Abstract: A method forms a passive acoustic track to cue an active multistatic acoustic tracking system. The passive track cue reduces the false track rate in the active tracker by focusing search area and selectively initiating active tracks. The passive track originates from a fixed passive acoustic horizontal line array (HLA). The HLA cannot determine target range or resolve left-right ambiguity but can predict Closest-Point-of-Approach (CPA) events. For each CPA event, a cue is forwarded to the active system for initiation. The method presents a minimal parametric representation for a passive acoustic track and uses an algorithm to obtain initial estimated parameters to initiate the passive track more effectively. A performance evaluation is given. The method also includes conversion of the passive track to normalized-coordinates for use with multistatic tracking systems. The passive track quality is assessed to determine whether it is sufficient to justify cueing the active multistatic system.

Abstract: A low-cost high-resolution staring infrared imaging sensor for viewing a large Field Of Regard (FOR) while integrating over a small IFOV to detect small dim targets by subdividing the FOR into a plurality of internal optical paths without the use of mechanically-movable parts. Each of the plurality of internal optical paths may be further subdivided by a plurality of steerable micro-mirrors to reduce the IFOV and enhance long-range target acquisition capability. The sensor includes a primary lens for accepting infrared radiation from a Field Of Regard (FOR), a plurality of primary mirrors each disposed to reflect a portion of an FOR image along a different optical path, a secondary lens in each optical path to focus the FOR image portion onto a secondary mirror for reflection along a preselected direction, and a tertiary lens in each optical path to focus the FOR image portion onto an image detector array.

Abstract: A low-cost high-resolution staring infrared imaging sensor for viewing a large Field Of Regard (FOR) while integrating over a small IFOV to detect small dim targets by subdividing the FOR into a plurality of internal optical paths without the use of mechanically-moveable parts. Each of the plurality of internal optical paths may be further subdivided by a plurality of steerable micro-mirrors to reduce the IFOV and enhance long-range target acquisition capability. The sensor includes a primary lens for accepting infrared radiation from a Field Of Regard (FOR), a plurality of primary mirrors each disposed to reflect a portion of an FOR image along a different optical path, a secondary lens in each optical path to focus the FOR image portion onto a secondary mirror for reflection along a preselected direction, and a tertiary lens in each optical path to focus the FOR image portion onto an image detector array.