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Datum: 28.08.2017

IAG Young Authors Award 2016

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The IAG Young Author Award 2016 is given to Olga Didova for her paper “An approach for estimating time-variable rates from geodetic time series”, which has been published in the Journal of Geodesy (2016).




The article considers the problem of estimating trends in mass loss over Antarctica from GRACE and GPS time series in the presence of inter annual and seasonal variability.
The optimization problem is solved using a gradient-based local solver, which can deal with nonconvex problems. To increase the probability of finding the global minimum, Olga suggests to define a random set of uniformly distributed starting values and selects the starting values that provides a solution which has the smallest log likelihood objective function. To improve the chance of finding the global minimum, Olga suggests several measures to limit the parameter search space. Moreover, she introduces inequality constraints on some of the hyperparameters, and suggests a method, involving among others a likelihood ratio test and an algorithm for determining the degrees of freedom for this test, to verify whether the constraints are supported by the data.


IAG-Newsletter | July 2017 (S.4)