频率域提取接收函数时引入“水准量”来代替垂向分量频谱中比较小的成分以保证反褶积结果的稳定性,却降低了精度,尤其对反映深部壳幔结构的低频信息影响较大;实际的等效震源时间函数长度是有限的,由于地震记录上后续干扰震相能量的影响,垂直分量波形往往比较复杂,若将其直接作为等效震源时间函数必然影响所提取接收函数的精度.针对以上问题,本文改进“水准量”的使用方法,并采取折中方案选取“水准量”和等效震源时间函数的长度,以便在频率域反褶积中得到稳定的接收函数,同时提高反褶积的精度.对观测数据的试验效果显示,本文方法提取的接收函数稳定性好、精度高,是一种有效的提取台站高质量接收函数的方法.
“Water level” is brought into estimation of receiver function in frequency-domain to replace the value that is smaller than the level in vertical component, so that to improve the stability of deconvolution. However this will reduce the resolution of receiver function, especially the lower-frequency information which has significant meaning for studying the structure of crust and upper mantle. Furthermore, the effective source function actually has a finite length, and the vertical component is often very complicated because of the strong energy of later wave phases present on the seismic records. So it will absolutely affect the resolution of receiver function if the long record is used as an effective source function. In order to estimate stable receiver function with high resolution in frequency-domain, this paper proposed to improve the usage of “water level” and select an appropriate “water level” and effective source function length by tradeoff method. Its application to the observational data indicates that the method in this paper is effective to estimate receiver functions with high stability and resolution in frequency-domain.