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Response Surface Methods For Spatially-Resolved Optical Measurement TechniquesResponse surface methods (or methodology), RSM, have been applied to improve data quality for two vastly different spatially-resolved optical measurement techniques. In the first application, modern design of experiments (MDOE) methods, including RSM, are employed to map the temperature field in a direct-connect supersonic combustion test facility at NASA Langley Research Center. The laser-based measurement technique known as coherent anti-Stokes Raman spectroscopy (CARS) is used to measure temperature at various locations in the combustor. RSM is then used to develop temperature maps of the flow. Even though the temperature fluctuations at a single point in the flowfield have a standard deviation on the order of 300 K, RSM provides analytic fits to the data having 95% confidence interval half width uncertainties in the fit as low as +/- 30 K. Methods of optimizing future CARS experiments are explored. The second application of RSM is to quantify the shape of a 5-meter diameter, ultra-lightweight, inflatable space antenna at NASA Langley Research Center. Photogrammetry is used to simultaneously measure the shape of the antenna at approximately 500 discrete spatial locations. RSM allows an analytic model to be developed that describes the shape of the majority of the antenna with an uncertainty of 0.4 mm, with 95% confidence. This model would allow a quantitative comparison between the actual shape of the antenna and the original design shape. Accurately determining this shape also allows confident interpolation between the measured points. Such a model could, for example, be used for ray tracing of radio-frequency waves up to 95 GHz. to predict the performance of the antenna.
Document ID
20030025751
Acquisition Source
Langley Research Center
Document Type
Preprint (Draft being sent to journal)
Authors
Danehy, P. M.
(NASA Langley Research Center Hampton, VA, United States)
Dorrington, A. A.
(National Academy of Sciences - National Research Council Hampton, VA, United States)
Cutler, A. D.
(George Washington Univ. Hampton, VA, United States)
DeLoach, R.
(NASA Langley Research Center Hampton, VA, United States)
Date Acquired
August 21, 2013
Publication Date
January 9, 2003
Subject Category
Optics
Report/Patent Number
AI AA Paper 2003-0648
Meeting Information
Meeting: 41st Aerospace Sciences Meeting and Exhibit
Location: Reno, NV
Country: United States
Start Date: January 6, 2003
End Date: January 9, 2003
Sponsors: American Inst. of Aeronautics and Astronautics
Distribution Limits
Public
Copyright
Public Use Permitted.
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