Server-Based GNSS Cross-Frequency Correction for Precise Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing precise positioning systems require GNSS signals received at the reference station and mobile device to be on the same carrier frequency, limiting flexibility and preventing correction data from being generated for frequencies not received by the reference station.
Innovation Solution
The system generates 'virtual' correction data, such as virtual pseudorange and carrier phase measurements, using linear combinations of measurements from different frequencies received at the reference station to correct for frequencies not received by the mobile device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the reference station and mobile device use the same carrier frequency for GNSS signals, then positioning accuracy is improved, but the system flexibility and applicable frequency range are reduced
Solution Approach 1:
The patent changes the frequency parameter by generating virtual correction data that maps measurements from frequencies received at the reference station to frequencies not received by the reference station. This allows the mobile device to use correction data for frequencies beyond what the reference station directly receives, expanding the applicable frequency range while maintaining positioning accuracy through the virtual correction mapping process.
2Device complexity
If the reference station receives only specific GNSS carrier frequencies, then the system complexity is reduced, but the ability to provide correction data for other frequencies is lost
Solution Approach 1:
The patent introduces an intermediary process at the reference station that generates virtual correction data. This intermediary function maps the limited frequency measurements received by the reference station to a broader frequency range, enabling the reference station to provide correction data for frequencies it does not directly receive, thus expanding correction data coverage without increasing hardware complexity.
3Reliability
If correction data is generated only for frequencies received at the reference station, then measurement reliability is improved, but the usability for mobile devices receiving different frequencies is reduced
Solution Approach 1:
The patent transforms the correction data parameter set by creating virtual corrections that map from the reference station's received frequencies to frequencies needed by the mobile device. This parameter transformation maintains the reliability of corrections based on actual measurements while extending compatibility to mobile devices receiving different frequencies through the virtual mapping relationship.
Data Source
AI summary
An example method performed at a mobile device for position determination may comprise receiving from a server correction data associated with (1) a first pseudorange measurement of a first GNSS signal sent from a satellite vehicle on a first GNSS carrier frequency and (2) a second pseudorange measurement of a second GNSS signal sent from the satellite vehicle on a second GNSS carrier frequency. The method also may comprise measuring a third GNSS signal sent from the satellite vehicle and received at the mobile device on a third GNSS carrier frequency, to generate a third pseudorange measurement. The method also may comprise determining the position of the mobile device using (a) the third pseudorange measurement of the third GNSS signal on the third GNSS carrier frequency and (b) the correction data. The correction data received from the server may include a virtual pseudorange measurement for the third GNSS carrier frequency.