RF Ranging Using Transponders in Opaque Environments
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Solution Overview
Problem
Existing RF ranging technologies face challenges in dense foliage environments, such as jungles, where GPS and laser-based methods are ineffective due to RF opacity and line-of-sight issues, necessitating a reliable method for determining perpendicular distances in survey work.
Innovation Solution
The implementation of an RF ranging system using transponders located on a property line, which transmit and receive RF signals at different frequencies, allowing a ranging device to calculate perpendicular distances by utilizing the known separation between transponders and the phase differences in the signals, thereby overcoming RF opacity and improving accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If GPS is used for surveying, then surveying is easy in most environments, but GPS fails in RF-opaque environments like jungles
Solution Approach 1:
The patent introduces transponders as intermediary devices placed along the property line. These transponders act as mediators between the ranging device and the property line, reflecting RF signals to enable distance measurement in environments where direct GPS signal propagation fails. The transponders convert the RF opaque environment into a measurable space by providing reflective surfaces that carry signal information back to the ranging device.
Solution Approach 2:
The patent replaces the electromagnetic wave-based GPS system with a mechanical/optical-inspired RF reflection system. Instead of relying on direct line-of-sight electromagnetic signals from satellites, the system uses RF signal transmission and reflection off transponders, analogous to how optical systems use light reflection. This substitution allows the system to function in RF-opaque environments where direct electromagnetic propagation is blocked.
2Measurement precision
If laser-based ranging is used, then ranging is accurate, but line-of-sight issues preclude use in jungle environments
Solution Approach 1:
The transponders serve as intermediary reflective elements that enable laser-like precision measuring in environments where direct line-of-sight is blocked. By placing transponders along the property line, they create measurable reflection paths through the RF-opaque jungle environment, allowing accurate distance measurement without requiring direct visual or electromagnetic line-of-sight between the ranging device and the target.
Solution Approach 2:
The patent changes the fundamental parameter of signal propagation by using lower frequency RF signals instead of high-frequency laser light. This parameter change allows the signals to penetrate and propagate through dense foliage and RF-opaque materials that block laser light, while maintaining the ability to measure distance with precision through phase-based measurement of the reflected signals.
3Device complexity
If RF signals are transmitted at the same frequency for both transmit and receive, then system is simple, but signal overlap occurs and measurement accuracy is reduced
Solution Approach 1:
The patent segments the RF signal frequencies into distinct transmit and receive frequency bands. By dividing the single frequency into two separate frequency segments, the system eliminates signal overlap between outgoing and returning signals. This frequency segmentation allows the receiver to distinguish clearly between the transmitted signal and the reflected signal, improving measurement accuracy without significantly increasing system complexity.
Solution Approach 2:
The patent introduces asymmetry in the frequency allocation by using different frequencies for transmission and reception. This asymmetric frequency assignment creates clear separation between the transmit and receive signal spaces, preventing mutual interference. The asymmetric design ensures that the receiver can accurately measure the reflected signal without contamination from the outgoing signal, thereby improving distance measurement 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
This solution enables accurate and efficient surveying in RF-opaque environments by isolating transmit and receive signals, mitigating overlap issues and improving distance measurement accuracy, allowing for precise determination of property boundaries.
Implementation Method 1
The transmit antenna transmits RF signals at a first carrier frequency (f1), where f1 is selected from frequencies of 30 Megahertz (MHz) to 1 Gigahertz (GHz). The receive antenna receives RF signals at a second carrier frequency (f2)
Implementation Method 2
The ranging device transmits RF signals to the transponders, which are received by the transponders and rebroadcasted back to the ranging device on a different frequency
Data Source
AI summary
The embodiments described herein provide ranging capabilities in RF-opaque environments, such as a jungle, utilizing transponders located on a property line. In particular, the embodiments described herein provide for determining a distance to a property line from a ranging device. The transponders are located on the property line and are separated from each other by a known distance. The ranging device transmits RF signals to the transponders, and receives RF signals returned by the transponders on a different frequency. The ranging device uses information about the transmitted and received RF signals and the known distance to calculate a distance from the ranging device to the property line.