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

2020 ◽  
Vol 10 (11) ◽  
pp. 3768
Author(s):  
Ruyun Tian ◽  
Junjie Zhang ◽  
Shuai Zhang ◽  
Longxu Wang ◽  
Hongyuan Yang ◽  
...  
Keyword(s):  
High Precision ◽  
Seismic Data ◽  
Energy Efficient ◽  
Time Synchronization ◽  
High Density ◽  
Seismic Survey ◽  
Data Synchronization ◽  
Synchronization Method ◽  
Synchronization Accuracy ◽  
Synchronization Performance

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.

scholarly journals An Energy Efficient Synchronization Protocol for Target Tracking in Wireless Sensor Array Networks

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1367
Author(s):  
Jie Shen ◽  
Ming Yin ◽  
Ji-An Luo ◽  
Zhi-Bo Wang ◽  
Zhi Wang ◽  
...  
Keyword(s):  
Target Tracking ◽  
Energy Efficient ◽  
Sensor Array ◽  
Time Synchronization ◽  
Wireless Sensor ◽  
Guarantee System ◽  
Network Maintenance ◽  
Array Synchronization ◽  
Synchronization Accuracy ◽  
Synchronization Protocol

Time synchronization is an important middleware function that supports the Quality of Service (QoS) of systems in wireless sensor array networks. Instead of providing high synchronization accuracy for all application scenarios, we argue that synchronization protocols should be application specific. In this paper, we exploit the synchronization requirements of target-tracking systems in wireless sensor array networks and propose an energy-efficient Sensor Array Synchronization Protocol (SASP), which provides the required synchronization accuracy to guarantee the QoS. Specifically, when no target appears, to guarantee system lifetime, coarse synchronization is achieved with little overhead by piggybacking time information onto periodical network maintenance packets. Once targets appear, SASP achieves high inter-array and relatively higher intra-array synchronization accuracy rather than the traditional network-wide high accuracy on average. In this way, it guarantees reliable communication and accurate data fusion, while reducing energy consumption. Theoretical analysis and extensive evaluations show the effectiveness of the proposed protocol.

High Precision GPS Clock Synchronization Method Based on Time Different Compensation

2015 ◽  
Vol 713-715 ◽  
pp. 1373-1376
Author(s):  
Xue Ming Zhai ◽  
Lei Yang ◽  
Liang Yang
Keyword(s):  
Power System ◽  
High Precision ◽  
Software Design ◽  
Simultaneous Measurement ◽  
Time Synchronization ◽  
Clock Synchronization ◽  
Synchronization Method ◽  
Gps Satellites ◽  
Simulation Results ◽  
Better Than

In order to solve the issues of time synchronization that occurs in simultaneous measurement in power system, designing a GPS clock synchronization method based on time different compensation which can guarantee high-precision whether the GPS satellites are locked or not. The paper provides the basic idea describe and the overall hardware and software design. Simulation results show that the scheme provides second pulse with error in 0.8μs when GPS is locked and provides second pulse with error in 7μs when GPS is unlocked for 12 hours. The accuracy is better than the existing references.

Preconditioning point-source/point-receiver high-density 3D seismic data for lacustrine shale characterization in a loess mountain area

2017 ◽  
Vol 5 (2) ◽  
pp. SF177-SF188 ◽  
Author(s):  
Wei Wang ◽  
Xiangzeng Wang ◽  
Hongliu Zeng ◽  
Quansheng Liang
Keyword(s):  
Data Quality ◽  
Seismic Data ◽  
Ordos Basin ◽  
Seismic Inversion ◽  
High Density ◽  
Seismic Survey ◽  
3D Seismic ◽  
Noise Characteristics ◽  
Lacustrine Shale ◽  
3D Seismic Data

In the study area, southeast of Ordos Basin in China, thick lacustrine shale/mudstone strata have been developed in the Triassic Yanchang Formation. Aiming to study these source/reservoir rocks, a 3D full-azimuth, high-density seismic survey was acquired. However, the surface in this region is covered by a thick loess layer, leading to seismic challenges such as complicated interferences and serious absorption of high frequencies. Despite a specially targeted seismic processing workflow, the prestack Kirchhoff time-migrated seismic data were still contaminated by severe noise, hindering seismic inversion and geologic interpretation. By taking account of the particular data quality and noise characteristics, we have developed a cascade workflow including three major methods to condition the poststack 3D seismic data. First, we removed the sticky coherent noise by a local pseudo [Formula: see text]-[Formula: see text]-[Formula: see text] Cadzow filtering. Then, we diminished the random noise by a structure-oriented filtering. Finally, we extended the frequency bandwidth with a spectral-balancing method based on the continuous wavelet transform. The data quality was improved after each of these steps through the proposed workflow. Compared with the original data, the conditioned final data show improved interpretability of the shale targets through geometric attribute analysis and depositional interpretation.

scholarly journals Optimization of Time Synchronization and Algorithms with TDOA Based Indoor Positioning Technique for Internet of Things

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6513
Author(s):  
Kun Zhao ◽  
Tiantian Zhao ◽  
Zhengqi Zheng ◽  
Chao Yu ◽  
Difeng Ma ◽  
...  
Keyword(s):  
Internet Of Things ◽  
High Precision ◽  
Time Synchronization ◽  
Indoor Positioning ◽  
Least Square ◽  
Ultra Wideband ◽  
Positioning Error ◽  
Time Difference Of Arrival ◽  
Positioning Technique ◽  
Synchronization Performance

To provide high-precision positioning for Internet of Things (IoT) scenarios, we optimize the indoor positioning technique based on Ultra-Wideband (UWB) Time Difference of Arrival (TDOA) equipment. This paper analyzes sources of positioning error and improves the time synchronization algorithm based on the synchronization packet. Then we use the labels of the known position to further optimize the time synchronization performance, and hence improve TDOA measurements. After time synchronization optimization, a Weighted Least Square (WLS) and Taylor coordination algorithm is derived. Experiments show that our optimization reduces the average positioning error from 54.8 cm to 12.6 cm.

Dukhan 3D: An Ultra High Density, Full Wide Azimuth Seismic Survey for the Future

2009 ◽  
Author(s):  
Salva R. Seeni ◽  
Scott Robinson ◽  
Michel Denis ◽  
Patrick Sauzedde
Keyword(s):  
High Density ◽  
Seismic Survey ◽  
The Future
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