Method for installing radio wave sensor, radio wave sensor, and adjustment device

A method for installing a radio wave sensor configured to radiate a radio wave to a range including a target area that is set for detection of an object, the method comprising:

• a step of installing a reference object;
• and
• a step of adjusting a radio wave radiation direction of the radio wave sensor by rotating the radio wave sensor, using the reference object as a reference, wherein:
• the reference object is installed at a first position outside the target area,
• the step of adjusting the radio wave radiation direction includes aligning an adjustment direction having a first angle with respect to the radio wave radiation direction, with a reference direction extending from the radio wave sensor toward the reference object, and
• the first angle is identical to a second angle between the reference direction and a target direction extending from the radio wave sensor toward a second position in the target area, such that:
• the step of adjusting the radio wave radiation direction includes:
• aligning the radio wave radiation direction with the reference direction, and
• rotating the radio wave radiation direction after having aligned the radio wave radiation direction with the reference direction, thereby aligning the radio wave radiation direction with the target direction extending from the radio wave sensor toward the second position, wherein
• a rotation angle when rotating the radio wave radiation direction has a magnitude that corresponds to an angle between the reference direction and the target direction.