Active and adaptive imaging systems rely on accurate measurement, correction, and maintenance of the wavefront error in a collected signal. The performance of different sensing techniques will depend on the characteristics of the input optical signal, including such parameters as spatial and temporal disturbance bandwidths, absolute wavefront error, source spectral and radiometric content, and image sampling parameters. To determine the relative performance of error sensing techniques, it is useful to conduct the error sensing on identical inputs. This leads to the desire to have multiple simultaneous sensing capabilities within a given architecture. The BATC Wavefront Control Testbed error sensing assembly provides several types of wavefront sensing within a single sensor subassembly, allowing different techniques to be evaluated operating on the same input. Currently, the configuration provides the capability to sense wavefront errors through shearing interferometry, direct image position and intensity measurement, edge sampling, and Hartmann-based mask operations. This paper discusses the imaging and sensing capabilities of the assembly, describes the types of sensing that have been currently evaluated in sensing and correction experiments, and defines the parameters for extending the capability to include other types of sensing.

Date Published: 29 October 1999
PDF: 10 pages
Proc. SPIE 3785, Advanced Telescope Design, Fabrication, and Control, (29 October 1999); doi: 10.1117/12.367616

Published in SPIE Proceedings Vol. 3785:
Advanced Telescope Design, Fabrication, and Control
William Roybal, Editor(s)