地震数据采集器非线性指标测试方法及其影响分析

为了分析总谐波失真度和互调失真度这两个非线性指标的测试方法、输入信号幅值等变化对其测试结果的影响，本文从总谐波失真信号、互调失真信号的产生原理出发，详细地给出了两种指标的测试方法、数据处理方法及相关影响分析，并通过实际应用中不同类型的输入信号进行了总谐波失真度和互调失真度试验。测试结果表明:信号模式和信号幅值对总谐波失真度的影响显著；输入信号幅值对互调失真度的影响较大；输入信号的频率变化对两指标的测试结果无影响。本研究进一步细化了地震数据采集器性能指标的标准化测试方法，该方法可广泛应用于地震数据采集器的非线性指标测试。 

Test methods for nonlinear parameters of seismic data recorders and their effect analyses

Total harmonic distortion （THD） and intermodulation distortion （IMD） characteris-tics are two important nonlinear parameters of seismic data recorders. Input signal mode and peak value of sine-wave can affect the test results of these two characteristics. In order to deter-mine these effects, the basic principles on THD and IMD were introduced in this paper, and then test methods, data processing methods and effect analyses on THD and IMD were fully presented. Finally, some different kinds of sine-waves were input into the seismic data recorder to test THD and IMD. The test results show that the two signals with the same peak value but different input-mode have great impact on THD, and those with the same frequency but different peak value of sine-wave have great impact on IMD. However, signal frequency variation has no impact on THD and IMD. The research in this paper is of great value for quality test of seismic data recorder, which can be applied to test THD and IMD of seismic data recorders.