Though his experimental and theoretical work on gravity determinations had won international recognition for both him and the Survey, he was in frequent disagreement with its administrators from 1885 onward.
Fig. 6 Drop and set scatter of the absolute gravity observations at GPK1 in October 2013 Table 3 Absolute gravity determinations at the reference site GPK1 Date Duration (hours) Gravity (μGal) Uncertainty (μGal) 22/10/2013 11 9 80 916/04/2013.7 16/04/2013 5 9 80 910 145.3 2.1.
His research interests are mainly in the fields of Physical Geodesy specially geoid and gravity field determination, satellite gravimetry and gradiometry, adjustment theory, satellite orbit determination, geodetic network optimisation and design, theories of isostasy, Moho and density contrast determination, sub-lithospheric stress modelling using gravimetric data.
Based on preliminary modeling results, we expect at most a slight influence of the acceleration spikes on the GRACE gravity field determination.
Spectral analysis of the time series reveal that an influence onto gravity field determination due to these effects is very unlikely, but can theoretically not be excluded.
This necessitates a re-evaluation of the processes used in gravity field determination with an eye to numerical stability and computational precision.
In this contribution, we study the potential of various alternative satellite formations for gravity field determination in the post-GRACE era in a simulation environment.
The very low orbital altitude of the GOCE satellite and the availability of dense 1 s GPS tracking data are ideal characteristics to exploit the contribution of GPS high-low Satellite-to-Satellite Tracking (hl-SST) to gravity field determination.
As positions of low Earth orbiters (LEOs) may be determined from GPS measurements at each observation epoch by geometric means only, it is attractive to derive such kinematic positions in a first step and to use them in a second step as pseudo-observations for gravity field determination.
This is, on average, 1.5 times higher than the accuracy of known methods, for instance, based on the gravity center determination using a method of moment characteristics.
