Clutter suppressing device and radar apparatus provided with the same

• US 9,835,721 B2
• Filed: 08/26/2015
• Issued: 12/05/2017
• Est. Priority Date: 08/29/2014
• Status: Active Grant

• Current Assignee: Furuno Electric Co, Ltd
• Original Assignee: Furuno Electric Co, Ltd
• Inventors: Minowa, Masahiro
• Primary Examiner(s): Sotomayor, John B
• Application Number:
  US14/836,242
• Publication Number:
  US 20160061945A1
• Time in Patent Office: 832 Days
• CPC Class Codes: G01S 13/524 based upon the phase or frequency shift resulting from movement of objects, with reference to the transmitted signals, e.g. coherent MTi
• CPC Class Codes: G01S 13/95 for meteorological use
• CPC Class Codes: G01S 13/951 ground based
• CPC Class Codes: G01S 7/023 Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques auxiliary means for detecting or identifying radar signals or the like G01S7/021; means for anti-jamming G01S7/36
• CPC Class Codes: G01S 7/414 Discriminating targets with respect to background clutter
• 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

A clutter suppressing device for suppressing echo data of static clutter components indicating reflection waves caused by radar transmission signals reflecting on a static object is provided. The device includes a static clutter component suppressor configured to receive reception signals containing the static clutter components, and suppress the static clutter components, a reference data memory configured to store, as reference data, echo data of the reception signals obtained in fine weather and in which the static clutter components are suppressed by the static clutter component suppressor, and a rain component extracting module configured to extract echo data indicating rain components contained in the reception signals, by removing the reference data stored in the reference data memory from echo data of the reception signals obtained in rainy weather and in which the static clutter components are suppressed by the static clutter component suppressor.

Claims

1. A clutter suppressing device for suppressing echo data of static clutter components indicating reflection waves caused by radar transmission signals reflecting on a static object, each of the radar transmission signals transmitted at a predetermined azimuth at a predetermined time interval from a radar antenna provided at a predetermined observation location to observe meteorological weather, the clutter suppressing device comprising:

a static clutter component suppressor configured to receive reception signals containing the static clutter components, and suppress the static clutter components;

a reference data memory configured to store, as reference data, echo data of the reception signals obtained in fine weather and in which the static clutter components are suppressed by the static clutter component suppressor; and

a rain component extracting module configured to extract echo data indicating rain components contained in the reception signals, by removing the reference data stored in the reference data memory from echo data of the reception signals obtained in rainy weather and in which the static clutter components are suppressed by the static clutter component suppressor;

wherein the static clutter component suppressor includes;

an echo data memory configured to sequentially store a plurality of echo data of reflection waves caused by the radar transmission signals reflecting on objects;

a filter configured to select, from the plurality of echo data stored in the echo data memory, a data row in the azimuth direction for a predetermined distance, and suppress, in the data row, echo data of a target object moving at a speed within a predetermined range including zero speed; and

a suppression echo data output unit configured to output suppression echo data containing the echo data suppressed by the filter.

2. The clutter suppressing device of claim 1, wherein the static clutter component suppressor includes:

a suppression echo data memory configured to store the suppression echo data outputted from the suppression echo data output unit;

a first weighting module configured to weight each data of the data row in the azimuth direction for the predetermined distance selected from the plurality of echo data stored in the echo data memory, and obtain a first sum value of the weighted data;

a second weighting module configured to select, from the suppression echo data stored in the suppression echo data memory, a data row in the azimuth direction for the predetermined distance, weight each data of the data row, and obtain a second sum value of the weighted data; and

a difference calculating module configured to obtain a difference between the first and second sum values, and cause the suppression echo data output unit to output the difference as the suppression echo data.

3. The clutter suppressing device of claim 2, wherein the reception signals received by the static clutter component suppressor are signals containing the reflection waves from which interference components are removed.

4. A radar apparatus, comprising:

a clutter suppressing device for suppressing echo data of static clutter components indicating reflection waves caused by radar transmission signals reflecting on a static object, each of the radar transmission signals transmitted at a predetermined azimuth at a predetermined time interval from a radar antenna provided at a predetermined observation location to observe meteorological weather, the clutter suppressing device comprising;

a static clutter component suppressor configured to receive reception signals containing the static clutter components and the reflection waves from which interference components are removed, and suppress the static clutter components;

a reference data memory configured to store, as reference data, echo data of the reception signals obtained in fine weather and in which the static clutter components are suppressed by the static clutter component suppressor;

a rain component extracting module configured to extract echo data indicating rain components contained in the reception signals, by removing the reference data stored in the reference data memory from echo data of the reception signals obtained in rainy weather and in which the static clutter components are suppressed by the static clutter component suppressor;

a radar antenna configured to transmit each of the radar transmission signals at a predetermined azimuth from the radar antenna at a predetermined time interval;

a transmitter configured to output the radar transmission signal to the radar antenna; and

a receiver configured to receive a plurality of echo data of the reflection waves caused by the radar transmission signals reflecting on objects;

wherein the static clutter component suppressor includes;

an echo data memory configured to sequentially store the plurality of echo data of reflection waves caused by the radar transmission signals reflecting on the objects;

a filter configured to select, from the plurality of echo data stored in the echo data memory, a data row in the azimuth direction for a predetermined distance, and suppress, in the data row, echo data of a target object moving at a speed within a predetermined range including zero speed;

a suppression echo data output unit configured to output suppression echo data containing the echo data suppressed by the filter;

a suppression echo data memory configured to store the suppression echo data outputted from the suppression echo data output unit;

a first weighting module configured to weight each data of the data row in the azimuth direction for the predetermined distance selected from the plurality of echo data stored in the echo data memory, and obtain a first sum value of the weighted data;

a second weighting module configured to select, from the suppression echo data stored in the suppression echo data memory, a data row in the azimuth direction for the predetermined distance, weight each data of the data row, and obtain a second sum value of the weighted data; and

a difference calculating module configured to obtain a difference between the first and second sum values, and cause the suppression echo data output unit to output the difference as the suppression echo data.