DC-Coupled CW Doppler Radar for Water Level Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional water level gauging instruments face issues with biofouling, high costs, and low accuracy, particularly with radar techniques that suffer from multipath echoes and phase ambiguity due to large displacement measurements in water level monitoring.
Innovation Solution
A DC-coupled continuous wave (CW) Doppler radar system with a wireless, low-power design that uses a micro-controller for real-time data processing and transmission, employing adaptive-tuning to compensate for DC offsets and achieve sub-millimeter accuracy, and can be configured as a network for spatial variability assessment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional AC-coupled Doppler radar is used for water level measurement, then the system can detect water level changes, but it suffers from signal distortion and cannot accurately measure slow water level motion
Solution Approach 1:
The patent changes the coupling parameter from AC-coupled to DC-coupled architecture. This parameter change allows the radar system to maintain accurate measurement of slow-varying water level signals without the signal distortion that plagues AC-coupled systems, as DC coupling preserves the true baseline of slow movements.
Solution Approach 2:
The patent implements adaptive-tuning architecture that dynamically adjusts system parameters in real-time. This dynamic adaptation allows the system to compensate for varying signal conditions and maintain measurement accuracy across different water level motion rates, from very slow changes to faster variations.
2Measurement precision
If FMCW radar is used for water level gauging, then non-contact measurement is achieved, but the system suffers from multipath echoes that limit resolution and accuracy
Solution Approach 1:
The patent extracts and eliminates the harmful multipath echo components from the measurement system. By using DC-coupled CW Doppler radar instead of FMCW, the system removes the susceptibility to multipath echoes that plague FMCW systems, as the continuous wave approach with DC coupling naturally rejects stationary clutter reflections.
Solution Approach 2:
The patent converts the potentially harmful effect of clutter reflections into a benign DC offset that can be easily compensated. Rather than suffering from multipath echoes as in FMCW systems, the DC-coupled architecture transforms these reflections into a manageable offset that is corrected through adaptive-tuning, turning a harmful factor into a solvable parameter.
3Measurement precision
If pulse radar is used for water level measurement, then non-contact measurement is achieved, but measurement accuracy is lower compared to CW radar
Solution Approach 1:
The patent replaces the mechanical/pulsed radar approach with a continuous wave Doppler system. This substitution eliminates the need for complex pulse generation and timing hardware while achieving superior measurement accuracy through continuous signal processing and adaptive-tuning algorithms.
4Measurement precision
If conventional arctangent demodulation is used for large displacement measurement, then phase information can be recovered, but phase ambiguity occurs when displacement is comparable to radar distance
Solution Approach 1:
The patent implements feedback mechanisms through adaptive-tuning architecture that continuously monitors and corrects phase measurements. This feedback system resolves phase ambiguity by dynamically adjusting demodulation parameters based on the measured displacement magnitude, ensuring accurate phase information recovery even for large water level changes.
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 system provides accurate, continuous water level measurements with sub-millimeter precision, immune to multipath echoes, and capable of real-time data streaming, suitable for storm surge tracking and tidal zone assessments, with extended battery life and low maintenance.
Implementation Method 1
DC-coupled continuous wave (CW) Doppler radar system
Implementation Method 2
CW Doppler radar system with a wireless, low-power design that uses a micro-controller for real-time data processing and transmission
Data Source
AI summary
Devices, methods and systems for wave and water level measurement using a single DC (direct current)-coupled CW (continuous wave) Doppler radar for detecting water elevation changes in time when installed up to several meters from the water surface. The radar is wireless and can stream continuous data to a local PC (personal computer) or base station in range of its radio. The radar can sample up to 40 Hz and can run on batteries for continuous sampling. The radars can include multiple radar configurations of 1, 2 and 4 radar configurations. Applications for this radar can include the measurement of beach run-up, free surface elevation in tidal zones, and storm surge elevations near bridges and critical infrastructure during storm events.