<title>Actively controlled 5:1 afocal zoom attachment for common module FLIR</title>

Abstract

The U.S. Navy has several hundred P3 Orion Aircraft which utilize the AN/AAS-36 Texas Instruments FLIRs. The system is an 8 - 12 micrometers long wave IR imaging system using a linear HgCdTe detector array. The FLIR optics consists of the classic common module imager which is a 3-element IR lens with an external scan mirror which produces the linear pushbroom scan over the linear detector array. This system is actually a dual field of view, and a 3-element Galilean afocal telescope located in front of the imager is used for a 3X magnification. In the wide field of view mode the imager is simply used alone looking out into object space, with the 3X afocal telescope rotated with its optical axis orthogonal to the imager axis. In order to switch to the narrow field of view, the afocal telescope is rotated 90 degree(s) and the user acquires a net 3X magnification to the imagery. The loss of imagery during the field switching operation has always been seen as a problem, and it would be far more desirable to have a continuously varying magnification instead. For this reason, the Navy put out a Small Business Innovation Research solicitation in 1989 with the intent of developing a continuously varying IR zoom lens to retrofit into onto the TI FLIR. OPTICS 1, Inc. completed Phase I of this SBIR which demonstrated feasibility of the design concept, and we have been under contract on the Phase II program since April, 1990.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.