Radio Source Positioning Using TDOA/FDOA Ambiguity Resolution
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Solution Overview
Problem
Existing methods for positioning unknown target radio wave sources using direction information from array antennas are costly and increase hardware complexity, leading to ambiguity in positioning results.
Innovation Solution
A positioning device that utilizes multiple signal receiving units, correlation processing, geolocation point calculation, coordinate conversion, frequency distribution analysis, and error ellipse determination to estimate the position of an unknown target radio wave source without requiring direction information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If direction information is obtained using an array antenna, then positioning accuracy is improved, but hardware scale and cost increase
Solution Approach 1:
The invention extracts only the necessary information (TDOA and FDOA) from the received signals through correlation processing, without requiring full direction information from array antennas. This extracts the essential positioning data while avoiding the hardware complexity of array antennas.
Solution Approach 2:
The invention uses simple single-element antennas instead of expensive array antennas, accepting that individual measurements may have ambiguity but resolving it through multiple measurements and statistical processing. This replaces expensive, complex hardware with cheaper, simpler components.
2Measurement precision
If direction information is obtained using an array antenna, then positioning accuracy is improved, but cost increases
Solution Approach 1:
The invention uses simple single-element antennas instead of expensive array antennas, accepting that individual measurements may have ambiguity but resolving it through multiple measurements and statistical processing. This replaces expensive, complex hardware with cheaper, simpler components.
Solution Approach 2:
The invention extracts only the necessary information (TDOA and FDOA) from the received signals through correlation processing, without requiring full direction information from array antennas. This extracts the essential positioning data while avoiding the hardware complexity of array antennas.
3Adaptability or versatility
If TDOA and FDOA information is used for positioning, then positioning capability is achieved, but ambiguity occurs in positioning results
Solution Approach 1:
The invention uses feedback through iterative correlation processing and statistical analysis of multiple measurements. The system continuously refines the positioning estimate by comparing expected signal characteristics with actual measurements, resolving ambiguity through this feedback loop.
Solution Approach 2:
The invention performs excessive correlation processing by calculating TDOA and FDOA for multiple candidate positions and using statistical methods to identify the true position. This excessive computation resolves ambiguity that would otherwise require simpler, less accurate methods.
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
Enables accurate positioning of unknown target radio wave sources by eliminating the need for direction information, reducing hardware costs and complexity while resolving ambiguity.
Implementation Method 1
a correlation processing unit to calculate information of TDOA and FDOA by correlation processing between relevant complex signal vectors on a basis of the complex signal vectors acquired by the signal receiving units
Data Source
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AI summary
There are included a plurality of signal receiving units (301) provided one by one for a plurality of satellites (1) to acquire complex signal vectors of signals received by the satellites (1), a correlation processing unit (302) to calculate information of TDOA and FDOA by correlation processing between relevant complex signal vectors on a basis of the complex signal vectors acquired by the signal receiving units (301), a geolocation point calculating unit (303) to calculate a geolocation point corresponding to the TDOA and the FDOA on a basis of the information of the TDOA and the FDOA calculated by the correlation processing unit (302), a coordinate converting unit (306) to convert, on a basis of geolocation points calculated for a plurality of time periods by the geolocation point calculating unit (303), the geolocation points into information of latitude and longitude, a frequency distribution calculating unit (307) to calculate a frequency distribution of the geolocation point on a basis of the information of latitude and longitude obtained by the coordinate converting unit (306), a geolocation point extracting unit (308) to extract a geolocation point included in an area having a maximum frequency from the frequency distribution on a basis of the frequency distribution calculated by the frequency distribution calculating unit (307), and a position estimating unit to estimate a position of a target radio wave source (10) on a basis of the geolocation point extracted by the geolocation point extracting unit (308).