Systems and methods are disclosed to determine an unambiguous radial velocity for weather phenomena using weather radar that is not limited by the Doppler Dilemma. Some embodiments include transmitting a complex waveform and using the returned electromagnetic signal to determine the unambiguous radial velocity.

The present invention relates to a method for determining distance (R) and radial velocity (v) of an object in relation to a measurement location, in which method radar signals are emitted and after reflection on the object are received again at the measurement location, wherein the emitted radar signals are subdivided within a measuring cycle into numerous segments (10) in which the frequency of the radar signals is gradually changed from an initial value (f.sub.A, f.sub.B) to the end value and each received reflected signal is subjected across one segment (10) to a first evaluation to detect frequency peaks and additionally a subsequent second evaluation of the signals for the frequency peaks of all segments (10) of the measuring cycle is carried out to determine a Doppler frequency component as a measure of the radial velocity (v). According to said method, an ambiguity in the determination of the relative velocity (v) is eliminated by subdividing the segments (10) into at least two groups (A, B), the initial value (f.sub.A, f.sub.B) of which and/or end value of the changing frequency are different, by subjecting the segments (11, 12) of each group (A, B) separately to the second evaluation and by determining a phase difference of the signals occurring during the second evaluation of the segments (11, 12) of each group (A, B) and corresponding to each other, thereby removing ambiguities in the determined velocity.

According to an embodiment, positioning system includes transmitter apparatus transmits radio wave and receiver apparatus receives target echo. Transmitter apparatus comprises first receiver and transmitter. First receiver receives GPS signal and outputs reference signal. Transmitter transmits radio wave at time interval based on reference signal. The receiver apparatus includes second receiver, detector and first and second calculators. Second receiver receives GPS signal and outputs time information. Detector receives target echo and outputs reception signal added received time information. First calculator calculates Doppler frequency based on reception frequency and transmission frequency. Second calculator calculates time difference of echo based on Doppler frequency. Detector sets time filter to receive next pulse based on time difference and time information of reception signal.

Systems and methods to use radar systems for radio frequency identification (RFID) applications. The radar systems can be adapted to use RFID communications protocols and methods to enhance the usefulness of radar systems beyond the determination of the presence, distance, direction and/or speed of a vehicle or object, to additionally include the transmission of data such as object identification and additional messages or data.

A base station may allocate wireless communication resources to configure a synthetic wireless communication signal for use as a radar signal. The synthetic wireless communication signal may be configured according to a wireless communication protocol of a wireless communication network that is associated with the base station. The base station may transmit, from an antenna and toward an area associated with the base station, the synthetic wireless communication signal. The base station may detect a reflected signal that is associated with the synthetic wireless communication signal. The base station may process the reflected signal to generate radar data; and perform an action associated with the radar data and the 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.

Techniques for automatic adaptive scanning with a laser scanner include obtaining range measurements at a coarse angular resolution and forming a horizontally sorted range gate subset and a characteristic range. A fine angular resolution is determined automatically based on the characteristic range and a target spatial resolution. If the fine angular resolution is finer than the coarse angular resolution, then a minimum and maximum vertical angle is automatically determined in each horizontal slice extending a bin size from any previous horizontal slice. A set of adaptive minimum and maximum vertical angles is determined automatically by dilating and interpolating the minimum and maximum vertical angles of all the slices to the second horizontal angular resolution. A horizontal start angle, and the set of adaptive minimum and maximum vertical angles are sent to cause the ranging system to obtain measurements at the second angular resolution.

A method of determining an alignment error of an antenna is described, wherein the antenna is installed at a vehicle and in cooperation with a detection device, and wherein the detection device is configured to determine a plurality of detections. Determining the plurality of detections comprises emitting a first portion of electromagnetic radiation through the antenna, receiving a second portion of electromagnetic radiation through the antenna, and evaluating the second portion of electromagnetic radiation in dependence of the first portion of electromagnetic radiation in order to localize areas of reflection of the first portion of electromagnetic radiation in the vicinity of the antenna. The method comprises determining a first detection and at least a second detection by using the detection device, and determining the alignment error by means of a joint evaluation of the first detection and the second detection.

A configuration is provided with: a local oscillator 3 which generates M local oscillation signals L.sub.m(t) whose frequencies differ from one another by an integral multiple of an angular frequency ω; receiver devices 4-m each converting the frequency of a received signal Rx.sub.m(t) of one antenna element 2-m using one local oscillation signal L.sub.m(t) generated by the local oscillator 3, thereby generating a received video signal V.sub.m(t) having an antenna element number m; an adder 5 which adds the received video signals V.sub.1(t) to V.sub.M(t) generated by the receiver devices 4-1 to 4-M, and outputs a received video signal V.sub.sum(t) after addition; and an A/D converter 6 which A/D-converts the received video signal V.sub.sum(t) outputted from the adder 5, thereby to generate a received video signal V(n) which is a digital signal.

A radar apparatus according to an embodiment of the present invention includes an oversampler, a weight vector calculator, a meteorological parameter calculator, an error influence degree calculator, and an error reducer. The oversampler performs oversampling on a received signal to acquire a sampling signal. The weight vector calculator calculates a weight vector based on the sampling signal and a waveform information matrix. The meteorological parameter calculator calculates an estimated value of a meteorological parameter on an observation target based on the vector and the matrix. The error influence degree calculator selects a first observation target considering an estimated error included in the estimated value, or an error influence degree based on the estimated error. The error reducer subtracts an estimated error that the first observation target gives to an estimated value of a meteorological parameter on a second observation target, from the estimated value on the second observation target.