Petras Petroskevicius, Rosita Birvydiene, Romuald Obuchovski
Investigation on the determination feasibility of the nonparallelity of the gravity field equipotential surfaces
Conference Information: 
9th International Conference “Environmental Engineering”, 22–23 May 2014, Vilnius, LITHUANIA 
Source: 
ICEE2014  International Conference on Environmental
Engineering 
Book Series: 
International Conference on Environmental Engineering
(ICEE) Selected papers 
ISSN: 
eISSN 20297092 online 
ISBN: 
eISBN 9786094576409 
ISBN: 
ISBN 9786094576904 CD 
Year: 
2014 
Publisher: 
Vilnius Gediminas Technical University Press Technika 
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Abstract
Geodetic measurements are performed in heterogeneous gravity field.
Its equipotential surfaces have a complex shape. This needs to be estimated
when processing detail geodetic measurements data. Orthometric heights are
calculated from one of the equipotential surface – geoid. Applying the normal
height system and evaluating normal height differences needs to assess the
nonparallelity of the equipotential surfaces of the gravity field. For that
aim normal corrections, defining the nonparallelity of equipotential surfaces
of normal gravity field and the deviation of the equipotential surfaces of real
gravity field from the normal field are calculated. This work presents determination
feasibility of the gravity field equipotential surfaces nonparallelity in
Lithuanian territory. The six geodetic vertical network lines were selected
for a research; the length of all lines is about 300 km. The gravimetric measurements
by Scintrex CG5 were performed at 203 points of the net. A mean square error of
gravity acceleration values did not exceed 14 μGal. The normal corrections were
calculated for measured height differences between points. A research shows that
after reduction of a number of measured points twice, a mean square error of
gravity acceleration values, calculated from interpolated Bouguer gravity
anomalies, at the “not measured” points seeks 0.474 mGal, however the normal
correction values have changed only in 0.01 mm. The use of gravity acceleration
values, obtained from gravimetric map with the mean square error of 0.684 mGal,
changes normal corrections up to 0.04 mm.
Keywords: Nonparallelity; equipotential surface; normal correction.
