Abstract: A radiation absorber which is placed on the irradiated side of a conductive surface (L) whose surface resistance <0.1 &OHgr;/square. The radiation absorber comprises three layers, which from said conductive surface outwards consist of a first dielectric (B1), a resistive layer (C1) and a second dielectric (B2). The surface resistance of the resistive layer is 225 &OHgr;/square±25% and the thickness of the layer without a possible carrier <0.2 mm. The dielectric constant &egr;=2±25% for the two dielectric layers and their thicknesses are of the same order of magnitude. The total thickness dA of the absorber, with all the layers included, is selected according to the formula d A = 1 ϵ · λ 4 in order to give an absorption peak at a desired wavelength &lgr; expressed in meters.

Abstract: An apparatus for identifying a buried object using ground penetrating radar (GPR) in a system containing at least one GPR sensor, comprises a data processor for detecting spatial correlations in data received from a GPR sensor in the apparatus and an image processor capable of building a data structure corresponding to an image of the buried object from data processed by the data processor. A method for identifying a buried object using GPR in a system containing a GPR sensor comprising detecting spatial correlations in data received from the GPR sensor in the system and building a data structure corresponding to an image of the buried object from the received data.

Abstract: An imaging system uses wideband ‘RF daylight’ created by plural narrowband RF illumination sources, to passively generate spectrally different sets of RF scattering coefficients for multiple points within a prescribed three-dimensional volume being illuminated by the narrowband RF transmitters. To correct for the lack of mutual coherence among different RF illumination sources, the respective sets of scattering coefficient data are applied to a cultural feature extraction operator, to locate one or more strong cultural features spatially common to multiple images. For spatial points along the extracted cultural feature theoretical scattering coefficients are calculated. Differences between phase values of these calculated scattering coefficients and those of the collected and processed scattering energy are used to modify the measured scattering coefficient values for all spatial points in the illuminated region.

Abstract: A compact, autonomous motion detecting and alerting system alerts to the movement of objects of interest. Mounted on an environmentally sealed PC board are a transceiver such as a CW radar front-end, connectors, signal processors and a communications device. The system provides early warning of movement of an ice sheet or rubble field via the communication device that may be a cellular telephone. This system is mounted proximate the target surface under observation, oriented at pre-specified offset angles both laterally and in elevation. The target is illuminated and energy reflected therefrom is mixed with a portion of the transmitted signal to produce a difference frequency signal that is processed to establish existence of motion within a pre-specified velocity range. Upon verification of motion, notification is sent to a responsible authority. An autonomous or semi-autonomous power source and integral power management function may be incorporated on the same PC board.

Abstract: A radar device set on an automobile includes a transmitter for transmitting forward a beam of electromagnetic waves, a receiver for receiving reflected waves of the transmitted beam from a vehicle traveling in front, a measuring device for measuring a distance to the vehicle in front based on outputs from the receiver and a command outputting device for outputting a specified command signal when the distance measured by the measuring device is decreasing and reaches a threshold distance below which the measuring device becomes incapable of measuring the distance from the outputs from the receiver, and a beam adjusting device for changing either the elevation angle of the beam or its angular range of vision in response to the command signal.

Abstract: The present invention relates to a circuit and method for generation of trigger signals for a radar level gauging systems. A pulse-width modulator, has an input connected to a pulse-repetition-frequency generating oscillator. A monostable multivibrator, has an input connected to an output of the pulse-width modulator. First and second integrators are connected to an output of the pulse-width modulator and the monostable multivibrator respectively. A voltage summation element, is connected to an output of the first and second integrators respectively and at least one control signal input. A servo regulator provides a control loop between an output of the voltage summation element and a control port of the pulse-width modulator. A reference clock output is provided at the output of the monostable multivibrator and a second clock output is provided at the output of the pulse-width modulator.

Abstract: An automotive radar test system includes circuitry for multiple down and up conversions of a signal from the automotive radar. Conditioning circuitry delays an intermediate frequency signal (IF2) obtained after a second down conversion to simulate the delay of a return signal from an object located a particular distance from the automotive radar, and to attenuate the IF2 signal to simulate variable target sizes, and to generate a Doppler shift in the IF2 signal to simulate target speed. The conditioned signal is up-converted and transmitted back to the automotive radar system to determine if the automotive radar provides accurate readings for distance, size and speed. The radar test system further couples the second IF signal to a spectrum analyzer to determine if the automotive radar is operating in the desired bandwidth and to a power meter to determine if the automotive radar is transmitting at a desired power level.

Abstract: The invention provides a magnetron drive circuit which drives a magnetron to produce a generally rectangular-shaped narrow transmission pulse having sharply shaped rising and falling edges. The magnetron drive circuit includes a nonlinear load circuit and an active damper circuit. The nonlinear load circuit becomes on at around 80% of a peak output voltage of a pulse transformer (at which the magnetron begins to oscillate) is connected to a secondary winding of the pulse transformer in parallel with the magnetron. The active damper circuit absorbs residual energy left in the pulse transformer without any need for an absorption resistor conventionally connected between both ends of a primary winding of the pulse transformer.

Abstract: A system for tracking objects outdoors. Tags attached to objects such as trailers include GPS receivers. Tags transmit uncorrected position and satellite data to a base station, where differential corrections are applied, providing 2-5 meter accuracy of the position of the tag and object. Tags are on a low duty cycle. When a tag powers on, it receives accurate time and current satellite data from the base station, enabling the tags to acquire the satellite signal quickly and with minimum power consumption. When a tag is out of base station range, the tag periodically calculates and archives its position. The tag may also include Real Time Locating Systems technology, to enable tracking to continue when the tag moves indoors and becomes inaccessible to GPS satellite signals.

Abstract: A privacy enhancement device for electronic device such as a cellular telephone. The privacy enhancement device may include a jammer which may produces false information, e.g. false information indicative of pseudo ranges. In addition, the navigation information used on the position detecting device may be locally stored versions of dynamically changing information. The navigation operation may be carried out using a Web service.

Abstract: The phase difference between a known stable reference signal (11) and a known signal output by a wireless mobile communication device (5, 5B) is determined at several known locations (1-4, 1B-4B). The location of the wireless mobile communication device is then determined from the phase difference information. Also, the approximate location of a wireless mobile communication device (5A) can be estimated by transmitting a message from the device at a predetermined power level (71), and determining where among a plurality of predetermined locations (1A-4A) the transmitted message has been received.

Abstract: A system and method are provided that includes at least a pair of spaced antennas having overlapping fields of view. The system further includes at least a pair of receivers respectively coupled to the pair of antennas. Each of the receivers includes a spectral separator having a plurality of output signals. Each of the output signals represents a signal value at one of a plurality of predetermined frequencies. A plurality of analog to digital converters are coupled to a corresponding one of the spectral separators for respectively providing a digital representation of each of the output signals. A digital processor coupled to an output of each of the plurality of analog to digital converters calculates an angle of arrival of the transmitted signal in at least one dimension from the digital representations.

Abstract: The invention is a method of calibrating the sensor system of a wideband direction finder using a noise source. The sensor system includes at least two wideband tuners, and an analog/digital (A/D) converter connected to each wideband tuner. The calibration method involves selecting a common set of center frequencies for each of the wideband tuners. The wideband tuners receive a signal from the noise source on a per data frame basis. The passband of the received signal is then divided into a number of time-sampled data frames. For each time-sampled data frame, both a gain variation and a phase variation are calculated for the noise received at each wideband tuner. Gain and phase differences between the signal received by each wideband tuner within the same frame are compared. Based on the time-sampled data collected, the phase and gain differences for the signals received at the tuners which have not been previously mapped can be determined.

Abstract: An impulse radio system estimates a separation distance between an impulse radio transmitter and an impulse radio receiver. The system includes an impulse transmitter that transmits an impulse signal having an ultra-wideband frequency characteristic. An impulse receiver spaced from the transmitter receives the transmitted impulse signal and measures a signal strength of the received impulse signal. The receiver estimates the separation distance based on the measured signal strength. The receiver classifies a signal propagational/multipath environment using the received impulse signal, and then selects a radio propagation path loss model corresponding to a classified multipath environment. The receiver translates the measured signal strength to a separation distance based on the selected radio propagation path loss model.

Abstract: A dielectric-patch resonator antenna having a resonator formed from a dielectric material mounted on a ground plane with a conductive skirt, and a patch element disposed inbetween. The ground plane and patch are formed from conductive materials. First and second probes are electrically coupled to the resonator for providing first and second signals, respectively, to or receiving from the resonator. The first and second probes are spaced apart from each other. The first and second probes are formed of conductive strips that are electrically connected to the perimeter of the resonator and are substantially orthogonal with respect to the ground plane. A dual band antenna can be constructed by positioning and connecting two dielectric resonator antennas together. Each resonator in the dual band configuration resonates at a particular frequency, thereby providing dual band operation. The resonators can be positioned either side by side or vertically.

Abstract: Antennas for a communications device and wireless terminals are provided. A conductive element is provided along with a ground assembly including a ground element coupled to the conductive element. The ground element has a first state and a second state. The first state provides a first resonant frequency band when the ground element is in a first relative position that is a first distance from the conductive element. The second state provides a second frequency band when the ground element is in a second relative position that is a second distance, different from the first distance, from the conductive element.

Abstract: An antenna element is formed with an extended portion, bent in a U-shape, in at least one of a first conductor and a second conductor of a conductive path. This structure permits the conductive path to be extended without increasing the size of the overall shape, so that the overall shape of the antenna element can be made compact without relatively extending the conductive path.

Abstract: The invention is a planar antenna which comprises a plurality of antenna elements positioned relative to each other in a predetermined orientation. Each of the elements is selectively electrically connectable to one or more of the other antenna elements. A plurality of switches electrically connect the plurality of antenna elements to each other. The switches are opened and closed by a signal operating at high speed enabling the antenna to act alternately in a first antenna configuration and a second antenna configuration using the same antenna structure. Doppler signals from the first and second antenna configurations are processed to determine the direction of a person or object in relation to a door.

Abstract: An antenna element has parallel first conductor and second conductor connected by a short-circuit conductor to form a loaded inductance. A ground conductor is also formed on an outer surface of a device substrate which is formed with a conductive line comprised of the first conductor, second conductor and short-circuit conductor. The ground conductor has a terminate end connected to the conductive line, and is applied with a ground potential at a leading end. Since the ground conductor functions in a manner similar to a conventional short pin, the antenna element can provide a radiation resistance twice as much.

Abstract: A near-field plasma reader detects magnetic induction interference with objects having corresponding sensed loops to provide detection and communication between the reader and objects incorporating the sensed loops. The plasma reader has two or more plasma loop sensors in different orientations that are sequentially switched to scan across a range of directions without interference from adjacent loop antennas. The plasma reader is used for inventorying items, store checkouts and other wireless transactions.

Abstract: A transmission/reception apparatus has a first housing, a second housing, a folding section connecting the first and second housings, a first earth circuit board that has antenna circuitry thereon and that is provided with the first housing, a second earth circuit board that is provided with the second housing, and a flexible conduction member for connecting the first and second earth circuit boards. The first and second earth circuit boards and the flexible conduction member constitute an antenna apparatus, and during use of this antenna apparatus, a predetermined earth pattern length can be established by the first and second earth circuit boards.

Abstract: Electronic key reader includes a protective metal housing member having a front surface with a center and edges. At least one slot extends from at least one of the edges to the center of the front surface.

Abstract: A flexible interrogator antenna design having a single antenna with an inner and an outer antenna coil positioned in a flat, flexible, rectangular housing or mat which can be positioned in a configuration having two sides and a top across an easily erected temporary frame to form a walkthrough corridor or chute through which livestock having an attached transponder can be driven. The antenna is driven to generate multi-directional electromagnetic fields in each of an ‘X’, ‘Y’ and ‘Z’ axis associated with the walkthrough to detect transponders coming into the fields, regardless of transponder orientation.

Abstract: A dual band antenna feed is made with an embedded waveguide structure to enable combining of Ka and Ku band signals without the need for an additional cavity-type filter. The antenna feed includes a Ka and Ku band interface section (22) with two Ka band vertical polarization waveguide sections (31) and (32), and a single Ku band waveguide section (34) which carries both vertical and horizontal polarization Ku band signals. The opposing walls (36-37) of the Ku band waveguide (34) carrying the vertical polarization Ku band signals are transitioned to step down from an input section (40) to successively smaller dimensioned sections (41-44), and then to step back up in successively larger dimensioned sections (45-47) to an output section (48). The two Ka band sections (31-32) are fed into openings in Ku band section.(46), on opposite sides of the opening for the Ku band transition section (45). The output section (48) then provides a combined Ka band vertical and Ku band horizontal and vertical signals.

Abstract: A dielectric fill disposed in a waveguide is used to form an antenna feed. One attribute of the dielectric fill is to enable a reduction in aperture size that in turn increases the beamwidth. More specifically, an RF signal received or transmitted at the end of the waveguide can have a wider half-power beamwidth angle than otherwise achieved without the dielectric filling the waveguide. A portion of the dielectric fill may protrude beyond the end of the waveguide to match the waveguide to free space. If the waveguide section is cylindrical in cross-section, a transformed section formed of an annular dielectric ring may be used to match the feed to a rectangular waveguide.

Abstract: An optical antenna collects, modifies and emits energy at light wavelengths. Linear conductors sized to correspond to the light wavelengths are used. Nonlinear junctions of small dimension are used to rectify an alternating waveform induced upon the conductors by the lightwave electromagnetic energy. The optical antenna and junctions are effective to produce harmonic energy at light wavelengths. The linear conductors may be comprised of carbon nanotubes that are attached to a substrate material, which may then be connected to an electrical port.

Abstract: A method for modulating the amplitude of an antenna signal applied to an inductive-type antenna circuit by a control circuit having binary ports that can be set to high impedance and with a non-zero internal resistor. The signal providing the electric power supply of the antenna circuit is delivered by at least two ports of the control circuit, and the amplitude of the antenna signal is modulated by changing the output state of at least one of the ports. Particularly applied to contactless smart card readers.

Abstract: A display device is achieved using a simplified optical system which generates an expanded exit pupil without compromising magnification or resolution. Modulated light from a source is converged toward a focal point by an optics subsystem. A scanning subsystem deflects the converging light, and thus the focal point, along a raster pattern to define a curved intermediate image plane. An exit pupil expanding apparatus defines a curved surface which coincides with the curved image plane. Impinging light rays at a given instant in time span a given incidence angle. Exiting light rays span a larger angle. As a result, the exiting light spans a larger surface area of an ensuing eyepiece. In turn an expanded exit pupil occurs beyond the eyepiece. Embodiments of the expanding apparatus include a curved diffractive optical element, fiber optic face plate, lens array and diffuser. The diffractive optical element generates multiple exit pupils, while the other embodiments generate enlarged exit pupils.

Abstract: A tactual computer monitor includes rows and columns of rectangular cells. Each cell includes four rows and two columns of movable pins which are felt and read by a blind person. The pins are driven by electromechanical impact drivers and are held in position by resilient elastomeric cords. The impact drivers are carried on a bi-directional printhead which travels beneath the movable pins. An erasing mechanism is provided to positively drive the pins downwardly to erase the characters produced by the printhead.

Abstract: A transmissive display device using a micro light modulator that is capable of improving a light efficiency. In the display device, light-path converting members are provided on stationary members to change a path of a light inputted obliquely through stationary members and movable members vertically with respect to a display screen.

Abstract: An optically addressed direct view photo luminescent display having a phosphor panel having multi-color pixelated surface with molecularly aligned materials therein and a printed bar code pixel identifier on an internal side for providing feedback of scanning beam to pixel registration.

Abstract: An internal field activated display sheet is disclosed which comprises a medial plane disposed between reservoirs in the display sheet. The reservoirs communicate with each other through apertures in the medial plane, which includes a plurality of conductors. At least one of the reservoirs is filled with a liquid means, which is responsive to a peristaltic internal field developed within the medial plane. Applying a field across selected apertures in the medial plane causes the liquid means to be electrically pumped from one reservoir into the other, thereby displaying an image.

Abstract: A display device operable to generate images and a border image is disclosed. The display device in one example of the invention comprises an electrode structure coupled to a spatial light modulator display layer. The electrode structure is configured to define an active display area. The display also comprises a first electrode surrounding the electrode structure and a second electrode coupled to the spatial light modulator display layer. The second electrode is located above the first electrode and a voltage difference between the second electrode and the first electrode is used to generate the border image.

Abstract: A switching electrode connected to a switching element is provided on a first substrate. An opposing electrode, an insulation film, and a plurality of sub electrodes are provided on a second substrate. Moreover, a resistant film is provided on a first substrate. A switching electrode which is connected to the switching element and an electrode which is not connected to the switching element are provided on the resistant film. An opposing electrode which is not connected to the switching element is provided on the second substrate. Furthermore, a first electrode which is connected to a first switching element and a third electrode which is not connected to the switching element are provided on the first substrate. The first and third electrodes are opposed to the second electrode, which is connected to a second switching element, via an insulator. The opposing electrode which is not connected to the switching element is provided on the second substrate.

Abstract: Eight-bit digital image data of R, G and B output from an image data memory are corrected by conversion controllers to meet characteristics of a liquid crystal panel. The corrected data are input to a liquid crystal drive circuit as digital image data, and an image is displayed on the liquid crystal panel. A LUT stored in a LUT reference processor stores data (addresses) by a number that makes it possible to refer to input image digital data at one to one. A random number generator is for generating random numbers and supplying the random numbers to a round-to-integer processor as threshold value data. The round-to-integer processor compares the data referred to by the LUT reference processor with the threshold data, and carries out a round-to-integer processing.

Abstract: Provided is a liquid crystal display device capable of independently adjusting gradation for each of RGB. A control circuit outputs a clock signal, an image signal for each of RGB, and an adding circuit control signal. A gradation voltage generation circuit outputs a gradation voltage. A color correction voltage for each of RGB is generated in a color correction voltage generation circuit based on an input signal for color correction. A signal electrode drive circuit receives the clock signal, a control signal, the image signal, the adding circuit control signal, the gradation voltage, and the color correction voltage. A gradation voltage corresponding to a gradation value of the image signal for each of RGB is selected from the gradation voltage. The color correction voltage for each of RGB is added to the gradation voltage, then a sub-pixel data signal is generated and sent to a liquid crystal panel.

Abstract: A system and method for using gamma correction in a ferroelectric liquid crystal (FLC) display uses a reduced number of different increment values for generating a Vramp signal for the FLC display without noticeably increasing error. The increment values are based upon an inverse gamma curve having a selected gamma value. Using linear interpolation, the increment values are calculated with more increment values being calculated for the beginning of the curve than the flatter end portion of the curve. In addition, an illumination period and a balance period are used so that each pixel of the FLC display is on and off for the same amount of time. As a result, the average voltage across the FLC material is 0V.

Abstract: An active matrix liquid crystal display device comprising display elements (10) addressed via sets of row and column address conductors (14, 16) connected respectively to row and column drive circuits (30, 35) and with the column drive circuit (35) being operable to transfer data signals for the display elements of a row to groups of column address conductors (16) in sequence in respective group address periods in a multiplexing manner. The occurrence of undesirable display artifacts is alleviated by applying, during the group address period for one group, a pre-charging signal to the adjacent column address conductor of the next-addressed group according to the level (magnitude) of a data signal for a column conductor in that one group.

Abstract: A 3D encoder includes a body having several pin cavities. Several pins are also provided, wherein each pin is located within one of the pin cavities and wherein each pin is capable of sliding movement within its pin cavity. Each of the pins is capable of being displaced by contact with a surface of a 3D object to be encoded. A sensing mechanism is provided to determine an amount by which each of the pins is displaced due to contact between that pin and the surface of the 3D object. A computer can be used to translate displacement data into a 3D mapping representative of the 3D object being encoded. A method of creating a computerized representation of a 3D object is also provided and includes placing a 3D object in communication with a plurality of pins to deflect a position of each of the pins contacting the 3D object in an amount corresponding to a shape of a surface of the 3D object.

Abstract: A computer input device having a housing and an engagable scroll wheel. The scroll wheel is rotatable about an axis to preferably cause vertical scrolling of an image on a display. The rotatable member is laterally movable relative to the housing. A sensor is preferably positioned within the housing for sensing lateral movement of the rotatable member. In response to sensed lateral movement of the rotatable member, the image is horizontally scrolled, preferably in the direction of the lateral movement. The scrolling speed can be affected relative to the amount of displacement of the rotatable member and/or the amount of time that the rotatable member is displaced a predetermined amount. The computer input device having the rotatable member may take the form of a keyboard, a mouse, a trackball device, or another type of computer input device.

Abstract: A slide switch includes a case member; a slide member movable within a planar range of movement, conducting elements formed between the case member and the slide member, and an elastic member for holding the slide member in a neutral position where the conducting elements are non-conductive. The elastic member is an integral unit having a holding portion engaged with the slide member, and projecting portions extending from the holding portion along the planar range of movement toward inner walls of the case member. The conducting elements include contacts arranged on the inner wall of the case member, and conductors arranged on the holding portion of the elastic member. The conductors of the elastic member are movable into contact with the contacts of the case member by an external force for moving the slide member away from the neutral position against a biasing force of the elastic member, and separable from the contacts by the biasing force of the elastic member when the external force is removed.

Abstract: A communication terminal apparatus includes a communication section that controls communication to a destination and a browser that analyzes hypertexts, and displays an image in accordance with the analyzed hypertexts on a display, the image having at least an input field. Hardware keys are configured to input numbers and characters, and are selectively operable in a first mode to input a destination number to the communication section in order to communicate with the destination, and in a second mode to input data to the input field. A controller controls a status of the hardware keys in one of the first and second modes. The controller controls the hardware keys to input data to the browser when an input position is in the input field, and controls the hardware keys to input a destination number to the communication section when the input position is out of the input field.

Abstract: A powered touch screen input device is perpetually self-powered and free of any mechanical connection to the touch screen itself. The input device includes at least one photovoltaic cell supported thereon and disposed to receive light from the display screen associated with the touch screen device. The photovoltaic cell is connected to the electronic signaling circuit disposed within the input device. The input device comprises a stylus having a proximal tip connected to the electronic signaling circuit to generate or receive actinic radiation and interact with the touch screen device. A bezel extends about the barrel to enclose the photovoltaic cells and direct light from the display screen to the cells. Alternatively, RF energy may be transmitted to an antenna in the input device and rectified to drive the electronic signaling circuit.

Abstract: When charging at a voltage with a polarity different from that of a voltage charged in the capacitive display element, by turning the switch ON, after carrying out a charging/discharging to modulate the both electrodes of the capacitive display element to the ground potential, the same is charged at a voltage with another polarity. As compared with the case where the charging/discharging between the positive power supply voltage +VM and the negative power supply voltage −VM is made directly, the electric power consumption can be reduced to ½ when the same is once modulated to the ground potential 0V. The electric power consumption can be further reduced by modulating the intermediate potential in a plurality of steps.

Abstract: A programmable controller having a processing unit, a screen, a control panel, and signal inputs and outputs, all of which are accommodated in a common housing. Switching functions can be programmed by the user via a menu-driven user interface on the screen. The status display is capable of being switched between an active and an inactive display status of the screen.

Abstract: A difference in sampling data of continuous two pixels in a digital image signal is detected. A CPU monitors the value of an output signal and determines a control value of a control signal so as to make the difference greatest. In a sampling clock generation section, a sampling clock that is synchronous to a dot clock by a synchronous signal and the control signal is generated. When the difference becomes greatest, it is possible to sample an image signal level that is less susceptible to influences from rounding, and consequently to adjust the phase of the sampling clock without an input signal having a specific pattern.

Abstract: A matrix-type display device has a matrix display panel, a frame memory, and a graphics memory. Input image data are temporarily buffered in the graphics memory, then transferred to the frame memory and read out to drive the matrix display panel. Readout from the frame memory is cyclic, and is synchronized with a frame synchronization signal. A synchronizing circuit also synchronizes the transfer of data from the graphics memory to the frame memory with the frame synchronization signal, so that each displayed frame is generated from a single frame of image data, and not from parts of two different frames. Moving images can therefore be reproduced faithfully. This matrix-type display device is useful in mobile information-terminal equipment, such as mobile telephone sets.

Abstract: A three-dimensional display is provided that simplifies the display system and reduces hardware costs by using a predetermined mask unit positioned before the display screen of a CRT displaying an image. The three-dimensional display includes a synthesis unit, display unit, and mask plate. The shift circuit of the synthesis unit shifts the images of the perspective cameras from the image of the reference camera, while the mapping circuit combines the reference image and the shifted images of the cameras. Further, the filter circuit removes unnecessary pixels from the synthesized image, then the sync signal insertion circuit inserts a horizontal sync signal and vertical sync signal to produce a synthesized image. This synthesized image is displayed on the CRT display screen of the display unit. Light from the images captured by the cameras is focused at the viewing perspectives P1, P2, and P3 by the holes of the mask unit.

Abstract: A technique for the realistic simulation of visual scenes uses voxels generated from positional and elevational data combined with a stored color map to generate vertex and triangle data that is used by an accelerator card to render a visual scene on a display device. In this manner, the invention provides rendering efficiency and speed for highly detailed visual scenes while preventing overdraw.

Abstract: A method of indexing spatial object data comprises dividing space that contains objects based on the clustering of the objects within the space. A computer readable medium contains computer executable instructions. The instructions cause the computer to divide a space containing spatial objects based on clustering of the objects within the space. A method of searching spatial object data includes utilizing spatial object data that has been gridded based upon clustering of the spatial objects. The grids are then recursively checked to see if they cover a range of interest. If the grids overlap the range of interest objects within the grids are checked to see if they satisfy a search criterion.