Metrology Chief Engineer, RFC Mirror Lab (Steward Observatory)

Evaluation Strategy

• Implements a surface figure evaluation strategy for mirrors during production and according to sponsors'' requirements.

• For example, for one prescription of off-axis 8.4 meter diameter mirrors, there are seven different tests depending on the state of production and to allow enough testing redundancy to provide confidence the mirrors'' surface figure where deviations are within ~1/30th of a wavelength of green light, on average, of the required surface figure, and the process of designing and constructing the tests took several years.

• Implementation involves guiding the work of mechanical, electrical, and software engineers to design and install the equipment, and supervising the work of three optical/metrology engineers to perform the surface figure evaluations.

Systems Development

• Writes, or approves the writing of, procedures for evaluating the efficacy of the metrology systems for conducting the surface figure evaluations.
• As subject matter expert, writes reports describing the expected performance of systems under design, as well as the demonstrated capabilities of the metrology systems, their limitations, and the methods those limitations were calculated.
• Writes, or approves the writing of, complex data analysis code using MATLAB and Zemax to process the data gathered, and to display the results in a way that others can recognize and use for continued production.
• Writes, or approves the writing of, and implements MATLAB code to predict the surface figure effect of force array and temperature deviations from ideal.
• Writes, or approves the writing of, and implements MATLAB code to guide the automated control of hexapods that precisely position the elements of the surface figure evaluations.

Evaluation Design

• Designs the surface figure evaluation strategy for mirrors during production and according to sponsors'' requirements.
• Designs complementary surface figure evaluation tests according to the phase of mirror production and the tests'' sensitivities.
• Models the Zemax light ray traces to ensure the light sources, lenses, test optic (mirror in fabrication), cameras, detectors and other metrology equipment are positioned within exacting tolerance.
• Performs error analyses in order to specify positioning requirements to the mechanical, electrical, and software engineers designing system components.
• Factors in environmental effects during tolerancing.
• Advises principal investigators, college administrators and sponsors on the limits of surface figure evaluations and develops novel, state-of-the-art solutions when sponsor requirements make it necessary.

Team Leadership

• Supervises the three optical and metrology engineers who assist in design of tests and who perform the tests in the lab and across all areas of Steward Observatory.
• Provides technical expertise and advice when they encounter the novel situations typically encountered during the research activities that they support.
• Troubleshoots metrology system anomalies and leads cross-functional teams to discover and implement solutions.

Technical Operations and Support

• Guides technicians in installing and testing the mirror support actuators in polishing cells that support the mirrors during fine grinding and polishing and the thermal sensing system used in the conduct of surface figure tests.
• Confirms the work of mechanical engineers performing the finite element analyses that identify the ideal force arrays for mirror support, then works with the technicians to ensure the force arrays provided by the installed actuators are within the tolerance necessary.
• Works with the technicians to ensure the temperature distributions are being measured accurately.

Knowledge, Skills, and Abilities

• Expert in use of MATLAB and Zemax software.
• Expert in both visible light and infra-red light deflectometry systems.
• Expert in interferometry.
• Demonstrated communications and organizational abilities to work on interdisciplinary teams to design, build and employ complex metrology systems.
• Demonstrated ability to find novel solutions to unprecedented challenges.

Physical and Environmental Requirements:

• This position may involve working in high places, and in environments with noise exposure during glass generating and air cart operation.