Radar weather data signal processing method and signal processing module

• US 9,494,682 B2
• Filed: 04/08/2014
• Issued: 11/15/2016
• Est. Priority Date: 04/18/2013
• Status: Active Grant

• Current Assignee: Weatherlink Co., Ltd.
• Original Assignee: Weatherlink Co., Ltd.
• Inventors: Choi, Jeongho
• Primary Examiner(s): Sotomayor, John B
• Application Number:
  US14/411,562
• Publication Number:
  US 20150145718A1
• Time in Patent Office: 952 Days
• Field of Search: 342/26.R, 342 26 A- 26 D, 342188-189, 342194-196
• US Class Current: 1/1
• CPC Class Codes: G01S 13/282 using a frequency modulated carrier wave G01S13/286 takes precedence
• CPC Class Codes: G01S 13/95 for meteorological use
• CPC Class Codes: G01S 7/285 Receivers
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

Disclosed is a radar weather data signal processing module comprising: a pulse compression unit for pulse-compressing a received weather signal; a correlation coefficient calculation unit for calculating a correlation coefficient on the basis of the pulse-compressed weather signal; and a weather variable calculation unit for calculating a weather variable on the basis of the calculated correlation coefficient.

Claims

1. A radar weather data signal processing module comprising:

a pulse compression unit that pulse-compresses a received weather signal;

a correlation coefficient calculation unit that calculates a correlation coefficient based on the pulse-compressed weather signal; and

a weather variable calculation unit that calculates a weather variable based on the calculated correlation coefficient,

wherein the pulse compression unit comprises;

a format conversion unit that converts a horizontal polarized wave in-phase/quadrature-phase (I/Q) signal and a vertical polarized wave I/Q signal that are received weather signals, into a format of floating decimal point data;

a linear frequency modulation (LFM) signal-applying unit that applies a reference LFM signal;

a window application unit that applies window functions to the horizontal polarized wave I/Q signal and the vertical polarized wave I/Q signal that are converted by the format conversion unit and the reference LFM signal;

a fast fourier transform (FFT) performance unit that performs FFT on the signals to which the window functions are applied;

a convolution unit that performs convolution on the signals on which FFT is performed by the FFT performance unit; and

an inverse FFT (IFFT) performance unit that generates a compressed horizontal polarized wave I/Q signal and a compressed vertical polarized wave I/Q signal by performing IFFT on the convoluted signals.

2. The radar weather data signal processing module of claim 1, wherein the correlation coefficient calculation unit comprises:

a mode selection unit that selects a time domain mode or a frequency domain mode;

a time domain mode unit that calculates a single polarized wave correlation coefficient and a cross-polarized wave correlation coefficient by performing time domain clutter filtering on the compressed I/Q signal; and

a frequency domain mode unit that calculates a single polarized wave correlation coefficient by performing frequency domain clutter filtering on the compressed I/Q signal.

3. The radar weather data signal processing module of claim 1, wherein the weather variable calculation unit comprises:

a threshold variable calculation unit that calculates a threshold variable based on the calculated correlation coefficient;

a weather variable calculation unit that calculates a weather variable based on the calculated correlation coefficient;

a threshold processing unit that removes a weather variable less than a threshold value and causes a weather variable that exceeds the threshold value to pass, based on the threshold variable and the weather variable; and

a speckle removing unit that removes speckles from the weather variable that is threshold-processed by the threshold processing unit.

4. The radar weather data signal processing module of claim 3, wherein the weather variable calculation unit further comprises a distance averaging unit that averages a distance of the calculated correlation coefficient.

5. A radar weather data signal processing method, whereby a weather signal is processed by a radar weather data signal processing module, the radar weather data signal processing method comprising:

pulse-compressing a received weather signal using the radar weather data signal processing module;

calculating a correlation coefficient based on the pulse-compressed weather signal using the radar weather data signal processing module; and

calculating a weather variable based on the calculated correlation coefficient using the radar weather data signal processing module,

wherein the pulse-compressing comprises;

a format conversion operation of converting a horizontal polarized wave I/Q signal and a vertical polarized wave I/Q signal that are received weather signals, into a format of floating decimal point data using the radar weather data signal processing module;

applying window functions to the format-converted horizontal polarized wave I/Q signal and the vertical polarized wave I/Q signal and the reference LFM signal using the radar weather data signal processing module;

performing FFT on the signals to which the window functions are applied, using the radar weather data signal processing module;

performing convolution on the signals on which FFT is performed by the FFT performance unit using the radar weather data signal processing module; and

generating a compressed horizontal polarized wave I/Q signal and a compressed vertical polarized wave I/Q signal by performing IFFT on the convoluted signals using the radar weather data signal processing module.

6. The radar weather data signal processing method of claim 5, wherein the calculating of the correlation coefficient comprises:

selecting a time domain mode or a frequency domain mode using the radar weather data signal processing module;

calculating a single polarized wave correlation coefficient and a cross-polarized wave correlation coefficient by performing time domain clutter filtering on the compressed I/Q signal using the radar weather data signal processing module; and

calculating a single polarized wave correlation coefficient by performing frequency domain clutter filtering on the compressed I/Q signal using the radar weather data signal processing module.

7. The radar weather data signal processing method of claim 5, wherein the calculating of the weather variable comprises:

calculating a threshold variable based on the calculated correlation coefficient using the radar weather data signal processing module;

calculating a weather variable based on the calculated correlation coefficient using the radar weather data signal processing module;

removing a weather variable less than a threshold value and causing a weather variable that exceeds the threshold value to pass, based on the threshold variable and the weather variable using the radar weather data signal processing module; and

removing speckles from the weather variable that is threshold-processed by the threshold processing unit using the radar weather data signal processing module.

8. The radar weather data signal processing method of claim 7, wherein the calculating of the weather variable further comprises averaging a distance of the calculated correlation coefficient using the radar weather data signal processing module.