A radar of the present invention has: (1) an antenna unit for transmitting a radio wave and receiving a reflected wave of the radio wave; (2) rotating means for rotating the antenna unit about an axis along a direction of transmitting the radio wave; and (3) control means for detecting an azimuth of a target from the reflected wave, the azimuth using the axis as a reference and being defined in a plane determined from a posture of the antenna unit and the axis.
An attachment method attaches a bracket to a vehicle, and attaches a radar to the bracket so that an axis of a directivity pattern of an antenna directs upward with respect to a horizontal direction. The antenna of the radar has an asymmetric vertical directivity pattern with respect to the axis of the directivity pattern.
