CRPA Carrier Phase Correction for GNSS Positioning
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Solution Overview
Problem
Global Navigation Satellite Systems (GNSS) using Controlled Reception Pattern Antennas (CRPA) face challenges in accurately compensating for antenna element errors in carrier phase measurements, which are not effectively addressed by existing methods, leading to reduced accuracy in high-precision positioning applications.
Innovation Solution
The system employs azimuth- and elevation-dependent sky map correction constants to compute beam steering vectors, which are updated rapidly to compensate for vehicle motion, and combines these with phase calibration correction data to generate corrected beam steering control data, effectively compensating for carrier phase errors in CRPA systems during beam steering and adaptive nulling operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If CRPA systems use multiple element antennas to improve resistance to jamming and increase carrier-to-noise-density ratio, then reliability and signal quality are improved, but antenna element errors introduce carrier phase measurement errors that reduce measurement precision
Solution Approach 1:
The patent divides the CRPA system into multiple antenna elements, each with its own phase measurement channel. By segmenting the overall phase measurement into element-specific measurements, the system can identify and correct individual element errors through calibration, thereby maintaining high reliability while improving measurement precision through error compensation.
Solution Approach 2:
The patent introduces calibration parameters (phase correction values) for each antenna element that are determined through calibration procedures. These parameters are used to adjust and correct the phase measurements from each element, transforming the raw measurements into accurate corrected measurements that compensate for element-specific errors.
2Adaptability or versatility
If CRPA systems implement beam steering to track satellites and reject jamming signals, then adaptability and signal quality are improved, but dynamic beamforming introduces additional phase errors that worsen measurement precision
Solution Approach 1:
The patent performs calibration of the CRPA system in advance to determine phase correction parameters for each antenna element under different beam steering configurations. By pre-determining these correction values through calibration procedures, the system can compensate for beam steering-induced phase errors during actual operation, maintaining both adaptability and measurement precision.
3Device complexity
If conventional FRPA systems are used to simplify the reception system, then device complexity is reduced, but resistance to jamming and carrier-to-noise-density ratio deteriorate
Solution Approach 1:
The patent enables the CRPA system to perform self-calibration and self-correction by determining phase correction parameters through calibration procedures and automatically applying these corrections during operation. This self-service capability allows the complex multi-element system to maintain high reliability and jamming resistance while managing its own errors without external intervention.
Data Source
AI summary
This invention discloses a method for enhancing a Global Navigation Satellite System (GNSS), such as Global Positioning System (GPS), location calculation by supplying carrier phase corrections within a GNSS receiver used with a multiple element Controlled Reception Pattern Antenna (CRPA) receiver. GNSS carrier phase measurements should be compensated for receiver hardware and directionally dependent antenna errors to obtain desired accuracies for high precision GNSS positioning applications. One technique successfully employed in Fixed Reception Pattern Antenna (FRPA) GPS sensors applies a simple directionally dependent set of correction factors to the measurement outputs. For the complex case of a GNSS receiver employing a CRPA and dynamic beam steering, however, the multiplicity of combinations of antenna element outputs makes the FRPA compensation technique impractical. Compensation of carrier phase measurements is a problem not addressed in previous GPS CRPA beam steering sensors.