Improved area-based deformation analysis of a radio telescope’s main reflector based on terrestrial laser scanning
-
Christoph Holst
,
Axel Nothnagel
Abstract
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 variations and local deformations from best-fit approximations.
For the Effelsberg radio telescope, both groups of deformations are estimated from seven points clouds measured at different elevation angles of the telescope: the focal length decreases by 22.7 mm when tilting the telescope from 90 deg to 7.5 deg elevation angle. Variable deformations of ± 2 mm are detected as well at certain areas. Furthermore, a few surface panels seem to be misaligned.
Apart from these results, the present study highlights the need for an appropriate measurement concept and for preprocessing stepswhen using laser scanners for area-based deformation analyses. Especially, data reduction, object segmentation and laser scanner calibration are discussed in more detail. An omission of these steps would significantly degrade the deformation analysis and the significance of its results. This holds for all sorts of laser scanner based analyses.
© 2015 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- Masthead
- Research Articles
- Improved area-based deformation analysis of a radio telescope’s main reflector based on terrestrial laser scanning
- Precise Point Positioning using Multi-Constellation GNSS Observations for Kinematic Applications
- An Innovative Dual Frequency PPP Model for Combined GPS/Galileo Observations
- Performance Analysis of Fault Detection and Identification for Multiple Faults in GNSS and GNSS/INS Integration
- Analytic Error Assessment of Gyro-Free INS
- A mascon adjustment of the Earth’s gravity field using GOCE gradiometer data
Articles in the same Issue
- Masthead
- Research Articles
- Improved area-based deformation analysis of a radio telescope’s main reflector based on terrestrial laser scanning
- Precise Point Positioning using Multi-Constellation GNSS Observations for Kinematic Applications
- An Innovative Dual Frequency PPP Model for Combined GPS/Galileo Observations
- Performance Analysis of Fault Detection and Identification for Multiple Faults in GNSS and GNSS/INS Integration
- Analytic Error Assessment of Gyro-Free INS
- A mascon adjustment of the Earth’s gravity field using GOCE gradiometer data
