A time delay apparatus for generating a plurality of phase shifted signals is described comprising a phase tuner generating a phase control signal and a phase interpolator receiving at least one digital signal and generating the plurality of phase shifted signals by phase shifting the digital signal according to the phase control signal. Within each sub-net grouping, measured range information between units within the sub-nets and one or more reference units is gathered in at least a selected one of the units. The slanting angles of reflecting mirrors 181a14 181f move are set at angles that converge the reflected laser rays at a target area.