This disclosure enables various technologies for determining space object attitude stabilities from radar cross-section statistics. In particular, such determinations can be made via employing various phased-array radars with various fields of views, which can monitor various space objects (e.g., satellites, space debris, rocket bodies, space stations) over various periods of time (e.g., minutes, hours, days, weeks, months) as the space objects come into the fields of views. For example, a technique for estimating attitude stability of low-Earth RSOs using RCS statistics from various radars (e.g., group of radars, phased-array radar network). Assuming a non-isotropic shape, an Earth-oriented RSO can have an elevation-angle dependent RCS when viewed from a ground-based radar. Therefore, an RSO attitude stability can be tested by looking for a difference in a median or mean RCS when the RSO is viewed at different elevation angles.

Provided is a method for stably and flexibly performing ranging between a plurality of devices. According to an embodiment, a method of operating a first device for performing ranging by using ultra-wide band (UWB) may include: transmitting a first ranging control (RC) frame to a second device; performing ranging with the second device for a number of ranging rounds determined based on the first RC frame; changing at least one ranging parameter based on a change request received from the second device; and transmitting a second RC frame including the changed at least one ranging parameter.

A device and method therein for improving measurement result made by a radar unit are disclosed. The device comprises the radar unit and at least one motion sensor unit. The radar unit transmits at least one radar pulse in a frequency range and receives at least one radar pulse response associated to reflections of the at least one transmitted radar pulse. The radar unit determines at least one measurement based on the transmitted and received radar pulses. The radar unit further receives information on movement of the device from the at least one motion sensor unit during radar pulse transmission and reception and adjust the at least one measurement based on received information on movement of the device from the at least one motion sensor unit.

A level transmitter includes an analog-to-digital convertor clock signal generator that receives a transmitter clock signal that is used to establish when an incident signal is transmitted toward a material boundary. The analog-to-digital convertor clock signal generator uses the received transmitter clock signal to generate an analog-to-digital convertor clock signal. An analog-to-digital convertor samples an analog waveform based on the analog-to-digital convertor clock signal and generates a digital value for each sample of the analog waveform. An analysis module analyzes the digital values to determine a distance to the material boundary.

In at least one illustrative embodiment, a guided wave radar (GWR) level transmitter may comprise a timing circuit including a first oscillator circuit and a second oscillator circuit, a coincidence circuit configured to generate a coincidence signal indicative of phase shifts created by a difference between first and second frequencies of the first and second oscillator circuits, and a microcontroller configured to (i) determine a stretching factor based on the coincidence signal and at least one of the oscillator signals, (ii) calculate, when the stretching factor is within a first range, a distance to a media surface using the stretching factor, and (iii) adjust, when the stretching factor is outside of a second range, at least one of the first and second oscillator circuits to adjust the difference between the first and second frequencies.

A distance measuring apparatus includes: a DTC generator unit that generates DTC signals having edges delayed to define time segments; a template generator unit that generates template signals consecutively in a pre-designated number within the time segments in response to the DTC signals; a coarse time determiner unit that determines the time segment in which a delayed signal is received by calculating correlations with the consecutively generated template signals; a fine time measurer unit that determines the time at which the delayed signal is received within the time segment determined at the coarse time determiner unit from the results of calculating correlations between multiple template signals within the determined time segment and the delayed signal; and a distance calculator unit that calculates the total delay duration of the delayed signal and calculates the distance to the measurement target object from the calculated delay duration.

A method (e.g., a method for measuring a separation distance to a target object) includes transmitting an electromagnetic first transmitted signal from a transmitting antenna toward a target object that is a separated from the transmitting antenna by a separation distance. The first transmitted signal includes a first transmit pattern representative of a first sequence of digital bits. The method also includes receiving a first echo of the first transmitted signal that is reflected off the target object, converting the first echo into a first digitized echo signal, and comparing a first receive pattern representative of a second sequence of digital bits to the first digitized echo signal to determine a time of flight of the first transmitted signal and the echo.

The disclosure relates to a method for measuring fill level of a fill substance using terahertz (THz) pulses or for determining distance to an object using terahertz pulses, as well as to a fill-level measuring device suitable for performing such method. The THz pulses are transmitted with a repetition frequency, wherein the repetition frequency according to the invention is controlled in such a manner as a function of travel time that the repetition frequency increases in the case of decreasing travel time and decreases in the case of increasing travel time. The separation or the fill level is determined not based on the measured travel time, but is based on repetition frequency. An exact fill level determination can be performed based on THz pulses, even when the frequency of the THz pulses significantly fluctuates. Consequently, very simply embodied pulse production units with comparatively small requirements for frequency stability of the THz pulses can be used.

A pulsed radar level gauge comprising a pulse generator configured to generate a transmit signal (S.sub.T) in the form of a pulse train, a propagation device connected to direct the transmit signal (S.sub.T) into a tank and return a microwave return signal (S.sub.R), a receiver, sampling circuitry configured to provide a time expanded tank signal, and processing circuitry for determining said filling level based on the time expanded tank signal.

The gauge further comprises impedance increasing circuitry arranged to ensure that an input impedance of the receiver is at least 2 k and a delay line arranged between said receiver and said propagation device, the delay line configured to introduce a delay greater than said pulse duration, such that said time expanded signal) includes a transmitted pulse.

A first device includes: a first reference signal source; a first transmitting/receiving unit which transmits two or more first carrier signals and receives two or more second carrier signals using an output of the first reference signal source; and a calculating unit. A second device includes: a second reference signal source configured to be operated independently from the first reference signal source; and a second transmitting/receiving unit configured to transmit two or more second carrier signals and receive two or more first carrier signals using an output of the second reference signal source. A frequency group of two or more first carrier signals and a frequency group of two or more second carrier signals differ from each other. The calculating unit calculates a distance between the first device and the second device based on a phase detection result obtained by receiving the first and second carrier signals.