| 摘要 |
PROBLEM TO BE SOLVED: To achieve a high SN ratio when AGC processing by which echo components having different levels are amplified to an equivalent level. SOLUTION: A first beam formation part 31 divides each receive wave signal into a plurality of groups and forms a primary beam signal STB for each group. A first filter processing part 32 performs band restriction type filter processing for each of the primary beam signal STB. By these beam formation processing and band restriction processing, the SN ratio of the primary beam signal STB becomes greatly higher than the SN ratio of the receive wave signal. The primary beam signal STB after the filter processing is input to a AGC processing part 34 after TVC processing by a TVG processing part 33. The AGC processing part 34 amplifies the level of the primary beam signal STB to a clip level and outputs to a second beam formation part 35. The second beam formation part 35 generates a receive signal beam signal using the primary beam signal STB after the AGC processing. COPYRIGHT: (C)2011,JPO&INPIT |
