Abstract: A device and a method for detecting flying objects in a predeterminable spatial area with a detector responding to the flying object for detecting the flying object are configured with respect to a reliable and largely discreet detection of the flying objects in such a manner that at least three detectors coupled in the way of a network are distributed in the spatial area, and that the detectors operate in a passive manner.

Abstract: A method and apparatus for post processing a star tracker measurement to remove a systematic error characterizable at least in part by a pixel phase is disclosed. The method comprises the steps of computing the pixel phase along a first axis from a measured star position and a star tracker characteristic, computing a first axis error correction according to the computed pixel phase, and computing a compensated first axis star tracker measurement according to the measured star position and the first axis error correction.

Abstract: One version of the invention relates to a laser detection system that includes a ball lens and a plurality of fiber optic bundles placed adjacent the ball lens so that incoming light rays are focused onto the bundles by the ball lens. In one particular version of the invention, a ball lens is one that can provide an almost infinite number of “principal” axes for off-axis light. Each fiber optic bundle is aimed in a different direction from each other bundle so that each bundle will have a different FOV even though the same ball lens is used to focus the incoming light rays.

Abstract: An apparatus for determining star location includes a star tracker, a star catalog and a controller. The star tracker is used to sense the positions of stars and generate signals corresponding to the positions of the stars as seen in its field of view. The star catalog contains star location data that is stored using a primary and multiple secondary arrays sorted by both declination (DEC) and right ascension (RA), respectively. The controller checks the star catalog and determines which stars to track. The controller does this determination by using an algorithm to sort the primary and secondary arrays to determine which stars are located in the star tracker field of view. The controller then commands the star tracker to track these stars and uses them to determine the spacecraft attitude.

Abstract: A system for stabilizing an optical line of sight. An optical system including primary optics and relay optics includes a jitter rejection mirror located within the path of the relay optics. An auto alignment system is provided for maintaining alignment of the jitter rejection mirror in response to a control signal. An auto alignment sensor detects jitter in a reference beam passing through the jitter rejection mirror, and the generated control signal is used to reduce the jitter. The reference beam is supplied by a stabilized source of laser signals which are received by the primary optics, and relayed to the jitter rejection mirror.

Abstract: A laser optical sensing system and method for detecting target characteristics are disclosed. The system includes a laser source with at least two emission apertures from which laser signals are emitted. The system also includes at least one detector, which is operationally responsive to the laser source. The system includes a microprocessor that is operationally coupled to the detector(s) for processing signal data, a memory accessible by the microprocessor for storing target characteristics (e.g., unique signals), and a software module accessible by the microprocessor for enabling system training and detection operations. In operation, the laser source emits into an environment at least two laser signals, one from each emission aperture.

Abstract: Multiple laser optical sensing systems and methods for detecting target characteristics are disclosed. The present invention detects the presence of an object in a monitored area using an laser-based object detection system and may selectively cause a controlled response when an object is detected. At least two laser signals may be emitted into a monitored area using a vertical cavity surface emitting laser structure. At least one detector receives any laser signals not blocked by an object. The system determines the presence or absence of an object in the environment using a microprocessor and determines the objects characteristics by comparing received laser signals associated with it to object characteristics stored in a memory. The system may selectively causing a controlled response in accordance with the determination of object characteristics and/or correlating response criteria.

Abstract: A system for stabilizing an optical line of sight. An optical system including primary optics and relay optics includes a jitter rejection mirror located within the path of the relay optics. An auto alignment system is provided for maintaining alignment of the jitter rejection mirror in response to a control signal. An auto alignment sensor detects jitter in a reference beam passing through the jitter rejection mirror, and the generated control signal is used to reduce the jitter. The reference beam is supplied by a stabilized source of laser signals which are received by the primary optics, and relayed to the jitter rejection mirror.

Abstract: Structures and methods are provided for deriving corrected star coordinates Ccrctd from measured star coordinates Cms that include star tracker charge transfer efficiency (CTE) errors. The structures and methods are based on a recognition that measured star coordinates Cms of star image centroids include CTE errors which are functions of the CCD path lengths over which the associated electrical charges traveled. In particular, the errors are substantially a product of a respective path length and a star-coordinate error factor &xgr; which, in turn, is a function of the star image magnitudes msi. Information contained in different measured star coordinates Cms is organized to facilitate the derivation of an estimate &xgr;* of the star-coordinate error factor &xgr; with conventional estimation processes. The measured star coordinates Cms are then corrected with the error factor estimate &xgr;* to realize the corrected star coordinates Ccrctd and, thereby, improve the accuracy of spacecraft attitude control.

Abstract: A scanning sensor system includes a light sensor and a scanning telescope having a first telescope subassembly and a second telescope subassembly. Each of the telescope subassemblies has a primary telescope mirror oriented to receive an incident light beam over an angular viewing range as the primary telescope mirror is rotated about a primary-mirror rotation axis, and at least one additional telescope mirror positioned to receive a reflected light beam from the primary telescope mirror. A primary mirror drive rotates the primary telescope mirrors about the primary-mirror rotation axis at a primary mirror angular instantaneous rate of rotation. A half-angle derotation mirror has a derotation-mirror axis parallel to the primary-mirror rotation axis. The half-angle derotation mirror is positioned to reflect light in the optical path when each primary telescope mirror is within the angular viewing range and to direct the reflected image along the optical path toward the sensor.

Abstract: An arrangement for determining with high accuracy the angle of incidence of light, in particular sunlight, has low cost electronic components and low susceptibility to sources of interference and other error signals. An elongated photodiode array has a slot for a band of light to illuminate the photodiode array. The slot is arranged with a predefined spacing above and orthogonally to a preset longitudinal direction of the sensor array, which primarily presets the light's maximally detectable angle of incidence. The sensor array includes rows of several aligned congruent photodiode areas having substantially the same length and width. Each photodiode area has a size that generates a maximum photoelectric current when illuminated by the band of light. This current is sufficient in amount to be divided into a selected number and size of digital resolution stages.

Abstract: An incremental rotary encoder having first and second sensors which each output two sine wave signals having a phase difference of 90 degrees while a rotary member of the incremental rotary encoder rotates. The incremental rotary encoder includes an absolute-zero-index detecting device, provided for the first sensor; at least one binary coding circuit which codes each of the two sine wave signals and the zero index signal into a corresponding binary signal; a holding device for holding the level data of the binary signal of each sine wave signal output from the second sensor when the absolute-zero-index detecting device outputs the zero index signal; and a controller for determining whether the phase of the two sine wave signals output from the second sensor advances or delays with respect to the phase of the two sine wave signals output from the first sensor.

Abstract: A two axis gimbal is provided comprising a support structure, a spherical bearing mounted to the support structure and defining a channel therethrough, and a shaft extending through the channel. The gimbal may also include a reflector connected to the shaft. A drive mechanism, such as a spherical motor, is mounted to the support structure and is adapted to rotate the shaft in two orthogonal axes, i.e., pitch and roll. Power and signal cables are connected to the drive mechanism. The gimbal of the present invention may also include pairs of sensors and sensor triggers for monitoring the position of the shaft and the reflector relative to the pitch and roll axes. The design of the two axis gimbal of the present invention permits the cables to remain stationary during operation of the gimbal.

Abstract: A system and method which substantially eliminates systematic error in a centroid determination of reconstructed waveforms from images generated by an image sensor. In accordance with the invention, a predetermined wavefront error is added to an input wavefront and the wavefront is detected. The predetermined wavefront error is effective to improve centroid determination. In the illustrative embodiment, the input wavefront is passed through a random phase plate. The phase plate is an optical window in which the thickness in a z-axis varies randomly over an X/Y plane. The random phase plate acts as a low pass filter and the output of the phase plate is an aberrated wavefront. That is, the nonuniform thickness of the phase plate generates random spatial phase errors in the optical wavefront. The autocorrelation function of the phase plate is such that random phase errors in the optical wavefront will filter out spatial frequencies higher than one cycle per pixel.

Abstract: A sensor chip is arranged on a top of a housing. An optical lens having a recess in a lower surface thereof is arranged above the sensor chip. A shading plate having a through hole is arranged between the lens and the sensor chip. A shape and size of an opening of the recess of the lens are substantially the same as a shape and size of a top opening of the through hole of the shading plate. An outer peripheral edge of the opening of the recess of the lens is vertically substantially aligned with an outer peripheral edge of the top opening of the through hole of the shading plate. Furthermore, the lower surface of the optical lens is engaged with a top surface of the shading plate.

Abstract: The invention concerns the identification of stars. It consists in selecting “detected stars” among the sensed stars; coupling the detected stars; selecting all or part of the doublets of the catalogue which are most likely to have been present in the visual field of the sensor, the likely doublets and their stars constituting a set D; pairing stars of D with detected stars; and supplying all or part of the paired couples of stars to a processing system. The method is characterized in that it comprises at least the consolidating classification of the set D stars and at least a step using this classification for reducing the number of stars to be paired and/or for carrying out the pairing, and/or for selecting the paired couples. The invention is applicable in particular for determining the attitude of an aircraft or submarine.

Abstract: An optical system includes a curved window, an asymmetric, scoop-shaped optical corrector adjacent to a curved inner surface of the window, an optical train positioned such that the optical corrector lies between the curved window and the optical train, a movable optical train support upon which the optical train is mounted, and a sensor disposed to receive an optical ray passing sequentially through the window, the optical corrector, and the optical train. The optical corrector has an inner surface and an outer surface, at least one of which has a shape defined by an asymmetric polynomial.

Abstract: A photoconductive detector (3) comprises a single continuous photoconductive strip consisting of two interleaved photoconductive spiral paths (1, 2) separated by much thinner gaps (5, 6). The two spiral paths (1, 2) have the same central point (19). The detector (3) is substantially planar and has the overall shape of roughly a circle (10). A circular band (4) of incident radiation (16) crosses the gaps (5, 6) in a nearly parallel fashion, rather than nearly perpendicularly as in the prior art, lessening unwanted modulations of the detected signal. The terminal (11) to terminal (12) resistance of the detector (3) is increased to the point where, when the photodetector (3) is made of the preferred HgCdTe, simple thermo-electric coolers are sufficient to enable use of the detector (3) as an infrared detector (3) in a heat-seeking missile (17).

Abstract: A tracking system having an acquisition sight for use by a pilot to acquire and track a target. Once the target is acquired an operator using a track handle can control tracking of the target. The operator monitors the target utilizing narrow and wide field of view monitors. A computer receives azimuth and elevation positional signals from the tracking device which may be the acquisition sight, the track handle, or other tracking device. The computer then processes the azimuth and elevation data and provides azimuth and elevation angle signals to a gimballed mirror steering the mirror to the target. The mirror receives image forming light from the target and then directs the image forming light to a wide field of view camera and a zoom telescope. The wide field of view camera is connected to the wide field of view monitor displaying the target on the monitor.