The Faculty of Agriculture: Search
Now showing items 1-10 of 11
Estimation of Focal Length Variations of a 100-m Radio Telescope's Main Reflector by Laser Scanner Measurements
(2012-08)
Due to gravitation, the main reflector of a radio telescope underlies a deformation which causes
a change in focal length depending on the variations of the elevation angle of the telescope. In order
to estimate these ...
Modeling the Beam Deflection of a Gantry Crane under Load
(2014-02)
Gantry cranes load and unload containers from container ships. To ensure safety and operation, the deflection of their main beams under load should be analyzed. This deflection depends on the weight of the loaded container ...
Accurate georeferencing of TLS point clouds with short GNSS observation durations even under challenging measurement conditions
(2018-08-29)
The accuracy of georeferenced TLS point clouds
is directly influenced by site-dependent GNSS effects, deteriorating
the accuracy of the ground control point coordinate
estimation. Especially under challenging GNSS ...
Automatic optimization of height network configurations for detection of surface deformations
(2013-05-18)
Levellings are performed to observe height changes of different epochs at discrete surveying points. A
reliable estimation of surface deformations by a bivariate polynomial needs a sufficient configuration of the underlying ...
Aiming at self-calibration of terrestrial laser scanners using only one single object and one single scan
(2014-12-05)
When using terrestrial laser scanners for high quality analyses, calibrating the laser scanner is crucial due to unavoidable misconstruction of the instrument leading to systematic errors. Consequently, the development of ...
Biased and unbiased estimates based on laser scans of surfaces with unknown deformations
(2014-10-02)
The estimates based on laser scans of surfaces with unknown deformations are biased and not reproducible when changing the scanning geometry. While the existence of a bias is only disadvantageous at some applications, ...
Flächenhafte Deformationsanalysen mit terrestrischen und Nahbereichslaserscannern: eine Gegenüberstellung anhand von Beispielen
(2014)
Dieser Beitrag stellt einen Überblick über den Ablauf einer flächenhaften Deformationsanalyse basierend auf terrestrischen Laserscannern (TLS) dar, wobei speziell auf die Datenerfassung, Vorverarbeitung und Auswertung ...
Improved area-based deformation analysis of a radio telescope’s main reflector based on terrestrial laser scanning
(2015-03-14)
The main reflectors of radio telescopes deform due to gravitation when changing their elevation angle. This can be analyzed by scanning the paraboloid surface with a terrestrial laser scanner and by determining focal length ...
Impact of spatial correlations on the surface estimation based on terrestrial laser scanning
(2017-07-19)
In terms of high precision requested deformation analyses, evaluating laser scan data requires the exact knowledge of the functional and stochastic model. If this is not given, a parameter estimation leads to insufficient ...
Challenges and present fields of action at laser scanner based deformation analyses
(2016-03-31)
Due to improved laser scanning technology, laser scanner based deformation analyses are presently widespread. These deformation analyses are no longer based on individual points representing the deformation of an object ...
