EOP sigmas

EOP sigmas from Goddard VLBI operational solutions.

The plot of the differences NEOS Intensive minus 24 hours VLBI experiment. The differences were produced for all pairs of the of experiments in 1997.0-2001.0 with the differences in the middle epoch of the sessions less than 12 hours. UT value and sigmas of 24 hours experiment was propagated to the time epoch of the Intensive using UT1, UT1 rate, sigmas and correlations between UT1 and UT1 rate. UT1 values from intensives and 24 hour experiments were considered as uncorrelated.

The average weighted mean (bias ) is -10 -+ 8 musec.
w.r.m.s of the differences is 29 musec.
Chi/ndg = 4.1

It means that our formal uncertainties of UT1 from Intensives are too optimistic.

Plot of weighted root means square of post-fit residuals from IRIS-A NAVNET NEOS-A VLBI experiments

EOP sigmas from 2000a solution

EOP rate sigmas from 1204a solution

The differences in EOP from the independent NEOS and CORE-A experimentes which ran simultanously and used different VLBI networks.

X pole coordinates

Y pole coordinates

UT1 angle

Nutation in longitude

Nutation in obliquity

UT1 rate

       Comparison NEOS-A  versus  CORE. Solution 2001a
--------------------------------------------------------------------
|   N | parameter    |       bias       |  w.r.m.s.      | Chi/ndg |
|-----|--------------|------------------|----------------|---------|
|  73 | X pole       |   61.8 -+  17.2  |  232.1 muas    |   2.52  |
|  73 | Y pole       |   46.7 -+  14.1  |  165.3 muas    |   1.90  |
|  73 | UT1 angle    |   -1.8 -+   0.7  |    9.8 musec   |   2.85  |
|  73 | Nutation psi |   83.5 -+  28.5  |  338.6 muas    |   1.97  |
|  73 | Nutation eps |   39.8 -+  10.9  |  126.4 muas    |   1.85  |
|  73 | Ut1 rate     |   -1.8 -+   1.7  |   22.9 musec/d |   2.62  |
|_____|______________|__________________|________________|_________|

Data losses

Data losses: the ratio of the number of used observations to the number of corrleated observations from IRIS-A NAVNET NEOS-A VLBI experiments.

Data losses: the ratio of the number of observations discarded by analyst to the number of recoverable observations (which potentially can be used in analysis) from IRIS-A NAVNET NEOS-A VLBI experiments.

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Last update: 02-FEB-2001 20:57:46