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Abstract

Data provided by geomagnetic observatories are fundamental in geomagnetic field studies and are widely used in other applications. Often they are combined with satellite and ground survey data. Unfortunately, the definitive observatory data are only available with a time lag ranging from several months up to more than a year. The main reason for this lag is the annual production of the final calibrated values, i.e. baselines that are used to correct preliminary data from continuously recording instruments at the observatory. To increase the prompt availability of calibrated observatory data, INTERMAGNET has recently started to distribute quasi-definitive data. These data are calibrated with temporary baselines and reported much faster than annual definitive data. In this thesis it is shown that the preparation of definitive geomagnetic data, i.e. definitive calibration values, is possible within a calendar year for most observatories of the INTERMAGNET type. An original method for prompt and automatic estimation of temporary quasi-definitive baselines is presented. Results of this baseline calculation obtained in a mostly automatic manner and comparisons with the baselines reported on INTERMAGNET DVDs for the 2009-2011 period are presented. The high quality of definitive and quasi-definitive baselines obtained by the new method indicate its suitability for data processing for nearly fully automatic observatories when automated absolute instruments will be deployed at remote sites. However, the automatic instruments show a larger scatter and an automated processing protocol should be robust to outliers. Data from Lonjsko Polje observatory are used to simulate datasets from an automated absolute instrument producing 24 observations per day. Results of these tests also confirmed robustness and reliability of the proposed method.