In paper the determination problem of the location of the moving unobserved armored trucks (tanks) (1+2) kilometers away is considered. Based on the seismic location method by use of 3D coordinates detection set the computational algorithm of determination of the bearing angle and distance to unobserved target are presented, and computational errors are estimated. Also, for the purpose of angle errors minimization in target direction the triangular form of 3D detectors in one seismic location cell is offered. The optimal geometry disposition of 3D detectors in seismic location cells is determined. Offered method is effective in case of relief when seismic-acoustic signal is propagated by approximately straight line. This method can be applied only to homogenous medium, for example, to mountainous, to solid rocky soil.