04249791 is referenced by 5 patents and cites 3 patents.

An objective with two lens elements has a first fully-reflective plane mir between the lens elements, and a second such mirror between the objective and a detector. The outermost lens element and the first mirror are carried in a housing rotatable with respect to another housing carrying the other lens elements and the second mirror. The other housing is rotatable about an axis between the second mirror and the detector. The system may thus do elevation scanning by rotating the first housing, and azimuth scanning by rotating the two housings about the mentioned axis. Image stabilization is accomplished by appropriately stabilizing one or both mirrors.

Title
Optical scanning system using folding mirrors and with stabilization
Application Number
6/18380
Publication Number
4249791
Application Date
March 7, 1979
Publication Date
February 10, 1981
Inventor
William S Flogaus
Alexandria
VA, US
David P Helm
Burke
VA, US
Agent
Aubrey J Dunn
Milton W Lee
Nathan Edelberg
Assignee
The United States of America represented by the Secreatry of the Army
DC, US
IPC
G02B 23/00
View Original Source