Kabushiki Kaisha Toyota Chuo Kenkyusho

Yoshikazu Asano

Kunitoshi Nishikawa

Tomohisa Harada

Mitoshi Fujimoto

Shigeki Ohshima

High-frequency signals from an oscillator (,) are transmitted, through a power divider (,) and a switch (,), from transmission antennas (T,, T,, T,). Reflection waves reflected by targets are received by reception antennas (R,, R,) to thereafter be fed via a switch (,) to a mixer (,). The mixer (,) is supplied with transmission high-frequency signals from the power divider (,) to retrieve beat-signal components therefrom, which in turn are converted into digital signals for the processing in a signal processing circuit,. The transmission antennas (T,to T,) and the reception antennas (R,, R,) are switched in sequence whereby it is possible to acquire signals equivalent to ones obtained in radars having a single transmission antenna and six reception antennas.

Holographic radar

A signal processing unit detects the azimuthal direction of a target in accordance with the phase difference between signals received by two receiving antennas. Then, by sequentially switching plural transmitting antennas having mutually different beam directions with a switching device, received signals are obtained using each of the transmitting antennas.

Radar

A land vehicle navigation system is adapted to display the present position of a vehicle by receiving signals from a combination of satellites under the global positioning navigation system. The present position of the vehicle is displayed on a screen, superposed over map data. To obtain the best global positioning data, the combination of satellites is selected in connectio with the visibility. To perform the positive reception of signals from the satellites as the vehicle is running in an urban area, data relating to the building height around the area can be obtained from a geographical information section including data indicative of the map and the building height distribution with respect to the area to determine the visibility.

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Aichi, Japan

Yoshikazu Asano