RF Orthogonal Interferometry for Jam-Resistant Projectile Guidance
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Solution Overview
Problem
Conventional projectile guidance systems are vulnerable to GPS jamming and spoofing, especially in GPS-denied or GPS-limited environments, and pseudolite deployments are risky and susceptible to jamming due to their reliance on GPS-like transmissions.
Innovation Solution
A navigation method using a local domain radio frequency (RF) orthogonal interferometry (OI) system that provides GPS-like performance without the need for GPS, employing a radio frequency orthogonal interferometry array to create a reference frame for guiding projectiles, which leverages multiple orthogonal waveforms to reduce multipath effects and uses a projectile state estimator for navigation, eliminating the need for an inertial measuring unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS is used for guiding projectiles, then navigation accuracy is improved, but vulnerability to jamming and spoofing increases
Solution Approach 1:
The patent introduces an RF orthogonal interferometry system as an intermediary navigation method that does not rely on GPS satellites. Instead of receiving signals from external satellites, the system uses ground-based RF transmitters and orthogonal interferometry processing to determine position, thereby mediating between the need for accurate navigation and the vulnerability to GPS jamming
Solution Approach 2:
The patent changes the fundamental parameters of the navigation system by transitioning from GPS satellite-based RF signals to ground-based RF transmitters, and from conventional interferometry to orthogonal interferometry with MIMO radar technologies. This parameter change enables jam-resistant navigation while maintaining accuracy
2Adaptability or versatility
If pseudolites are deployed to extend GPS capability, then navigation coverage is improved, but risk to installer and susceptibility to jamming increases
Solution Approach 1:
The patent extracts the navigation aid function from GPS satellites and pseudolites and relocates it to ground-based RF transmitters that work in conjunction with orthogonal interferometry processing on the projectile. This extraction eliminates the need for physical deployment of pseudolites in hostile regions while maintaining navigation coverage
Solution Approach 2:
The patent replaces the mechanical deployment and physical presence of pseudolites with a signal-processing-based orthogonal interferometry system. Instead of physically placing transmitters along the path, the system uses orthogonal waveform processing to achieve the same navigation effect without physical infrastructure in hostile zones
3Reliability
If conventional interferometer design is used, then GPS-denied navigation is achieved, but multi-path effect and performance are worsened
Solution Approach 1:
The patent applies composite methodologies by combining MIMO radar technologies with orthogonal interferometry principles. This composite approach integrates multiple orthogonal waveforms and signal processing techniques to achieve enhanced performance and reduce multi-path effects compared to conventional interferometer designs
Solution Approach 2:
The patent introduces additional dimensions to the interferometry system by employing multiple orthogonal waveforms and MIMO (multiple-input multiple-output) radar technologies. This dimensional expansion in the signal space allows the system to distinguish between direct and multi-path signals, thereby reducing multi-path effects and improving measurement precision
4Measurement precision
If inertial measuring unit is used for navigation, then guidance accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces the mechanical inertial measuring unit (IMU) with an RF-based orthogonal interferometry positioning system. Instead of using accelerometers and gyroscopes to calculate position through integration, the system uses RF signal processing to directly determine position, thereby eliminating complex mechanical sensors while maintaining guidance accuracy
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 RF/OI system offers accurate guidance with ±5 m range and ±100 m azimuth and elevation accuracy, achieving a circular error probable (CEP-50) of 30 m, and is resistant to jamming, allowing for effective navigation and targeting in GPS-denied environments without the need for onboard IMU or precise alignment.
Implementation Method 1
radio frequency (RF) orthogonal interferometry (OI) techniques
Implementation Method 2
uses multiple orthogonal waveforms to achieved enhanced performance
Data Source
AI summary
The system and method of projectile flight management using a combination of radio frequency orthogonal interferometry for the long range navigation and guidance of one or more projectiles and a short range navigation and guidance system to provide for more accurate targeting.