Ground Navigation Reference Fusion for GPS-Denied Guidance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing navigation systems, particularly in GPS-denied environments, suffer from systematic errors that accumulate over time and are susceptible to jamming or spoofing, leading to inaccurate position and velocity measurements, making them unreliable for long-term navigation and control.
Innovation Solution
A self-contained navigation system using a combination of Doppler LIDAR sensors, a clock, heading sensors, and terrain matching systems to measure speed and distance relative to a reference frame, providing accurate and continuous navigation without external signals, with low systematic errors and low probability of detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If GPS-based navigation systems are used, then position and velocity measurements can be obtained, but the system becomes susceptible to jamming and spoofing attacks, leading to unreliable navigation in GPS-denied environments
Solution Approach 1:
The patent introduces an intermediary reference frame (ground-based or inertial) that mediates between the vehicle's motion and the measurement system. By measuring velocity relative to this stable reference frame rather than relying on external GPS signals, the system achieves reliable navigation without susceptibility to GPS jamming and spoofing attacks
Solution Approach 2:
The patent replaces the electronic GPS signal-based navigation system with a physics-based measurement system using Doppler LIDAR and inertial sensors. This substitution uses fundamental physical principles (Doppler effect, inertial navigation) that cannot be easily jammed or spoofed, thereby improving reliability in GPS-denied environments
2Reliability
If inertial navigation systems are used, then navigation can continue without external signals, but systematic errors accumulate over time, leading to inaccurate position and velocity measurements
Solution Approach 1:
The patent implements feedback by continuously measuring velocity relative to a stable reference frame using Doppler LIDAR and using these measurements to correct the inertial navigation system's accumulated errors. The reference velocity measurements serve as feedback that resets the drift in position and velocity calculations
Solution Approach 2:
The patent merges inertial navigation system (INS) with Doppler LIDAR velocity measurements and terrain reference navigation (TRN) to create a hybrid navigation system. This combination leverages the short-term accuracy of INS with the long-term stability of reference-frame measurements, preventing error accumulation
3Measurement precision
If Doppler LIDAR sensors are used to measure velocity relative to ground, then accurate navigation can be achieved in GPS-denied environments, but the system complexity increases due to multiple sensors and processing requirements
Solution Approach 1:
The patent makes the Doppler LIDAR system multi-functional by using it for both velocity measurement relative to the ground and for terrain mapping. The same sensor hardware performs multiple navigation functions, reducing overall system complexity despite the advanced capabilities required
Solution Approach 2:
The patent segments the navigation system into distinct functional modules: Doppler LIDAR for velocity measurement, inertial sensors for attitude and acceleration, and a navigation computer for integration. This modular segmentation makes the complex system more manageable and easier to implement
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
Enables accurate, long-term navigation and situational awareness in GPS-denied environments, allowing vehicles to safely navigate and avoid hazards with minimal detection risk, even in high target traffic conditions.
Implementation Method 1
Doppler LIDAR sensors, a clock, heading sensors, and terrain matching systems to measure speed and distance relative to a reference frame
Implementation Method 2
Doppler LIDAR sensors, a clock, heading sensors, and terrain matching systems to measure speed and distance relative to a reference frame
Data Source
AI summary
Methods and apparatus for providing self-contained guidance, navigation, and control (GN&C) functions for a vehicle moving through an environment on or near the ground, in the air or in space without externally provided information are disclosed. More particularly, one embodiment of the present invention includes a Heading Sensor (36), an Absolute Location Sensor (38), a timer (40), a Range Doppler Processor (42), a Navigation Reference Sensor (44), an Area Range and a Velocity Sensor (46) which provide enhanced navigation information about a universal reference frame (22) and one or more targets (20).