Precise Point Positioning Signal Smoothing for Fast Convergence
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Solution Overview
Problem
The initial converging time for precise point positioning (PPP) in satellite positioning systems is excessively long, typically ranging from 20 to 40 minutes or more, due to amplified noise energy and the need for error correction in satellite signals.
Innovation Solution
A method and apparatus that combine satellite signals from target and reference satellites to eliminate signal errors, using a between-satellite single difference (BSSD) process and adaptive carrier smoothing technology to reduce noise levels and improve positioning efficiency, with the smoothing process weighted by the satellite elevation angle to enhance convergence speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional PPP method is used to achieve high positioning accuracy by eliminating signal errors, then positioning precision is improved, but converging time becomes excessively long (20-40 minutes or more)
Solution Approach 1:
The patent applies preliminary action by performing smoothing processing on code data before using it for positioning calculations. The smoothing process pre-processes the code measurements to reduce noise energy and amplify useful signal components, so that when the PPP convergence begins, the data is already optimized for faster convergence. This preliminary preparation of data quality accelerates the initial convergence stage without compromising the final positioning accuracy.
Solution Approach 2:
The patent changes parameters by introducing a smoothing window parameter and applying different smoothing techniques (such as exponential smoothing or moving average) to the code data. By adjusting the smoothing window size and selecting appropriate smoothing methods, the system optimizes the balance between noise reduction and convergence speed, enabling faster convergence while maintaining the precision required for accurate positioning.
2Measurement precision
If satellite signals are combined to eliminate signal errors, then positioning accuracy is improved, but device complexity increases due to additional processing steps
Solution Approach 1:
The patent applies the taking out principle by extracting and separately processing the code data component from the satellite signals. Instead of processing all signal components together through complex error elimination algorithms, the method extracts code data and applies dedicated smoothing processing to it. This separation simplifies the overall processing architecture while maintaining the ability to eliminate signal errors and achieve high positioning accuracy.
Data Source
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AI summary
Precise point positioning (PPP) method and a PPP device are provided. The precise point positioning method includes obtaining a first satellite signal of a target satellite and a second satellite signal of a reference satellite. The first satellite signal and the second satellite signal are combined to eliminate a signal error and obtain a combined satellite signal. A smoothing process is performed on a code data of the combined satellite signal, to obtain a satellite positioning data for positioning process. The satellite positioning data includes modified code data and modified carrier-phase data.