Emitter Location via Combined AOA and TDOA Localization
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Solution Overview
Problem
Existing geolocation techniques for electromagnetic signal emitters, such as TDOA, FDOA, and AOA localization, face challenges including target ambiguity, limited accuracy, and ambiguity due to grating lobes, especially when receiver distances are large.
Innovation Solution
A method and system that combine first location information, estimated based on signal propagation effects, with second location information, determined by assessing the direction of the signal, to accurately locate an emitter of an electromagnetic signal. This combination mitigates ambiguity and improves accuracy by confining the search space and optimizing receiver positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If larger receiver distances are used for AOA localization, then resolution is improved, but grating lobes occur causing ambiguity
Solution Approach 1:
The patent combines AOA localization results with TDOA/FDOA localization results to resolve the ambiguity caused by grating lobes. The AOA method provides high resolution with large receiver distances, while TDOA/FDOA methods provide additional constraints that eliminate ambiguous solutions, achieving both high resolution and unambiguous localization.
Solution Approach 2:
The patent introduces TDOA/FDOA localization as an intermediary method that complements AOA localization. This intermediary approach provides additional measurement constraints that help disambiguate the grating lobe issues in AOA localization, enabling accurate location determination without relying solely on AOA measurements.
2Measurement precision
If TDOA/FDOA localization is used, then localization can be achieved, but accuracy is limited by time/frequency synchronization
Solution Approach 1:
The patent merges AOA localization with TDOA/FDOA localization to compensate for the limitations of each individual method. The AOA method provides angular information that can resolve ambiguities in TDOA/FDOA results, while the TDOA/FDOA methods provide distance constraints that help refine AOA localization, achieving higher overall accuracy without requiring perfect synchronization.
3Ease of manufacture
If individual measurements are evaluated separately, then processing is simplified, but synergies between different localization techniques are not exploited
Solution Approach 1:
The patent combines multiple localization techniques (AOA, TDOA, FDOA) into a unified processing framework that exploits the synergies between different measurement types. By integrating the results from all three methods and using their complementary strengths, the system achieves higher localization accuracy than any single method could provide alone.
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
The combined approach enhances the accuracy and reduces ambiguity in locating electromagnetic signal emitters, achieving a level of precision similar to larger receiver distances without the associated loss in accuracy, and increases the robustness of the localization method.
Implementation Method 1
estimating or determining a first location information which delineates a region in which the emitter is located, wherein the first location information is estimated or determined based on assessing or utilizing a propagation effect of the signal
Implementation Method 2
A further geolocation technique is Angle of Arrival (AOA) localization which is based on measuring the direction in which the signal is received from the target emitter
Data Source
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AI summary
Disclosed herein are a system and a method comprising the following steps: receiving an electromagnetic signal emitted by an emitter at two or more receivers of a first plurality of receivers, estimating or determining a first location information which delineates a region in which the emitter is located, wherein the first location information is estimated or determined based on assessing or utilizing a propagation effect of the signal, receiving said signal emitted by an emitter at two or more receivers of a second plurality of receivers, estimating or determining a second location information, based on an assessment of a direction in which the signal is received at said two or more receivers of said second plurality of receivers, wherein said second location information comprises a set or distribution of possible locations of the emitter, estimating or determining a location of the emitter based on a combination of the first location information and the second location information, and providing information on the estimated or determined location of the emitter to a user device or database.