Low Visibility Takeoff Guidance Using GNSS Delta Range
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Solution Overview
Problem
Manned aircraft operating in low visibility conditions often require expensive Category II or III instrument landing systems, which are not available at most airports, leading to reduced takeoff capabilities and significant flight delays or cancellations.
Innovation Solution
A navigation system utilizing global navigation satellite system (GNSS) carrier phase or delta range relative navigation to provide high accuracy and integrity guidance for takeoff, without the need for ground infrastructure, using existing avionics equipment like inertial reference systems and head-up displays, to determine the aircraft's position relative to the runway centerline.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Category II or III instrument landing systems are installed at airports, then low visibility takeoff capability is improved, but installation and maintenance cost increases significantly
Solution Approach 1:
The system uses the aircraft's own existing avionics equipment (GPS receivers, inertial reference systems, head-up displays) to provide the guidance functionality, eliminating the need for external ground infrastructure. The aircraft serves itself with navigation capabilities that would otherwise require expensive airport-installed equipment.
Solution Approach 2:
The navigation function is extracted from ground-based infrastructure and relocated to the aircraft itself. By using space-based GPS satellites and onboard processing equipment, the system removes the dependency on Category II/III ILS ground installations while achieving the same low-visibility takeoff guidance objective.
2Measurement precision
If Category II or III instrument landing systems are installed at airports, then guidance accuracy in low visibility conditions is improved, but the number of airports requiring such infrastructure is limited
Solution Approach 1:
The system uses universal space-based GPS satellites that are available globally at all airports, replacing the airport-specific Category II/III ILS infrastructure. This enables any airport with standard GPS receivers to provide high-accuracy low-visibility takeoff guidance, making the capability universally available rather than limited to 80-90 specific airports.
Solution Approach 2:
Space-based GPS satellites serve as an intermediary between the aircraft and the ground, providing positioning and guidance data without requiring physical infrastructure at the airport. This intermediary layer enables high accuracy guidance while maintaining adaptability to any airport location.
3Device complexity
If existing avionics equipment is used for low visibility takeoff guidance, then device complexity is reduced, but navigation accuracy must meet high integrity requirements
Solution Approach 1:
The system merges multiple existing avionics subsystems (GPS receivers, inertial reference systems, head-up displays) into an integrated low-visibility takeoff guidance solution. By combining these existing components and their data streams, the system achieves high navigation accuracy without adding new complex hardware, as the synergistic integration of standard equipment meets the stringent integrity requirements.
Data Source
AI summary
Systems and methods for navigation of a vehicle use a processing system. The systems and methods can allow an aircraft to take-off in low visibility conditions. The processing system includes a cross tracker, an error processor and an error estimator. The cross tracker is configured to determine a cross track deviation using a hybrid positon and runway heading data. The error processor is configured to determine the hybrid positon from inertial reference system data and corrected error data, and the error estimator is configured to provide the corrected error data using estimates derived from delta range data from a global navigation satellite system receiver.