Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki Kaisha

Japan Aerospace Exploration Agency

Tomoya Matsuda

Hiroshi Sakamaki

Takamichi Nakamizo

Ikuya Kakimoto

Masahiro Hagio

Yoshihito Hirano

Takao Yamamoto

Shumpei Kameyama

Toshiyuki Ando

Nobuhiro Suzuki

Toshio Wakayama

Kimio Asaka

Masashi Furuta

Yoshinori Okuno

Taiji Harada

Marie Kawai

Naoki Matayoshi

Hidetaka Kiyosue

A radar system, a radar device, and an interference avoidance method are obtained that can utilize frequency effectively even in three or more radar devices. A radar system includes three or more radar devices and a schedule management controller. Schedule management controller predicts an interference time period that is a time period during which the overlapping scanning/radiation range is generated, determines a first interference avoidance measure that is a measure to cause radar devices to use respective different use frequencies while keeping a restriction on the number of frequency channels, in the predicted interference time period, and determines a second interference avoidance measure to be performed by a radar device that is unable to avoid interference by the first interference avoidance measure.

Radar system, radar device, and interference avoidance method

A secondary echo and a primary echo subjected to topographic echo processing are compared with each other. When there is a topographic echo in the primary echo or the secondary echo determined as a strong echo, an echo resulting from removal of the topographic echo is defined as a strong-topographic-echo-removed reception signal. Electric power of the topographic echo in the secondary echo or the primary echo determined as a weak echo and the strong-topographic-echo-removed reception signal are defined as weak echo parameters. Electric power of the weak echo estimated from a reception signal in a weak echo region resulting from phase correction of a reception signal resulting from removal of a frequency component of the strong echo from the strong-topographic-echo-removed reception signal representing the weak echo parameter, a spectral width of the weak echo representing the weak echo parameter, and a Doppler velocity of the weak echo are provided as spectral parameters.

Signal processing apparatus and signal processing method

A signal processing apparatus that performs signal processing on a Doppler spectrum derived from a reception signal of a reflected wave of pulsed undulation repeatedly transmitted into a space removes a topographic echo spectrum from the Doppler spectrum and extracts a plurality of candidate points of a target echo spectrum from the Doppler spectrum from which the topographic echo spectrum has been removed. Furthermore, the signal processing apparatus determines positional relation between the candidate points and a plurality of removed points of the topographic echo spectrum removed from the Doppler spectrum and extracts as an interpolation point, a point where the target echo spectrum is missing by removal of the topographic echo spectrum based on positional relation between the candidate points and the removed points in a direction of a frequency axis.

Based on a reception signal of a reflected wave of pulsed undulation repeatedly transmitted into a space, a Doppler spectrum derived from the reception signal, and a topographic-echo-removed spectrum resulting from removal of a topographic echo from the Doppler spectrum, a first weather echo region is found by using a weather parameter among weather parameters that is different in behavior between a weather echo and the topographic echo, and a second weather echo region is found by using a weather parameter among the weather parameters a behavior of which is not dependent on a Doppler velocity. The weather echo region is determined based on the first weather echo region and the second weather echo region. A signal processing apparatus and a signal processing method with which a zero-Doppler weather echo attenuated, that is, erroneously suppressed, by topographic echo removal processing is readily reconstructed are thus obtained.

A linear-depolarization ratio calculator () is configured so as to determine a radar reflectivity factor Zin transmission of a horizontally polarized wave and reception of a horizontally polarized wave, the radar reflectivity factor being a reflected wave intensity after integration of a reflected wave intensity V(n) calculated by a reflected-wave intensity calculator (), and a radar reflectivity factor Zin transmission of a horizontally polarized wave and reception of a vertically polarized wave, the radar reflectivity factor being a reflected wave intensity after integration of a reflected wave intensity V(n+2) and calculate a linear depolarization ratio LDRwhich is the ratio between the radar reflectivity factor Zand the radar reflectivity factor Z. As a result, even when three types of polarized-wave transmission/reception processing elements are repeatedly performed, the linear depolarization ratio LDRcan be calculated.

Dual polarization radar apparatus and radar signal processing method

In a wind profiler, the number of acquisition ranges is expanded up to heights where noise is introduced into a received signal, even in the case where noise due to transmit/receive switching is introduced. A signal processing device in a wind profiler emits an electromagnetic wave pulse into a space, switches from transmitting to receiving, receives an electromagnetic wave reflected from a target to be observed, and measures wind speed from a Doppler frequency of the received electromagnetic wave, and includes an unnecessary data determiner that detects a noise section in which switching noise occurs due to the switching between transmitting and receiving, and an unnecessary data eraser that converts a received signal in the noise section to substantially insignificant data.

Signal processing device and signal processing method in wind profiler

A measurement system for an aircraft having the three-axis components of the airspeed of the aircraft, the three-axis components of the wind speed currently encountered by the aircraft, and the wind speed distribution ahead of the aircraft simultaneously in real time. It comprises a Doppler anemometer measuring the airflow speeds at a plurality of points separated by a prescribed distance in the beam irradiation direction that changes in a time series, and an inertial data measurement device measuring the movement information and positional information of the aircraft. Moreover, the display system of the aircraft includes the horizontal two-axis airspeed of the aircraft, the three-axis components of the wind speed currently encountered by the aircraft, and information on the wind speed distribution ahead of the aircraft are displayed simultaneously in real time.

Airspeed / wind speed measurement device for aircraft, and display device for same

A radar signal processing unit comprises a Fourier transform sectionfor executing Fourier transform of the received signal to a frequency signal, a frequency domain power calculation sectionfor calculating a power spectrum of electric power for each frequency from the frequency signal, an abnormal echo removal sectionfor determining the abnormal echo based on the power value of the power spectrum and outputting only the power spectrum not corresponding to the abnormal echo, an incoherent processing sectionfor performing incoherent integration of only the power spectrum not corresponding to the abnormal echo and averaging, and a signal detection sectionfor calculating the physical quantity of the atmosphere from the incoherent-integrated power spectrum.

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Tokyo, Japan

Tomoya Matsuda