scholarly journals Improvement and Simulation of an Autonomous Time Synchronization Algorithm for a Layered Satellite Constellation

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Feijiang Huang ◽  
Xiaochun Lu ◽  
Guangcan Liu ◽  
Liping Sun ◽  
Wang Sheng ◽  
...  
Keyword(s):  
Time Synchronization ◽  
Earth Orbit ◽  
Satellite Constellations ◽  
Satellite Constellation ◽  
Ground Station ◽  
Synchronization Algorithm ◽  
Satellite Visibility ◽  
Simulation Results ◽  
Simulation Errors ◽  
System Time

Autonomous time synchronization for satellite constellations is a key technology to establish a constellation system time without the use of a ground station. The characteristics of satellite visibility time for layered satellite constellations containing geostationary earth orbit (GEO), inclined geosynchronous orbit (IGSO), and medium earth orbit (MEO) satellites are simulated by establishing a visible satellite model. Based on the satellite visible simulation results for a layered constellation, this study investigates the autonomous time synchronization algorithm that corresponds to the layered constellation structure, analyzes the main error of the time synchronization algorithm, and proposes methods to improve the characteristics of satellite movement in the constellation. This study uses an improved two-way time synchronization algorithm for autonomous time synchronization in the GEO-MEO satellite layer of a layered satellite constellation. The simulation results show that in a condition with simulation errors, the time synchronization precision of this improved algorithm can be controlled within 5 ns and used in high-precision autonomous time synchronization between layered satellite constellations.

scholarly journals Design Coverage Optimization Based on Position of Constellations and Cost of the Launch Vehicle

2021 ◽  
Vol 17 ◽  
pp. 1160-1190
Author(s):  
Saeid Kohani ◽  
Peng Zong ◽  
Fengfan Yang
Keyword(s):  
Genetic Algorithms ◽  
Optimal Design ◽  
Launch Vehicle ◽  
Multiple Objective ◽  
Satellite Constellations ◽  
Coverage Optimization ◽  
Satellite Constellation ◽  
Constellation Design ◽  
Global Coverage ◽  
Simulation Results

This research will analyze the tradeoffs between coverage optimization based on Position dilution of precision (PDOP) and cost of the launch vehicle. It adopts MATLAB and STK tools along with multiple objective genetic algorithms (MOGA) to explore the trade space for the constellation designs at different orbital altitudes. The objective of optimal design solutions is inferred to determine the economic and efficient LEO, MEO, HEO or hybrid constellations and simulation results are presented to optimize the design of satellite constellations. The benefits of this research are the optimization of satellite constellation design, which reduces costs and increases regional and global coverage with the least number of satellites. The result of this project is the optimization of the number of constellation satellites in several orbital planes in LEO orbit. Validations are based on reviewing the results of several simulations. The results of graphs and tables are presented in the last two sections and are taken from the results of several simulations.

scholarly journals Time Synchronized High Performing Cluster-Based Routing Algorithm for Wireless Sensor Networks

2013 ◽  
Vol 5 (11) ◽  
pp. 561-567
Author(s):  
Huifang DENG
Keyword(s):  
Wireless Sensor Networks ◽  
Energy Consumption ◽  
Sensor Networks ◽  
Data Fusion ◽  
Total Energy ◽  
Time Synchronization ◽  
Routing Algorithm ◽  
Wireless Sensor ◽  
Synchronization Algorithm ◽  
Simulation Results

In this paper, we investigated the data fusion routing algorithm and the time synchronization algorithm for the wireless sensor networks. First, we proposed a new data fusion routing algorithm - Low Energy Consumption Cluster-Based Routing Algorithm (LECCBRA). Simulation results show that the total energy can be effectively saved, and the balance in energy consumption between clusters can be achieved with LECCBRA, thus the network lifetime is extended. Second, we proposed a time synchronization algorithm - Clustering-based Time Synchronization (CBTS), which is suitable for LECCBRA. Performance analysis and simulation results show that the total energy can be effectively saved, and the accuracy can be improved.

Sign in / Sign up

Export Citation Format

Share Document