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US 2003/0112173 A1Published application
Radar apparatus, signal processing method and program
AssigneeFujitsu Limited
InventorsTetsuo Seki, Osamu Isaji
Life of this patent
Estimating the term…
Abstract
As to a beat signal of a received wave, for instance, a plurality of FFT-based frequency spectra of every FM rise zone are accumulated in an accumulation unit. A judgment unit judges a valley section from the plurality of frequency spectra accumulated. A peak frequency extraction unit acquires, as beat frequencies of different targets, respective beat frequencies of peak sections located at both sides of the valley sections judged.
Claims10
A radar apparatus comprising:
- a sending/receiving unit which sends from its antenna a sending signal which has been frequency modulated by a triangular wave signal, said sending/receiving unit mixing a signal received from said antenna and a local signal branched off from said sending signal, to thereby generate a beat signal;
- a frequency analyzing unit which analyzes the frequency of said beat signal for each rise zone and each fall zone of the frequency modulated by said triangular wave signal;
- an accumulation unit which accumulates a plurality of frequency spectra by frequency analysis at least for each said rise zone;
- a judgment unit which judges a characteristic section from said plurality of frequency spectra accumulated in said accumulation unit;
- a peak frequency extraction unit which acquires, as beat frequencies of different targets, respective beat frequencies of peak sections located at both sides of said characteristic section judged by said judgment unit;
- and
- an operation unit which calculates the distance to a target and the relative speed thereto, based on said beat frequencies.
4 more elements
A signal processing method of an FM-CW radar, the method comprising:
- a sending/receiving step which includes sending from an antenna a sending signal which has been frequency modulated by a triangular wave signal, and mixing a signal received from said antenna and a local signal branched off from said sending signal, to thereby generate a beat signal;
- a frequency analysis step which includes analyzing the frequency of said beat signal for each rise zone and each fall zone of the frequency modulated by said triangular wave signal;
- an accumulation step which includes accumulating a plurality of frequency spectra by analyzing the frequency at least for each said rise zone;
- a judgment step which includes judging a characteristic section from said plurality of frequency spectra accumulated;
- a peak frequency extraction step which includes acquiring, as beat frequencies of different targets, respective beat frequencies of peak sections located at the both sides of said characteristic section judged;
- and
- an operation step which includes calculating the distance to a target and the relative speed thereto, based on said beat frequencies.
4 more elements
A program causing a computer mounted on a radar apparatus to execute:
- a frequency analysis step which includes inputting a beat signal acquired by sending from an antenna a sending signal which has been frequency modulated by a triangular wave signal, and by mixing a signal received from said antenna and a local signal branched off from said sending signal, and analyzing the frequency of said beat signal for each rise zone and each fall zone of the frequency modulated by said triangular wave signal;
- an accumulation step which includes accumulating a plurality of frequency spectra by analyzing the frequency at least for each said rise zone;
- a judgment step which includes judging a characteristic section from said plurality of frequency spectra accumulated;
- a peak frequency extraction step which includes acquiring, as beat frequencies of different targets, respective beat frequencies of peak sections located at the both sides of said characteristic section judged;
- and
- an operation step which includes calculating the distance to a target and the relative speed thereto, based on said beat frequencies.
3 more elements
A radar apparatus comprising:
- an antenna which is mechanically scanned within a predetermined angular range;
- a sending/receiving unit which sends from said antenna a sending signal which has been frequency modulated by a sending triangular wave signal, said sending/receiving unit mixing a signal received from said antenna and a local signal branched off from said sending signal, to thereby generate a beat signal;
- a frequency analyzing unit which analyzes the frequency of said beat signal for each rise zone and each fall zone of the frequency modulated by said triangular wave signal;
- an accumulation unit which accumulates a plurality of changes in spectral value of a specific beat frequency acquired by said frequency analyzing unit, corresponding to changes in the antenna scanning angle, for each different antenna scanning angle within a predetermined angular range;
- a judgment unit which judges a characteristic section from changes in spectral value corresponding to a plurality of antenna scanning angles accumulated in said accumulation unit;
- a peak frequency extraction unit which acquires, as beat frequencies of targets present in different directions of scanning angle, spectral values of peak sections located at both sides of said characteristic section judged by said judgment unit;
- and
- an operation unit which calculates the distance to a target and the relative speed thereto correlated with the antenna angle, based on said beat frequencies.
5 more elements
A program causing a computer mounted on an FM-CW radar to execute:
- a frequency analysis step which includes inputting a beat signal acquired by sending a sending signal which has been frequency modulated by a triangular wave signal, from an antenna which is mechanically scanned within a predetermined angular range, and by mixing a signal received from said antenna and a local signal branched off from said sending signal, and analyzing the frequency of said beat signal for each rise zone and each fall zone of the frequency modulated by said triangular wave signal;
- an accumulation step which includes accumulating a plurality of changes in spectral value of a specific beat frequency acquired by said frequency analysis, corresponding to changes in the antenna scanning angle, for each different antenna scanning angle within a predetermined angular range;
- a judgment step which includes judging a characteristic section from changes in spectral value corresponding to a plurality of antenna scanning angles accumulated in said accumulation unit;
- a peak frequency extraction step which includes acquiring, as beat frequencies of targets present in different directions of scanning angle, spectral values of peak sections located at both sides of said characteristic section judged by said judgment unit;
- and
- an operation step which includes which calculates the distance to a target and the relative speed thereto correlated with the antenna angle, based on said beat frequencies
3 more elements
A radar apparatus comprising:
- an antenna securely installed on a structure;
- a sending/receiving unit which sends from its antenna a sending signal which has been frequency modulated by a triangular wave signal, said sending/receiving unit mixing a signal received from said antenna and a local signal branched off from said sending signal, to thereby generate a beat signal;
- a frequency analyzing unit which analyzes the frequency of said beat signal for each rise zone and each fall zone of the frequency modulated by said triangular wave signal;
- an accumulation unit which accumulates a plurality of frequency spectra by frequency analysis at least for each said rise zone;
- a judgment unit which judges a characteristic section from said plurality of frequency spectra accumulated in said accumulation unit;
- a peak frequency extraction unit which acquires, as beat frequencies of different targets, respective beat frequencies of peak sections located at both sides of said characteristic section judged by said judgment unit;
- an operation unit which calculates the distance to a target and the relative speed thereto, based on said beat frequencies;
- and
- an antenna drive unit which periodically moves the installation position of said antenna within a specified range conforming to the wavelength used.
6 more elements
Dependencies are inferred from the claim text.