GNSS Receiver Stokes Parameter Polarization Multipath Mitigation
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Solution Overview
Problem
Current Global Navigation Satellite System (GNSS) technologies face limitations in accuracy and reliability due to obstacles like buildings, vegetation, and atmospheric conditions, which can lead to inaccurate positioning and interference from electronic devices, especially in urban areas where direct line-of-sight to satellites is obstructed.
Innovation Solution
The implementation of Hybrid Compact Polarimetry (HCP) GNSS systems that use Stokes parameters to calibrate and process GNSS signals, mitigating multipath effects by synthesizing new polarization signals and utilizing reflected signals to enhance positioning accuracy and reliability, even in obstructed environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional GNSS systems are used, then the system is simple and easy to operate, but positioning accuracy deteriorates in obstructed environments due to multipath interference
Solution Approach 1:
The patent changes the polarization parameter of GNSS signals by synthesizing hybrid compact polarimetry (HCP) signals with specific polarization states. This allows the system to exploit polarization diversity to distinguish direct signals from multipath reflected signals, thereby improving positioning accuracy in obstructed environments without requiring complex additional hardware
Solution Approach 2:
The patent replaces traditional signal processing methods with Stokes parameter-based polarization analysis. By using Stokes parameters to characterize and process GNSS signals, the system achieves better multipath mitigation through polarization information extraction rather than relying on complex temporal or spatial filtering mechanisms
2Reliability
If direct signals only are used, then the processing is simple, but reliability deteriorates when line-of-sight is obstructed by buildings or vegetation
Solution Approach 1:
The patent converts harmful multipath reflected signals into beneficial information sources by analyzing their polarization characteristics using Stokes parameters. The system identifies and utilizes reflected signals that carry useful positioning information, transforming what was traditionally considered noise or interference into a valuable resource for maintaining reliability in obstructed environments
Solution Approach 2:
The patent adds the polarization dimension to GNSS signal processing by incorporating Stokes parameters (S0, S1, S2, S3) that describe the polarization state. This fourth dimension of signal characterization enables the system to separate direct and reflected signals based on their different polarization properties, improving reliability without requiring additional spatial or temporal dimensions
3Measurement precision
If multipath signals are eliminated, then positioning accuracy improves, but signal availability decreases in obstructed environments
Solution Approach 1:
The patent segments the total signal power into distinct components based on polarization characteristics using Stokes parameter analysis. By separating direct signals from reflected multipath signals through polarization decomposition, the system can selectively process each component, maintaining accuracy while preserving useful signal components that would otherwise be discarded
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
HCP GNSS systems provide improved positioning accuracy and reliability by minimizing multipath interference and utilizing signal reflections, enabling effective navigation in challenging environments and offering additional applications for Earth observation, such as soil moisture and environmental monitoring.
Implementation Method 1
Each satellite further includes at least one pair of antennas, and a transmitter configured to transmit GNSS positioning signals to a receiver... the at least one pair of antennas is a pair of orthogonally polarized antennas... one antenna of the pair of antennas measures horizontal components of the reflected signals, and the other antenna of the pair of antennas measures vertical components of the reflected signals
Data Source
AI summary
Systems and methods for a global positioning system using Global Navigation Satellite System (GNSS) signals and Stokes Parameters in accordance with embodiments of the invention are illustrated. One embodiment includes a GNSS. The GNSS includes at least four satellites and a receiver. Each satellite includes at least one pair of antennas, and a transmitter configured to transmit GNSS positioning signals to a receiver. The receiver includes a memory containing a positioning application, and a processor comprising a set of one or more processors, the positioning application configures the processors to determine a position of the receiver by performing the steps of collecting horizontal and vertical linear components of transmitted GNSS positioning signals, computing Stokes parameters of collected GNSS signals, obtaining tuning parameters based on computed Stokes parameters, synthesizing new polarization signal using tuning parameters, and processing new polarization signal to obtain a position of the location.