FIG Peer Review Journal


The Meaning of Redundancy - 3D Topology and Geometric Parameterization (2768)

Lothar Gründig (Germany)
Mr. Christian Clemen
Technische Universität Berlin
Institut für Geodäsie und Geoinformationstechnik
Fachgebiet für Geodäsie und Ausgleichungsrechnung
Strasse des 17. Juni 135
Sekreteriat H20
Corresponding author Mr. Christian Clemen (email: clemen[at], tel.: 0049 30 314 26483)

[ abstract ] [ handouts ] [ handouts ]

Published on the web 2008-03-21
Received 2008-01-31 / Accepted 2008-03-14
This paper is one of selection of papers published for the FIG Working Week 2008 in Stockholm, Sweden and has undergone the FIG Peer Review Process.

FIG Working Week 2008
ISBN 978-87-90907-67-9 ISSN 2307-4086


Database normalization is a standard technique to ensure data integrity. Explicitly specified 3D topology as well ensures geometric consistency. This article explains a stepwise reduction of redundancy in the 3D data model. Whereas the topological normalization is well discussed in literature the geometric normalization is a subject to recent research. This approach of data normalization is motivated by the need for applying geodetic adjustment techniques to measured (observed) three-dimensional building models. The article examines different usage of the term redundancy and then shows up the normalization of the “polygon soup” data model to an almost redundant free data model. In contrast to existing CAD or GIS data models, the discussed approach does not use any coordinates, instead it utilizes normal vectors to planes. Using this approach, the number of unknowns is significantly reduced, resulting in fewer measurements to be observed. The primary reason for normalization is not to reduce the amount of data being stored but rather to ensure consistency and to allow suitable geometric generalization. In addition efficient adjustment techniques can be applied.
Keywords: Geoinformation/GI; Engineering survey; Cadastre; Low cost technology