Satellite Receiver Positioning Accuracy via Preliminary Time Updates

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Solution Overview

Problem

Satellite radiowave receiving devices face inaccuracies in date and time calculations, leading to prolonged Time to First Fix (TTFF) due to incorrect positional information of positioning satellites, which affects the accuracy and speed of determining the device's position.

Innovation Solution

The device includes a processor that uses preliminarily obtained date and time information and valid positional information to perform positioning operations within a predetermined maximum interval, and updates date and time information within a shorter interval than the maximum positioning interval, allowing for more frequent and accurate calculations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If positioning operations are performed frequently to obtain accurate position, then positioning accuracy is improved, but power consumption and processing load increase

Engineering Contradiction:

Improvepositioning accuracyVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The system performs preliminary date and time updates at shorter intervals than positioning operations. By maintaining up-to-date date and time information independently of positioning frequency, the system prepares accurate timing data in advance, enabling accurate positioning calculations when needed without requiring frequent full positioning operations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system separates the date and time update function from the positioning operation function. Date and time are updated at one interval while positioning occurs at a different, less frequent interval. This segmentation allows each function to operate independently at its optimal frequency, reducing overall system load while maintaining accuracy.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If date and time information is updated frequently to ensure accuracy, then positioning accuracy is improved, but processing time and energy consumption increase

Engineering Contradiction:

Improvedate and time accuracyVSAvoidprocessing time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

Date and time information is updated preliminarily and frequently at intervals shorter than positioning intervals. This preliminary updating ensures that when positioning operations occur, the most accurate date and time data is already available, eliminating the need for time-consuming real-time updates during positioning.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system implements periodic updates of date and time information at fixed intervals that are independent of positioning operations. This periodic action ensures consistent data freshness without the variable processing delays associated with event-driven updates during positioning operations.

Inventive Principle:

Principle #19Periodic action

3Loss of time

If positioning operations use retained satellite positional information to reduce TTFF, then time to first fix is reduced, but positioning accuracy deteriorates due to inaccurate date and time

Engineering Contradiction:

ImproveTime to First FixVSAvoidpositioning accuracy

Core Design Contradiction:

Loss of timeVSMeasurement precision

Solution Approach 1:

The system performs preliminary updates of date and time information at intervals shorter than positioning intervals. This ensures that when positioning operations occur using retained satellite positional information, the date and time data is already current and accurate, preventing the accuracy deterioration that would otherwise result from using stale timing data.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system continuously updates date and time information based on received satellite signals and uses this updated information to correct the counted date and time. This feedback mechanism ensures that even when using retained positional information for quick positioning, the timing data remains accurate through continuous correction from actual satellite signals.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS10890666B2Satellite radiowave receiving device, electronic timepiece, control method for obtaining positioning information, and recording medium

Publication Date: 2021.01.12 CASIO COMPUTER CO LTD

AI summary

A satellite radiowave receiving device includes a receiver performing a receiving operation of radiowaves transmitted from a positioning satellite and a processor controlling a positioning operation. The processor performs the positioning operation within at least a predetermined maximum positioning interval from a last positioning operation using preliminarily obtained date and time information and valid positional information on the positioning satellite to obtain a current position of the satellite radiowave receiving device and date and time information. The processor causes the receiver to perform the receiving operation within at least a predetermined date and time updating interval shorter than the predetermined maximum positioning interval from a last time when date and time information is obtained from radiowaves transmitted from a positioning satellite to obtain date and time information without the positioning operation.