Building Qt Based Platform For Determining First Arrival Times

First Arrival play an important role in geophysical exploration, especially in complexnear-surface region, first arrival is even more important. However the first arrival pickingalgorithm research and the software platform are generally independent of each other. So it isnecessary to studies how to put those two together and build a perfect automatic-pickingplatform.This paper starts with first arrival determining algorithm, by comparison thosealgorithms; choose the multi-window energy ratio algorithm and neural network algorithm asthe platform’s algorithms. The multi-window energy ratio algorithm has the characteristics ofhigh speed, stability and gets reasonable results in both high SNR seismic data and low SNRseismic data. But when training the neural network, using the Back-Propagation for the initialtraining samples, and using the Cascade-Correlation algorithm for the subsequent trainingdata. The neural network identify the first arrival time by mean square root amplitude ratio,frequency, amplitude, adjacent-channel correlation and curve length ratio. At the same time,this paper also introduce some improved technologies to make the results more accurate, suchas constrained by velocity field, the error point detection and correction, the phase inversionetc. When the algorithm design has done, the main works are building this platform’sarchitecture and related modules. With all of those works, we can build an operation processfor determining first arrival times. After the design works, we choose the Qt framework as themain development environment, according to the current conditions and the efficiency of thisplatform. The Qt framework based software not only ensures this program can runs acrossdifferent platforms, but also ensures the efficiency of this program.During the studies of the software, first, the main work is design the algorithms, thenbuild the software’s architecture and related modules; thirdly programing implementation ofthis program. This whole process gives reference to the development of others related platforms. At last, the actual data calculation show this platform can correctly and efficiencydetermine the first arrival times,which has significant theoretical value and practicalapplication value.