Radio seismic system

Claim 1

A SEISMIC EXPLORATION APPARATUS COMPRISING, IN COMBINATION: (1) A CONTROL UNIT COMPRISING A FIRST OSCILLATOR MEANS FOR PRODUCING A FIRST OUTPUT SIGNAL HAVING A FIRST FREQUENCY AND A SECOND OUTPUT SIGNAL HAVING A SECOND FREQUENCY, AND MEANS FOR SELECTIVELY TRANSMITTING ONE OF SAID FIRST AND SECOND OUTPUT SIGNALS FROM A FIRST POINT; (2) SHOT POINT EQUIPMENT COMPRISING MEANS FOR RECEIVING THE THUS TRANSMITTED SIGNAL AT A SECOND POINT, MEANS FOR GENERATING SEISMIC SIGNALS AT SAID SECOND POINT, AND MEANS RESPONSIVE TO SAID MEANS FOR RECEIVING TO ENERGIZE SAID MEANS FOR GENERATING SEISMIC SIGNALS ONLY WHEN SAID THUS TRANSMITTED SIGNAL HAS SUBSTANTIALLY THE SAME FREQUENCY AS SAID SECOND OUTPUT SIGNALS; AND (3) SAID MEANS TO ENERGIZE COMPRISING A FIRST FLIP FLOP CIRCUIT, MEANS FOR APPLYING SAID THUS TRANSMITTED SIGNAL TO AN INPUT OF SAID FIRST FLIP FLOP CIRCUIT, PULSE COUNTING MEANS, MEANS FOR APPLYING AN OUTPUT OF SAID FIRST FLIP FLOP CIRCUIT TO AN INPUT OF SAID PULSE COUNTING MEANS, A SECOND FLIP FLOP CIRCUIT, A CAPACITOR CONNECTED ACROSS THE OUTPUT OF SAID PULSE COUNTING MEANS AND ACROSS AN INPUT OF SAID SECOND FLIP FLOP CIRCUIT TO PRODUCE A VOLTAGE THEREACROSS REPRESENTATIVE OF THE INSTANTANEOUS AVERAGE OF THE NUMBER OF PULSES COUNTED BY SAID PULSE COUNTING MEANS, SAID SECOND FLIP FLOP CIRCUIT BEING CAUSED TO CHANGE STATE WHEN THE INPUT VOLTAGE THERETO EXCEEDS A PREDETERMINED VALUE, AND MEANS FOR ACTUATING SAID MEANS FOR GENERATING SEISMIC SIGNALS RESPONSIVE TO AN OUTPUT OF SAID SECOND FLIP FLAP CIRCUIT.