Mobile GNSS Satellite Trajectory Prediction Using Compact Force Models
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current GNSS satellite trajectory prediction models are limited by their complexity and require high calculation capabilities, making it difficult to implement satellite trajectory prediction on mobile devices like PDAs and smartphones, which lack the necessary processing power, resulting in prolonged Time to First Fix (TTFF) when valid ephemeris is not available.
Innovation Solution
A method and device that utilize a microprocessor in a mobile apparatus to obtain satellite navigation messages, determine propagating conditions, estimate satellite trajectory prediction models, and compute acquisition assistance data using satellite trajectory extension data, allowing for satellite signal acquisition even without valid ephemeris, by employing compact force or adjusted orbit models for efficient trajectory prediction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional satellite trajectory prediction methods are used, then prediction accuracy is maintained, but calculation capability requirements are too high for mobile devices
Solution Approach 1:
The patent extracts and implements a simplified satellite trajectory prediction algorithm that can be executed on mobile device microprocessors. By taking out the essential prediction functionality from complex ground-based processing systems and adapting it for mobile computation, the invention enables trajectory prediction on resource-constrained devices while maintaining acceptable accuracy for TTFF improvement.
Solution Approach 2:
The patent modifies prediction model parameters and computational complexity to suit mobile device capabilities. By adjusting the parameters of the satellite trajectory prediction model and optimizing calculation procedures, the invention achieves a balance between prediction accuracy and computational requirements that can be satisfied by mobile microprocessors.
2Loss of time
If satellite trajectory prediction is implemented on mobile devices, then TTFF is reduced, but device complexity increases
Solution Approach 1:
The patent implements preliminary satellite trajectory prediction on the mobile device before actual satellite signal acquisition is needed. By pre-computing satellite positions and prediction data using the microprocessor, the system prepares assistance data in advance, significantly reducing the Time to First Fix when the receiver needs to acquire satellite signals, while the complexity is managed through efficient algorithm implementation.
3Loss of time
If valid ephemeris is not available, then position fixing cannot be achieved with conventional methods, but TTFF can be reduced by using trajectory extension data
Solution Approach 1:
The patent prepares satellite trajectory extension data and prediction models in advance on the mobile device, creating a cushion of pre-computed assistance data. When valid ephemeris is not available from external sources, this pre-prepared trajectory data serves as a backup, allowing the receiver to continue acquiring satellite signals and determining position without complete loss of functionality, thus maintaining reliability while reducing TTFF.
Data Source
AI summary
A method and device for using satellite trajectory extension data in a mobile apparatus. The device in accordance with the present invention comprises an I/O interface and a microprocessor. The input/output (I/O) interface is used for obtaining at least one satellite navigation message for a satellite. The microprocessor is used for determining a propagating condition according to the satellite navigation message, estimating a plurality of parameters of a satellite trajectory prediction model according to the propagating condition to establish an estimated satellite trajectory predication model, propagating a set of satellite trajectory extension data by using the estimated satellite trajectory prediction model, computing acquisition assistance data according to the satellite trajectory extension data and acquiring signals of the satellite by using the acquisition assistance data.