Abstract: A guided wave radar level measurement instrument comprises a probe defining a transmission line for sensing material level. A pulse circuit is connected to the probe for generating pulses on the transmission line and receiving reflected signals from the transmission line. The pulse circuit comprises a pulse generator for generating a transmit pulse, a bridge circuit having a diode switched front end connected between the pulse generator and a differential circuit. The transmission line is connected to one side of the differential circuit. Generated pulses from the pulse generator are supplied to both sides of the differential circuit and reflected signals from the transmission line are supplied to one side of the differential circuit.

Abstract: A Doppler radar system that avoids blind ranges, range ambiguities, blind speed and/or Doppler ambiguities. Pulse width, repetition interval and pulse type are varied from pulse to pulse within a coherent processing interval.

Abstract: A method for determining a height above ground of an aircraft broadly comprises the steps of generating a transmit signal with a transmitter, transmitting the transmit signal with a first antenna, generating a local oscillator signal with a local oscillator, receiving a receive signal with a second antenna, mixing the receive signal with the local oscillator signal to generate a baseband signal, determining a frequency of interest of the baseband signal, and calculating an aircraft altitude corresponding to the frequency of interest.

Abstract: A system and methods for co-site and multi-path interference mitigation are presented. A reflection signal is received from at least one aircraft surface at a sensor near a receiver antenna, and a conformal reflective phased array antenna coupled to at least one aircraft surface is configured to steer the reflection signal. The reflection signal is steered using the conformal reflective phased array antenna to reduce an amplitude of the reflection signal at the receiver antenna based on the reflection signal received at the sensor.

Abstract: A signal generating circuit includes an oscillator to produce an oscillation signal controlled in oscillating frequency by an analog control signal. The circuit includes: a digital phase detector detecting phase information of the oscillation signal and outputting digital phase information; a first differentiator differentiating the digital phase information and outputting digital frequency information; a comparator comparing a frequency setting code setting the oscillating frequency with the digital frequency information and outputting digital frequency error information; and a low-pass filter removing a high-frequency component of the digital frequency error information.

Abstract: AltBOC-modulated satellite navigation signals transmitted in the two partial bands E5a and E5b of the so-called E5 frequency band are received using a common antenna (19) and thereafter are processed separately in an analog manner in the HF front-end in two physically different incoming signal paths for the two partial bands and then digitized and coherently summed to form a complete digital E5 band signal, which is fed to a digital signal processor, in which code acquisition and code tracking are performed using PRN reference code sequences produced in the receiver and tracking of the carrier phase is performed and raw data for the final navigation calculation are determined therefrom.

Abstract: A holographic imaging system including a transmission line coupled to an antenna at one end and to a signal source at another end. The antenna defines an aperture through which a signal generated by the signal source is transmitted incident to an object located remotely from the aperture and through which a signal reflected from the object is received by the antenna aperture. A standing wave probe phase-referenced to the antenna aperture samples the reflected signal. A detector connected to the standing wave probe receives the sampled reflected signal and provides an output signal that represents a real-valued signal proportional to an in-phase component of the reflected signal from the object. A processor executes an imaging algorithm for generating a multi-dimensional profile representative of the object based on the output signal from the detector.

Abstract: A method of synthetic aperture radar autofocus for ground penetration radar. The method includes transmitting a signal via an antenna; receiving a reflected signal comprising a plurality of image blocks via the antenna; reading each image block from the reflected signal via a processor; locating prominent targets in each image block via the processor; estimating ground penetration phase error via the processor in each image block via phase error inputs including pulling range and quantization level by generating a 1D phase error and converting the 1D phase error into a 2D phase error of an image spectra; refocusing each image block according to estimated ground penetration phase error for that image block via the processor; and forming an image mosaic comprising each refocused image block via the processor.

Abstract: A direct-to-digital software defined radar system includes a high-speed digitizer coupled directly to a receive antenna and outputs a digital signal to a processor which receives the digitized signal, along with an arbitrarily-defined reference signal provided by signal generator, and indexes the signal data according to time and geo-location, arranges the data according to a three-dimensional data structure, declutters and filters and refines the data for storage or display.

Abstract: The present invention relates to a method of verifying a measurement accuracy of a level gauge system. The method comprises determining a first measurement value indicative of a time-of-flight of a first electromagnetic reflection signal to a reference reflector and back; determining a measurement unit verification measurement value based on a response signal from a verification arrangement; determining a second measurement value indicative of a time-of-flight of a second electromagnetic reflection signal to the reference reflector and back; and determining a verification result based on the first measurement value, the second measurement value and the measurement unit verification measurement value. Through embodiments of the present invention, it will be verified that the measurement unit is functioning correctly and that level gauge system works as it should also after being reconnected to the propagation device.

Abstract: A method for determining the filling level of a product in a tank using electromagnetic signals, comprising: a) generating a transmission signal having a predetermined length; b) propagating the signal towards the product; c) receiving a reflected signal; d) determining whether the received signal overlaps the transmitted signal in the time-domain; e) setting an overlap-parameter to 1 if overlap is detected, otherwise setting the overlap-parameter to 0; if the state of the overlap parameter is not changed and if no overlap is detected, generate a signal having a length exceeding the previous length and repeat step b); and if the state of the overlap-parameter is not changed and if an overlap is detected, generate a signal having a length shorter than the previous length and repeat step b); and if the state of the overlap-parameter is changed, determine the filling level based on the length of the transmitted signal.

Abstract: A method for detecting a message provided with a preamble with a number of pulses in a signal sent by an interrogator or a transponder in mode S, said method including a step for decomposition of said signal into an amplitude signal and into a complex phase signal, a step for detection of said preamble by correlating the amplitude signal with a replica signal of the expected pulses, and a phase control step executed by adding together the samples of the phase signal for the duration of the pulses of said preamble and by comparing the sum obtained with a threshold. The method may include a step for time synchronization by correlation of the complex phase signal with a reference sequence formed by one or more known bits before the decoding of the data. The method applies notably to the decoding of interrogation messages borne by low-power signals.

Abstract: A weather radar system is coupled to a weather radar antenna. The weather radar system includes a processor for combining or summing portions of the radar return data to obtain a null. The processor associates the null with the ground (e.g., steers the null toward ground or processes data so that the null corresponds to ground) to obtain a null to alleviate ground clutter when sensing weather. The null can be a single null or multiple nulls associated with different ranges.

Abstract: A radar system including a switching mode power converter. A pulse radar unit is configured to transmit RF pulses with a pulse repetition frequency. The power converter includes a switching controller that is configured to control at least one switching element. The switching controller is configured to receive a frequency modulated input signal. The modulation frequency of the input signal is configured to be derived from the pulse repetition frequency of the radar unit.

Abstract: Phase noise analyzing system that analyzes phase noise in radio frequency (RF) signals provided by a device under test when coupled thereto includes a low noise receiver that receives at a first input, signal from the device under test when coupled thereto, a low noise synthesizer that provides output to the receiver, a frequency domain analyzer that receives output from the receiver, a time domain analyzer that receives output from the receiver, a switching system that controls signal flow to and from the receiver, the synthesizer, the frequency domain analyzer and the time domain analyzer, and a computer that controls the switching system to perform the analysis of phase noise in signals provided by the device under test.

Abstract: A system for displaying vertical weather information on an aviation display aboard an aircraft, the aircraft including an aircraft radar system for scanning a target, is provided. The system includes processing electronics configured to receive a target selection from a user input device, to receive an altitude value of an echo top of the target based on radar return data, and to cause the altitude value to be displayed on plan view of weather images on an aviation display in response to the received target selection.

Abstract: A method for reducing sidelobe interference in a radar or communication system. The method includes selecting a desired amplitude weight (WD) to be applied to radar or communication antenna elements and determining phase weights for the radar or communication system elements such that each pair of adjacent, phase weighted elements provides the desired amplitude weight when summed.

Abstract: The present invention concerns an active electronically scanned array antenna comprising: an active array, configured for radiating/receiving radiofrequency signals through first radiating openings that lie on a ground plane; and a dielectric cover arranged at a given distance from the ground plane so that between said dielectric cover and said ground plane an air gap is present. Said active electronically scanned array antenna is characterized in that it further comprises one or more calibration devices operable for calibrating said active electronically scanned array antenna, each calibration device comprising a respective radiating portion arranged between the dielectric cover and the ground plane and configured for receiving radiofrequency signals radiated through corresponding first radiating openings and for radiating radiofrequency signals in the air gap towards said corresponding first radiating openings.

Abstract: A dual monopulse/interferometer antenna and radar system. In one example, the antenna includes an active electronically steered monopulse array, and is configurable into an interferometer mode which uses a subset of the array elements of each quadrant of the monopulse array. In one example, the RF feed network that combines signals received from each element in the array to produce monopulse return signals is modified in the interferometer mode to couple out the subset of array elements to produce return signals that are analyzed using interferometric processing.

Abstract: A radar data acquisition system including a polarimetric phased array antenna and a radar control and processing system. The polarimetric phased array antenna includes a support system, an array of panels and a switching network. One or more of the panels include a dual pole antenna for at least one of transmitting and receiving a dual polarization electromagnetic beam. The switching network communicates with the panels such that at least one of power, radar and control signals are sent to and received from one or more selected panels. The radar control and processing system communicates with the switching network for forming electromagnetic signals directed to one or more selected panels such that the selected panels form a dual polarization electromagnetic beam, and for reading signals sensed by one or more selected panels and for decoding the signals into an electronic radar output.