Radar Precipitation Detection via Beat Signal Spectral Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In-vehicle radar devices inaccurately determine weather conditions due to a low number of reflection points from stationary objects, leading to false readings of fine weather during precipitation.
Innovation Solution
A precipitation determining device that uses frequency-modulated radar waves and analyzes beat signals to determine spectral similarity with precipitation reference spectra, regardless of the number of reflection points, and calculates correlation between azimuth information to differentiate between precipitation and non-precipitation objects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the conventional method of determining precipitation based on the number of reflection points from stationary objects is used, then the determination process is simple, but the accuracy of precipitation detection deteriorates when the number of reflection points is low
Solution Approach 1:
The patent changes the detection parameter from counting reflection points to analyzing the spectral characteristics of beat signals. By examining the frequency spectrum of the beat signal and comparing it with reference spectra, the system can identify precipitation even when reflection points are sparse, thus improving detection accuracy without significantly increasing system complexity
Solution Approach 2:
The patent replaces the mechanical counting method with signal processing analysis. Instead of simply counting reflection points, the system performs frequency analysis on beat signals and compares spectral patterns, substituting a more sophisticated analytical approach that provides better accuracy under varying conditions
2Ease of operation
If the number of reflection points criterion is used to determine fine weather, then the determination is straightforward, but false positives occur when reflection points are sparse due to long distances
Solution Approach 1:
The patent introduces spectral analysis as an intermediary step between receiving the radar signal and determining weather conditions. The beat signal spectrum serves as an intermediary that carries information about the nature of reflected objects, allowing the system to distinguish between sparse reflection points caused by distance versus those caused by precipitation
Solution Approach 2:
The patent performs preliminary spectral analysis of the beat signal before making the final weather determination. By pre-analyzing the frequency characteristics and comparing them with reference spectra, the system prepares classification information that improves the reliability of the subsequent weather determination
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
Improves the accuracy of precipitation detection by reducing false positives and accurately identifying precipitation presence, even when reflection points are sparse or from stationary objects.
Implementation Method 1
a transmitting means (32, 33, 34, 36), a receiving means (40, 42, 43), an analyzing means (50, 84, S140), and a precipitation determining means (50, 84, S350 to S380). Of these components, the transmitting means transmits a radar wave
Implementation Method 2
The receiving means receives an incoming wave which is a reflected wave of a radar wave transmitted from the transmitting means, and mixes the received incoming wave with the radar wave transmitted from the transmitting means to derive respective beat signals
Data Source
AI summary
A radar device includes a transmission part that transmits a radar wave which has been frequency-modulated such that one measurement cycle has a rising section in which a frequency increases and a falling section in which a frequency decreases, a reception part that derives respective beat signals of the rising section and the falling section, and a signal processor that performs a precipitation determining process on the basis of an analysis of the beat signals. In the precipitation determining process, in the absence of objects other than precipitation objects from a transmission range of the radar wave, it is determined whether a spectral similarity of the frequency spectra of the rising and falling section with precipitation reference spectra is not less than a threshold, and if the spectral similarity is not less than the threshold as a result of the determination, it is determined that precipitation is present.