Abstract: A point sampling method for improving the images produced by a computer graphics system which uses quality measures together with a hill-climbing technique to generate an optimal rook placement of sample points. Two quality measures are used, the root-mean-square (rms) transition error and the maximal circle size. To derive the optimal rook placement, points are placed initially in any rook placement, such as along the diagonal of the pixel. New rook placements are generated by interchanging the x-coordinates of any pair of points. The optimal placement is determined by in a sequence of steps. At each step, all possible pair interchanges are tested by computing the quality measure for each of the possible interchanges. After all are evaluated, the sequence is concluded by making the interchange that provided the most improvement in the quality measure. The point placement after each interchange is used as the basis for the next step in the process.

Abstract: A system wherein light from a fluorescent lamp is dimmed by modulating the pulse-width of current pulses. A current-command signal is applied to a lamp driver in response to a voltage-level corresponding to a given, selectable level of desired lamp brightness. The lamp driver operates as a flyback AC power source that advantageously uses a FET switch to decouple the lamp and a resonant bridge, with the current-sampling process. The circuit samples only the inductor current while the FET switch is active. Because the sample is decoupled from the lamp and bridge, this sampling provides particularly tight control of the regulation process needed to control the incoming noise and transients that affect the power supplied to the lamps. The lamp driver a can also operate as a synchronously-driven resonant forward converter that senses the current actually supplied to the lamp and responds to changes in the fluorescent lamp's condition since the lamp is coupled to the circuit.

Abstract: A smart weed recognition and identification system comprises a chlorophyll sensor for detecting green vegetation and memory map means for storing images which contain different forms of green vegetation. The memory maps stored in memory are processed to eliminate the background information and leave a memory map containing only green vegetation. The enhanced memory map is further processed by an operation of segmentation into identifiable regions and the identifiable green vegetation regions are processed to identify unique attributes for each of the regions.

Abstract: A technique for fingerprint classification and/or identification, in which a fingerprint is defined by areas containing patterns of ridges and valleys. At least one local pattern is determined using locations and characterizations of the fingerprint, which are indicated by a rapid change in direction of the ridges and valleys. The fingerprint is classified into types based upon the relative locations and characterizations of said local pattern(s). The fingerprint identification process can utilize minutiae location and angles as well as local pattern characterizations. Neural networks are utilized in determining the local patterns. The amount of data required to store data defining the fingerprints using the local pattern and/or minutiae techniques is significantly reduced.

Abstract: Apparatus and method synchronize one or more digital clock signals from separate oscillators, to another clock oscillator via a common non-continuous signal, and provide error signals to indicate when one or more oscillators are out of tolerance.

Abstract: The data is processed using a quadratic phase removal process to remove quadratic phase variations contained in the interference to compress the interference to its narrowest extent in a range frequency dimension. Partial motion compensation may be optionally employed using the partial motion compensation process to remove incidental Doppler modulation of the interference caused by motion of the radar during data collection, and to center the Doppler spectrum of radar and interference signals at a convenient frequency. The data is processed using an azimuth Fourier transform to compress the interference to its narrowest extent in an azimuth dimension to localize the interference into peaks while leaving the desired radar signals dispersed throughout the data in one or both dimensions.

Abstract: Commutation switches for electronically scanning cylindrical arrays are disclosed. One embodiment reduces the number of transfer switches needed in a commutation switch by utilizing the commutation inversion property inherent to transfer switches having a binary number of input and output ports. A second embodiment having inversion capability provides a transfer switch with non-binary number of input and output ports. Commutation switches employing transfer switches of the second embodiment exhibit reduced complexity over the prior art and provide lower signal loss than that achievable with commutation switches of the prior art.

Abstract: A method and apparatus for generating imagery animation in a color video monitor as may be used for visual training. A high resolution photo image of a particular station which is to be the subject for simulation training is generated and it is electronically scanned to produce a digitized photo image of the station. The digitized photo image is edited to remove all images exhibiting dynamic characteristics and the resultant photo image is stored in graphics processor video memory designated for background static object imagery. The removed dynamic object images are rendered and stored in graphics processor video memory designated for foreground dynamic object imagery. The background static and foreground dynamic object imageries are combined in a composite video signal which is applied to a trainee video monitor. Once the background static object imagery is generated in the monitor, only the foreground dynamic object images are manipulated by the graphics processor for real-time imagery animation.

Abstract: A process provides radar scan conversion from radar amplitude data in polar coordinates to rectangular coordinates by a digital computer which receives (r,.theta.) coordinate amplitude data from a radar receiver and which supplies (x,y) coordinate amplitude which covers a rectangular-shaped display area of a monitor display. A software program generates an aggregate radial scan pattern that consists of a plurality of radials each of which have active lengths that span one or more of a plurality of selected zones of the display such that as the average azimuthal resolution associated with each zone increases, the number of generated radials match the average azimuthal resolution of the display for each zone. The display can be generated as an offset display relative to the antenna center of a display that has no offset.

Abstract: A broken tine detector for agricultural machines is provided for machines such as balers and forage harvesters. The tines form a first plate of a capacitor which rotates about the axis of a reel. The second plate of the capacitor may be provided by a back-plate which is located at the front of an agricultural machine adjacent to the ends of the tines and which is connected to machine ground. An alternate embodiment of the invention is devised by utilizing conductive strips on a tine guard. Each of the conductive strips may be utilized to form the second plate of the capacitor. The row of tines pass through individual slots in the tine guard so that a particular row in which the tine is broken may be detected. When a tine is broken the total capacitance between the tines and the back-plate will change and will be detected, and an indication will be supplied to an operator so that the operator may stop the machine and remove the tines.

Abstract: A pseudo-code representation and a C language representation of a scan converter system whereby radar amplitude data specified in polar coordinates may be displayed on a computer monitor display controlled by rectangular coordinates is provided. The invention utilizes a look-up table that is built using a two-phase algorithm. The look-up table is set into an initial state after which a mapping process takes place in which all of the (x,y) coordinate values covering the display area are inversely projected to the nearest (r,.theta.) coordinate values using trigonometric and approximation procedures. Since more than one (x,y) value may map to the same (r,.theta.) value, these values are linked together to form a patch. All of the (r,.theta.) coordinates will not be hit in this mapping process. Therefore, a second phase of projection occurs. Each (r,.theta.

Abstract: The invention described herein uses the periodicity of the relative height of the surface of a crop or soil surface that is measured over a large area to control the position of a farm vehicle as it passes between rows of crops. The range and angle of return wave energy that are caused by a scanning beam of energy that sweeps across the crop canopy are measured. Signal processing techniques are employed to utilize the range and angle information to derive steering correction signals to control the farm vehicle. There is no contact with the crop and, therefore, there is no entangling with the crop or weeds with the invention. In addition, a plurality of heights are simultaneously determined across the path of the vehicle which are averaged by signal processing techniques. In this manner local anomalies due to weeds, clumps of soil, damaged or missing plants and erosion will not confuse the device or decrease its accuracy.

Abstract: Broadband, monolithic, planar m.times.m and m.times.n transfer switches with diode switching elements are disclosed. Symmetry of the switches maintain equal insertion amplitude and phase performance. Compensation of phase unbalance caused by diode parasitic capacitance is provided by inductors serially coupled between the diodes and the input and output terminals of the transfer switch. Stripline transmission lines are utilized and isolation between the transmission lines is provide in regions of stripline cross over in the plane.

Abstract: Apparatus and a method for increasing the speed of acquisition of PN coded signals includes a novel PN code clock extraction circuit which is coupled in parallel to a code tracking loop and acquisition loop of a PN receiver of the type having a replica PN code generator which is slip controlled to synchronize with the received PN coded signals. The novel PN code clock extraction circuit detects the clock transition of the received PN coded signals and synchronized the replica PN code generator clock transition signals so that there is no misalignment during acquisition. A switch control in the acquisition loop circuit senses the synchronization of the replica PN code generator transition and the received PN code transition and disconnects the PN code clock extraction circuit after synchronization of clock transition and before acquisition of the PN code so that the acquisition loop detects the PN code synchronization with a full strength signal.

Abstract: Apparatus for rapidly acquiring a high performance gain long PN code having a preamble header in real time includes appratus for rapid acquiring and tracking a short PN code in said preamble header and further includes apparatus for demodulating and tracking a long PN code which follows said preamble header. After acquiring the short PN code, the short PN replica code is applied to the long code demodulation and tracking apparatus. The short PN code is employed to synchronize the long code demodulation and tracking apparatus by detecting the time of occurrence of a sync word in said preamble header and is employed to generate a switch point signal and switch from a short PN replica code to a long PN replica code at the input to the long code demodulation and tracking device in real time.

Abstract: A polarization diverse image sensor identifies different objects of green vegetation and produces a vegetation index of such vegetation. The sensor defines the degree, angle and intensity of polarization. This information is stored in a memory for producing an image memory map of the polarized pixel data. Differential pixel data is computed and then employed to generate a new polarization difference image which is further processed by histogramming slices of the new image to obtain a segmented image of the green vegetation. The attributes of the segmented image are then compared with segmented data which was previously stored in a model base library to obtain a match or no match of the identification of the green vegetation. If match is obtained, a controller issues control signals which controls the spray heads and chemicals carried on a moving spray platform. However, if no match is obtained, the original raw data is labeled, formatted and stored in the model base library as reference data.

Abstract: An apparatus and method for on-the-go measuring of the amount and quality of grain being harvested including a first light source for projecting a first light image onto a pile of grain on a conveyor in a harvesting machine to cream a three-dimensional light image on the pile of grain on the conveyor and then converting the light image into coordinates for comparison to reference coordinates to determine the volume of the pile of grain on the conveyor belt; and an apparatus for determination of the amount of moisture in the pile of grain by projecting a second light image of a first wavelength onto the pile of grain, with the wavelength of the light of a frequency responsive to the amount of moisture in the pile of grain, and measuring the amount of reflectance of the light image of the first wavelength; and projecting a third light image of a second wavelength on the pile of grain, with the second wavelength of light in a region where reflectance is not responsive to the amount of moisture in the pile of gra

Abstract: A variable buoyancy buoy includes a shell and expansion apparatus. The two are combined in a manner to provide a watertight structure with an internal region wherein a constant pressure is maintained that is substantially equal to the pressure at a predetermined depth below the water surface. At depths above the predetermined depth the internal pressure is greater than the external water pressure. This differential pressure causes the buoy to expand, thereby increasing its buoyancy.

Abstract: This invention provides an apparatus including a plurality of omnidirectional hydrophone sensors in a particularly configured array comprised of ring members which are carried between a plurality of tensioned cables, the cables being tensioned by an anchor weight at the bottom end of the array and a capsule float at the top end, the configuration enabling simplified signal processing techniques to achieve sound source discrimination in both azimuth and elevation within an underwater environment.

Abstract: A scanner for implementation with ladar, and visual band passive IR systems. An optic fiber is positioned such that one end thereof is maintained at the focal point of a lens system. A permanent magnetic is attached to the optic fiber near that end, with the permanent magnet being positioned within a space subjected to varying magnetic fields induced by pairs of orthogonally positioned electromagnets. The end of the optic fiber scans the image of the lens, with the scanning pattern being controlled by the varying magnetic fields induced by the electromagnetic pairs. Another end of the optic fiber is connected through a coupler to an infrared/optic detector and a laser diode. The coupler allows for duplexing of light energy from the laser diode to the lens and for the receiving of light energy from the lens to the detector.