Abstract: A missile guidance system with a fixed body missile seeker having an adjustable look angle. The missile seeker has a fixed camera whose look angle is adjustable to keep a moving target within the field of view of the camera. The target is tracked by a tracker to generate target angle and line of sight rate signals. The target angle signal is input to pointing angle adjustment apparatus which adjusts the look angle of the camera. The pointing angle adjustment apparatus may comprise a stepper motor that controls the angular position of a gimbal on which the camera is mounted. Alternatively, the pointing angle adjustment apparatus may comprise one or more stepper motors that control an adjustable zoom lens or a plurality of optical wedges, respectively. A body angular rate output signal of a body-fixed inertial measurement system is summed with the line of sight rate signals from the tracker to determine the inertial line of sight rate of the moving target.

Abstract: This invention is directed to an electronic gimbal system (10) which stabilizes a digital video image of a particular scene taken by a sensor which is under disturbance forces. The video image is stored as a two-dimensional array of pixel locations (12) and is applied to an address look-up calculator (14) along with a signal from an inertial sensor (16). The inertial sensor (16) determines the offset of the array of pixel locations from an inertial reference frame and adjusts the input array accordingly. In one particular implementation, the address look-up calculator (14) applies a bilinear interpolation to the pixel location in order to provide a weighted sum of pixel intensities for each offset pixel location.

Abstract: A multiplexer for compressing two television programs into the bandwidth normally required for a single television signal is disclosed wherein vertically adjacent lines in the odd and even field of each frame are summed and differenced in pairs having the same color subcarrier phase. "Line pair signals" respectively comprising the sum and difference of each line pair are then formed after the difference signal is time compressed without an overall increase in bandwdth. The line pair signals for each frame of one program are alternately transmitted with the line pair signals of a frame from the second program. The line pair signals of a video frame are fewer in number and longer in duration than NTSC field lines. Timing is such that one frame of both programs is transmitted during the time allotted to the transmission of one frame under the NTSC standard. The lines from odd fields of each program are reconstructed after transmission by adding the appropriate difference signals and sum signals.

Abstract: A system (20) for identifying and tracking targets in an image scene having a highly cluttered background. An imaging sensor and processing subsystem (21) provides a video image of the image scene. A size identification subsystem (23) removes background clutter from the image by filtering the image to pass objects whose sizes are within a predetermined size range. A feature analysis subsystem (24) analyzes the features of those objects which pass through the size identification subsystem and determines if a target is present in the image scene. A gated tracking subsystem (25) and scene correlation and tracking subsystem (26) track the target objects and image scene, respectively, until a target is identified. Thereafter, the tracking subsystems lock onto the target identified by the system (20). Several methods relating to target acquisition are also disclosed.

Abstract: Operating at real-time data rates, the disclosed hardware network generates a signal which closely approximates the Mth-largest of a set of R input data signals. The operational basis of this network is a comparison (121-127) between the input data (101-107) and a monotonically-scanning reference function (110). At that point (140, 150, 160) when the lower (R-M+1) of the inputs have been equaled by an increasing reference, the reference has become the same as the Mth-largest and is used (119b, 165, 170, 175) as the filter output. Analogous operation is achieved with a decreasing reference.When the number R of inputs is odd and M is made equal to ((R+1)/2), the network becomes a real-time median filter.

Abstract: Operating at real-time data rates, the disclosed hardware apparatus determine which one of a set of R input data signals is the Mth-largest. Mutual comparisons between the data values themselves provides the basis for the mechanized determination schemes.After every data signal is pair-wise compared (112-167) with every other data signal, each subset of results (C12-C17, C12-C27, C13-C37, C14-C47, C15-C57, C16-C67), consistng of the outcome of the comparisons between a given data signal and all other data signals, is tested (210-260) to determine whether the results indicate that (M-1) of the other data signals are greater than the given signal. That data signal whose result set satisfies this (M-1) condition is the Mth-largest and is used (270, 280) as the network output (285).For data that is serially-presented (490,400) a network simplification makes set-testing possible after only one data value, that most-recently-presented, is compared (412-417) to all other (R-1) signals of the set.

Abstract: Operating at real-time data rates, hardware logic networks (FIGS. 3-6) receive onto a data-channel array (390 in FIG. 3) a set of unordered input data values and iteratively pair-wise transpose the set members until their positional order on the array coincides with the order the members would assume if their magnitudes were arranged according to sequential ordinal rank. Pair-wise comparisons between the data values themselves provide the basis for the mechanized pair-wise transposition schemes.Within each network, a key building block for performing both the pair comparisons and member transpositions is a Number Pair Orderer (NPO) (FIG. 2). Each NPO compares (210) two data elements and passes the smaller to one of its outputs (240), while passing the larger to the other of its outputs (260). Individual NPO's are arranged into two groups (311-315 and 321-325), each of which operates iteratively upon pairs of substantially all of the data values.