Improved processing method of UEGN-2002 gravity network measurements in Hungary

Abstract

A new method and software has been made and tested in the Hungarian part of the UEGN-2002 network. Making a suitable base gravity network and providing proper data for UEGN-2002 has required some experimental measurements and many important investigations. In case of precise gravity measurements the determination of the vertical gradient's real value is necessary. Using the real or normal value of vertical gradients may give 6-10 μGal differences of height reductions depending on the reference height of the instruments. Taking into account the periodical errors of LCR gravimeter's reading device is very important; neglecting the periodical errors may give 25-30 μGal errors of Δg between measured points depending on the instrument (in case of our instruments LCR 963 and 1919 it was found to be below 2 μGal). We have found that the accuracy of the parameter estimation increases with fewer periods estimated. We suggest to always using a full parameter set for the estimation of the periodical correction. Based on our investigations the reliability of the MGH-2000's adjusted data is significantly better, than the reliability of the European network's one (probably because of the different reliabilities of the different European countries' gravity data). According to our plans, after the final adjustment of UEGN-2002 we are going to readjust the Hungarian MGH-2000 taking into account the adjusted g values of UEGN-2002. © Springer-Verlag Berlin Heidelberg 2007.