数模检波器信号响应的时频分析

理论上，数字检波器与模拟检波器对相同地震信号的频幅响应和相位响应各有不同，但在实际记录中响应差别却存在与理论的不一致性。而利用频谱分析等常规分析方法，记录响应的差别较难分析出来。为了进一步分析实际记录响应，从局部精细对比差异，针对两者输出信号类型的不同，将记录转换到加速度域中，利用自适应核时频分析方法对其进行时间频率域分析，以及主频段重构记录，提高差异分析精度。分析结果验证两种检波器记录响应应当转换至同一个域中对比，数字检波器响应频带宽，动态范围大，相位随频率的响应变化小，对于小于15Hz的低频信号与高频弱信号的响应能力强。

Time--Frequency of MEMS Accelerometers and Analog Geophones Signal Response

Theoretically, MEMS accelerometers and analog geophones have different responses to the same seismic signal, including frequency--amplitude response and frequency--phase response, but in the actual recording, the different responses are not consistent in theory. Using convention- al analytical method such as spectrum analysis, the recording of the different responses are difficult to be analyzed. For the purpose of making a further analysis on the actual recording responses, their local differences are compared carefully and based on the differences of the two, the recording is converted to the accelerating domain and then the adaptive optimal--kernel time--frequency a- nalysis method is adopted to analyze the time--frequency domain. Furthermore, the reconstructed recording of the main frequency band is improved in the accuracy of differences analysis. The re- suits verify that the two types of detector record responses should be converted to the same domain to be compared, the responses of MEMS accelerometers have a wide frequency band, the dynamic range is big and the change of the phase frequency response is small, which has strong response tothat which is less than 15Hz in the low frequency signal and the high--frequency, but weak signal responses.