Surface-Mountable Antenna Array for GPS-Independent Altitude and Speed
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
GPS-based navigation systems in aircraft are vulnerable to interference, jamming, and spoofing, and conventional radio altimeters and Doppler radars have limitations that affect their reliability and require complex cable length management.
Innovation Solution
A surface-mountable antenna module integrates radio altimeter and Doppler radar functionalities, performing digitization and signal processing at the antenna level, allowing for robust altitude and speed measurements independent of GPS, with reduced interference and flexible cable length requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS-based navigation systems are used for aircraft navigation, then location accuracy and ease of deployment are improved, but vulnerability to interference, jamming, and spoofing increases
Solution Approach 1:
The navigation system is segmented into multiple independent measurement sources: GPS receiver, radio altimeter, and Doppler radar. Each component operates independently to provide location and altitude data, so that if one source is compromised by interference or jamming, the other sources can continue to function and provide backup navigation capability.
2Measurement precision
If conventional radio altimeters with LRU and RF cabling are used, then altitude measurement capability is provided, but system complexity and fault conditions increase
Solution Approach 1:
The radio altimeter and Doppler radar are merged into a single integrated antenna module with shared transmit and receive antennas. This consolidation eliminates the need for separate LRUs and RF cabling for each system, reducing the number of connection points and potential fault conditions while maintaining both altitude measurement and ground speed measurement capabilities.
Solution Approach 2:
The integrated antenna module performs multiple functions: it serves as both the radio altimeter antenna for altitude measurement and the Doppler radar antenna for ground speed measurement. The single module handles both transmit and receive operations for both functions, eliminating the need for duplicate dedicated hardware for each measurement type.
3Measurement precision
If separate radio altimeter and Doppler radar systems are deployed, then both altitude and ground speed measurements are obtained, but device complexity and cable management requirements increase
Solution Approach 1:
The radio altimeter and Doppler radar share a common antenna module, transmit path, and receive path. The integrated design allows both measurement functions to operate through shared hardware components, eliminating the need for separate RF cabling and reducing cable management complexity to minimal connections between the single antenna module and the processor.
4Ease of operation
If integrated antenna module with digitization is used, then cable length flexibility is improved, but manufacturing complexity may increase
Solution Approach 1:
The system replaces traditional analog RF signal transmission through cables with digital signal transmission. Digitization occurs at the antenna module, converting RF signals to digital data that can be transmitted through standard digital interfaces. This substitution allows flexible cable lengths since digital signals are less susceptible to attenuation and interference, and the cable becomes a simple data conduit rather than a precision RF transmission line.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The integrated system provides reliable altitude and speed measurements, resistant to interference and spoofing, with a compact form factor suitable for retrofitting existing systems, and eliminates the need for precise cable length management.
Implementation Method 1
a radio altimeter, which typically includes an antenna mounted to a surface of the aircraft and a line replaceable unit (LRU) that sends radio frequency (RF) signals to and receives return RF signals from the antenna via RF cabling
Implementation Method 2
The radio altimeter is configured to measure a height of the aircraft above the ground using a transmitted RF wave and a reflected RF wave from the ground below the aircraft
Implementation Method 3
Doppler radars have been deployed in order to measure ground speed independent of GPS or inertial measurements
Data Source
AI summary
A radio device includes a surface-mountable antenna module. The surface-mountable antenna module includes a housing configured to mount to an external surface of a vehicle. The surface-mountable antenna module also includes a receiver configured to receive an output radio frequency (RF) signal. The surface-mountable antenna module includes an antenna configured to transmit the output RF signal and receive a return RF signal. The surface-mountable antenna module also includes circuitry coupled to the antenna. The circuitry is configured to generate a digitized output RF signal and generate a digitized return RF signal. The surface-mountable antenna module further includes an electrical connector coupled to the circuitry. The electrical connector is configured to output data representing the digitized output RF signal and the digitized return RF signal.