Beacon Signal Coherent Combination for TOA FOA Precision
Solution Overview
Problem
The existing distress beacon location systems, such as MEOSAR, face challenges in reliably and precisely determining the position of beacons due to insufficient signal-to-noise ratios caused by environmental and atmospheric factors, which prevents accurate determination of Time of Arrival (TOA) and Frequency of Arrival (FOA) measurements.
Innovation Solution
A method involving a constellation of satellites that detect and retransmit signals to ground stations, where an analysis module combines and realigns the signals to improve the signal-to-noise ratio, determines the message content and modulation parameters, and uses these parameters to locate the beacon by generating a synthetic signal and comparing it with received signals to calculate TOA and FOA.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ground stations use received beacon signals directly for location determination, then the system operates with simple processing, but the signal-to-noise ratio is insufficient to reliably determine TOA and FOA measurements
Solution Approach 1:
The patent combines signals received from multiple satellites at a ground station by coherently adding them after aligning their phases and frequencies. This signal combination increases the signal-to-noise ratio, enabling reliable determination of TOA and FOA measurements that would be impossible with individual satellite signals alone.
2Quantity of substance
If multiple satellites transmit beacon signals, then more location data is available, but the heterogeneous signal degradation from different paths prevents reliable processing
Solution Approach 1:
The patent transforms the signals by adjusting their frequency and phase parameters to compensate for Doppler shifts and path differences. By changing these parameters to align all signals to a common reference, the system can reliably process multiple signals from different satellites despite their initially heterogeneous degradation.
3Measurement precision
If the system waits for sufficient signal quality from individual satellites, then measurement accuracy is maintained, but location determination cannot be achieved when signal conditions are poor
Solution Approach 1:
The patent enables location determination in poor signal conditions by combining multiple weak satellite signals into a single strong composite signal. This allows the system to achieve both measurement precision and productivity simultaneously, as the combined signal provides sufficient quality for accurate TOA and FOA measurement even when individual satellite signals are too weak.
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 method enhances the detection and location precision of beacons by improving the signal quality and accuracy of TOA and FOA measurements, enabling reliable beacon location even in conditions with insufficient signal-to-noise ratios.
Implementation Method 1
combining the readjusted signals to generate a synthetic signal having an improved signal-to-noise ratio
Implementation Method 2
measure the time of arrival of the signals (TOA for Time of Arrival) as well as the frequency shift that these signals (FOA for Frequency of Arrival) have undergone by Doppler effect
Data Source
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AI summary
The method involves transmitting signals received from a satellite (101) toward an analysis module (150) by a receiving station (112). The signals are readjusted relative to each other in frequency and/or time. The readjusted signals are combined to generate a combined signal having improved signal to noise ratio. Message contents and/or modulation parameters are determined from the signal. Temporal and frequential variations of the signals are phase searched by carrying out calculation of correlation on a synchronization word. Independent claims are also included for the following: (1) a method for localizing transmitting signals emitted from a terrestrial beacon (2) a localization system.