CAJ | 학술논문

阐述了时频分析技术中重排算法的基本思想,给出了部分重排算法的局部能量重心表达式;设计了两个数值实验,利用几种重排算法对单道地震信号进行了计算和分析比较.结果表明:重排算法不仅能有效抑制交叉项,同时也能提高时频聚集性,从而获得更理想的局部信号特征.其中以重排 Spectrogram 分布的时频聚集能力最佳,尤其适合于突出主频信号;重排平滑伪Wigner-Ville分布同样也能够获得较理想的时频效果,但稍弱于前一种方法;重排伪MH分布的时频聚集性相对较差,没有对分散的能量进行有效的重新分配处理.重排算法因其突出的时频聚集能力,应用在地震剖面中可以得到更加细致的瞬时频率特征.
천술료시빈분석기술중중배산법적기본사상,급출료부분중배산법적국부능량중심표체식;설계료량개수치실험,이용궤충중배산법대단도지진신호진행료계산화분석비교.결과표명:중배산법불부능유효억제교차항,동시야능제고시빈취집성,종이획득경이상적국부신호특정.기중이중배 Spectrogram 분포적시빈취집능력최가,우기괄합우돌출주빈신호;중배평활위Wigner-Ville분포동양야능구획득교이상적시빈효과,단초약우전일충방법;중배위MH분포적시빈취집성상대교차,몰유대분산적능량진행유효적중신분배처리.중배산법인기돌출적시빈취집능력,응용재지진부면중가이득도경가세치적순시빈솔특정.
The main idea of reassignment method in time-frequency analysis is presented and some expressions used to compute the accurate location of the local energy gravity center are given;then two numerical experiments are presented to show how these reassignment methods work individually as used to process single-trace seismic data. Based on the experiments, some conclusions are drawn that the reassignment methods can not only effectively reduce cross-terms, but also lead to a good time-frequency concentration. Compared with others, the reassignment spectrogram has the best potential for ideal time-frequency concentration, especially when the dominant frequen-cies are required to be underlined. The reassignment smoothing pseudo Wigner-Ville distribution can also achieve perfect effects though it is a little worse than the former one. The pseudo Margenau-Hill distribution is the worst of the three, since it fails to relocate the dispersive energy to the calculated center. A pretty precise instantaneous fre-quency section can be produced when the reassignment method is applied to deal with seismic signals.