| 摘要 |
PURPOSE:To obtain an inexpensive device by providing switches which change connections between plural element antennas and transducers provided on one acoustooptic element as many as the element antennas, and electric circuits. CONSTITUTION:Four elements 1a-1d are provided and transducers 6a-6d as many as the elements are also provided. The antennas 1b, 1c, and 1d and transducers 6b, 6c, and 6d are selected to find an arrival electric wave roughly while detecting a wide range of + or -90 deg. all the time. Then, the switches 21 and 24 are operated for the precise measurement of the direction to select the antennas 1a, 1c, and 1d and transducers 6a, 6c, and 6d, and reception and analysis are performed to perform detection <=2 deg. precision. In this case, the object area is about + or -30 deg., so the precise measurement tracking ability is improved by rotating the array direction of the antennas to said rough detection direction. Therefore, detection ability close to that of a radio wave detector using four channels is attained by using a receiver of substantially three channels. |
