| 摘要 |
PURPOSE:To reduce interference with a disturbing wave, and to improve angle- measuring accuracy by eliminating the need for an inter-beam interpolating process at boundary part among beam groups, by forming beams at the beam-group boundary part in the same direction as beams at the ajacent beam-group boundary part. CONSTITUTION:In required vertical-surface covering area 2 to antenna 1, 20-1 20-2 and 20-3 are lowermost beam groups using frequencies (f1), (f2) and (f3), and theta20-1, theta20-2 and theta20-3 are respective beam directions. Next, 21-1 is the lowermost beam in the 2nd beam group from the bottom and its beam direction theta21-1 agrees with theta20-3. Therefore, an interpolating process to obtain altitude information on a target is performed with frequency difference f2-f1=DELTAf between beams 20-1 and 20-2, but since the beam directions between beams 20-3 21-1 are equal, there is no need for interpolation. After this, an interpolating process as to the 2nd beam group can be done with frequency difference DELTAf. Therefore, correlation among inter- beam received signals is uniform in any direction and uniform angle-measuring accuracy can be obtained over the entire covering area. |
