39.2 -4.7 FEB 5 50849 .00214 .16873 .155157 -30.844843 -41.2 -5.2 FEB 10 50854 -.01039 .17040 .145452 -30.854548 -39.7 -5.8 FEB 15 50859 -.02269 .17286 .135672 -30.864328 -39.5 -5.5 FEB 20 50864 -.03473 .17616 .125669 -30.874331 -40.4 -6.3 FEB 25 50869 -.04649 .18033 .115339 -30.884661 -39.1 -6.5 MAR 2 50874 -.05792 .18539 .104647 -30.895353 -39.7 -6.0 MAR 7 50879 -.06895 .19135 .093588 -30.906412 -40.1 -7.3 MAR 12 50884 -.07956 .19819 .082182 -30.917818 -38.3 -7.0 MAR 17 50889 -.08969 .20590 .070463 -30.929537 -39.3 -7.3 MAR 22 50894 -.09931 .21447 .058489 -30.941511 -38.7 -8.2 MAR 27 50899 -.10837 .22385 .046312 -30.953688 -37.7 -7.6 Note. In UT1R, the effects of zonal tides with periods shorter than 35 days are removed; UT1-UT1R ( smaller than 0.0025s in absolute value ) should be added after quadratic interpolation of UT1R.Section 2 of this Bulletin gives the daily interpolation of x, y, UT1, duration of day, dPsi, and dEpsilon. 2 - SMOOTHED VALUES OF X, Y, UT1, D, DPSI, DEPSILON (IERS EVALUATION) at one-day intervals. For smoothing characteristics, see Table2 in the explanatory supplement. The reference system is described in the 1996 IERS Annual Report. 1997/98 MJD x y UT1-UTC UT1-UT1R D dPsi dEpsilon (0 h UTC) " " s ms ms 0.001" 0.001" DEC 1 50783 .17550 .22339 .269429 .480 1.375 -43.1 -5.4 DEC 2 50784 .17317 .22148 .268054 .710 1.381 -42.7 -5.3 DEC 3 50785 .17181 .21908 .266653 .917 1.422 -42.2 -5.1 DEC 4 50786 .17044 .21709 .265194 1.049 1.512 -41.7 -4.9 DEC 5 50787 .16875 .21558 .263617 1.063 1.650 -41.3 -4.7 DEC 6 50788 .16652 .21389 .261891 .938 1.825 -41.0 -4.4 DEC 7 50789 .16400 .21202 .259974 .676 2.046 -41.0 -4.2 DEC 8 50790 .16148 .21028 .257813 .309 2.238 -41.0 -4.1 DEC 9 50791 .15925 .20841 .255520 -.107 2.293 -41.3 -4.0 DEC 10 50792 .15726 .20659 .253250 -.505 2.230 -41.5 -4.0 DEC 11 50793 .15561 .20499 .251080 -.817 2.114 -41.9 -4.1 DEC 12 50794 .15414 .20349 .249033 -.998 1.963 -42.1 -4.1 DEC 13 50795 .15229 .20223 .247153 -1.030 1.785 -42.2 -4.3 DEC 14 50796 .14987 .20074 .245451 -.935 1.630 -42.2 -4.4 DEC 15 50797 .14668 .19837 .243876 -.753 1.537 -42.0 -4.4 DEC 16 50798 .14374 .19606 .242361 -.536 1.494 -41.8 -4.4 DEC 17 50799 .14116 .19416 .240875 -.326 1.480 -41.5 -4.4 DEC 18 50800 .13904 .19240 .239393 -.153 1.505 -41.2 -4.4 DEC 19 50801 .13734 .19107 .237862 -.031 1.564 -41.0 -4.2 DEC 20 50802 .13509 .19048 .236266 .037 1.611 -40.9 -4.2 DEC 21 50803 .13232 .18964 .234645 .058 1.642 -40.9 -4.1 DEC 22 50804 .12969 .18819 .232988 .048 1.689 -41.0 -4.1 DEC 23 50805 .12682 .18683 .231273 .029 1.726 -41.3 -4.1 DEC 24 50806 .12359 .18508 .229543 .025 1.704 -41.6 -4.2 DEC 25 50807 .12075 .18322 .227872 .054 1.619 -41.8 -4.4 DEC 26 50808 .11812 .18149 .226307 .131 1.513 -42.1 -4.5 DEC 27 50809 .11551 .17987 .224846 .260 1.414 -42.2 -4.5 DEC 28 50810 .11295 .17853 .223475 .437 1.333 -42.2 -4.6 DEC 29 50811 .11041 .17753 .222170 .640 1.290 -42.0 -4.5 DEC 30 50812 .10760 .17650 .220880 .830 1.301 -41.8 -4.5 DEC 31 50813 .10484 .17550 .219551 .958 1.364 -41.5 -4.4 JAN 1 50814 .10262 .17459 .218143 .974 1.478 -40.9 -4.3 JAN 2 50815 .10040 .17381 .216592 .849 1.656 -40.7 -4.2 JAN 3 50816 .09786 .17311 .214837 .586 1.870 -40.5 -4.2 JAN 4 50817 .09558 .17266 .212868 .220 2.047 -40.4 -4.1 JAN 5 50818 .09316 .17230 .210764 -.191 2.100 -40.5 -4.1 JAN 6 50819 .09053 .17171 .208689 -.578 2.026 -40.6 -4.1 JAN 7 50820 .08812 .17119 .206730 -.881 1.914 -40.8 -4.3 JAN 8 50821 .08551 .17066 .204870 -1.058 1.776 -41.1 -4.3 JAN 9 50822 .08252 .16991 .203177 -1.092 1.588 -41.3 -4.3 JAN 10 50823 .07941 .16897 .201685 -.996 1.437 -41.6 -4.4 JAN 11 50824 .07634 .16848 .200290 -.806 1.399 -41.6 -4.3 JAN 12 50825 .07285 .16828 .198872 -.572 1.421 -41.7 -4.3 JAN 13 50826 .06954 .16794 .197433 -.339 1.453 -41.6 -4.2 JAN 14 50827 .06677 .16778 .195958 -.142 1.538 -41.3 -4.1 JAN 15 50828 .06383 .16767 .194353 .001 1.633 -41.1 -4.0 JAN 16 50829 .06050 .16752 .192691 .088 1.667 -40.9 -3.9 JAN 17 50830 .05737 .16748 .191024 .124 1.697 -40.9 -4.0 JAN 18 50831 .05424 .16758 .189305 .126 1.745 -40.9 -4.1 JAN 19 50832 .05121 .16796 .187542 .113 1.764 -41.0 -4.2 JAN 20 50833 .04837 .16836 .185784 .110 1.750 -41.2 -4.5 JAN 21 50834 .04499 .16828 .184049 .139 1.732 -41.4 -4.7 JAN 22 50835 .04167 .16808 .182324 .214 1.717 -41.5 -5.0 JAN 23 50836 .03822 .16784 .180615 .340 1.678 -41.4 -5.1 JAN 24 50837 .03481 .16762 .178965 .513 1.687 -41.0 -5.3 JAN 25 50838 .03163 .16754 .177235 .715 1.688 -40.5 -5.3 JAN 26 50839 .02869 .16757 .175564 .912 1.708 -40.1 -5.4 JAN 27 50840 .02587 .16756 .173850 1.058 1.777 -39.7 -5.3 JAN 28 50841 .02310 .16761 .171910 1.097 1.978 -39.6 -5.2 JAN 29 50842 .02041 .16765 .169849 .986 2.141 -39.3 -5.1 JAN 30 50843 .01776 .16770 .167631 .713 2.308 -39.2 -4.9 JAN 31 50844 .01511 .16780 .165251 .305 2.428 -39.2 -4.7 3 - NORMAL VALUES OF THE EARTH ORIENTATION PARAMETERS AT FIVE-DAY INTERVALS (IERS evaluation). Raw normal values Uncertainties 1997/98 MJD x y UT1-UTC dPsi dEps x y UT1 dPsi dEps (0 h UTC) " " s 0.001" 0.001" 0.0001s 0.001" DEC 2 50784 .17306 .22141 .268054 -42.45 -5.04 .12 .14 .09 .29 .17 DEC 7 50789 .16385 .21209 .259970 ~ ~ .10 .13 .80 ~ ~ DEC 12 50794 .15432 .20359 .249036 -41.72 -3.75 .09 .11 .07 .28 .17 DEC 17 50799 .14112 .19406 .240875 -41.44 -4.34 .13 .13 .07 .27 .15 DEC 22 50804 .12967 .18819 .232988 -41.05 -4.14 .11 .12 .06 .28 .16 DEC 27 50809 .11569 .18002 .224845 ~ ~ .12 .14 .10 ~ ~ JAN 1 50814 .10251 .17443 .218143 -40.78 -4.32 .15 .14 .08 .28 .16 JAN 6 50819 .09072 .17204 .208696 -41.11 -4.48 .13 .15 .09 .36 .22 JAN 11 50824 .07622 .16854 .200287 ~ ~ .10 .12 .08 ~ ~ JAN 16 50829 .06041 .16743 .192693 -40.93 -4.11 .12 .13 .06 .28 .16 JAN 21 50834 .04501 .16811 .184049 -41.38 -4.68 .10 .11 .07 .22 .15 JAN 26 50839 .02872 .16721 .175522 ~ ~ .14 .17 .06 ~ ~ JAN 31 50844 .01573 .16688 ~ ~ ~ .30 .31 ~ ~ ~ 4 - DURATION OF THE DAY AND ANGULAR VELOCITY OF THE EARTH (IERS evaluation). The data of this section are smoothed, with the same characteristics as UT1R in section 1. They are corrected for the effects of zonal tides with periods up to 35 days. Section 2 gives the daily interpolation of D. Date (0h UTC) DR OmegaR 1997 MJD s (microrad/s) DEC 2 50784 .00161 72.921 15011 DEC 7 50789 .00173 15001 DEC 12 50794 .00186 14990 DEC 17 50799 .00168 15005 DEC 22 50804 .00168 15005 DEC 27 50809 .00157 15014 5 - INFORMATION ON TIME SCALES All information concerning time scales : announcements of the leap seconds (Bulletin C) and of the value of DUT1 (Bulletin D) can be found in our web/ftp site : World Wide Web : http://hpiers.obspm.fr Anonymous ftp : hpiers.obspm.fr or 145.238.100.28 6 - SUMMARY OF CONTRIBUTED EARTH ORIENTATION PARAMETERS SERIES This section gives the average precision of the individual series contri- buting to the combination and their average agreement with it. The periods covered start at the beginning of the first month in Section 1 and end with the last available value in the individual series considered. The complete list of measurements is available in the electronic-mailed version of Bulletin B in section 7. Units : 0.001" for x,y , 0.0001s for UT1, 0.001" for dPsi, dEpsi. -------------------------------------------------------------------------------- EOP series Mean formal uncertainty Periods covered Weighted RMS agreement with Bulletin B -------------------------------------------------------------------------------- x y UT D dPsi dEps Data Number VLBI EOP(IAA) 97 R 04 .14 .12 .05 - .25 .10 8 50785.25 to 50834.25 .27 .26 .10 - .30 .14 EOP(USNO) 97 R 08 .12 .10 .04 .16 .18 .07 8 50785.25 to 50834.25 .16 .18 .02 .29 .11 .03 EOP(USNO) 97 R 09 - - .12 - - - 36 50783.69 to 50839.70 - - .11 - - - GPS EOP(CODE) 96 P 03 .01 .01 - .01 - - 55 50783.50 to 50837.50 .12 .15 - .17 - - EOP(EMR) 96 P 03 .07 .07 - .11 - - 59 50783.50 to 50841.50 .20 .25 - .39 - - EOP(ESOC) 96 P 01 .05 .05 - .05 - - 48 50783.50 to 50830.50 .20 .21 - .24 - - EOP(GFZ) 96 P 02 .02 .02 - .03 - - 48 50783.50 to 50830.50 .13 .19 - .27 - - EOP(JPL) 96 P 03 .03 .03 - .08 - - 48 50783.50 to 50830.50 .20 .10 - .34 - - EOP(NOAA) 96 P 01 .04 .04 - .14 - - 53 50783.50 to 50835.50 .33 .36 - .47 - - EOP(SIO) 96 P 01 .06 .07 - .17 - - 48 50783.50 to 50830.50 .22 .14 - .49 - - EOP(IGS) 95 P 02 .09 .14 .20 .09 - - 48 50783.50 to 50830.50 .10 .10 .32 .21 - - EOP(IGS) 96 P 02 .19 .26 .38 .14 - - 59 50783.50 to 50841.50 .18 .21 .66 .20 - - EOP(IERS) 97 P 01 .10 .13 .21 .14 - - 59 50783.50 to 50841.50 .10 .06 .37 .14 - - SLR EOP(CGS) 97 L 02 .24 .24 .21 - - - 57 50783.00 to 50839.00 .55 .51 1.03 - - - EOP(CSR) 95 L 01 .52 .49 .37 - - - 19 50783.96 to 50837.97 .28 .24 1.04 - - - EOP(DUT) 98 L 01 .18 .17 - - - - 18 50784.00 to 50835.00 .37 .40 - - - - EOP(IAA) 96 L 02 .16 .16 .30 .15 - - 59 50783.00 to 50841.00 .15 .17 .38 .13 - - EOP(MCC) 97 L 01 .10 .10 - .11 - - 15 50784.00 to 50829.00 .40 .39 - .56 - - BULLETIN A EOP(NEOS) 97 C 01 .12 .13 .14 - - - 59 50783.00 to 50841.00 .09 .09 .15 - - -