Autonomous Seismic Data Acquisition Unit

Abstract

A method, apparatus and system for acquiring land seismic data includes acquiring seismic data with a first autonomous seismic data acquisition unit and a second autonomous seismic data acquisition unit wherein each acquisition unit comprises a plurality of digitally controlled temperature-compensated crystal oscillators. Oscillator-based timing signals are acquired that are associated with the plurality of digitally controlled temperature compensated crystal oscillators and a time correction is determined to apply to the seismic data acquired with the first autonomous seismic data acquisition unit. The time correction is determined using the oscillator-based timing signals from the first and second autonomous seismic data acquisition units.

1 . A seismic data receiver, comprising:
 a transducer configured to receive an acoustic signal and in response operable to generate an electrical signal;   a processor configured to receive the electrical signal and in response operable to generate seismic data;   a memory device coupled to the processor for storing the seismic data;   a plurality of independent clocks each generating a respective clock signal, at least one of the clock signals being used to generate a reference clock signal to be associated with the seismic data; and   a power source operable to supply electrical power to the processor, memory device and the clocks.   
   
   
       2 . The seismic data receiver of  claim 1 , wherein the plurality of clock signals is recorded for use in computing a time correction value. 
   
   
       3 . The seismic data receiver of  claim 1 , wherein the plurality of clock signals is recorded for use in computing a time correction value for adjusting the seismic data. 
   
   
       4 . The seismic data receiver of  claim 1 , wherein one or more clock signals from the plurality of clock signals are analyzed to determine if the seismic data from the receiver is excluded from processing. 
   
   
       5 . The seismic data receiver of  claim 1 , wherein one or more selected clock signals from the plurality of clock signals are excluded from use in improving accuracy of the reference clock signal. 
   
   
       6 . The seismic data receiver of  claim 1 , wherein the power source is a battery. 
   
   
       7 . The seismic data receiver of  claim 1 , wherein the plurality of clock signals is recorded and compared to an external reference clock signal to compute a time correction value for adjusting the seismic data. 
   
   
       8 . The seismic data receiver of  claim 1 , further comprising a program code stored in the memory device for computing a time correction value using recorded clock signals and an external reference clock signal, the time correction value being used to adjust the seismic data. 
   
   
       9 . The seismic data receiver of  claim 1 , wherein at least one of the clocks is a crystal oscillator. 
   
   
       10 . The seismic data receiver of  claim 1 , wherein at least one of the clocks is a temperature compensated crystal oscillator. 
   
   
       11 . The seismic receiver of  claim 1 , further comprising an analog to digital converter configured to receive the electrical signal and operable to generate a digital signal for application to the processor. 
   
   
       12 . The seismic receiver of  claim 1 , further comprising a system bus configured to transmit the electrical signal from the transducer to the processor and to transmit the electrical power from the power source to the processor, the memory device and the clocks. 
   
   
       13 . The seismic receiver of  claim 1 , further comprising a first external interface electrically coupled to the power source for charging the power source from an external power source. 
   
   
       14 . The seismic receiver of  claim 1 , further comprising a second external interface electrically coupled to the memory device for retrieving stored seismic data. 
   
   
       15 . A seismic data acquisition system, comprising:
 a plurality of autonomous seismic receivers, at least one of the autonomous seismic receivers comprising:
 a transducer configured to receive an acoustic signal and in response operable to generate an electrical signal; 
 a processor configured to receive the electrical signal and in response operable to generate seismic data; 
 a memory device coupled to the processor for storing the seismic data; 
 a plurality of independent clocks each generating a respective clock signal, at least one of the clock signals used to generate a reference clock signal to be associated with the seismic data; and 
 a power source operable to supply electrical power to the processor, memory device and the clocks. 
   
   
   
       16 . The system of  claim 15 , wherein the plurality of clock signals is recorded for use in computing a time correction value. 
   
   
       17 . The system of  claim 15 , wherein the plurality of clock signals is recorded for use in computing a time correction value for adjusting the seismic data. 
   
   
       18 . The system of  claim 15 , wherein the power source is a battery. 
   
   
       19 . The system of  claim 15 , wherein the autonomous seismic recorders are coupled to a cable. 
   
   
       20 . The system of  claim 15 , wherein the autonomous seismic recorders are interconnected by separate connecting segments, wherein adjacent pairs of recorders are connected by a respective connecting segment. 
   
   
       21 . The system of  claim 15 , wherein one or more clock signals from the plurality of clock signals are analyzed to determine if the seismic data from the receiver is excluded from processing. 
   
   
       22 . The system of  claim 15 , wherein one or more selected clock signals from the plurality of clock signals are excluded from use in improving accuracy of the reference clock signal. 
   
   
       23 . A seismic data receiver, comprising:
 a transducer configured to receive an acoustic signal and in response operable to generate an electrical signal;   a processor configured to receive the electrical signal and in response operable to generate seismic data;   a memory device coupled to the processor for storing the seismic data;   a plurality of temperature compensated, crystal oscillators each generating a respective clock signal, at least one of the clock signals being used to generate a reference clock signal to be associated with the seismic data; and   a rechargeable battery operable to supply electrical power to the processor, memory device and the clocks.   
   
   
       24 . The seismic data receiver of  claim 23 , wherein the processor generates a time correction value using the plurality of clock signals and an external reference clock signal to adjust the seismic data.