Ground Transmitter Self-Surveying via Wideband Code Modulation
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Solution Overview
Problem
Local positioning systems employing ground transmitters face challenges in achieving centimeter-level accuracy for self-surveying without access to GPS satellites and require complex multi-frequency carrier signal transmission and geometric motion.
Innovation Solution
An array of ground transmitters uses wideband code modulation with a chipping rate greater than 30 MHz to self-survey locations by generating and tracking ranging signals, allowing each transmitter to determine its relative position without geometric motion or multi-frequency signal transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS RTK solutions are used for surveying ground transmitters, then positioning accuracy is improved, but the method fails when ground transmitters are placed at locations with poor or no access to GPS satellites
Solution Approach 1:
The patent introduces an intermediary reference transmitter that provides reference signals to enable relative positioning between ground transmitters without requiring GPS satellites. This intermediary reference signal allows the system to function in GPS-denied areas while maintaining centimeter-level accuracy through signal processing and geometric relationships between transmitters.
2Measurement precision
If ground transmitters move relative to each other for self-surveying, then positioning can be achieved, but the system requires complex geometric motion information
Solution Approach 1:
The patent enables ground transmitters to self-survey their relative locations by having each transmitter track the reference signals from other transmitters. The system automatically resolves integer biases in a cascaded manner using the tracked signals, eliminating the need for external geometric motion information or complex surveying operations while achieving centimeter-level accuracy.
3Measurement precision
If ground transmitters transmit and track multi-frequency carrier signals for self-surveying, then positioning accuracy is improved, but the system complexity increases
Solution Approach 1:
The patent extracts the essential functionality for self-surveying by using wideband code modulation signals instead of complex multi-frequency carrier signals. The system achieves positioning accuracy by processing the code modulation signals through correlation and bias resolution techniques, eliminating the need for multiple frequency carriers while maintaining centimeter-level precision.
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 self-surveying of ground transmitters at a centimeter-level without GPS access, providing a 3-D positioning solution to rovers with improved accuracy and reduced complexity.
Implementation Method 1
Each ground transmitter of the array is capable of self-surveying its own location relative to the location of other ground transmitters in the array by generating ranging signals associated with a wideband code modulation with a chipping rate of faster than 30 MHz
Data Source
AI summary
A precise positioning method and system is disclosed for allowing an array of ground transmitters to self-survey their relative location at centimeter-level accuracy by transmitting, amongst the ground transmitters in the array, bi-directional ranging signals associated with a wideband code modulation with a chipping rate faster than 30 MHz.