Lightning Location Using Autocorrelation Time Offset Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing time-difference-of-arrival (TDOA) systems for locating lightning strikes face a tradeoff between accuracy and communication link bandwidth, requiring large amounts of data to be transmitted to a central processor, which is inefficient and prone to noise interference.
Innovation Solution
The method involves positioning multiple monitoring stations with synchronized time stamp generators and replica waveform processors to calculate time offsets between received and replica waveforms, allowing for localized autocorrelation and reduced data transmission, enhancing signal-to-noise ratio and eliminating the need for extensive bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electromagnetic waveforms are demodulated at remote monitoring stations and entire digitized signals are forwarded to central processor, then location accuracy is improved, but communication bandwidth requirements increase significantly
Solution Approach 1:
The patent extracts only the essential timing information (time of arrival estimates) from the complete electromagnetic waveforms at each remote monitoring station. Instead of transmitting entire digitized signals, the system processes and extracts only the critical temporal parameters needed for location determination, significantly reducing data transmission volume while maintaining location accuracy.
Solution Approach 2:
The patent performs preliminary signal processing and time of arrival estimation at each remote monitoring station before transmission. By pre-processing the signals locally to extract timing information, the system prepares the data in advance, reducing the burden on communication links and enabling accurate location determination without transmitting complete waveform data.
2Measurement precision
If time difference of arrival estimation is performed with high accuracy requirements, then location precision is improved, but signal-to-noise ratio requirements increase
Solution Approach 1:
The patent introduces synchronized timing signals as an intermediary reference that enables accurate time of arrival estimation without requiring direct comparison of noisy received waveforms. By using a common timing reference distributed to all monitoring stations, the system mediates the measurement process, allowing precise timing measurements even in the presence of noise.
Solution Approach 2:
The patent uses replicated timing signal copies distributed to multiple monitoring stations as a reference for synchronization. Each station receives an identical copy of the timing signal, enabling consistent time reference across all locations and improving the reliability of time difference measurements by eliminating timing drift and synchronization errors.
3Measurement precision
If complete digitized signals are transmitted to central processor, then autocorrelation processing accuracy is improved, but communication link data rate requirements increase
Solution Approach 1:
The patent extracts only the essential timing parameters from complete digitized signals at remote monitoring stations before transmission. By performing autocorrelation processing locally to extract time of arrival estimates, the system removes unnecessary data, transmitting only the critical timing information needed for final location determination, thus reducing data transmission rates while maintaining processing accuracy.
Solution Approach 2:
The patent segments the signal processing function between remote monitoring stations and the central processor. Remote stations perform initial signal processing and extraction of timing parameters, while the central processor performs final location determination. This segmentation allows accurate autocorrelation processing to be distributed, reducing the data burden on communication links.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach improves the accuracy of lightning strike location determination while significantly reducing data transmission requirements and noise interference, achieving better signal-to-noise ratios and more efficient communication.
Implementation Method 1
an autocorrelation process is used at each of the three or more of monitoring stations to determine a time offset between an occurrence of the known waveform in the signal, and an occurrence of the replica waveform
Implementation Method 2
a GPS timing signal can be used to help synchronize the time stamp generator provided in each monitoring station
Implementation Method 3
receiving a signal at each of the three or more monitoring stations from a common source having a source location
Data Source
AI summary
There is disclosed a system for identifying a source location of an electromagnetic signal having a known waveform. Radio receiving equipment located at three of more monitoring stations receives and demodulates a radio frequency signal from a common source. A time stamp generator applies a time stamp to each block of N digital data samples derived from the received radio frequency signal at each monitoring station. A GPS timing signal can be used to synchronize the time stamp generator in each monitoring station. Further, replica generating hardware and/or software at each monitoring station periodically synchronously generates a replica waveform. An autocorrelation processor at each monitoring station determines a time offset between an occurrence of the known waveform in the signal, and an occurrence of the replica waveform at each monitoring station. The system also includes communication devices at each monitoring station for communicating the time offset from each monitoring station to a central processor which calculates a position of the source location using the time offset communicated from each monitoring station.