Satellite State Predictor for GPS Positioning Without Ephemeris

Solution Overview

Problem

GPS receivers face challenges in determining position when current broadcast ephemeris data is unavailable, leading to increased processing time and power usage, particularly in environments where signal strength is low or obstructions prevent clear reception.

Innovation Solution

A device with a satellite state predictor that calculates current satellite states using previously received broadcast ephemeris data through numerical integration of satellite equations of motion, incorporating luni-solar and Earth orientation models, allowing position determination without relying on real-time ephemeris data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If GPS receiver collects new broadcast ephemeris data from satellites or servers, then position determination accuracy is improved, but processing time and power usage increase

Engineering Contradiction:

Improveposition determination accuracyVSAvoidprocessing time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary action by collecting and storing broadcast ephemeris data in advance before position determination is needed. When current ephemeris data is unavailable due to signal loss or server unavailability, the stored historical data enables the receiver to continue providing position services without requiring real-time data collection, thus reducing processing time and power consumption while maintaining acceptable position accuracy.

Inventive Principle:

Principle #10Preliminary action

2Measurement precision

If GPS receiver collects new broadcast ephemeris data from satellites or servers, then position determination accuracy is improved, but power usage increases

Engineering Contradiction:

Improveposition determination accuracyVSAvoidpower usage

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system performs preliminary action by collecting and storing broadcast ephemeris data in advance before position determination is needed. When current ephemeris data is unavailable due to signal loss or server unavailability, the stored historical data enables the receiver to continue providing position services without requiring real-time data collection, thus reducing processing time and power consumption while maintaining acceptable position accuracy.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If GPS receiver relies on real-time broadcast ephemeris data, then position determination reliability is improved, but availability decreases in poor signal environments

Engineering Contradiction:

Improveposition determination reliabilityVSAvoidavailability in poor signal environments

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system performs preliminary action by collecting and storing broadcast ephemeris data in advance before position determination is needed. When current ephemeris data is unavailable due to signal loss or server unavailability, the stored historical data enables the receiver to continue providing position services without requiring real-time data collection, thus reducing processing time and power consumption while maintaining acceptable position accuracy.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system prepares beforehand by storing historical ephemeris data in a database, creating a cushion of available data that can be used when real-time data becomes unavailable. This prior cushioning allows the receiver to maintain position determination capability in poor signal environments or when servers are unavailable, thereby improving adaptability while maintaining reliability through the use of stored historical data.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS7839330B2Determining position without current broadcast ephemeris

Publication Date: 2010.11.23 QUALCOMM INC

AI summary

Devices and methods are described for determining position information without broadcast ephemeris data for extended time periods. A client device is disclosed that stores satellite states determined from broadcast ephemeris and numerically integrates equations of motion with regard to the stored satellite states to determine current satellites states. The client device uses the current satellite states in conjunction with received satellite signals to determine where the satellite signals were received.