A system for observing a flow characteristic of a fluid is provided. The system includes a nadir-facing sensor, an angle flow sensor, and processing circuitry. The nadir-facing sensor and the angle flow sensor are both provided at a distance above the fluid. The nadir-facing sensor and the angle flow sensor are both radar sensors. The processing circuitry is configured to receive sensor data from the nadir-facing sensor and the angle flow sensor. The sensor data includes at least one of a fluid speed or a fluid surface level. The processing circuitry is configured to determine the flow characteristic based upon the sensor data.

Systems and methods for using velocity measurements to adjust Doppler filter bandwidth are provided herein. In certain embodiments, a method for adjusting bandwidth for at least one Doppler filter in a Doppler beam sharpened radar altimeter comprises receiving a velocity measurement; adjusting the bandwidth of the at least one Doppler filter based on the velocity measurement; and transmitting a radar beam, wherein the radar beam is aimed toward a surface. The method further comprises receiving at least one reflected signal, wherein the at least one reflected signal is a reflection of the radar beam being reflected off of at least one portion of the surface; and filtering the at least one reflected signal with the at least one Doppler filter to form at least one Doppler beam.

Disclosed herein are an apparatus and method for extracting ocean wave information. The apparatus for extracting ocean wave information includes a radar image reception unit for receiving a radar image from a radar antenna, a digital conversion unit for converting the received radar image into a digital format, an analysis preparation unit for setting analysis sections of the radar image and performing temporal accumulation on the analysis sections, a three-dimensional (3D) spectrum-conversion unit for converting accumulated analysis sections into a 3D spectrum in a 3D frequency domain by performing a temporal/spatial 3D Fast Fourier Transform (FFT) on the accumulated analysis sections, and an ocean wave information extraction unit for extracting ocean wave information based on the 3D spectrum.

An apparatus comprising circuitry configured to transfer motion information obtained from a plurality of sensors of different or similar type to a common representation.

The radar system 11 comprises a plurality of transmission antennas 12 which irradiate electromagnetic waves, a plurality of receiving antennas 13 which receive the irradiated electromagnetic waves that have been reflected and generating measurement signals, radar signal transmission and receiving means 14 for obtaining the measurement signals, movement estimation means 15 for estimating the movement of an object, and motion-compensated image generation means 16 for generating a radar image based on the measurement signals and the estimated object movement.

Embodiments relate to machines comprising a movable part, transceiver circuitry configured to transmit a radio signal towards the movable part and to receive a reflection of the radio signal from the movable part, evaluation circuitry configured to determine a position or a speed of the movable part based on at least the received radio signal. A distance between an antenna of the transceiver circuitry and the movable part is less than 5 cm.

A method for active neutralization of the effect of the vibrations of a rotary-wing aircraft for a monostatic Doppler radar includes a first step of measuring and temporally extrapolating the vibration modes at the transmitting-receiving radar antenna, using a 3-axis vibration sensor, fixed to the antenna and near the phase centre of the antenna; then a second step of estimating the expected movements of the transmitting-receiving antenna or of the first transmitting antenna and the second receiving antenna; then a third step of compensating the expected movements of the transmission radar antenna in the transmission chain or in the reception chain of the radar transmitter, wherein the projection of the movement vector of the phase centre O on an aiming direction is calculated to determine the value of the compensation phase shift to be applied.

A system includes a movable part that is rotatably movable, the movable part comprising a first portion and a second portion; transceiver circuitry configured to transmit a radio signal towards the movable part and to receive a receive radio signal from the movable part; and evaluation circuitry configured to determine a rotational position of the movable part based on the receive radio signal. The first portion of the movable part has a first electromagnetic reflectivity for the radio signal and the second portion of the movable part has a second electromagnetic reflectivity for the radio signal. The first electromagnetic reflectivity differs from the second electromagnetic reflectivity.

Embodiments relate to machines comprising a movable part, transceiver circuitry configured to transmit a radio signal towards the movable part and to receive a reflection of the radio signal from the movable part, evaluation circuitry configured to determine a position or a speed of the movable part based on at least the received radio signal. A distance between an antenna of the transceiver circuitry and the movable part is less than 5 cm.

A method for active neutralization of the effect of the vibrations of a rotary-wing aircraft for a monostatic Doppler radar includes a first step of measuring and temporally extrapolating the vibration modes at the transmitting-receiving radar antenna, using a 3-axis vibration sensor, fixed to the antenna and near the phase centre of the antenna; then a second step of estimating the expected movements of the transmitting-receiving antenna or of the first transmitting antenna and the second receiving antenna; then a third step of compensating the expected movements of the transmission radar antenna in the transmission chain or in the reception chain of the radar transmitter, wherein the projection of the movement vector of the phase centre O on an aiming direction is calculated to determine the value of the compensation phase shift to be applied.