Abstract: A method for sensing using a multi-band photovoltaic detector, the method including biasing the photovoltaic detector using a bias voltage at a mid-point of a detector substrate bias voltage range, selecting a first band of the multi-band photovoltaic detector, sensing a first current from a first diode of the multi-band photovoltaic detector, the first diode being associated with the first band, selecting a second band of the multi-band photovoltaic detector; and sensing a second current from a second diode of the multi-band photovoltaic detector, the second diode being associated with the second band.

Abstract: A radiation detector having a pair of adjacent mesas disposed on a common layer. The common layer comprises a first semiconductor layer having a first conductivity type and an energy bandgap responsive to radiation in a first spectral region. Each of the mesas comprises: a second semiconductor; and a third semiconductor layer disposed on the second semiconductor layer having the first conductivity type and an energy bandgap responsive to radiation in a second spectral region. The second semiconductor layer may have a conductivity type opposite the first conductivity type or the three layers may provide an nBn or pBp structure. The third semiconductor layer of the second mesa produces minority carriers, in response to the radiation in the second spectral region, flowing as unwanted carriers into the common layer towards the first mesa. A barrier region is disposed in the common layer to prevent the unwanted carriers from passing from the second mesa to the first mesa.

Abstract: A method for sensing using a multi-band photovoltaic detector, the method including biasing the photovoltaic detector using a bias voltage at a mid-point of a detector substrate bias voltage range, selecting a first band of the multi-band photovoltaic detector, sensing a first current from a first diode of the multi-band photovoltaic detector, the first diode being associated with the first band, selecting a second band of the multi-band photovoltaic detector; and sensing a second current from a second diode of the multi-band photovoltaic detector, the second diode being associated with the second band.

Abstract: According to certain embodiments, alpha image data of an alpha frame corresponding to an alpha portion of a scene is accessed. Beta image data of a beta frame corresponding to a beta portion of the scene is accessed. The alpha frame and the beta frame have an overlapping region. Alpha-beta pairs are generated for the overlapping region. Each alpha-beta pair comprises an alpha value of the alpha image data and a beta value of the beta image data that both correspond to the same portion of the scene. A function is applied to each alpha-beta pair to determine first frame image data for the overlapping region. The first frame image data comprises information to generate a first frame of the scene.

Abstract: According to certain embodiments, alpha image data of an alpha frame corresponding to an alpha portion of a scene is accessed. Beta image data of a beta frame corresponding to a beta portion of the scene is accessed. The alpha frame and the beta frame have an overlapping region. Alpha-beta pairs are generated for the overlapping region. Each alpha-beta pair comprises an alpha value of the alpha image data and a beta value of the beta image data that both correspond to the same portion of the scene. A function is applied to each alpha-beta pair to determine first frame image data for the overlapping region. The first frame image data comprises information to generate a first frame of the scene.

Abstract: A nonuniformity correction processor (30) adapted for use with a focal plane array of detectors. The inventive processor (30) includes a nonuniformity correction circuit (32, 38, 42, 53, 54, 56, 58) for generating current nonuniformity correction terms (32) and applying the terms to information (26) received from the scene via the focal plane array of detectors. A triggering circuit (44) selectively enables the nonuniformity correction circuit (32, 38, 42, 53, 54, 56, 58) in response to a motion signal (50) from a motion detector (40, 46, 48, 52). In a specific embodiment, the nonuniformity correction circuit (32, 38, 42, 53, 54, 56, 58) further includes a filtering circuit (38) for generating intermediate nonuniformity correction terms (42, 53) in response to the scene information (26) received from the focal plane array of detectors.

Abstract: A multispectral imaging sensor. The inventive sensor (10) includes a broadband detector (30) capable of sensing electromagnetic energy across a spectra of interest. A filter arrangement (20) is mounted within the sensor in alignment with the detector (30). The sensor arrangement (20) includes a first filter (24) with a first passband, a second filter (26) with a second passband, and a mechanism for selectively positioning either the first filter (24) or the second filter (26) in optical alignment with the detector (30). In a specific embodiment, infrared and visible light are directed to the filter arrangement by a reflective optical arrangement (16, 18, 19). The positioning arrangement includes a turntable (22) on which the first filter (24) and second filter (24) are disposed.

Abstract: A system (10) for focusing an array (12) of detectors. The invention (10) includes a target (16) disposed in the line-of-sight of the array (12). In accordance with the invention, the target (16) has a plurality of elongate apertures therein. The target (16) is mounted about the line-of-sight of the array relative to an axis extending through the plane of the input aperture of the array and transverse to the line of sight. The array (12) is sampled to provide a plurality of output signals. The output signals have amplitude minima and maxima corresponding to the detection of the apertures by individual detectors in the array (12). The maxima of the output signals are used to focus the array (12).