Ground Clock Synchronization via Satellite Pulses
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for synchronizing widely distributed ground clocks are impractical and prone to errors due to the absence of line of sight between distant stations and atmospheric and fiber noise in communication links.
Innovation Solution
A system utilizing a fast-moving emitter, such as an airplane or satellite, that sends narrow pulses at frequent intervals, which are received and recorded by ground stations with frequency-locked clocks, allowing for synchronization without requiring an accurate clock on the emitter, and using a synchronization algorithm to determine time offsets and station positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If signals are exchanged between ground stations using Einstein synchronization protocol, then relative synchronization offsets can be determined, but the method becomes impractical and error-prone due to absence of line of sight and atmospheric/fiber noise
Solution Approach 1:
The patent introduces a satellite as an intermediary element that transmits timing signals to multiple ground stations. This satellite-mediated approach replaces direct ground-to-ground signal exchange, eliminating line-of-sight constraints between ground stations and reducing atmospheric/fiber noise effects. The satellite acts as a common reference point that all ground stations can independently access, thereby improving both measurement precision and reliability of synchronization offset determination.
Solution Approach 2:
The patent transitions from a two-dimensional ground-based synchronization network to a three-dimensional space-based reference system. By utilizing satellites in orbit, the system adds the vertical dimension to the synchronization architecture, allowing ground stations to receive timing signals from above rather than requiring direct lateral communication paths. This dimensional change eliminates line-of-sight blockages between ground stations and reduces propagation through noisy atmospheric and fiber channels.
2Reliability
If widely distributed ground clocks are synchronized using traditional methods, then synchronization can be achieved, but the process is time-consuming and impractical for distant stations
Solution Approach 1:
The patent implements preliminary action by having the satellite continuously transmit timing signals and by pre-establishing the synchronization infrastructure. Ground stations can immediately begin measuring time offsets as soon as they receive satellite signals, without requiring complex preliminary coordination between distant ground stations. The satellite continuously provides reference timing, allowing stations to synchronize as needed rather than requiring scheduled synchronization events.
Solution Approach 2:
The satellite-based timing system provides universal service to multiple ground stations simultaneously. A single satellite transmission serves as a common reference for all ground stations in its coverage area, eliminating the need for separate synchronization procedures between each pair of stations. This multi-functional approach allows any ground station to synchronize with any other station by independently measuring their respective offsets from the same satellite reference, dramatically reducing the time and complexity of synchronization.
3Ease of operation
If line of sight is required between ground stations for signal exchange, then direct synchronization can be attempted, but the absence of line of sight between distant stations makes the method impractical
Solution Approach 1:
The satellite serves as a mobile intermediary that can position itself to maintain line of sight with multiple ground stations simultaneously or sequentially. Rather than requiring fixed ground stations to have direct line of sight to each other, the satellite moves in orbit to provide unobstructed signal paths to all stations in the network, greatly expanding geographic coverage while maintaining operational simplicity.
Solution Approach 2:
The patent employs dynamic positioning of the satellite in orbit to adapt to the geographic distribution of ground stations. The satellite's motion allows it to maintain line-of-sight connections with stations that are geographically distant or separated by obstacles on the ground. This dynamic approach replaces the static line-of-sight requirement between fixed ground stations with a mobile platform that can continuously adjust its position to provide clear signal paths, thereby enhancing both ease of operation and geographic adaptability.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A system and method of synchronizing clocks within a system having a plurality of base stations, wherein each base station includes a frequency locked clock. A fast moving emitter transmits pulses that are received at each base station. A time of arrival for each pulse received by each base station is recorded and the recorded times of arrival are communicated to at least one of the other base stations. The clocks are synchronized as a function of the recorded times of arrival received from each base station.