Wireless exploration seismic system

Abstract

Systems and methods for seismic data acquisition employing a dynamic multiplexing technique. The dynamic multiplexing technique may include advancing one or more modules in a seismic array through a multiplexing signature sequence in successive transmission periods. The multiplexing signature sequence may be random or pseudo-random. A shared multiplexing signature sequence may be used at all the modules in the seismic array. As such, modules belonging to a common collision domain may operate out of phase with respect to the shared multiplexing signature sequence.

What is claimed is: 
     
         1 . A method for use in seismic data acquisition, comprising the steps of:
 disposing, in series, a plurality of seismic data acquisition modules that are operative to wirelessly communicate acquired seismic data, wherein said acquisition modules define a wireless serial data transfer path for relaying data from upstream acquisition modules to downstream acquisition modules and a data collection unit;   assigning a first acquisition module in said serial data transfer path a first multiplexing signature sequence, wherein in successive transmission periods, the first acquisition module advances sequentially through a first plurality of multiplexing signatures of the first multiplexing sequence;   assigning a second acquisition module in said serial data transfer path a second multiplexing signature sequence, wherein in successive transmission periods, the second acquisition module advances sequentially through a second plurality of multiplexing signatures of the second multiplexing sequence.   
     
     
         2 . The method according to  claim 1 , further comprising:
 first transmitting, using a first multiplexing signature of the first plurality of multiplexing signatures, seismic data from the first acquisition module to at least one downstream acquisition module; and   second transmitting, using a second multiplexing signature from the second plurality of multiplexing signatures, seismic data from the second acquisition module to at least one downstream acquisition module.   
     
     
         3 . The method according to  claim 2 , wherein the first multiplexing signature sequence and the second multiplexing signature sequence comprise a random sequence of multiplexing signatures. 
     
     
         4 . The method according to  claim 3 , further comprising:
 detecting when the first multiplexing signature used in the first transmitting is the same as the second multiplexing signature used in the second transmitting; and   first retransmitting, using the next multiplexing signature from the first multiplexing signature sequence, seismic data from the first acquisition module to at least one downstream acquisition module; and   second retransmitting, using the next multiplexing signature from the second multiplexing sequence, seismic data from the second acquisition module to at least one downstream acquisition module.   
     
     
         5 . The method according to  claim 2 , wherein the first multiplexing signature is different than the second multiplexing signature. 
     
     
         6 . The method according to  claim 2 , wherein at least a portion of the first transmitting and at least a portion of the second transmitting occur during a common transmission period. 
     
     
         7 . The method according to  claim 6 , wherein the first multiplexing signature sequence and the second multiplexing signature sequence comprise the same pseudo-random sequence of multiplexing signatures. 
     
     
         8 . The method according to  claim 7 , wherein the first acquisition module and the second acquisition module operate out of phase with respect to the shared pseudo-random sequence of multiplexing signatures. 
     
     
         9 . The method according to  claim 8 , wherein the multiplexing signatures comprise a plurality of different frequencies. 
     
     
         10 . The method according to  claim 2 , further comprising:
 assigning the first multiplexing signature sequence to a third data acquisition module.   
     
     
         11 . The method according to  claim 10 , wherein the first and third acquisition modules are positioned in the serial transmission path at first and second locations, and wherein a distance between the first and second locations is greater than a transmission range of the first and third acquisition modules. 
     
     
         12 . A method for use in seismic data acquisition, comprising:
 disposing a plurality of seismic data acquisition modules in an array, wherein each seismic data acquisition module is operative to wirelessly communicate with at least one other seismic data acquisition module in said array to define at least a first serial data transmission path;   assigning each of said plurality of seismic data acquisition modules in said first serial data transmission path a multiplexing signature sequence for use in transmitting said seismic data, wherein at least one multiplexing signature is assigned to first and second seismic data acquisition modules in said first serial data transmission path during a first common transmission period;   during the first common transmission period, transmitting seismic data from said first and second seismic data acquisition units using said at least one multiplexing signature;   advancing the first and second seismic data acquisition modules in the multiplexing signature sequence such that the first and second seismic data acquisition modules are assigned at least one different multiplexing signature during a second common transmission period.   
     
     
         13 . The method according to  claim 12 , wherein the multiplexing signature sequence is a random sequence of multiplexing signatures. 
     
     
         14 . The method according to  claim 13 , wherein the method further comprises:
 detecting a data collision between the first and second seismic data acquisition unit during the first common transmission period; and   retransmitting the seismic data during the second common transmission period using the at least one different multiplexing signature.   
     
     
         15 . The method according to  claim 12 , wherein the multiplexing signature sequence is a pseudo-random sequence. 
     
     
         16 . The method according to  claim 15 , wherein the multiplexing signature sequence for the first seismic data module and the second seismic data module is the same. 
     
     
         17 . The method according to  claim 16 , wherein the first seismic data module and the second seismic data module are out of phase with respect to the multiplexing signature sequence. 
     
     
         18 . A system for use in seismic data acquisition, comprising:
 a plurality of seismic data acquisition modules, disposed in series, operable to wirelessly communicate acquired seismic data, wherein said acquisition modules define a wireless serial data transfer path for relaying data from upstream acquisition modules to downstream acquisition modules and a data collection unit;   a first acquisition module in said serial data transfer path for transmitting seismic data using a first multiplexing signature from a first multiplexing signature sequence during a first transmission period, wherein said first acquisition module advances through said first multiplexing signature sequence in successive transmission periods; and   a second acquisition module in said serial data transfer path for transmitting seismic data using a second multiplexing signature from a second multiplexing signature sequence during the first transmission period, wherein said second acquisition module advances through said second multiplexing signature sequence in successive transmission periods;   wherein said first multiplexing signature and said second multiplexing signature are different during the first transmission period.   
     
     
         19 . The system according to  claim 18 , wherein said first multiplexing signature sequence and said second multiplexing signature sequence are a common pseudo-random sequence of a plurality of frequencies. 
     
     
         20 . The system according to  claim 19 , wherein said first acquisition module and said second acquisition module are out of phase with respect to the common pseudo-random sequence. 
     
     
         21 . The system according to  claim 20 , further comprising:
 a third acquisition module in said serial data transfer path for transmitting seismic data using the first multiplexing signature from the first multiplexing signature sequence during the first transmission period, wherein said third acquisition module advances through said first multiplexing signature sequence in successive transmission periods;   wherein the first acquisition module and third acquisition module are at a first location and a second location, the first location and second location being separated by a distance greater than the transmission range of the first and third acquisition module.   
     
     
         22 . The system according to  claim 21 , wherein the first and third module are in phase with respect to the common pseudo-random sequence.