Land seismic reflection detection technology of airgun source：A case study of the Tongling experiment of “Yangtze River Geoscience Project”

In order to explore the feasibility and effectiveness of the large capacity airgun source in the regional structure detection and whether the airgun source can be used for water-land measurements in flowing water body of inland, the Tongling experiment of “Yangtze River Geoscience Project” was carried out in 2015. This paper comprehensively analyzes the influencing factors of the land reflection experimental results of large capacity airgun source in the respects of the experimental observation system, distribution of common middle points, fold times and the data characteristics of single shots. The experimental results show that: ① Large capacity airgun source can be used for the detection of crustal structure in inland water body; ② According to the requirements of the target layer, the reflection angle analysis should be designed reasonably, thus it will solve the problems of insufficient reflection angle caused by small offset and the insufficient energy resulted from large offset; ③ During the process of curve data collection, the observation system needs to be designed so as to improve the coverage number of the common central bin; ④ According to the size of the airgun source, the maximum and minimum offsets are important to ensure the accuracy of the analysis of the surface imaging speed and the reasonable distribution of the surface offset attribute.