Stabilizing remote clocks in a network
First Claim
1. A method of coordinating the timing cycle frequency of a subordinate clock to that of a reference clock, said clocks being components of communicating modules in a communications network, comprising the steps of:
- transmitting from said reference clock a synchronization signal comprising a first delineated sequence of reference timing cycles;
generating by said subordinate clock a second delineated sequence of subordinate timing cycles substantially corresponding to said reference timing cycles;
receiving said synchronization signal by said subordinate clock;
comparing and recording a first phase displacement between a reference timing cycle and a subordinate timing cycle;
comparing and recording a subsequent phase displacement between said reference timing cycle and said subordinate timing cycle;
determining a phase displacement differential between said first phase displacement and said subsequent phase displacement; and
,adjusting the frequency of said subordinate timing cycles by a percentage of said phase displacement differential.
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Accused Products
Abstract
The present invention utilizes signals such as interrogate commands generated from a Master Clock or other High Precision Clocks in a distributed sensor data acquisition system featuring a communications network (such as a land/transition zone seismic data acquisition system) to stabilize the oscillator (timing cycle) frequency of Remote Clocks elsewhere in the network. The disclosed invention is characterized by the utilization of highly stable timing signals from a Master Clock or other High Precision Clocks as a calibration standard to improve the oscillator frequency of distributed Remote Clocks of lesser inherent stability. Implementation of the disclosed invention results in improved synchronization of seismic amplitude data concurrently acquired over a wide area and improved subsurface geologic resolution.
35 Citations
19 Claims
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1. A method of coordinating the timing cycle frequency of a subordinate clock to that of a reference clock, said clocks being components of communicating modules in a communications network, comprising the steps of:
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transmitting from said reference clock a synchronization signal comprising a first delineated sequence of reference timing cycles; generating by said subordinate clock a second delineated sequence of subordinate timing cycles substantially corresponding to said reference timing cycles; receiving said synchronization signal by said subordinate clock; comparing and recording a first phase displacement between a reference timing cycle and a subordinate timing cycle; comparing and recording a subsequent phase displacement between said reference timing cycle and said subordinate timing cycle; determining a phase displacement differential between said first phase displacement and said subsequent phase displacement; and
,adjusting the frequency of said subordinate timing cycles by a percentage of said phase displacement differential. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. In a network connected system comprising a reference clock and one or more subordinate clocks, the combination comprising:
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reference clock means for generating and transmitting a synchronization signal comprising a first delineated sequence of reference timing cycles; subordinate clock means for generating a second delineated sequence of subordinate timing cycles substantially corresponding to said reference timing cycles; first means for receiving said synchronization signal by said subordinate clock; second means for comparing and recording a first phase displacement between a reference timing cycle and a subordinate timing cycle; third means for comparing and recording a subsequent phase displacement between said reference timing cycle and said subordinate timing cycle; fourth means for determining a phase displacement differential between said first phase displacement and said subsequent phase displacement; and
, fifth means for adjusting the frequency of said subordinate timing cycles by a percentage of said phase displacement differential. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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Specification