A method for inspecting a conduit comprising the steps of: emitting an outgoing signal into the conduit to establish an acoustic plane wave within the conduit; and detecting a reflected outgoing signal from the conduit, wherein the outgoing signal is arranged such that low frequency components contribute to more of the outgoing signal, from a time perspective, than high frequency components.

A method for operating multiple sensors of a vehicle in at least partially spatially coinciding detection areas and in a shared frequency domain. In the method, at a transmission point in time, at least two sensors transmit simultaneously on separate instantaneous frequencies separated by a frequency gap, the frequency gap including at least one instantaneous receive bandwidth of the sensors, each instantaneous frequency being blocked for a use by the sensors after the transmission point in time for the duration of a time gap, the time gap including at least one signal propagation time across a reception range of the sensors.

A method for determining at least one physical parameter of a system comprising at least two reflection objects is presented, comprising: producing a transmission signal comprising at least one modulated electromagnetic or acoustic wave; receiving a first reception signal that is based on the transmission signal reflected by a first reflection object; receiving a second reception signal that is based on the transmission signal reflected by a second reflection object; receiving a third or further reception signal(s) that is/are based on the transmission signal reflected by a first or second or further reflection object(s); ascertaining the at least one physical parameter of the system on the basis of the first reception signal and further reception signals; ascertaining unknown distances between reflection objects or material properties, composition or nature of the media between the reflection objects of the system on the basis of the first reception signal and further reception signals.

A method for determining at least one physical parameter of a system comprising at least two reflection objects is presented, comprising: producing a transmission signal comprising at least one modulated electromagnetic or acoustic wave; receiving a first reception signal that is based on the transmission signal reflected by a first reflection object; receiving a second reception signal that is based on the transmission signal reflected by a second reflection object; receiving a third or further reception signal(s) that is/are based on the transmission signal reflected by a first or second or further reflection object(s); ascertaining the at least one physical parameter of the system on the basis of the first reception signal and further reception signals; ascertaining unknown distances between reflection objects or material properties, composition or nature of the media between the reflection objects of the system on the basis of the first reception signal and further reception signals.

In one embodiment, a method includes transmitting, from a first transducer of an electronic device, a first audio signal to a surface near the electronic device. The first audio signal is generated based on a frequency sweep across a range of frequencies. The method also includes receiving, at a second transducer of the electronic device, a second audio signal that is at least partly reflected off the surface. The method then determines an attribute of the surface based on the received second audio signal.

A method of and apparatus for processing received radiation (e.g. RADAR radiation) reflected from a target, the method comprising generating a set of predicted targets, the set of predicted targets comprising at least one member, each member representing a state of the target, generating a predicted waveform for the radiation for each member dependent upon the state of the target, and comparing each predicted waveform with a waveform of the received radiation to determine the accuracy with which the state of the target represented by the member for which the predicted waveform was generated matches an actual state of the target.

A survey system including a multibeam echo sounder having a single projector array and a single hydrophone array constructs a multi-component message for ensonifying multiple fans and deconstructs a corresponding message echo for use in analyzing the returns from each fan.

A signal processing device for processing a signal of a reflected wave which is a wave reflected in a medium and is received by a receiver, when a wave propagating through the medium is continuously transmitted by a transmitter. The signal processing device includes: an estimation unit configured to estimate a lower limit distance of a detection distance range for which an intensity level of a scattered wave from the medium in the detection distance range is equal to or smaller than an allowable level; and a scattering reduction unit configured to remove, from a signal of the reflected wave received, a signal of the scattered wave from the medium in a masking region from the receiver to the lower limit distance to perform output.

A signal processing device for processing a signal of a reflected wave which is a wave reflected in a medium and is received by a receiver, when a wave propagating through the medium is continuously transmitted by a transmitter. The signal processing device includes: an estimation unit configured to estimate a lower limit distance of a detection distance range for which an intensity level of a scattered wave from the medium in the detection distance range is equal to or smaller than an allowable level; and a scattering reduction unit configured to remove, from a signal of the reflected wave received, a signal of the scattered wave from the medium in a masking region from the receiver to the lower limit distance to perform output.

To acquire a beat frequency necessary for target extraction, target speed estimation, and Doppler influence detection by preventing the necessary beat frequency from overlapping unnecessary frequencies in a heterodyne processing result, an apparatus includes a wave receiver that receives a reflected wave of a chirp wave reflected from a target, and outputs a reception wave signal, a dual-sweep signal generator that generates a dual-sweep signal of the chirp wave, having a frequency which does not overlap that of the chirp wave, and a heterodyne processor that generates a beat frequency by multiplying the reception wave signal and the dual-sweep signal as a heterodyne signal.