A method for optical distance measurement is provided, which comprises emitting a plurality of measurement pulses, reflecting emitted measurement pulses on at least one object within a measurement range with a length and receiving reflected measurement pulses. N subsets of measurement pulses are emitted, wherein each subset comprises a constant pulse interval. The constant pulse interval of different subsets is different, wherein the least common multiple of the constant pulse intervals of the N subsets corresponds to at least twice the length of the measurement range.

A synthetic aperture radar (SAR) generates concurrent first radar pulses in first frequency channels. The SAR transmits, and receives returns of, the concurrent first radar pulses by first antenna feeds that form first beams in the first frequency channels and that are directed to respective first subswaths of a swath on the Earth separated by subswath gaps. The SAR generates concurrent second radar pulses in second frequency channels. The SAR transmits, and receives returns of, the concurrent second radar pulses by second antenna feeds configured to form second beams in the second frequency channels and that are directed to respective second subswaths of the swath on the Earth and that coincide with the subswath gaps. The SAR processes the returns of the first radar pulses from the first subswaths and the returns of the second radar pulses from the second subswaths to form a SAR image contiguous across the swath.

A method for operating a stepped frequency radar system is disclosed. The method involves performing stepped frequency scanning across a first frequency range using frequency steps of a first step size, the stepped frequency scanning performed using at least one transmit antenna and a two-dimensional array of receive antennas, changing from the first step size to a second step size, wherein the second step size is different from the first step size, and performing stepped frequency scanning across a second frequency range using the at least one transmit antenna and the two-dimensional array of receive antennas and using frequency steps of the second step size.

Method for determining product surface distance in a tank comprising: i) generating a transmission signal as a first pulse train; ii) generating a reference signal having a second pulse train by time delaying said first pulse train; wherein each pulse in said first and second pulse trains have essentially identical waveforms and pulse repetition frequency; iii) guiding said transmission signal towards the product surface; iv) receiving a reflected signal; v) forming a correlation value based on a time correlation between the reference signal and the reflected signal; vi) carrying out steps i) to v) in sequence for at least three different pulse repetition frequencies, until at least three pairs of correlation values and associated pulse repetition frequencies have been stored; vii) determining said distance based on said at least three pairs of correlation values and associated pulse repetition frequencies, and said fixed time delay.

The present disclosure concerns a method of measuring the distance between a device and an object comprising the steps of determination of a first estimated distance based on the time of flight of first light pulses having a first period; determination of a second estimated distance based on the time of flight of second light pulses having a second period different from the first period; determination based on the interval between the first and second estimated distances of whether the device is in a wraparound area among wraparound areas; and if the device is in a wraparound area among wraparound areas, adding to the first estimated distance a compensation having its value depending on the wraparound area.

Various exemplary embodiments relate to a method for determining the velocity of an object using radar system having a processor, including: receiving, by a processor, a first digital signal corresponding to a first transmit signal; receiving, by the processor, a second digital signal corresponding to a second transmit signal; processing the first digital signal to produce a first range/relative velocity matrix; detecting objects in the first range/relative velocity matrix to produce a first detection vector; unfolding the first detection vector; processing the second digital signal to produce a second range/relative velocity matrix; interpolating the second range/relative velocity matrix in the relative velocity direction wherein the interpolated second range/relative velocity matrix has a frequency spacing corresponding to the frequency spacing of the first range/relative range velocity matrix in the relative velocity direction; detecting objects in the second range/relative velocity matrix to produce a second detection vector; unfolding the second detection vector; and determining a true velocity of the detected objects based upon the unfolded first and second detection vectors.

A method for operating a stepped frequency radar system is disclosed. The method involves performing stepped frequency scanning across a frequency range using frequency steps of a step size, the stepped frequency scanning performed using at least one transmit antenna and a two-dimensional array of receive antennas, changing at least one of the step size and the frequency range, and performing stepped frequency scanning using the at least one transmit antenna and the two-dimensional array of receive antennas and using the changed at least one of the step size and the frequency range.

A method of determining a filling level of a product in a tank, comprising, for each transmit pulse repetition frequency in a sequence of different transmit pulse repetition frequencies: generating and transmitting an electromagnetic transmit signal in the form of a pulse train of transmit pulses, the pulse train exhibiting the transmit pulse repetition frequency; propagating the transmit signal towards a surface of the product in the tank; returning an electromagnetic reflection signal resulting from reflection of the transmit signal at the surface back towards the transceiver; receiving the reflection signal; determining a measure indicative of signal disturbance of the reflection signal; evaluating the measure indicative of signal disturbance of the reflection signal in view of a predefined signal disturbance criterion; and determining the filling level based on at least one of the reflection signals fulfilling the signal disturbance criterion.

Methods and systems for monitoring a health parameter in a person using a radar system are disclosed. A method involves performing stepped frequency scanning below the skin surface of a person using at least one transmit antenna and a two-dimensional array of receive antennas, the stepped frequency scanning being performed using frequency steps of a first step size, changing the first step size to a second different step size in response to a change in reflectivity of blood in a blood vessel of the person, performing stepped frequency scanning below the skin surface of the person using the second step size after the step size is changed from the first step size to the second step size, and outputting a signal that corresponds to a blood pressure level in the person in response to the stepped frequency scanning at the first step size and at the second step size.

A method for operating a stepped frequency radar system is disclosed. The method involves performing stepped frequency scanning across a frequency range using frequency steps of a step size, the stepped frequency scanning performed using at least one transmit antenna and a two-dimensional array of receive antennas, changing at least one of the step size and the frequency range, and performing stepped frequency scanning using the at least one transmit antenna and the two-dimensional array of receive antennas and using the changed at least one of the step size and the frequency range.