Combined Altitude Display Data Fusion for Terrain Interference

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Solution Overview

Problem

Current altimeters face challenges in providing accurate true altitude estimates over a large range, particularly in aircraft applications, due to issues with radar-based systems in uneven terrain, GPS signal obstructions, and barometric pressure variations affected by local weather conditions.

Innovation Solution

A method and apparatus for fusing data from two dissimilar altitude sources, including digital and analog interfaces, to generate a combined altitude value by using a data fusion component that processes signals from altimeters with different input formats, such as synchro signals and barometric pressure, to minimize disadvantages and enhance accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If radar-based altimeter is used to estimate absolute altitude, then absolute altitude can be obtained, but accuracy deteriorates in uneven terrain or foliage conditions

Engineering Contradiction:
Improveabsolute altitude estimation accuracyVSAvoidterrain and foliage interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent combines radar altitude measurements with barometric pressure altitude measurements to create a fused altitude estimate. The data fusion component integrates both sources, using the radar for absolute altitude reference and barometric data for continuous tracking, thereby compensating for radar's vulnerability to terrain interference while maintaining absolute altitude accuracy.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention creates a composite altitude measurement system that integrates multiple measurement principles (radar and barometric) into a unified measurement approach. This composite system leverages the strengths of each individual system while mitigating their respective weaknesses through weighted fusion algorithms.

Inventive Principle:
Principle #40Composite materials

2Measurement precision

If GPS is used to provide true altitude, then true altitude information is obtained, but reliability deteriorates when satellite signals are obstructed

Engineering Contradiction:
Improvetrue altitude accuracyVSAvoidsignal availability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces barometric pressure altimetry as an intermediary measurement system that can operate independently of satellite signals. When GPS signals are obstructed, the barometric system serves as a reliable backup, and the data fusion component seamlessly transitions between GPS and barometric data sources to maintain continuous true altitude information.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If barometric pressure is used to estimate true altitude, then true altitude can be obtained, but accuracy deteriorates due to local weather conditions

Engineering Contradiction:
Improvetrue altitude estimation accuracyVSAvoidweather condition interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent employs feedback mechanisms where the radar altitude measurements provide reference information that corrects barometric altitude drift caused by weather conditions. The data fusion component continuously compares barometric trends with radar reference points, applying corrections to compensate for pressure system errors and maintain accurate true altitude estimation.

Inventive Principle:
Principle #23Feedback

4Measurement precision

If multiple altitude sources are combined, then accuracy over wide altitude range is improved, but device complexity increases

Engineering Contradiction:
Improvealtitude estimation accuracyVSAvoidsystem integration complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The data fusion component is designed as a universal interface that can process multiple altitude measurement formats (radar, barometric, GPS) through a unified algorithmic framework. This multi-functional design allows the same component to handle different input types without requiring separate processing paths, thereby managing complexity while maintaining measurement precision.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3655723B1Device and method for combined altitude display
Publication Date: 2022.10.19 ELBIT SYSTEMS OF AMERICA LLC
  • EP3655723B1 patent drawingFigure 1A
  • EP3655723B1 patent drawingFigure 1B
  • EP3655723B1 patent drawingFigure 2

AI summary

A combined altitude display apparatus for generating a combined altitude value is provided. The apparatus comprises a first altitude input interface, wherein the first altitude input interface receives a first altitude value; a second altitude input interface, wherein the second altitude input interface receives a second altitude value, wherein the second altitude value indicated by the second altitude input interface has a cyclical range; an altitude output interface, wherein the altitude output interface outputs a third altitude value; and a data fusion component coupled to the first altitude input interface and the second altitude input interface and configured to calculate the third altitude value based on the first altitude value and the second altitude value.