Abstract: For a sensor network having reference nodes and sensor nodes, A method and apparatus using a distance determining algorithm for a sensor network having reference nodes and sensor nodes. A distance determining algorithm is executed to determine an adequate distance between reference nodes within a preset error range, and a position location table is created. A sensor node sends a location information request to reference nodes, receives the position location table and location information from the reference nodes, and computes the coordinates of its position. Alternatively, without requesting transmission of the position location table, the sensor node may receive calculated coordinates of its position directly from a reference node.

Abstract: A detection system and method. The inventive system includes an arrangement for receiving a frame of image data; an arrangement for performing a rate of change of variance calculation with respect to at least one pixel in said frame of image data; and an arrangement for comparing said calculated rate of change of variance with a predetermined threshold to provide output data. In the illustrative embodiment, the frame of image data includes a range/Doppler matrix of N down range samples and M cross range samples. In this embodiment, the arrangement for performing a rate of change of variance calculation includes an arrangement for calculating a rate of change of variance over an N×M window within the range/Doppler matrix. The arrangement for performing a rate of change of variance calculation includes an arrangement for identifying a change in a standard deviation of a small, localized sampling of cells.

Abstract: To cater for the positioning of an aircraft in a boundary zone between two adjacent multilateration systems, the controller (14) in one system receives Time Difference of Arrival data provided by the controller (15) in the second system. The controller (15) derives the TDoA data from time of arrival data provided by its receiver stations (9-13). By furnishing TDoA data the timings of the two systems do not need to be synchronised. The controller (14) uses the TDoA data and also time of arrival data from its local receiver stations (4-8) to perform a multilateration to determine the location of the aircraft (16).

Abstract: In one embodiment, an initial estimated location of a mobile electronic device is determined using a location determination method (LDM). An accuracy for the LDM is determined. An initial set of landmarks is determined based upon the initial estimated location and the determined accuracy. For each landmark in the initial set of landmarks, a likelihood is calculated that the mobile electronic device is located about that landmark. A landmark from the initial set of landmarks is selected based on the likelihoods. The location of the mobile electronic device is set to a known location of the selected landmark.

Abstract: Systems and methods for detecting global positioning system (GPS) measurement errors are provided. In this regard, a representative system, among others, includes a navigation device that is configured to receive GPS signals from signal sources, the navigation device being configured to calculate pseudoranges (PRs) and delta ranges (DRs) based on the received GPS signals, the navigation device including a consistency check algorithm that is configured to: determine mismatches between the respective calculated PRs and DRs, and indicate that an error exists in the respective calculated PRs and DRs based on their mismatch and mismatch accumulations. This algorithm can be independent of navigation state and is capable of detecting slow-changing errors.

Abstract: The antenna apparatus includes first to fourth antenna elements successively arranged at regular angular intervals around the central point on the same plane and respectively having first to fourth feed points, and a phase shifter delaying the phase of the received electric wave approximately by 90 degrees. The unidirectivity of the antenna apparatus is controlled in four directions of 0 degree, 90 degrees, 180 degrees and 270 degrees by selectively connecting the first to fourth feed points, the phase shifter and a television receiver. Therefore, multipath interference in these directions can be suppressed.

Abstract: A thin, light and soft electromagnetic wave absorber is disclosed exhibiting an excellent workability. The first conductor element group of a first conductor element layer consists of aligned cross conductor elements and square conductor elements in regions surrounded by cross conductor elements. A radio wave incident from the first conductor element layer side is received by each element, internally subjected to multiple reflection and then absorbed by a first loss material layer. Since the first conductor element group is realized by the cross conductor elements and the square conductor elements, receiving effect is enhanced and the radio wave can be collected with a high collection efficiency.

Abstract: A system and method for determining whether an estimated location of a wireless device includes one or more forged satellite measurements. An estimated location of the wireless device may be determined from signals received from a first set of satellites, and a set of residuals obtained as a function of the estimated location. The obtained set of residuals may then be compared to a reference set of residuals. If the comparison between the obtained set and reference set of residuals is less than a predetermined threshold, then the estimated location may be identified as having one or more forged satellite measurements.

Abstract: A radar level gauge (RLG) system and method for determining a filling level of a filling material in a tank is disclosed. The RLG system comprises a transmitter for generating and transmitting an electromagnetic transmitter pulse signal, a transmitter controller for controlling means for pulse width adjustment for adjusting the pulse width of the transmitter pulse signal in dependence of at least one application specific condition. Further, the system comprises a signal medium interface connectable to means for directing said transmitter pulse signal towards said filling material and for receiving a reception pulse signal reflected back from said filling material; a receiver for receiving said reception pulse signal from the tank; and processing circuitry for determining the filling level of the tank based on said reflection pulse signal received by said receiver. The application specific condition(s) is e.g.

Abstract: A method (200) and apparatus (100) for calibrating a global positioning system oscillator is disclosed. The apparatus may include a global positioning system receiver (120), a temperature compensated oscillator (130) coupled to the global positioning system receiver, a controller (140) coupled to the global positioning system receiver, and an offset module (150) coupled to the controller. The controller can control the operations of the apparatus. The offset module can send a calibration signal to the global positioning system receiver using values corresponding to an oscillator frequency rate of change vs. time.

Abstract: Embodiments of a switchable high-power transmit module to selectively provide a high-power microwave signal in excess of one kilowatt to one of first and second output paths are disclosed herein. The module includes a switch to receive a lower-power microwave signal from a source, a first ninety-degree coupler for directing power from the switch to first and second paths, a first high-power amplifier disposed in the first path, a second high-power amplifier disposed in the second path, and a second ninety-degree coupler to receive output signals of the first and second amplifiers. The switch is configured to selectively couple the lower-power microwave signal between first and second input ports of the first ninety-degree coupler.

Abstract: A system and methods for radar and communications applications. In one embodiment the present system comprises a wireless, space-fed, phased array of antennas including a plurality of unit cells. A first one of the unit cells includes a first one of the antennas and a unit cell command interpreter configured to receive a command, determine whether the command is intended for the first unit cell, and relay the command to logic for enabling a phase shift controller of the first antenna. In one embodiment the present methods comprise the step of wirelessly beaming microwave power from a power and control beam transmit unit to illuminate a wireless, space-fed, phased array of antennas including a plurality of unit cells. The method further comprises the steps of beaming a command to the array and converting the microwave power into direct current within a first one of the unit cells. The first unit cell includes a first one of the antennas.

Abstract: A radar apparatus transmits a pulse signal including pulses having at least two different pulselengths in a specific transmit pulse pattern and receives a returning echo signal through a single antenna. A tuning voltage setting timing generator generates a timing of setting a tuning voltage according to a combination of transmission pulselengths and a tuning processor performs tuning operation in a manner suited to a current transmission pulselength based on the tuning voltage setting timing. The radar apparatus may include a tuning voltage alteration decider for deciding whether or not to alter the tuning voltage based on a combination of alternate pulselengths before altering the pulselength of the pulse signal generated by a transmitter and the tuning processor alters the tuning voltage based on the result of decision made by the tuning voltage alteration decider.

Abstract: A method for the detection of moving objects by SAR images envisages the steps of: generating a pulse-repetition frequency signal starting from a radar signal; and generating a sequence of SAR images starting from the pulse-repetition frequency signal. In particular, SAR images with low azimuth resolution are generated by of coherent integration of the pulse-repetition frequency signal for a sub-aperture time shorter than an aperture time. In addition, the method envisages generating difference images through point-to-point difference between subsequent low azimuth resolution SAR images, and recognizing patterns associated to moving objects in the difference images.

Abstract: The invention relates to an FMCW radar system and a method of operating an FMCW radar system to produce a linear frequency ramp. The FMCW radar system includes a VCO, a frequency divider coupled to the VCO output, followed by an A/D converter. A down-converter shifts the digitally converted signal to baseband samples, followed by a low-pass filter coupled to an output thereof. A VCO frequency estimator produces instantaneous VCO frequency estimates from phase differences determined from the filtered baseband samples. A D/A converter coupled to an output of the VCO frequency estimator produces an input signal for the VCO to produce therewith a linear VCO frequency ramp. A ?-? modulator is coupled between the VCO frequency estimator and the input of the D/A converter to produce a dithered VCO control signal, thereby increasing the effective number of bits of the D/A converter.

Abstract: Apparatus having corresponding methods and computer-readable media comprise a receiver adapted to receive a plurality of single-frequency network (SFN) signals at a predetermined frequency; a correlator adapted to correlate the SFN signals with a predetermined reference signal, wherein correlating produces a plurality of correlation peaks; a grouper circuit adapted to group the correlation peaks into arrival groups such that the correlation peaks in different arrival groups are known to be from different transmitters; and a selection circuit adapted to select the earliest correlation peak in each arrival group as a leading correlation peak.

Abstract: A multi-channel, dual-band, radio frequency (RF) transmit/receive (T/R) module, for an active electronically scanned array, is provided. The module includes a compact, RF manifold connector and at least four T/R channels. Each of the T/R channels includes a notch radiator, a diplexer coupled to the notch radiator, a power amplifier, including at least one dual-band gain stage, coupled to the notch radiator, a low noise amplifier, including at least one lower-band gain stage and at least one upper-band gain stage, coupled to the diplexer, and a T/R cell, including a phase shifter, a signal attenuator and at least one dual-band gain stage, coupled to the power amplifier, the low noise amplifier and the manifold connector.

Abstract: A hovering helicopter has a radar transmitter/receiver for transmitting radar pulses for illuminating a target for SAR imaging, and rotor blades for generating lift. Radar reflectors are on the rotor blades. The radar reflectors are oriented to reflect the radar pulses from the transmitter to the target as the rotor blades rotate. The radar pulses reflected by the moving reflector from the transmitter are timed to generate the synthetic aperture image using radar returns from the target. The receiver also receives blade returns directly reflected from the moving reflectors attached to the lift rotor blades. The receiver analyzes the blade returns to extract motion details of the reflectors and uses the motion details for motion compensation of target returns for SAR imaging.

Abstract: An example radar system for a vehicle comprises a radar antenna, operable to produce a radar beam, and a lens assembly including at least one active lens, the radar beam passing through the lens assembly. The radar beam has a field of view that is adjustable using the active lens. In some examples, the active lens comprises a metamaterial, the metamaterial having an adjustable property such as an adjustable negative index, the field of view being adjustable using the adjustable property of the metamaterial.

Abstract: A radar system is configured to predict future storm cell characteristics and display an indication of the characteristics on an electronic display. The system has an antenna configured to receive radar returns from radar scans of storm cells. The system includes processing electronics configured to determine a characteristic of a first storm cell from the radar returns and identify at least one second storm cell. The at least one second storm cell is in the same weather system as the first storm cell. The processing electronics are configured to determine the characteristic for the at least one identified second storm cell, compare the characteristic of the first storm cell with the characteristics of the at least one second storm cell, determine a growth rate of the first storm cell, and calculate a predicted height of the first storm cell at a future time based on the comparison and determined growth rate.