Positioning Signal Transmitter Using Carrier Phase and Code Integration
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Solution Overview
Problem
Current satellite navigation systems, such as GPS, face limitations in positioning accuracy due to reliance on code-based measurements, which are prone to ambiguity and uncertainty, especially in point positioning mode, where the phase of the carrier wave is not reliably determinable without continuous measurement from multiple satellites.
Innovation Solution
An apparatus and system that transmit a positioning signal with improved periodicity and error correction information, allowing receivers to accurately calculate positional information by matching internal signals with phase-level precision, using sawtooth waveforms and orbit information, and incorporating correction data to enhance accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If code-based measurement is used for positioning, then positioning can be achieved with limited satellites, but positioning accuracy is limited to a few meters due to ambiguity and uncertainty
Solution Approach 1:
The patent combines code-based measurement and carrier wave phase measurement into a unified positioning method. The receiver simultaneously processes both code data and carrier phase data, merging their advantages to achieve high-accuracy positioning even with limited satellite visibility. This integration allows the system to overcome the limitations of using either method alone.
Solution Approach 2:
The patent changes the measurement parameter from code-based ranging to carrier wave phase-based ranging. By utilizing the phase information of the carrier wave, which has much finer resolution (centimeter level) compared to code length (meter level), the system achieves significantly improved positioning accuracy while maintaining compatibility with existing satellite navigation infrastructure.
2Measurement precision
If carrier wave phase measurement is used for positioning, then positioning accuracy can be improved to centimeter level, but at least five satellites must be visible and continuous measurement is required
Solution Approach 1:
The patent applies preliminary action by continuously tracking and accumulating carrier phase measurements over time. The system maintains continuous phase measurement records and uses this historical data to resolve ambiguities and improve positioning accuracy, allowing reliable positioning even when satellite visibility is temporarily limited. This preliminary accumulation of measurement data enables the system to meet accuracy requirements with fewer simultaneously visible satellites.
3Ease of operation
If point positioning mode is used, then positioning can be performed in stand-alone manner, but accuracy is limited and uncertainty of multiple solutions remains high
Solution Approach 1:
The patent implements feedback mechanisms where the receiver continuously monitors measurement quality, ambiguity resolution status, and positioning accuracy. Based on this feedback, the system dynamically adjusts its processing strategy, such as switching between different ambiguity resolution methods or requesting additional measurement epochs, thereby maintaining high accuracy in stand-alone point positioning mode without requiring external reference stations.
4Measurement precision
If RTK mode is used to achieve high accuracy positioning, then carrier wave phase can be utilized, but at least five satellites must be visible and reference station data is required
Solution Approach 1:
The patent extracts and utilizes only the essential elements needed for high-accuracy positioning from the RTK methodology, specifically the carrier phase measurement and ambiguity resolution techniques. By removing the requirement for reference station infrastructure and adapting the ambiguity resolution to work with limited satellites in point positioning mode, the system achieves RTK-level accuracy without the associated system complexity and infrastructure requirements.
Data Source
AI summary
An apparatus that can transmit a signal enabling higher accuracy of calculating positional information is provided. A transmitting apparatus transmitting a positioning signal includes an oven controller crystal oscillator (OCXO) having a thermostatic oven that keeps the temperature of a quartz resonator constant and oscillates such that variation in output frequency caused by the ambient temperature change is minimized, a voltage controlled oscillator (VCO) outputting a signal modulated in accordance with the signal from OCXO, multipliers, a code generator outputting code patterns for respectively identifying each of artificial satellites on which the transmitting apparatus is mounted to multiplier, a memory storing a navigation message, a transmitting portion, and an antenna.