Evaluation of environmental stresses on GNSS-monuments
Ladda ner
Typ
Examensarbete för masterexamen
Master Thesis
Master Thesis
Program
Publicerad
2011
Författare
Lehner, Wolfgang
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
The aim of this thesis is to analyze four different constructions of GNSS-antenna monuments with respect to deformations due to solar radiation, temperature variations and wind. It was commissioned by Lantmäteriet, the Swedish mapping, cadastral and land registration authority and realized in cooperation between Vienna University of Technology and Chalmers University of Technology. In the first part of the project a simulation with a finite element modelling program was calculated. The values gained from the simulations reached a maximum of 1.4 mm due to wind, 1.2 mm due to solar radiation and 0.8 mm due to thermal expansion. In the second part outdoor measurements were carried out at Onsala Space Observatory where a sample of each monument type was installed. With modern Leica TS30 total stations and precision retro-reflection prisms displacements of up to 4 mm were measured. The mast that Lantmäteriet suggested, deformed the least compared to the other three. Its maximum displacement in height and position was less than one millimeter.
Beskrivning
Ämne/nyckelord
Geovetenskap och miljövetenskap , Grundläggande vetenskaper , Earth and Related Environmental Sciences , Basic Sciences