Abstract: A fill level measurement device for determining a topology of a filling material surface is provided, including an antenna apparatus including an array of radiator elements and a rotatable mount configured to rotate the antenna apparatus about an axis that is in parallel with the array, such that a plurality of emission angles of the antenna apparatus are electronically and mechanically settable relative to the filling material surface without local overscanning occurring.

Abstract: A method and apparatus for determining ground clearance of a structure are provided. The method includes removing reflection points caused by noise from first reflection point information based on temporal persistency and generating second reflection point information, extracting visual features from an image of a camera based on convolutional neural network, projecting the second reflection point information onto the image, generating region proposals based on the projected second reflection point information and the image, the region proposals indicating potential horizontal structures above a path, detecting stationary horizontal structure above a path based on the generated region proposals, and determining distance between ground and the detected stationary horizontal structure based on the projected reflection point information and the image.

Abstract: A system and method of capturing and rendering stereoscopic panoramic content is provided. The system may capture information from a virtual scene to generate a stereoscopic panorama in the form of a stereoscopic cube map. Using the pre-captured cube map, the system may render stereoscopic images during gameplay, image viewing, and/or playback of a three dimensional video. The system may capture camera distance information during capture for use in distortion reduction during image rendering and playback. The system may implement additional distortion reduction measures. Further, the system may use the capture camera distance information to write to depth buffers corresponding to rendered images for use when introducing dynamic gameplay elements into the scene. Additionally, the system may use realistic camera models to simulate human anatomy and reduce distortions associated with simplistic camera models.

Abstract: An apparatus includes a transmitter configured to transmit a signal having an electromagnetic pulse towards material in a tank. The apparatus also includes a receiver configured to receive a signal having multiple reflections of the pulse, including a process connector reflection. The apparatus further includes at least one processing device configured to determine a measurement associated with the material in the tank based on the received signal. To determine the measurement, the at least one processing device is configured to identify the process connector reflection in the received signal using an asymmetrical model. The transmitter, the receiver, and the at least one processing device could form at least part of an electronics assembly, and a connecting cable could couple the electronics assembly and a process connector. The asymmetrical model could have different lobes of different shapes.

Abstract: An apparatus includes at least one processing device configured to determine an optimal pulse width for obtaining level measurements associated with material in a tank. The at least one processing device is also configured to generate a control signal that causes a transmitter of a guided wave radar (GWR) to transmit a signal having the optimal pulse width. The at least one processing device is further configured to send the control signal to the transmitter. The at least one processing device can also be configured to alter a length of the optimal pulse width in order to reduce false echoes detected by the GWR, reduce a size of an upper dead zone of the GWR, and/or detect a change of impedance to identify a fault of a process connector in the GWR.

Abstract: A removable portable wireless fluid sensor system for use in hydrocarbon wells having a sensor assembly with a guided wave radar level and interface transmitter, a single flex probe with a sensor wire, a top tank mounting system for supporting the single flex probe, at least one turbulence breaker, and a secondary wireless controller in communication with a primary wireless controller. The secondary wireless controller communicates with the single flex probe, the guided wave radar level and interface transmitter, and the primary wireless controller. The removable portable wireless fluid sensor system is configured for detecting fluid levels in tanks accurately as levels change due to coiled tubing operations in completions of hydrocarbon wells, snubbing operations in completions of hydrocarbons wells, water transfer operations during fracturing of a hydrocarbon well, and flow back fluid measurement and well testing procedures for hydrocarbon wells.

Abstract: A method for measuring fill level and a measuring device for performing the method, wherein, in measuring cycles following one after the other, signal pulses of predetermined frequency sent by means of a transmitting and receiving system with a predetermined repetition frequency into a container, and their signal components reflected back in the container in the direction of the transmitting and receiving system after a travel time dependent on their traveled path, are received as received signal. A fill level is measured taking into consideration a phase relationship between the transmitted and received signals related physically with the fill level to be measured.

Abstract: The invention relates to a frequency generator for generating two pulse repetition frequency signals with slightly different frequencies for a radar measuring device. The frequency generator comprises an oscillator, which generates an oscillator signal, a first signal path for generating a first pulse repetition frequency signal from the oscillator signal, and a second signal path for generating a second pulse repetition frequency signal from the oscillator signal.

Abstract: An illustrative example device for steering a beam of radiation includes at least one compressible optic component including at least one lens in a compressible optic material adjacent the lens. An actuator controls an orientation of the lens by selectively applying pressure on the compressible optic material.

Abstract: A radar sensor includes a mixer configured to receive an radio frequency (RF) input signal to down-convert the RF input signal into a base-band or intermediate frequency (IF) band, an analog-to-digital converter (ADC), and a signal processing chain coupled between the mixer and the ADC. The radar sensor further includes an oscillator circuit that is configured to generate a test signal. The ADC is coupled to an output of the signal processing chain, and is configured to generate a digital signal by digitizing an output signal of the signal processing chain, the output signal being derived from the test signal. The radar sensor further includes a digital signal processing circuit coupled to the ADC downstream thereof, the digital signal processing circuit being configured to perform a spectral analysis on frequency values of the digital signal.

Abstract: A liquid level sensing apparatus (10) for long-distance automatically enhancing a signal-to-noise ratio is applied to a measured target (20). The liquid level sensing apparatus (10) includes a sensing module (102), a long-distance command receiving module (104) and at least a brake module (106). The sensing module (102) transmits a sensing signal (108) to the measured target (20). The sensing signal (108) touches the measured target (20) to reflect back a reflected signal (110). The sensing module (102) receives the reflected signal (110) to measure the signal-to-noise ratio and to measure a height of the measured target (20). The long-distance command receiving module (104) is electrically connected to the sensing module (102). The long-distance command receiving module (104) receives a long-distance command signal (302). The brake module (106) is mechanically connected to the sensing module (102).

Abstract: Provided are a method and a system for a slag thickness detection and a slag-adding prediction. The method includes: acquiring real-time measurement data and real-time auxiliary data of a slag point on a surface of a protective slag layer of a casting mold; calculating a real-time slag thickness value corresponding to the slag point by using the real-time measurement data and the real-time auxiliary data of the slag point; and predicting a location on the surface of the protective slag layer where a slag-adding is to be performed and a slag-adding time when the slag-adding is to be performed based on a change in the real-time slag thickness value corresponding to the slag point by taking a preset slag thickness value as a reference.

Abstract: The invention relates to an apparatus for transmitting and receiving electromagnetic waves (EM waves) for ascertaining and monitoring a fill level of a medium in a container, comprising a first hollow conductor with a first coupling element for the out- and in-coupling of EM waves, a second hollow conductor with a second coupling element for the out- and in-coupling of EM waves, a horn radiator for radiating and focusing of EM waves, wherein the first and second hollow conductors are dimensioned such that EM waves out-coupled from the first and second coupling elements radiate from the horn radiator scattered and with weak intensity, or scattered and weak intensity EM waves, which are received from the horn radiator, couple to the first and second coupling elements, and EM waves out-coupled only from the first coupling element radiate from the horn radiator focused and with strong intensity, or focused and strong intensity EM waves, which are received from the horn radiator couple only to the first coupling e

Abstract: A radar measurement apparatus works according to the FMCW principle and includes a radar transmission unit, and a radar receiving unit, which is designed to receive a radar received signal reflected on a surface of the medium or other target in a pipe or tube, to convert the received signal into an intermediate frequency signal by mixing with the transmission signal, or a signal derived therefrom, and based on an intermediate signal to determine distance to the surface of the medium or other target. The radar receiving unit applies a phase correction to the intermediate signal produces a phase corrected, intermediate frequency signal, wherein the phase correction lessens or removes a dispersion dependent phase fraction in the phase of the intermediate signal and adds a non-dispersion effects dependent phase fraction.

Abstract: In a method for ascertaining and monitoring fill level of a medium in a container by means of a field device using a travel time measuring method, wherein transmission signals are transmitted toward the medium and reflection signals are received; the received reflection signals are registered as echo signals in an echo function, or envelope curve, dependent on travel time or travel distance; by means of an echo search algorithm, at least one wanted echo signal is ascertained in the echo function, or envelope curve; by means of at least one filter with filter parameters the echo function, or the envelope curve, is preprocessed; at least a first filter range with a first width is predetermined at the position of the wanted echo signal in the echo function, or in the envelope curve, and at least three filter ranges are formed in the echo function, or in the envelope curve.

Abstract: To determine an echo curve using a fill level measurement device operating according to the FMCW principle, the echo curve is calculated from corresponding sampling values at a first resolution. After this, a particular portion of the echo curve is calculated at a second, higher resolution using the DTFT algorithm. This can reduce the complexity required for calculating the echo curve.

Abstract: Methods, apparatuses, and computer readable medium including computer program products, are provided for determining the depth of water in a well. A method may include coupling a signal onto a cable connected to a submersible well pump. The method may further include monitoring the cable to determine a first time corresponding to a first reflection of the signal caused by the cable entering a water column between a water surface and the submersible pump. The method may further include monitoring the cable to determine a second time corresponding to a second reflection of the signal caused by an impedance mismatch between the cable surrounded by water and a motor in the submersible well pump. The method may further include determining a water height between the submersible pump and the water surface from the first time and the second time.

Abstract: A proximity sensor for measuring the distance from an object contains a microwave oscillator providing, as an output signal, a transmission wave emitted toward the object as a free space transmission wave reflected by the object, the object being electrically conductive or having at least one electrically conductive surface, as a free space reflection wave and is received by the proximity sensor as a reflection wave. The reflection coefficient is determined from the transmission and reflection waves and is provided by the proximity sensor as a measure of the distance. The transmission wave is guided in a waveguide as a waveguide transmission wave and is injected into the waveguide with a wave mode which results in the waveguide transmission wave being separated at the aperture at the front end of the waveguide into the free space transmission wave and in the free space transmission wave propagating to the object.

Abstract: A radar level gauge comprising a physical communication interface bi-directional communication of data structured according to either a first digital communication protocol or a second digital communication protocol, first communication circuitry for communicating measurement data from the field device, second communication circuitry for enabling configuration of the field device, protocol identification circuitry connected to the communication interface for intercepting data and configured to parse intercepted data to identify the digital communication protocol, and control circuitry for directing the intercepted data to one of the first and second communication circuitries based on the identified protocol.

Abstract: A method of modeling a pulsed radar gauge (PRG) that includes a transceiver coupled by a process connection to a probe installed on a tank having at least one product material therein. A mathematical model is provided that includes (i) dielectric properties and dimensions of materials used in the process connection, (ii) at least one tank dimension, (iii) dielectric characteristics of the product material, and (iv) a probe length. Using a processor implementing a stored echo prediction algorithm that utilizes the mathematical model inputting pulse characteristics including a shape of an input radar pulse launched by a transmitter of the transceiver onto the probe into the mathematical model, and generating a predicted echo curve from the mathematical model.

Abstract: A spectroscopic scanning device, a portable spectroscopic scanning system, and methods for using the spectroscopic scanning device are described that include at least one focusing element configured to collect light, a beam-steering element configured to direct a portion of the collected light from the at least one focusing element, and a detector configured to receive the directed light from the beam-steering element, wherein the beam-steering element is operable to successively select portions of light from a plurality of locations within its field of regard.

Abstract: A method and device for level measurement according to the propagation time method in which at least one conductor unit (1) is supplied with pulse-like electromagnetic transmission signals and in which electromagnetic response signals are tapped from the conductor unit (1). The method for level determination is improved as compared to the prior art by the conductor unit (1) being supplied with transmission signals with either positive or negative polarity.

Abstract: A high liquid-level alarm device is configured such that one casing includes a plurality of liquid-level alarm units, the liquid-level alarm units are directed for monitoring one liquid level, issue an alarm for a different height of the liquid level, have radio wave detection units for detecting a radio wave, respectively, each of the liquid-level alarm units has a radio wave detection unit for detecting a radio wave, transmits a radio wave when not detecting a radio wave, and performs a determination operation as to whether a predetermined liquid level is reached, and when one of the liquid-level alarm units is performing the determination operation, the rest of the liquid-level alarm units do not perform the determination operation.

Abstract: A multivariable fluid level detection system comprising a guided wave radar probe with sensor or sensors integral to the probe for producing sensor signal(s), a transmitter for transmitting guided microwave pulses down the probe, a receiver for receiving reflected microwave pulses, and a processor for producing a measurement of fluid level based upon a time difference between transmission of a pulse and receipt of a reflected pulse and the sensor signal(s).

Abstract: A method for analyzing a level gauge, comprising storing in a storage device a consecutive sequence of data triplets including a time stamp, a filling level measurement, and an echo curve information, plotting a trend line including filling level as a function of time, graphically indicating a pointer in the trend line, displaying an echo curve corresponding to a point in time initially represented by the pointer, receiving user input indicating a set of points along a section of the trend line selected for analysis, and for each point in the set of points, moving the pointer to this point and replacing contents of the second graphical element, such that an echo curve displayed in the second graphical element always corresponds to a point in time represented by a current position of the pointer. The invention enables a user to analyze operation of the level gauge during a time period corresponding to the selected trend line section.

Abstract: An example method for downhole fluid measurement may include positioning a first sensor within a downhole casing. The first sensor may include a first flexible material, a first transmitter coupled to the first flexible material, and a first receiver coupled to the first flexible material. A first signal within a fluid in the downhole casing may be generated using the first transmitter. A first response of the fluid to the first signal may be measured using the using the first receiver. The first response may be processed to determine at least one parameter of the fluid.

Abstract: A microwave module 1 for a fill level measuring device 2 operating with the runtime method, has a chip for generating and/or receiving microwave signals and a carrier element. To provide an advantageous as possible microwave module, the chip is located in a cavity 9 of the carrier element 8.

Abstract: A method for providing narrow-band interference unaffected measurement of a distance to a surface of a product kept in a tank, comprising mixing a return signal with a transmit signal to provide an intermediate frequency signal, and determining the distance, based on the intermediate frequency signal. The step of determining the distance further comprises dividing the intermediate frequency signal into a plurality of frequency portions, wherein each frequency portion corresponds to a frequency interval of the transmit signal, identifying disturbed frequency portions as frequency portions affected by narrow-band interference, and determining the distance based on frequency portions being unaffected by narrow-band interference. By dividing the IF-signal into frequency portions corresponding to frequency intervals of the transmit signal, frequency intervals where narrow-band interferences are present may be detected.

Abstract: The present invention relates to a guided wave radar level gauge for determining a filling level of a product contained in a tank, said guided wave radar level gauge i.a. comprising a probe comprising a plurality of elongate probe sections each being pivotably connected to an adjacent probe section by means of a joint, said joint allowing probe sections to pivot between an operating state where said probe sections are substantially aligned along a straight line, and a transporting state. The present invention also relates to a probe, and to a method for arranging a guided wave radar level gauge in a tank.

Abstract: A circuit arrangement for converting from a differential signal path (IFoutA - IFoutB) at the output of a mixer to a signal path (Ssin gle) referenced to a reference potential. A controllable switch element is provided in each of the two single signal paths (IFoutA, IFoutB) of the differential signal path (IFoutA-IFoutB), wherein a first memory element is connected in series with the two switch elements, and wherein there is provided for the two switch elements at least one control, which during a charging phase of the first memory element connects the differential signal path (IFoutA-IFoutB) at the output of the mixer with the first memory element and applies the output signal on the differential output of the mixer for charging the first memory element.

Abstract: A method is based on measuring a distance to a reference reflector arranged at a known distance, in order to calibrate and/or monitor a coherent frequency modulation, continuous wave radar, fill-level measuring device, wherein the reference reflector can be reliably identified. To this end, a reference reflector executing oscillations toward the fill-level measuring device with an oscillation frequency is used, which is inserted in the beam path of periodically linearly frequency modulated transmission signals transmitted from the fill-level measuring device. The fill-level measuring device receives fractions of the transmission signals reflected back on reflectors in the container and records based on these received signals and their time correlation relative to the respectively associated transmission signal for each received signal an echo function, which shows the amplitudes of the received signal as a function of the associated position of the associated reflector.

Abstract: A method, apparatus and computer-readable medium for determining a strain component for a deformation mode of a member is disclosed. A plurality of measurements is obtained, wherein each of the plurality of measurements relates to a strain at a location of the member. A deformation mode is selected and an adjustable filter is applied to the plurality of strain measurements to determine the strain component for the selected deformation mode.

Abstract: A self-diagnosing FMCW radar level gauge and a method for providing self-diagnosing with a radar level gauge is provided in a radar level gauge comprising a transceiver, a mixer, a signal propagating device and a signal propagation path connecting the transceiver and the signal propagating device, a filter arrangement and processing circuitry. The filter arrangement provides a filtered intermediate frequency signal. The transceiver outputs either a diagnostic sweep configured such that a reference echo from the signal propagation path is detectable in said filtered intermediate frequency signal, or a measurement sweep configured such that the reference echo is suppressed in the filtered intermediate frequency signal and that a surface echo is detectable. The processing circuitry is configured to self-diagnose the radar level gauge based on the reference echo, and to determine the distance to the surface based on the surface echo.

Abstract: A method for measurement of a distance to a surface of a product kept in a tank method comprises transmitting a pulse train of distinct carrier wave pulses having a duration greater than 1 microsecond and shorter than 100 milliseconds, the pulse train has an average duty cycle of less than 50 percent, each pulse has a defined center frequency, selected according to a frequency scheme within a predetermined frequency range, greater than 5% of an average center frequency. The method further comprises correlating actual phase properties of received pulses with expected phase properties to provide an updated estimation of the distance. The present invention is based on transmitting a set of carrier wave pulses, each having a distinct frequency selected within a frequency range. The method is therefore referred to as a Frequency Modulated Pulsed Wave (FMPW).

Abstract: In order to determine the topology of a bulk-material surface, a series of echo curves are measured under different main emission directions of the antenna. The main emission directions are generated using at least one prism, which lies in the beam path of the level indicator and is rotated. It is thereby possible to achieve in a compact design the decoupling of beam generation from mechanical deflection of the main emission direction.

Abstract: The present invention relates to a radar level gauge system comprising a signal propagation device; a microwave signal source; a microwave signal source controller; a mixer configured to combine a transmit signal from the microwave signal source and a reflection signal from the surface to form an intermediate frequency signal; and processing circuitry coupled to the mixer and configured to determine the filling level based on the intermediate frequency signal.

Abstract: An I/Q mixer and processing method for a radar system include an RF input and an LO input. Phase shifters apply a selectable phase shift to the LO signal to produce a first phase-shifted version of the LO signal and a second phase-shifted version of the LO signal, the first and second phase-shifted versions of the LO signal being in quadrature. A first set of switches is controllable to selectively apply the selectable phase shift to the LO signal. A first mixer unit receives the RF signal at a first input of the first mixer unit, and a second mixer unit receives the RF signal at a first input of the second mixer unit.

Abstract: Downhole water level detecting apparatus for detecting the level of water in a formation in the region of a well installation. The detecting apparatus includes a transmitter for applying electrical signals to a signaling loop at a first location. The signaling loop includes a downhole metallic structure of the well installation and an earth return. The detecting apparatus also includes a detector for monitoring electrical signals in the signaling loop, and an evaluation unit arranged for determining a level of water in the formation relative to the downhole metallic structure in dependence on the monitored signals.

Abstract: The present invention relates to a radar level gauge comprising a reference reflector arranged at a known reference reflector level in a tank. The radar level gauge is controllable between a filling level measuring state and a proof test state. In the proof test state, the radar level gauge is configured to determine a first verification level based on a reference reflector echo resulting from reflection of an electromagnetic transmit signal at the reference reflector; determine a second verification level based on a surface echo resulting from reflection of an electromagnetic transmit signal at the surface of the product; and provide the first verification level and the second verification level to allow determination of a proof test result based on at least the first verification level, the known reference reflector level and the second verification level.

Abstract: The present invention relates to reflector arrangement for proof test of a radar level gauge and to a radar level gauge system comprising such a reflector arrangement. The reflector arrangement comprises a pliable elongated member for attachment to a fixed structure in the tank; a weight attachable to the pliable elongated member; and a reflector member for reflecting an electromagnetic signal impinging on the reflector plate. The weight is configured to be coupled to the reflector member in such a way that an orientation of the weight determines an orientation of the reflector member.

Abstract: The present invention relates to a radar level gauge system comprising PLL circuitry for generating an output signal. The PLL circuitry is configured to indicate a lock state of the PLL circuitry; and signal modifying circuitry is connected to the PLL circuitry for receiving the output signal and for modifying at least one property of the output signal for forming the transmit signal. The signal modifying circuitry is arranged and configured to receive a PLL status signal indicative of the lock state of the PLL circuitry, and to modify the at least one property of the output signal in response to the PLL status signal indicating that the PLL circuitry is in a locked state.

Abstract: An apparatus for determining or monitoring the fill level of a substance in a container, including a high frequency oscillator, an in/out coupling unit, an antenna, which transmits measuring signals, which are coupled in via the in/out coupling unit, in the direction of the surface of the fill substance, respectively receives the measuring signals reflected on the surface of the fill substance, and an evaluating circuit, to which the measuring signals reflected on the surface of the fill substance are supplied and which ascertains the fill level in the container via a travel-time difference method. The high frequency oscillator includes a transistor with a source branch, a drain branch and a gate branch, at least one frequency tuning component and at least one frequency determining component. The frequency determining component of the high frequency oscillator is arranged in the source branch of the transistor.

Abstract: The present invention relates to a method of determining a filling level of a product contained in a tank by propagating a first transmitted electromagnetic signal in a first frequency range and a second transmitted electromagnetic signal in a second frequency range different from the first frequency range along a transmission line probe towards a surface of the product in the tank, receiving a first reflected electromagnetic signal in the first frequency range and a second reflected electromagnetic signal in the second frequency range, and determining the filling level based on a time-of-flight of the first reflected electromagnetic signal and a difference in time-of-flight of the first reflected electromagnetic signal and the second reflected electromagnetic signal.

Abstract: A method for determining the fill level of a medium, wherein a transmission signal is transmitted, a return signal is received, and the return signal is evaluated in view of the process variable in a manner which allows a general and flexible handling of interfering signals in the received signals. This result is obtained by filtering at least one of the return signal, a signal derived from the return signal and an envelope curve formed from the return signal into at least one sub-signal, and using said at least one sub-signal for evaluating the return signal for at least determining the fill level.

Abstract: A mode filter for an antenna having at least one element aperture is provided. The mode filter includes at least one waveguide extension to extend the at least one element aperture, and at least one two-by-two (2×2) array of quad-ridged waveguide sections connected to a respective at least one waveguide extension. When the at least one waveguide extension is positioned between the at least one element aperture and the at least one two-by-two (2×2) array of quad-ridged waveguide sections, undesired electromagnetic modes of the antenna are suppressed.

Abstract: A level measuring system which operates according to the radar principle for measuring the level of a medium which is located in a vessel has a signal transmission apparatus for emission of an electromagnetic signal, an electronic apparatus which generates an electromagnetic signal, and a pressure-tight and/or diffusion-tight separating element. The electronic apparatus is made in several parts, one of which is a signal generating component. The signal generating component and another component of the electronic apparatus are made as independent units which are spatially separated from one another. There is a communication apparatus between the signal generating component and the other component, and there is a pressure-tight and/or diffusion-tight separating element between the other component and the signal transmission apparatus.

Abstract: A method and system for estimating a path difference between two paths followed by a target signal transmitted by a spacecraft or aircraft to a first receiving antenna and a second receiving antenna of a receiving base, respectively. A useful-phase difference is measured between signals corresponding to the target signal received on the first receiving antenna and second receiving antenna. The path difference is estimated on the basis of the measurements of the useful-phase difference. A calibration signal is transmitted to the receiving base and a calibration phase difference between signals corresponding to the calibration signal received on the first receiving antenna and second receiving antenna is measured. Variations are compensated in the measurements of the calibration-phase difference relative to the measurements of the useful-phase difference.

Abstract: A method for monitoring the state of a fill level measuring device (1) operating according to the radar principle and such a fill level measuring device, wherein the fill level measuring device (1) has at least one transceiver unit (2) for transmitting and receiving electromagnetic signals, and at least one antenna (3) for guiding, radiating and receiving electromagnetic signals. The antenna (3) has at least one interior space (4), and wherein the antenna (3) has a transmission characteristic with regard to the transmission of electromagnetic signals. Electromagnetic signals are emitted or directed at least partially in the direction of a wall section (5) of the interior space (4) of the antenna (3), the received electromagnetic signals are evaluated with respect to the transmission characteristic of the antenna (3), and the result of the evaluation is compared to at least one stored reference value.

Abstract: A method of determining a filling level of a product contained in a tank using a level gauge system, comprising the steps of: transmitting a first signal towards a surface of the product; receiving a first echo signal; determining a present echo characteristic value based on the first echo signal; and comparing the present echo characteristic value and a stored echo characteristic value. If a difference between the present echo characteristic value and the stored echo characteristic value is greater than a predefined value, the method further comprises transmitting at least a second transmit signal towards the surface; receiving at least a second echo signal; and determining the filling level based on the at least second electromagnetic echo signal.

Abstract: A method of determining a filling level comprising transmitting a first transmit signal exhibiting a first ratio between bandwidth number of frequencies; receiving a first reflection signal; mixing the first transmit signal and the first reflection signal to form a first intermediate frequency signal; and determining a first data set indicative of a first set of surface echo candidates based on the first intermediate frequency signal. The method further comprises transmitting a second transmit signal exhibiting a second ratio between bandwidth and number of frequencies being different from the first ratio; receiving a second reflection signal; mixing the second transmit signal and the second reflection signal to form a second intermediate frequency signal; and determining a second data set indicative of a second set of surface echo candidates based on the second intermediate frequency signal. The filling level determined based on subsets of the first and second sets.