Patent ID: 8154954

Claim:
A projectile positioned proximate an underground target, the projectile being one of an array of projectiles, the projectile including: at least one transducer for communicating acoustical signals through the ground, the at least one transducer being configured to transmit a first acoustical signal to at least one other projectile in the array and receive a second acoustical signal from the at least one other projectile; a processor for controlling the communication of the at least one transducer and calculating a time delay between the transmission of the first acoustical signal and the reception of the second acoustical signal; a communication module configured to provide communication between the at least one transducer and the processor; and a clock configured to synchronize communication between the at least one transducer and the at least one other projectile, wherein the processor is configured to determine a location of the projectile relative to the array of projectiles based on the time delay.