为研究气枪的激发特性,并为气枪发射台的堪选、建设提供参考依据,在宾川地震信号发射台进行了不同气枪组合的激发试验,并对试验数据进行了分析。结果表明:(1)单支气枪激发100多次的叠加信号可以被在150km外的地震台记录到;(2)单支气枪激发与4支气枪同时激发的信号频率基本相同,且衰减基本一致,但4支气枪同时激发信号的均方根振幅约为单支气枪的4倍;(3)当气枪组合激发的信号的信噪比达到10dB时,相关系数可以达到0.99以上;(4)4支气枪同时激发的激发效率是单支气枪的4倍。从分析结果可看出,宾川地震信号发射台在牺牲一定效率的情况下,单支气枪激发信号可以替代4支气枪组合的激发信号。
In order to study the excitation characteristic of the air gun, and provide the reference for the chosen site and construction of the air gun transmitting seismic station, we take the excitation test of air guns with various combi- nations at the Binchuan Transmitting Seismic Station (TSS). Analyzing the selected test data, we found the fol- lowing results : ( 1 ) The stacked air gun signals excited by the single gun for more than 100 times can be clearly recorded at the seismic station with an epicentral distance of 150 kin. (2) The frequencies of signals excited by single and four air guns are basically same, and their corresponding attenuations are basically similar, however the RMS amplitude of the signal excited by four air guns is about 4 time as much as that of single air gun. (3) When the SNR of signal exited by single gun reaches 10 dB, the correlation coefficient of it could reach a bove 0. 99. (4) The excitation efficiency ratio of signals excited by single gun and four guns is 1 : 4. The analy- sis result shows that the signal excited by single gun can be replaced by the combination signal excited by four guns in case of losing some efficiency.