But if the goal is to reproduce sounds accurately, then a speaker must be either an acoustic point source (monopole, omni-directional) or an acoustically small bi-directional source (dipole).
The results show that the annular array in different combination and excitation condition has radiation characteristics of monopole, dipole and quadrupole of acoustic logging.
实验结果表明，在不同组合和激励条件下，圆弧阵具有声波测井的单极子、偶极子和四极子声源的辐射特征。
3
Described are an effective method and practical applications for determining the formation stress field using borehole cross-dipoleacoustic logging data.