| 摘要 |
The method employs an array of ultrasonic transducers oriented so as to emit in the same direction at right angles to three coplanar axes (e.g. X1) inclined to one another at 60 degrees . The radiation pattern has a main lobe (2) with secondary lobes (3-5) on either side. The direction of aim is varied by phasing so that a region of observation is swept while the amplitude of the returned echo from an object (6) is measured. When the amplitude reaches its maximum value, the deviation (u) of the main lobe from a reference direction (D0) is measured. |
