福建南一水库气枪震源实验激发效果最优分析与研究
Study of the Optimal Excitation Effect of Air-gun SourceExperiments in Nanyi Reservoir, Fujian Province

气枪主动源探测实验需要获得信噪比较优的波形数据，因此实验前很有必要进行不同工况的激发实验。通过综合分析台站记录特征，寻找最优激发效果的工况条件，为后续定点激发奠定重要基础。本文在福建南一水库大容量气枪震源实验时通过单次激发分析、叠加分析、信噪比系数等方法综合研判工况激发效果，确定出最优工况，再利用台网噪声评估对得到的最优工况做进一步验证。结果表明：南一水库最优工况为：水深25 m、枪阵沉放深度12 m、枪阵尺寸7 m×7 m。该最优工况激发时段未处在低噪声时刻，说明该工况的激发效果确为优越，结果较为可靠。
Waveform data with optimal signal-to-noise ratios are required in air-gun active-source experiments, so excitation experiments must be performed under various operating conditions. By comprehensively analyzing the characteristics of station records to identify conditions that yield an optimal excitation effect, we can lay the foundation for subsequent fixed-point excitation experiments. In this study, we used three methods——single-shot analysis, superposition analysis, and the coefficients of signal-to-noise ratios——to comprehensively analyze the excitation effects of air-gun source experiments under different operating conditions in Nanyi Reservoir, Fujian province. We then determined the optimal condition. We also evaluated network noise to further verify this optimal condition. The results indicate that the optimal condition in Nanyi Reservoir is a water depth of 25 m, an air-gun array sinking depth of 12 m, and an air-gun array size of 7 m×7 m. In addition, the excitation time of this optimal operating condition does not occur in a low-noise moment, which verifies the good stimulation effect of this condition and the reliability of the results.