Data processing for fabrication of GMT primary segments

Raw data to final surface maps

Michael T. Tuell, William Hubler, Hubert M. Martin, Steven C. West, Ping Zhou

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Citations (Scopus)

Abstract

The Giant Magellan Telescope (GMT) primary mirror is a 25 meter f/0.7 surface composed of seven 8.4 meter circular segments, six of which are identical off-axis segments. The fabrication and testing challenges with these severely aspheric segments (about 14 mm of aspheric departure, mostly astigmatism) are well documented. Converting the raw phase data to useful surface maps involves many steps and compensations. They include large corrections for: image distortion from the off-axis null test; misalignment of the null test; departure from the ideal support forces; and temperature gradients in the mirror. The final correction simulates the active-optics correction that will be made at the telescope. Data are collected and phase maps are computed in 4D Technology's 4SightTM software. The data are saved to a.h5 (HDF5) file and imported into MATLAB® for further analysis. A semi-automated data pipeline has been developed to reduce the analysis time as well as reducing the potential for error. As each operation is performed, results and analysis parameters are appended to a data file, so in the end, the history of data processing is embedded in the file. A report and a spreadsheet are automatically generated to display the final statistics as well as how each compensation term varied during the data acquisition. This gives us valuable statistics and provides a quick starting point for investigating atypical results.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
PublisherSPIE
Volume9151
ISBN (Print)9780819496195
DOIs
StatePublished - 2014
EventAdvances in Optical and Mechanical Technologies for Telescopes and Instrumentation - Montreal, Canada
Duration: Jun 23 2014Jun 27 2014

Other

OtherAdvances in Optical and Mechanical Technologies for Telescopes and Instrumentation
CountryCanada
CityMontreal
Period6/23/146/27/14

Fingerprint

files
Telescopes
Telescope
Fabrication
Mirrors
Statistics
telescopes
fabrication
Spreadsheets
statistics
Thermal gradients
mirrors
MATLAB
spreadsheets
Optics
Data acquisition
astigmatism
Pipelines
Null
Mirror

Keywords

  • Alignment aberrations
  • Automation
  • Data processing
  • Force and temperature compensations
  • MATLAB®
  • Morphing distortion correction
  • Surface maps

ASJC Scopus subject areas

  • Applied Mathematics
  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

Tuell, M. T., Hubler, W., Martin, H. M., West, S. C., & Zhou, P. (2014). Data processing for fabrication of GMT primary segments: Raw data to final surface maps. In Proceedings of SPIE - The International Society for Optical Engineering (Vol. 9151). [91513T] SPIE. https://doi.org/10.1117/12.2057044

Data processing for fabrication of GMT primary segments : Raw data to final surface maps. / Tuell, Michael T.; Hubler, William; Martin, Hubert M.; West, Steven C.; Zhou, Ping.

Proceedings of SPIE - The International Society for Optical Engineering. Vol. 9151 SPIE, 2014. 91513T.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Tuell, MT, Hubler, W, Martin, HM, West, SC & Zhou, P 2014, Data processing for fabrication of GMT primary segments: Raw data to final surface maps. in Proceedings of SPIE - The International Society for Optical Engineering. vol. 9151, 91513T, SPIE, Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation, Montreal, Canada, 6/23/14. https://doi.org/10.1117/12.2057044
Tuell MT, Hubler W, Martin HM, West SC, Zhou P. Data processing for fabrication of GMT primary segments: Raw data to final surface maps. In Proceedings of SPIE - The International Society for Optical Engineering. Vol. 9151. SPIE. 2014. 91513T https://doi.org/10.1117/12.2057044
Tuell, Michael T. ; Hubler, William ; Martin, Hubert M. ; West, Steven C. ; Zhou, Ping. / Data processing for fabrication of GMT primary segments : Raw data to final surface maps. Proceedings of SPIE - The International Society for Optical Engineering. Vol. 9151 SPIE, 2014.
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