An object detection apparatus for detecting objects around the apparatus by transmitting a probe wave and receiving reflections from the objects. If it is determined that both first and second object positions can be calculated using a combination of first direct and indirect waves and a combination of second direct and indirect waves, respectively, and at least one of third and fourth object positions can be calculated using a combination of the second direct wave and the first indirect wave and a combination of the first direct wave and the second indirect wave, only the first object position is calculated. The second direct wave is received at a first location after receipt of the first direct wave at the first location. The second indirect wave is received at a second location away from the first location after receipt of the first indirect wave at the second location.