TDOA Locating via Autocorrelation Maximum Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing Time-Difference-Of-Arrival (TDOA) locating systems face challenges in accurately locating radio frequency emitters, particularly with narrowband signals below 30 kHz, due to high data transmission requirements and limited communication infrastructure, which increases costs, weight, and power consumption of sensor devices.
Innovation Solution
The method reduces data transmission by computing and transmitting only the time stamps of the maximum values of the autocorrelation function from sensor devices to the processing center, using interpolation and curve fitting to improve precision, and employing a GPS-derived timing reference for synchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complete signal data is transmitted from sensor devices to processing center, then locating precision is maintained, but data transmission requirements and communication infrastructure costs increase
Solution Approach 1:
The patent extracts only the essential information (time stamps of maximum autocorrelation values) from the complete signal data and transmits only this extracted information to the processing center. This eliminates the need to transmit entire signal segments while preserving the critical timing information required for TDOA location calculations, directly resolving the contradiction between maintaining precision and reducing data volume.
Solution Approach 2:
The patent performs preliminary processing at the sensor devices by computing the autocorrelation function and identifying maximum values before transmission. This preliminary action pre-computes the essential features needed for location determination, so that only processed results (time stamps) need to be transmitted rather than raw signal data, thereby reducing data transmission requirements while maintaining locating capability.
2Measurement precision
If high data transmission rates are used to maintain precision, then locating accuracy is improved, but device weight and power consumption increase
Solution Approach 1:
By extracting only the time stamp information from complete signal data, the patent dramatically reduces the amount of data that needs to be transmitted and processed. This extraction approach maintains the essential timing information needed for precise location determination while eliminating redundant data, thereby reducing power consumption for data transmission and processing without sacrificing locating precision.
Solution Approach 2:
The patent performs preliminary computation of autocorrelation functions and identification of maximum values at the sensor devices before transmission. This preliminary processing reduces the data volume that requires high-power transmission and centralized processing, thereby reducing overall system power consumption while maintaining the precision required for accurate location determination.
3Measurement precision
If more communication infrastructure is deployed to support high data rates, then locating precision is maintained, but system cost and device weight increase
Solution Approach 1:
The patent extracts only the critical time stamp information from complete signal data for transmission. This extraction eliminates the need for high-bandwidth communication infrastructure that would be required to transmit full signal segments, thereby reducing system complexity and infrastructure requirements while maintaining the precision needed for accurate location determination through TDOA calculations.
Solution Approach 2:
By performing preliminary processing at the sensor devices to compute autocorrelation functions and extract maximum value time stamps before transmission, the patent reduces the communication requirements to minimal data rates. This preliminary action eliminates the need for complex high-data-rate communication infrastructure while preserving the locating precision capability.
Data Source
AI summary
A method and an apparatus for TDOA-locating of an unknown emitter of RF-signals are provided, wherein the amount of data that have to be transmitted from the sensor devices to the processing centre of the locating system is greatly reduced. According to the invention the signals received at the sensor devices of the locating system are synchronized, sampled and autocorrelated. The autocorrelation function thus obtained is divided into segments of an appropriate duration. The maximums of the autocorrelation function in each segment provide a unique characterizing feature of the time of arrival of the RF-signals at each sensor device. The maximums of the autocorrelation function are transmitted to the processing centre of the system. The travelling time difference of the sensor signals needed for locating the unknown emitter are simply computed by the differences of the transmitted maximums.