Multilateration Receiver Time Offset Calibration
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Solution Overview
Problem
Existing locating methods using multilateration by time difference of arrival are limited by the intrinsic imprecision of the common time reference, leading to potential errors of about 30 meters in determining the position of an unknown signal transmitter.
Innovation Solution
A method that precedes multilateration by evaluating and correcting time offsets between synchronized receivers' common time references, using a transmitter of known position to determine and reset these offsets, thereby achieving a single common time reference for improved precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multilateration by time difference of arrival is used with synchronized receivers, then the location of the transmitter can be determined, but the precision is limited due to imprecision in the common time reference values received by each receiver
Solution Approach 1:
The patent applies preliminary action by performing a calibration phase before the actual multilateration measurement. During this calibration phase, a transmitter of known position transmits calibration signals that are received by all receivers. The system calculates expected time differences of arrival based on known geometry and compares them with measured values to determine time offset corrections for each receiver. These corrections are applied before the actual location measurement, thereby eliminating time reference imprecision and enabling high-precision location determination.
2Ease of operation
If the common time reference is sent by GPS with 100 ns imprecision, then receivers can be synchronized, but this results in potential error of about 30 meters in the location determination
Solution Approach 1:
The patent uses an intermediary calibration transmitter with known position to mediate the synchronization process. Instead of relying directly on the imprecise GPS time reference, the system introduces a calibration transmitter that sends signals to all receivers. By measuring the time differences of arrival from this known position and comparing with geometrically calculated expected values, the system determines precise time offset corrections for each receiver. This intermediary calibration step transforms the imprecise GPS synchronization into precise receiver timing, enabling accurate location determination.
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 significantly reduces or eliminates the potential error in locating an unknown transmitter, achieving a precision of up to 1 meter or better by resetting the time axes of receivers to a common reference, enhancing the accuracy of the location determination.
Implementation Method 1
a step of multilateration by time difference of arrival, which is done with the signals sent by the transmitter with unknown position and respectively received by the receivers
Data Source
AI summary
The invention relates to a method for locating a signal transmitter whose position is unknown, by the use of signal receivers which are synchronized with each other to a common time reference and whose positions are known, comprising: a step of multilateration by time difference of arrival, which is done with the signals sent by the transmitter with unknown position and respectively received by the receivers, characterized in that: said step of multilateration by time difference of arrival is preceded by a step of evaluation of the time offsets between the values from the common time reference respectively known by the receivers, and said step of multilateration by time difference of arrival is done by correcting said temporal offsets so as to reset the receivers to said same common time reference value.