Radar Target Detection Method and Radar Apparatus Using the Same

• US 20080100499A1
• Filed: 10/24/2007
• Published: 05/01/2008
• Est. Priority Date: 10/31/2006
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Nishimura, Tetsu
• Granted Patent: US 7,692,575 B2
• Time in Patent Office: Days
• US Class Current: 342/75
• CPC Class Codes: G01S 13/34 using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal
• CPC Class Codes: G01S 13/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S13/46
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/93271 in the front of the vehicles
• CPC Class Codes: G01S 7/03 Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver
• CPC Class Codes: G01S 7/352 Receivers
• CPC Class Codes: G01S 7/356 involving particularities of FFT processing

Abstract

A radar target detection method in which an azimuth at which a target is located is detected on the basis of reception signals obtained through antenna elements of an array antenna by detecting a change in levels of spectrum peaks in an azimuth spectrum of reception signal intensities, calculating a level of correlation between the level change of each spectrum peak and a directivity pattern of the array antenna in an azimuth range corresponding to the spectrum peak, and determining an azimuth corresponding to one of the spectrum peaks having the highest corresponding correlation level to be the azimuth at which the target is located.

Claims

1. A radar target detection method comprising:

obtaining reception signals by transmitting and receiving waves through antenna elements of an array antenna;

calculating reception signal intensities at arbitrary specified azimuth angles in a predetermined detection area;

detecting a level change of spectrum peaks in an azimuth spectrum of the reception signal intensities;

calculating a level of correlation between the level change of each spectrum peak and a directivity pattern of the array antenna in an azimuth range corresponding to that spectrum peak; and

determining an azimuth corresponding to the spectrum peak having the highest corresponding correlation level to be the azimuth at which a target is located.

2. The radar target detection method of claim 1,

wherein when the azimuth corresponding to the spectrum peak changes with time, a change in a spectrum peak level according to the azimuth change is detected, and the detected spectrum peak level change is approximated using a predetermined function so that the level of correlation between the spectrum peak level change and the directivity pattern is calculated.

3. The radar target detection method of claim 2,

wherein the spectrum peak level change is linearly approximated.

4. The radar target detection method of claim 1, further comprising:

correcting the level change of the spectrum peaks on the basis of distances calculated from the reception signals.

5. The radar target detection method of claim 1, further comprising:

setting a plurality of directivity patterns; and

calculating a level of correlation between a change in a directional level due to switching between the plurality of directivity patterns and a change in the spectrum peak level due to the switching for each azimuth corresponding to an individual spectrum peak.

6. A radar apparatus comprising:

a transmitting antenna and a receiving antenna, at least either of which is an array antenna composed of a plurality of antenna elements disposed linearly at a predetermined spacing; and

a target detecting unit configured to;

obtain reception signals by transmitting and receiving waves through the antenna elements of the array antenna;

calculate reception signal intensities at arbitrary specified azimuth angles in a predetermined detection area;

detect a level change of spectrum peaks in an azimuth spectrum of the reception signal intensities;

calculate a level of correlation between the level change of each spectrum peak and a directivity pattern of the array antenna in an azimuth range corresponding to that spectrum peak; and

determine an azimuth corresponding to the spectrum peak having the highest corresponding correlation level to be the azimuth at which a target is located.

7. The radar apparatus of claim 6,

wherein the antenna elements are disposed with a spacing of at least one half wavelength of a transmission signal.

8. The radar apparatus of claim 6, further comprising a switching unit configured to switch a front direction of the array antenna.

9. The radar apparatus of claim 8, wherein the switching unit is a mechanical switch.