Avionics Display Geodetic Datum Compliance Detection
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Solution Overview
Problem
Current aircraft navigation systems lack a mechanism to differentiate between compliant and non-compliant regions for Global Navigation Satellite System (GNSS) navigation, leading to potential inaccuracies during landing approaches, especially in areas using non-standard geodetic reference systems like Russia and China.
Innovation Solution
A system comprising a route compliance module that defines a geodetic reference datum standard, a navigation system database with compliance information, and a flight management system to identify and visually differentiate non-compliant regions on a coverage map, adjusting the display to indicate non-compliant areas and disabling GPS approaches when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If GPS based navigation is used in countries using non-WGS-84 geodetic reference systems, then navigation coverage is maintained, but position accuracy deteriorates due to datum incompatibility
Solution Approach 1:
The system applies different geodetic reference datums to different geographical regions. The FMS stores multiple datum information (WGS-84 and local datums like PZ-90) and automatically selects the appropriate datum based on the current flight location and airport of destination, ensuring position accuracy is maintained locally in each region while preserving global navigation coverage
Solution Approach 2:
The system changes the geodetic reference datum parameter based on location. The route compliance module queries the navigation database to determine which datum applies to the current region and adjusts the coordinate system accordingly, transforming position data between different datums to maintain measurement precision across different geographical areas
2Measurement precision
If pilots manually deselect GPS before approach in non-compliant areas, then position accuracy is improved, but navigation efficiency deteriorates due to additional manual intervention
Solution Approach 1:
The FMS automatically performs datum selection and coordinate transformation without pilot intervention. The route compliance module autonomously queries the navigation database, determines the appropriate datum for the current region and destination airport, and adjusts the navigation system accordingly, eliminating the need for manual GPS deselection while maintaining position accuracy
Solution Approach 2:
The system provides feedback to the pilot about the geodetic reference datum status. The display system shows information about WGS-84 compliance status and automatically adjusts navigation parameters based on the determined datum, giving the pilot awareness of the system's automatic actions while maintaining navigation efficiency
3Measurement precision
If compliance information is stored in the navigation database, then position accuracy is improved, but system complexity increases due to additional data management requirements
Solution Approach 1:
The system merges geodetic reference datum compliance information with the existing navigation database structure. The route compliance module integrates datum information alongside existing navigation data (waypoints, airports, routes), utilizing the same database query mechanisms and storage structures already present in the FMS, thereby avoiding additional complex data management systems while improving position accuracy
Data Source
AI summary
Systems and methods are provided for displaying portions of a route on a coverage map that are non-compliant for a Global Navigation Satellite System (GNSS) navigation system in an aircraft. A route compliance module defines a geodetic reference datum standard based on the GNSS navigation system. A navigation system database has compliance information corresponding to each of a plurality of airports. A flight management system determines the route of the aircraft and a visual display displays the route and the coverage map. The route compliance module identifies a non-compliant region of the coverage map that is not compliant with the geodetic reference datum standard based on the compliance information and adjusts the visual display to differentiate a non-compliant portion of the route extending within the non-compliant region of the coverage map.