Abstract: Embodiments of the disclosed invention relate to identifying safe landing sites on a surface. More particularly, three-dimensional image data is obtained from a surface. That image data is processed using morphological operations to create a smoothed surface. The smoothed surface data is then used to calculate slopes, to identify areas of the surface that present a slope hazard. The smooth data obtained for identifying slope hazards can also be used in connection with identifying surface features, including bumps or holes, that create surface feature hazards. After identifying the slope and/or surface feature hazards, a hazard map indicating safe and not safe landing areas can be created.

Abstract: A dual-polarized antenna array is disclosed. The antenna array includes a plurality of self supporting, electrically conductive members. Tapered elements of neighboring electrically conductive members define tapered slots that form part of radiating structures. The radiating structures additionally include a slot line in communication with the tapered slot. A back cavity can be included as part of a BALUN structure that is integral to an electrically conductive member.

Abstract: Methods and systems for adaptively controlling the illumination of a scene are provided. In particular, a scene is illuminated, and light reflected from the scene is detected. Information regarding levels of light intensity received by different pixels of a multiple pixel detector, corresponding to different areas within a scene, and/or information regarding a range to an area within a scene, is received. That information is then used as a feedback signal to control levels of illumination within the scene. More particularly, different areas of the scene can be provided with different levels of illumination in response to the feedback signal.

Abstract: Conformal antennas and methods for radiating radio frequency energy using conformal antennas are provided. In particular, one or more tapered feeds can be provided as part of or interconnected to a conductive top plate. The one or more tapered feeds have a depth that decreases from a feed point to a tip. The tip of the one or more tapered feeds is adjacent a cavity formed over a lens region. An aperture over the lens region can be covered or filled by an impedance surface. This impedance surface may comprise a frequency selective surface. Alternatively, a frequency selective surface can be provided over the lens region of an antenna incorporating one or more stripline feeds.

Abstract: A frozen surface technology is provided that can be used to provide a precisely defined surface. The frozen surface technology can include the use of a frozen membrane. For instance, frozen membrane mirrors and methods of producing frozen membrane mirrors are provided. The frozen membrane mirror includes a membrane material having a reflective surface. Active control is used to maintain a desired figure of the reflective surface while a solidifying material is applied to a back side of the membrane material. Active control of the figure of the reflective surface is maintained while the solidifying material cures. Once the solidifying material has been applied and cured, active control can be removed.

Abstract: A switched beam antenna system is provided. The antenna system includes a plurality of feed elements arranged radially about a center point. A feed switch provides equidistant signal paths between each antenna element and a transceiver. The production of an antenna beam in a desired direction is achieved by controlling a switch to selectively operate a feed element associated with a beam coverage area that encompasses the desired steering angle.

Abstract: A dual-polarized antenna array is disclosed. The antenna array includes a plurality of self supporting, electrically conductive members. Tapered elements of neighboring electrically conductive members define tapered slots that form part of radiating structures. The radiating structures additionally include a slot line in communication with the tapered slot. A back cavity can be included as part of a BALUN structure that is integral to an electrically conductive member.

Abstract: An antenna system that includes one or more radiator packages on a first side of an antenna substrate and one or more support packages on a second side of the antenna substrate are provided. Embodiments of the present invention include antenna systems incorporating a plurality of radiator packages on a first side of the antenna substrate and a plurality of support packages on the second side of the antenna substrate. The radiator packages generally include a radiator element and an integrated circuit that are incorporated into a common package. The integrated circuit of the radiator package can comprise an amplifier and/or other electronic components. The support packages generally provide one or more additional electronic components. For example, a support package integrated circuit can provide a phase shifter, amplifier, and/or other electronic components. The antenna substrate generally incorporates electrical conductors for operatively interconnecting each radiator package to at least one support package.

Abstract: The present invention relates to a temporal depolarization assembly. The depolarization assembly operates to produce light that, over some period of time, is depolarized. The depolarization assembly includes first and second variable retarders. The variable retarders are operated to produce a retardance that varies in time. In addition, the modulator axis of a first one of the variable retarders is held at an angle to the modulator axis of the second one of the variable retarders. The frequency at which the retardance of the variable retarders varies is selected to be some fraction of the integration time of a sensor associated with the polarization assembly.

Abstract: Field widening lens methods and systems are provided. The field widening lens includes a non-planar primary mirror and a secondary mirror. In addition, separate input and output ports are provided. The field widening lens further provides for an optical path difference for rays within the lens that is essentially zero for any ray within the field of view of an optical system including the field widening lens, regardless of the angle at which the ray entered the lens.

Abstract: The present invention pertains to the identification of a set of measurement data, using an a priori model database, which is then used in the determination of a pose solution using LADAR data. In particular, a model database of a target scene is created. The model database includes location information for a plurality of points within the target scene, and separation distances between sets of those points defining triangles. LADAR data obtained from a target scene is processed to extract features. Location information and separation distances between sets of extracted features defining triangles are placed in a measurement database. Separation distances contained in the measurement database are compared to separation distances contained in the model database. If a match is found, a rotation quaternion and translation vector are calculated, to transform the data in the measurement database into the frame of reference of the data in the model database.

Abstract: A switched beam antenna system is provided. The antenna system includes a plurality of feed elements arranged radially about a center point. A feed switch provides equidistant signal paths between each antenna element and a transceiver. The production of an antenna beam in a desired direction is achieved by controlling a switch to selectively operate a feed element associated with a beam coverage area that encompasses the desired steering angle.

Abstract: A pulse data recorder system and method are provided. Upon the arrival or occurrence of an event or signal, the state of a digital switch is set. Upon receiving a pulse from a readout clock, the state of the switch is stored in a buffer memory, and the state of the switch is reset. As the readout clock is run, a time history of the state of the switch is obtained. The pulse data recorder can feature a plurality of unit cells, for use in imaging or other multiple pixel applications.

Abstract: A pulse data recorder system and method are provided. Upon the arrival or occurrence of an event or signal, the state of a digital switch is set. Upon receiving a pulse from a readout clock, the state of the switch is stored in a buffer memory, and the state of the switch is reset. As the readout clock is run, a time history of the state of the switch is obtained. The pulse data recorder can feature a plurality of unit cells, for use in imaging or other multiple pixel applications.

Abstract: The present invention pertains to systems and methods for the capture of information regarding scenes using single or multiple three-dimensional LADAR systems. Where multiple systems are included, those systems can be placed in different positions about the imaged scene such that each LADAR system provides different viewing perspectives and/or angles. In accordance with further embodiments, the single or multiple LADAR systems can include two-dimensional focal plane arrays, in addition to three-dimensional focal plane arrays, and associated light sources for obtaining three-dimensional information about a scene, including information regarding the contours of the objects within the scene. Processing of captured image information can be performed in real time, and processed scene information can include data frames that comprise three-dimensional and two-dimensional image data.

Abstract: Methods and systems for adaptively controlling the illumination of a scene are provided. In particular, a scene is illuminated, and light reflected from the scene is detected. Information regarding levels of light intensity received by different pixels of a multiple pixel detector, corresponding to different areas within a scene, and/or information regarding a range to an area within a scene, is received. That information is then used as a feedback signal to control levels of illumination within the scene. More particularly, different areas of the scene can be provided with different levels of illumination in response to the feedback signal.

Abstract: Dual band antenna systems and methods providing isolation between bands are provided. The system includes a pair of superimposed antenna radiating elements, each of which is connected to an associated feed network. The feed networks may comprise a quadrature hybrid networks. Coupling paths between the first and second feed networks are arranged such that a first component of a first signal coupled from a first feed network to a second feed network will be 180° out of phase with a second signal component of the first signal coupled from the first feed network to the second feed network at the input/output of the second feed network. The resulting destructive interference results in isolation between the bands.

Abstract: Lidar systems and methods are provided. The lidar system includes an optical autocovariance receiver and one or more chemical composition sensors or processors, in addition to a Doppler signal processor for obtaining relative wind speed information. The additional processors may include a high spectral resolution lidar signal processor and/or a differential absorption lidar processor that receive input signals from the optical autocovariance receiver. Receivers that may be incorporated into the lidar system, in addition to the optical autocovariance receiver, include a depolarization receiver, a Raman receiver, and/or an Etalon receiver.

Abstract: A low-profile lens element for steering a beam is provided. Specifically, the low-profile lens element is mechanically rotatable such that a beam can be steered in any direction within three-dimensional space. The lens element may include a number of discrete portions for differentially delaying adjacent discrete portions of a beam in order to effect beam steering. These discrete portions may vary in width. In addition, multiple lens elements may be provided.

Abstract: A Space-based Calibration Transfer Spectroradiometer (SCATS) instrument that establishes a maintainable SI traceable radiometric calibration on-orbit with long-term stability accuracy, such as is required for long term climate monitoring missions, is provided. The SCATS instrument includes sensors that directly measure the highly stable solar irradiance and/or the lunar irradiance, and the Earth radiance through an invariant instrumental optical path. This common path measurement concept eliminates uncertainties associated with the calibration and degradation of intervening solar attenuation elements that represent the current state of the art. The SCATS instrument can be used to calibration of hyperspectral and multi-spectral sensors operating from the ultra-violet to long wave infrared. A suitable selection of detectors and filters enables this wide wavelength application.