Surface Scanning Analysis with the Laser Antenna Surface Scanning Instrument
No Thumbnail Available
Links to Files
Permanent Link
Author/Creator
Author/Creator ORCID
Date
Department
Program
Citation of Original Publication
Max Mayang Mason, Surface Scanning Analysis with the Laser Antenna Surface Scanning Instrument, https://www.nrao.edu/students/2020/Reports/MasonMax.pdf
Rights
This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.
Abstract
The surface of the Green Bank Telescope (GBT) is subject to deformations due to heating, wear and tear, and other external factors. These physical deformations do not harm the telescope, and they can be accounted for by using the actuators that are built in between the panels of the dish. However, efficient observations require the shape of the dish to remain as close to a paraboloid. In order to improve the efficiency of the observations, the surface of the telescope is scanned using the laser antenna surface scanning instrument (LASSI). Many small holes exist in between panels, which makes it difficult to accurately measure the deformations. In order to make accurate measurements of these deformations, a mask is applied to any small holes or unwanted artifacts. Once these holes and/or artifacts are masked, the deformations of the primary reflector may be measured with a higher accuracy. In order to determine how to best implement the mask, the author investigated how masking before smoothing affects the measurement of deformations with respect to masking only after smoothing. This was executed by taking residuals between the active surface of the dish and surface scans of the dish, before and after the additional mask was applied. These residuals were compared with different methods of statistical analysis. The residual analysis showed that more masking showed no improvement to the data. This suggests that, given the current data processing, masking is not the limiting factor setting the accuracy of the measured deformations.