Weather Radar Signal Processing for Interference Removal

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Solution Overview

Problem

Weather radar systems face interference issues when operating at close locations with different transmission frequencies, leading to reduced signal sensitivity and inaccurate measurement of received power and Doppler velocity due to radio interference from other radar sites.

Innovation Solution

A weather radar apparatus with a signal processing unit that distributes received signals to multiple paths, extracts and removes interference waves by using band-pass filters, quadrature detection, Fast Fourier Transform, and Inverse Fast Fourier Transform to identify and subtract interfering frequencies, thereby improving signal sensitivity and accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple radar stations operate at close locations with different transmission frequencies, then radar coverage and observation capability are improved, but radio interference occurs between signals received by the two stations

Engineering Contradiction:
Improveradar coverageVSAvoidradio interference
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The invention extracts and removes interference wave signals from the received signal by distributing the signal to multiple paths, using band-pass filters to separate interference frequencies, and subtracting the extracted interference from the main path signal. This resolves the contradiction by eliminating the harmful interference while preserving the multi-station radar coverage capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces an intermediary signal processing system that includes distribution units, band-pass filters, and subtraction units. This intermediary processing chain mediates between the interfering radar signals and the desired weather observation signals, separating and removing interference while preserving useful signal components.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If signal processing is performed to remove interference waves, then measurement accuracy of received power and Doppler velocity is improved, but signal processing complexity increases

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The signal processing system is segmented into distinct functional modules: distribution units that split signals into multiple paths, band-pass filters that separate frequency components, extraction units that isolate interference signals, and subtraction units that remove interference. This modular segmentation improves measurement accuracy while organizing complexity into manageable, standardized components.

Inventive Principle:
Principle #1Segmentation

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

Effectively removes interference waves, enhancing the sensitivity of received signals and allowing for accurate measurement of received power and Doppler velocity, even in the presence of nearby radar interference.

Implementation Method 1

an extraction unit, configured to extract, from a signal of the other path, an interference wave signal extracted from another radio station

Methodology Applied
Scientific EffectBand-pass filtering: Filter (electronic)

Implementation Method 2

quadrature detection, Fast Fourier Transform, and Inverse Fast Fourier Transform to identify and subtract interfering frequencies

Methodology Applied
Scientific EffectQuadrature detection: Homodyne Detection

Implementation Method 3

Fast Fourier Transform, and Inverse Fast Fourier Transform to identify and subtract interfering frequencies

Methodology Applied
Scientific EffectFast Fourier Transform:

Implementation Method 4

Fast Fourier Transform, and Inverse Fast Fourier Transform to identify and subtract interfering frequencies

Methodology Applied
Scientific EffectInverse Fast Fourier Transform:

Implementation Method 5

a transmitting/receiving unit, configured to transmit a radar wave to an observation target and receive a reflected wave

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 6

a distribution unit, configured to distribute a received signal of the reflected wave to a main path and at least another path

Methodology Applied
Scientific EffectSignal distribution:

Data Source

PatentEP2296009B1Weather radar apparatus and signal processing method thereof
Publication Date: 2017.07.26 KK TOSHIBA
  • EP2296009B1 patent drawingFigure 1
  • EP2296009B1 patent drawingFigure 2~4
  • EP2296009B1 patent drawingFigure 3

AI summary

According to one embodiment, a weather radar apparatus includes a transmitting/receiving unit (12, 13) configured to transmit a radar wave to an observation target and receive a reflected wave, a distribution unit (17) configured to distribute a received signal of the reflected wave to a main path and at least another path, an extraction unit (17) configured to extract, from a signal of the other path, an interference wave signal extracted from another radio station, and a removing unit (17) configured to remove the interference wave signal extracted from a signal of the main path.