Abstract: A radar pulse detection and classification system receives times-of-arrival of pulses from simultaneous emitters over a wide range of pulse repetition frequencies (PRF's). The pulses are deinterleaved into bands of pulse repetition intervals (PRI's) so that a fixed number of pulses are required for detection of an emitter regardless of the PRI of the emitter. The pulse periodicities of the pulses in a pulse stream are determined by autocorrelation, and candidate emitter PRI's are selected from the pulse periodicities which were determined by autocorrelation. The pulses of candidate emitters are time-integrated to obtain time-integrated signals, and emitters are detected from peaks in the time-integrated signals. The time-continuity of said pulses are measured to determine emitter existence. The system receives pulses from both jittered and non-jittered emitters.

Abstract: An algorithm for detecting and tracking dynamically-related sets of unstable passive sonar signals is disclosed. The algorithm detects, enhances, tracks and displays both stable and unstable passive sonar signals, while organizing them into dynamically-related groups. The algorithm is implemented as part of a general purpose digital computer/peripheral system that performs:power spectrum analysis on the segmented time-waveform from the hydrophone,processing of the spectra for detection and enhancement of the signal by the novel algorithms of the present invention and other methods,formatting and displaying of the detected and enhanced signals.The algorithm of the present invention (the ABT, or Automatic Band Tracking algorithm) detects persistent signals having related features by means of correlation and enhances by mathematical integration (or smoothing) of the detected signals.

Abstract: A demodulation system extracts data from an input amplitude modulated signal electromagnetic wave with a signal multiplying means that has two input terminals both of which are coupled to receive the input amplitude modulated signal. An output terminal of the multiplying means provides an output signal which is the instantaneous square of the input amplitude modulated signal. A lowpass filter is coupled to the output terminal of the signal multiplying means to reject at least twice the carrier frequency 2(.omega..sub.c) and higher frequency components, and to pass the second harmonic and lower frequencies of the modulation signal 2(.omega..sub.m(max)) to provide a filtered signal that is representative of the square of the amplitude modulation of the input signal. This demodulation method approaches ideal square law detection with power measurement of the input amplitude modulated signal. The filtered signal is supplied to an analog-to-digital converter to supply a digital data output.

Abstract: A CCD camera is adapted for detecting red and near-infrared wavelengths by employing filters that are constructed to allow for the passage of only red light in certain areas and near-infrared light in other areas of the filter. The areas are designed to match the pixel geometry of the lens of a primary color CCD camera that has a predefined pattern of red, blue and green pixels. The match is such that the red bandpass filter areas overlay the red pixels, and the near-infrared bandpass filter areas match the blue and green pixel areas. The red, green and blue output lines of the CCD camera are supplied to a signal processor which uses the signals on these lines to provide combinations of red and near-infrared magnitude that are capable of detecting vegetation from a background. The camera is suitable for full color use again merely by removing the filter that provides R and NIR sensing without otherwise disabling or modifying the camera.

Abstract: A radar scan conversion from radar data in polar coordinates to radar data in rectangular coordinates is employed to supply (x,y) coordinate data to a display, which has variable azimuthal pixel resolution that increases from the center of the display to its periphery. An aggregate radial scan pattern is generated on the display that consists of a plurality of radials each of which have active lengths that span one or more of a plurality of selected boundary resolution zones of the display. These zones are defined by a series of different hyperbolically-based resolution boundaries which define resolution zones of increasing azimuthal resolution values as the zones extend further from the center of said display towards the periphery of said display. The number of radials that are generated on said display match the average azimuthal resolution of said display for each zone.

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: 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: An on-the-go probe for determining the presence of chemical residue in a soil using Transient Infrared Spectroscopy by pulling a soil implement through the soil with the soil implement having a heating or cooling source for temporarily creating a temperature differential between a layer of soil proximate the soil implement and a layer of soil remote from the soil implement, and moving the soil sufficiently fast with respect to heating source to enable measuring the radiation characteristics of the thin layer of soil before the thin layer of soil begins to self-absorb and substantially change its emission characteristics.

Abstract: Target tracking basic sensors are used alone or in multi-sensor combination for multi-target surveillance systems. Optimal assignment of targets to pseudo sensor combinations of single basic sensor groups or to sensor groups formed of a plurality of basic sensors is provided subject to given constraints on basic sensor capacity for a given definition of optimal. The approach taken here is to determine the predicted gain in information content of a track i after it is updated with data from pseudo sensor i for all pairs i,j. This information content is then used to predict without making actual observations by using the properties of the Kalman covariance matrix. Assignments of tracks to pseudo sensors are then made on a continuing basis so that the total information gain is maximized. This is achieved by imposing unique constraints on the pseudo sensors and then calculation maximized information gain using linear programming methods.

Abstract: A acoustic-penetrometer probe and method for determining the presence of materials in a region proximate the penetrometer probe through measurement of reflected acoustic waves, with the probe having a driving head on one end to permit forcing the driving head into the soil, with the probe including an acoustic generator mounted in the probe for generating a below-ground acoustic wave that normally travels away from the acoustic generator, and an acoustic detector located in the probe to measure acoustic waves reflected from objects or materials located proximate the probe to thereby provide a user with information on the presence of materials proximate a radial region located around the probe.

Abstract: The present invention utilizes the advantages of a switching regulator, such as, for example, the one shown in the National Semiconductor September 1992 publication, without the addition of additional complex control circuitry to provide a highly efficient controller for controlling the average optical output from a laser diode.

Abstract: A phase detecting system is provided for detecting when phase differences which occur between first and second clock pulses from a clock generator exceed acceptable tolerances, regardless of whether the first clock pulse leads the second clock pulse or the second clock pulse leads the first clock pulse. Two identical phase detectors are utilized each of which includes a phase detecting circuit, one group of signal delay elements that allow flip-flops in the phase detecting circuits time to set in order to detect the phase changes, and another group of signal delay elements coupled to the flip-flops which are set so the phase detecting circuit is capable of detecting the nominal phase delay times between the first and second clock pulses.

Abstract: A bus control and error detection system is provided for a bus system in which data and address signals are transferred between a microsequencer and a number of operational stations which are coupled to the bus. Tri-state drivers are employed in the microsequencer and in the stations which are constructed such that two of the three states of these tri-state drivers are utilized to provide the two states of binary logic operation, and the third state is a high impedance state that protects the components that are coupled to the bus during predefined abort condition which are detected in the system. An abort detection circuit is included in each of the operational stations which is coupled to receive control signals from the microsequencer and which is constructed to emit an ABORT signal output to the microsequencer when the control signals indicate that an abort condition has occurred for the associated operational station.

Abstract: A data protection and correction scheme is implemented by providing main and shadow stores for groups of data bits from a segmented data word. The data bits are divided into even and odd address groups for storage into even and odd storage sections. Each group of 3 bits from a 36-bit data word is supplied in uncomplemented form to even and odd address main stores and in a complemented form to even and odd address shadow stores. By storing the complemented parity bit with the uncomplemented data and the uncomplemented parity bit with the complemented data, the odd parity of the input data is converted to an even parity which may be checked upon read-out from the main store. If this parity test fails, the shadow store is accessed to supply the correct data. When a write address and a read address attempt to access the same storage address a conflict is detected and input data and parity are directly supplied to an output multiplexor.