CAJ | 학술논문

针对动基座重力测量,提出了处理重力信号的小波变换与经验模态分解级联方法.该方法采用DB4小波函数的强制阈值小波变换作为前端滤波器,将原始信号分解为12层,提取第7层作为中间结果,运用经验模态分解方法用作第二级滤波器,将输入分解为8个模态,提取残余分量和最大尺度的逼近模态作为级联滤波结果.对静态重力数据进行概率密度分析,给出了重力的统计特性以及测量结果的可信度.级联滤波结果与某航空重力系统处理结果对比表明:级联滤波方法能够在强噪声中提取出微弱的重力信号,并且由于引入前端滤波器减少了级联滤波器整体计算量,提高了重力测量的空间分辨率.
침대동기좌중력측량,제출료처리중력신호적소파변환여경험모태분해급련방법.해방법채용DB4소파함수적강제역치소파변환작위전단려파기,장원시신호분해위12층,제취제7층작위중간결과,운용경험모태분해방법용작제이급려파기,장수입분해위8개모태,제취잔여분량화최대척도적핍근모태작위급련려파결과.대정태중력수거진행개솔밀도분석,급출료중력적통계특성이급측량결과적가신도.급련려파결과여모항공중력계통처리결과대비표명:급련려파방법능구재강조성중제취출미약적중력신호,병차유우인입전단려파기감소료급련려파기정체계산량,제고료중력측량적공간분변솔.
The cascaded filter containing wavelet transform and empirical mode decomposition is proposed for gravity measurement on the moving base. The cascaded filter uses compulsory threshold decreasing noise wavelet transform with Daubechies4 wavelet function as front end filter. Raw signal is decomposed intol2 layers. The 7th layer is taken as intermediate result. Empirical mode decomposition is taken as the second filter. Input is decomposed into 8 modes, The last one is taken as cascaded filter result. Probability density distribution is analyzed based on the filtered static gravity signal. Statistical characteristics of gravity signal are given, and the credence of the measurement result is e-valuated. The cascaded filters result is compared with the result from some airborne gravity measurement system. The method can extract weak gravity signal from noisy background. Computation cost is saved with front end filter. The cascaded filter can improve resolution of gravity measurement.