Nippon Telegraph and Telephone Corporation

Ntt Corporation

Tatsuya Iizuka

Jun Kato

Naoko Kosaka

Toshimitsu Tanaka

Yohei Toriumi

Masato Maruyama

Go Itami

Fumihiko Ishiyama

A detecting system includes a tag, a radar device that transmits transmission radio waves to the tag and acquires reception radio waves produced by the transmission radio waves being reflected by the tag, and a detecting apparatus. The tag includes a pattern made of a plurality of materials that reflect or scatter radio waves received from the radar device, and the pattern includes a known pattern known to the detecting apparatus and an unknown pattern unknown to the detecting apparatus. The detecting apparatus includes a specifying unit that calculates a relative velocity between the radar device and the tag, with which the known pattern can be detected from the reception radio waves, and specifies a condition for the radar device to transmit transmission radio waves for estimating the unknown pattern, from the calculated relative velocity, and a notification unit that notifies the radar device of the specified condition.

Detecting system, detecting apparatus, detecting method, and program

A radar apparatus of the present embodiment includes a transmitting unit that transmits a frequency chirp signal whose frequency linearly changes with time, a receiving unit that receives a reflected wave that is the frequency chirp signal reflected by an object, a mixer that mixes the transmitted frequency chirp signal and the received reflected wave to obtain a beat signal, a frequency estimation unit that estimates a frequency of the beat signal, and a distance estimation unit that estimates a distance to the object based on the frequency of the beat signal. The frequency estimation unit calculates an autoregressive coefficient of an autoregressive model from a sequence of discrete signal values of the beat signal and estimates the frequency of the beat signal using a base frequency that is based on a pole of the autoregressive model.

Radar apparatus and distance measurement method

Growing community of inventors

Musashino, Japan

Tatsuya Iizuka