Abstract

A large number of thermal imaging systems use a scan mirror to create a two-dimensional image using a linear focal plane array. Trade-offs between center-pivot scan mirrors and rotary scan wheels will be discussed followed by a derivation of the scan wheel characteristics from optical system parameters. The number of facets on the scan wheel, along with its diameter and position, will be determined from system quantities such as focal length, aperture diameter, scan field of view, and scan efficiency. With the scan wheel and optical system defined, will be presented which quantify the ray clearance on the scan facets as well as the beam wander in the afocal attachment. Design examples will be used to illustrate the methodology.

© 1998 Optical Society of America