A High-Precision Energy-Efficient GPS Time-Sync Method for High-Density Seismic Surveys

Abstract

Large numbers of seismic channels and high-density energy-efficient acquisition systems are the development trend of seismic instruments and have attracted high R&D interests in recent years. The combination of remote sensing and wireless sensor network technology provides superior observation capabilities for high-density seismic exploration. However, large-scale and multi-node acquisition methods place higher requirements on time synchronization performance. Seismic data with poor time synchronization will cause considerable errors in the interpretation of seismic data and even have no practical significance. Thus, the strict time synchronization performance is the prerequisite and basis for the application of cable-less storage seismograph in high-density seismic array applications. The existing time synchronization methods have high power consumption and poor time synchronization accuracy, which is not suitable for the long-time task. In addition, these methods are affected by the number of nodes and the distance. This paper presents an energy-efficient time-sharing indexed interpolation intercept method for the seismic data synchronization. The time synchronization method uses the high-precision TCXO as the main clock and records GPS time in the SD card at intervals to achieve the high-precision time-stamp for the seismic data. Then the seismic data is intercepted intermittently based on precise time stamps, which achieves the strict seismic data synchronization. Performance analysis shows that the time synchronization accuracy of the proposed method is 0.6 μs and saves 73% energy of the time-sync periods compared to the common GPS timing method. The field measurement results indicate that the time synchronization accuracy is not associated with the working time and the distance between nodes so that the proposed synchronization method is suitable for the high-density seismic survey.

A Dynamic Framework for Internet-Based Network Time Protocol

“…GPS time synchronization has been widely used as an accurate timing reference in computer networks. A GPS time-sync method for seismic surveys with high precision is introduced in [ 18 ]. By installing GPS receivers at survey locations to synchronize seismic data capture equipment with nanosecond-level precision, this technology offers advantages such as precise data gathering and energy efficiency.…”

“…It ultimately enhances the network performance and reduces errors. However, the limitation of the works in [ 18 , 19 ] is their inability to receive signals in those locations where GPS is prohibited.…”

“…In short, existing architectures for GNTP [ 18 , 19 , 20 , 21 ] highlight the significant role of GPS technology in network coordination, navigation, and time synchronization. While these innovations enhance the efficiency, accuracy, and reliability of various systems and applications, their reliance on external GPS infrastructure and signals means that their suitability must be carefully evaluated in specific application scenarios.…”

“…Another low-power GPS synchronization method for wireless nodes is presented by [19]. Similar to the work in [18], this technique also ensures precise and continuous coordination using GPS signals to synchronize the clocks in wireless nodes. It ultimately enhances the network performance and reduces errors.…”

Optimal Estimation of Link Delays based on End-to-End Active Measurements

“…Therefore, if the source and destination of a flow are two different entities then the one-way delay is not accurately computable due to the time difference of source and destination. It is worth mentioning that GPS based clock synchronization [28] could be a viable solution, however, we prefer to work on a solution that does not require GPS module.All things considered, the applicable way of measuring one-way delay based on the analysis of flows' end-to-end delay is to set the source and destination to one node. This assumption brings up some implementation issues which is handled in our developed code (all code is open access and available from [8]).…”