Abstract: Systems and methods for measuring RCS patterns of large targets in a compact target range having limited size. The present invention utilizes a compact range whose sweet spot (corresponding to the imaged area of the target) is much smaller than the target size. Inverse synthetic array radar (ISAR) images of successive sections of the target are registered to form a composite image of the whole target. The image is then Fourier transformed to generate an RCS value of the full target. This procedure is repeated for successive measurement angles, an RCS versus .theta. plot is generated corresponding to the RCS pattern of the target. The multiple images may be generated by translating the target and computing RCS plots of the target by combining the multiple images produced during translation, or generating the the multiple images by moving feeds or using multiple feeds of the ISAR system.

Abstract: Systems for improving the quality of video images generated by a forward-looking infrared detector array include mechanisms for dynamically adjusting the output signals from one or more non-linear detectors in such an array. These systems and methods utilize the output signals from two or more detectors adjacent to each non-linear detector to provide accurate DC restoration to the signals from such non-linear detectors.

Abstract: A compact, inexpensive and mass-producible optical display system for an automobile creates a highly visible and sharp, high contrast and pleasing, multi-color magnified virtual image of a primary instrument cluster at a viewing distance which is greater than the actual optical distance between the dashboard and the driver's eyes in order to enhance instrument readability, minimize driver eye strain, and reduce eye focus problems which are associated with transitioning between the far range viewing used for watching the road ahead and the near range viewing used for glancing at the instruments. A non-pupil forming display system uses a single off-axis aspherical mirror with power to create a virtual image of a miniaturized, multi-color passive image source, such as a segmented LCD panel, which is backlighted by a small filament incandescent light bulb. The aspheric surface is optimized to minimize aberrations and reduce vertical disparity and field curvature.

Abstract: A method for precisely controlling the overall average diffraction efficiency of a hologram including the steps of (a) providing a hologram layer that includes a hologram formed pursuant to hologram forming exposure and development, (b) coating the hologram layer with a photoresist layer, (c) masking the photoresist layer with a mask having opaque and transparent areas wherein the proportion of the opaque areas relative to the transparent areas is selected pursuant to the desired diffraction efficiency, the opaque and transparent areas being sufficiently small so as to have little noticeable effect when the resulting hologram is played back, (d) exposing the photoresist layer to actinic illumination through the mask transparent areas, (e) developing the photoresist layer to remove the photoresist in the areas illuminated by the actinic illumination to uncover the areas of the recording material corresponding to the transparent areas of the mask, (f) etching the recording material to remove the areas thereof t

Abstract: A broadband transition between microstrip transmission line and slotline transmission line. The geometry of integrating the two transmission lines results in a broadband microstrip shunt circuit across the slotline, and a broadband slotline open circuit in the direction opposite of propagation on the slotline. This produces direct coupling between the two transmission lines. The transition does not require any intermediate transmission line types between the microstrip and slotline, and no frequency dependent tuning stubs are used to produce the shunt circuits and open circuits required for coupling. The result is a broadband transition which can be fabricated using standard etching techniques and requiring no plated through holes.

Abstract: Capture commands are generated for a set of data divided into groups where each group is identified by a control word. Typically the data set arrives at the present invention as a serial stream. The control words address registers in a first addressable memory array which contain high addresses to a second addressable memory array. The data words trigger a counter, the counts of which constitute low addresses to the second addressable memory array. The high address and the low address together address registers in the second array which contain capture commands. The capture commands signal other devices to capture the corresponding data out of the data set.

Abstract: A display corrector circuit 40 is disclosed which corrects for defocusing and horizontal and vertical spherical positional distortion of a point 22 upon a flat faced cathode ray tube display 16. The corrector 40 provides a plurality of programmable corrections and is based upon the first three terms of a Taylor series expansion of a polynomial functional representation of positional error.

Abstract: Linear signal reconstruction systems and methods that use mathematical relationships that exist between discrete time signals, digital to analog conversion characteristics and digital signal processing to produce a highly accurate, low noise, arbitrary analog signal from a discrete digital representation. This analog signal is produced by connecting discrete digital voltages through the use of a segmented straight line curve fit. This approach significantly reduces out of band harmonics that are normally associated with the stair-step approach while improving the output signal amplitude and phase accuracy. More specifically, the present system and method provides for reconstructing original analog signals from a digitized representation thereof. Digitized signals corresponding to the original analog signals are differentiated and then D to A converted into differentiated analog signals.

Abstract: In an electronically scanned array where each radiating element extends outwardly from a face of the array (10), an intra-array test probe (20) is employed to test the propagation characteristics of an individual radiating element (13). The intra-array test probe (20) is adapted to be removable fitted over the radiating element (13) at one end and coupled to a test instrument at the other end. The intra-array test probe (20) channels RF signals to or from the test instrument to the radiating element (13) under test to test the propagation characteristics of the radiating element.

Abstract: A dielectric material is formed into a structure having two parallel broad surfaces with one or more raised integral portions extending transversely across at least one of the broad surfaces. The exterior is uniformly conductively coated resulting in a parallel plate waveguide having a continuous transverse stub element disposed adjacent one plate thereof. Purely reactive elements are formed by leaving the conductive coating on the terminus of the stub element, or by narrowing the terminus of the stub element. Radiating elements are formed when stub elements of moderate height are opened to free space. Radiating, coupling and/or reactive continuous transverse stub elements may be combined in a common parallel plate structure in order to form a variety of microwave, millimeter wave and quasi-optical components including integrated filters, couplers and antenna arrays.

Abstract: An inductive charge port for an electric vehicle in which part of the inductive coupling transformer core is attached to the inside of an access door on the vehicle, and wherein only a primary coil assembly is inserted into the charging device when charging the vehicle. The charge port includes a primary coil assembly having a primary winding that is coupled by way of an electrical cable to a power source, and a secondary coil assembly disposed in the vehicle. A housing in the vehicle has the secondary coil assembly disposed therein. The secondary coil assembly includes a transformer core having a first portion disposed in the housing. A secondary winding is disposed in a cavity in the first portion of the transformer core which receives the primary winding therein. A hinged access door has a compressible, resilient member disposed on its inner wall and a second portion of the transformer core is secured to the compressible member.

Abstract: A helicopter sight system including an illuminated reticle for controllably providing reticle imaging illumination and an active display for controllably providing active display illumination that contains alignment information provided by an electronic aiming system, the active display and the reticle being controlled to provide respective imaging illumination at different times. The reticle illumination and the active display illumination are directed by a color beam combiner along a common axis to a focussing lens system which illuminates a transparent combiner to produce a reticle image and an active display image viewable by the operator of the helicopter.

Abstract: A metal flared notch radiator with separate and isolated transmit and receive ports for an active array. A 4-port circulator is integrated into the transition of the radiator so that the integrated device has have a separate transmit port, a separate receive port, and a separate termination port to provide isolation between the transmit and receive.

Abstract: A system and method that uses differential computation of position relative to a global positioning system (GPS) coordinate system and the computation of an optimum weapon flight path to guide a weapon to a non-moving fixed or relocatable target. The system comprises an airborne platform that uses a navigation subsystem that utilizes the GPS satellite system to provide the coordinate system and a synthetic array radar (SAR) to locate desirable targets. Targeting is done prior to weapon launch, the weapon therefore requires only a navigation subsystem that also utilizes the GPS satellite system to provide the same coordinate system that the platform used, a warhead and a propulsion system (for powered weapons only). This results in a very inexpensive weapon with a launch and leave (autonomous) capability. The computational procedure used in the platform uses several radar measurements spaced many degrees apart. The accuracy is increased if more measurements are made.

Abstract: The hermetic module (10) has a frame 12 with an integral heat sink panel (20) extending thereacross between the side walls (14, 16). High-density integrated circuit electronics are mounted on the heat sink panel by hybrid assembly techniques. Covers (36, 38) are welded to the walls to achieve closure. Feedthrough 74 includes connector block (84) extending through an opening in front bulkhead (76). The front bulkhead is Kovar clad, and seal is achieved by means of a Kovar flexible seal extending between the Kovar side of the front bulkhead and the Kovar ring on the connector block.

Abstract: A method and autofocus processor that is adapted to automatically correct focus phase errors associated with synthetic array radar signals. The method comprises processing the synthetic array radar signals to produce a SAR image; identifying and locating potential targets contained in the SAR image; storing the range bin and azimuth location of the target in a target list; bandpass filtering the SAR signals associated with the target scatterer to remove the interference therefrom; forming the pulse pair product of the phase history samples from each reference target to produce a differential phase function; integrating the differential phase function over all reference targets to provide the averaged differential phase history associated therewith; interpolating the averaged differential phase function to restore the original time scale and number of samples; and computing the focus error from interpolated differential phase history.

Abstract: The adequacy of the fillets (24, 26) by which the lead (22) is soldered to pad (18) on printed circuit board (16) is evaluated by providing low angle diffuse illumination from circular fluorescent lamp (34) and observing the image with a television camera (30). The electronic image information is digitized and analyzed to produce a signal corresponding to the adequacy of the fillets and thus the adequacy of the solder joint. Automatic inspection is achieved and the signal can be employed to translate the printed wiring board to a new position for automatic inspection of another solder joint.

Abstract: A high efficiency x-prism beamsplitter for use in such applications as helmet mounted visor displays. By using polarization-sensitive dielectric coatings arranged along with half-wave plates, the x-prism can theoretically deliver 50% illumination to each eye with no loss. In addition to the higher efficiency, the glare throughput found in conventional x-prisms can be theoretically reduced to zero.

Abstract: A guard hologram blocks ambient turn-on of an image hologram. In a center high-mounted rearview stoplight assembly, a guard hologram is used to prevent ambient turn-on by the sun and still allow optical transparency of the image hologram. The guard hologram preferred is optically mounted to the lamp side of the image hologram and includes two 0-degree reflection holograms separated by a halfwave film.

Abstract: A constant gain sector beam array is obtained by applying equal amplitude, equal phase excitations to a sector array characterized by a curved array geometry. In a simple form, the curve is the arc of a portion of a circle. The radiation pattern can be further enhanced by using a more complex curvature geometry, and by minor adjustments to the amplitudes in the slots. Other forms of shaped beams, such as a cosecant squared antenna pattern, may be obtained by appropriately shaping the curvature geometry.