CAJ | 학술논문

Seislet 变换是一种类小波变换方法，主要根据小波基沿地震同相轴的局部倾角方向来分析数据，其中，局部地震倾角的表征是该方法的核心。局部倾角的求取方法有很多种，但是往往在低信噪比的条件下存在着一些局限。根据共中心点道集中基于时距关系的地震倾角定义，提出一种适应于低信噪比条件下的倾角求取方法。对比基于时距关系与平面波分解滤波器计算出的局部地震倾角，结果证明，该方法能更加准确地表征低信噪比条件下同相轴的倾角信息。将基于时距关系的局部地震倾角用于 Seislet 框架，建立表征低信噪比数据的新型 Seislet 变换方法。在地震数据处理中，引入语音信号中改进的阈值方法。结合新型 Seislet 变换，提出阈值去噪方法，此方法不但适于地震数据，而且在提高信噪比方面也优于传统的阈值去噪方法。实际数据处理的结果验证了新型 Seislet 变换与改进阈值去噪方法的组合能够有效地解决低信噪比条件下的信号提取任务。
Seislet 변환시일충류소파변환방법，주요근거소파기연지진동상축적국부경각방향래분석수거，기중，국부지진경각적표정시해방법적핵심。국부경각적구취방법유흔다충，단시왕왕재저신조비적조건하존재착일사국한。근거공중심점도집중기우시거관계적지진경각정의，제출일충괄응우저신조비조건하적경각구취방법。대비기우시거관계여평면파분해려파기계산출적국부지진경각，결과증명，해방법능경가준학지표정저신조비조건하동상축적경각신식。장기우시거관계적국부지진경각용우 Seislet 광가，건립표정저신조비수거적신형 Seislet 변환방법。재지진수거처리중，인입어음신호중개진적역치방법。결합신형 Seislet 변환，제출역치거조방법，차방법불단괄우지진수거，이차재제고신조비방면야우우전통적역치거조방법。실제수거처리적결과험증료신형 Seislet 변환여개진역치거조방법적조합능구유효지해결저신조비조건하적신호제취임무。
Seislet transform is a wavelet-like transform based on wavelet base that analyzes seismic data along variable local event slopes.The calculation of the local event slopes is the key step of this method.There are many kinds of methods to calculate the local slopes.But in the condition of low SNR, these methods have some limits.We propose a method that is suitable for low SNR based on the definition of the slopes of t-x relationship in CMP traces.Comparing the slopes of t-x relationship in CMP traces with PWD method,we can see that the new method is more accurate in calculating the local slopes.Apply these slopes to Seislet frame to establish a new Seislet transform that characterize low SNR data.In seismic data processing,we introduce one method which works well for acoustic signals. We propose the new threshold method with Seislet transform.It is not only suitable for seismic signals, but also better than the traditional threshold method to improve SNR.The results show that the combination of the new Seislet transform and improved threshold method can extract signal in the condition of low SNR effectively.