Patent ID: 7755537

Claim:
A method of adjusting an orientation direction of an array antenna of a direction detection apparatus to be aligned along a specific direction, said array antenna comprising a plurality of antenna elements and said direction detection apparatus comprising a transmitting antenna and transmitting circuitry adapted to transmit radar waves, and receiving circuitry adapted to acquire respective received signals of said antenna elements, with said received signals resulting from reflected radar waves that are incident on said antenna elements, direction calculation circuitry adapted to calculate respective directions of said incident radar waves based on said received signals of said antenna elements, with said calculation being executed based on an assumption that a total number of said incident wave directions is a specific set value, output circuitry adapted to output information expressing said directions that are calculated by said direction calculation circuitry, and estimation setting circuitry adapted to derive an estimated number of said incident wave directions, based on said received signals of said antenna elements, and to establish said estimated number as said set value that is utilized by said direction calculation circuitry; wherein said method comprises adjusting said orientation direction of the array antenna to become aligned in a predetermined relationship to one or more stationary objects from which reflected radar waves are received by said array antenna and which are disposed at predetermined directions with respect to said antenna array, by: inhibiting said operation of said estimation setting circuitry for establishing said estimated number as said set value that is utilized by said direction calculation circuitry, establishing a predetermined fixed number as said set value that is utilized by said direction calculation circuitry, and adjusting said orientation direction based upon an estimated direction of at least one of said stationary reflecting objects as expressed by said information outputted by said output circuitry.