Radar apparatus or like

• US 20070126624A1
• Filed: 11/15/2004
• Published: 06/07/2007
• Est. Priority Date: 11/14/2003
• Status: Active Grant

• Current Assignee: Furuno Electric Co, Ltd
• Original Assignee: Furuno Electric Co, Ltd
• Inventors: Fujikawa, Takumi, Takemoto, Sae, Kondo, Motoji
• Granted Patent: US 7,679,548 B2
• Time in Patent Office: Days
• US Class Current: 342/185
• CPC Class Codes: G01S 7/14 Sector, off-centre, or expanded angle display
• CPC Class Codes: G01S 7/298 Scan converters

Abstract

A radar apparatus or like is provided in which a rate at which detected image data is written into an image memory is prevented from decreasing, irrespective of an enlarged amount of the detected image data. When an azimuth direction enlargement section 90a of a W data generator 9 receives detected image data of a certain sweep, the azimuth direction enlargement section 90a outputs the detected image data to an image memory 10, and delays the detected image data, depending on a cycle of an azimuth direction shift timing signal. Next, when detected image data of a next sweep is drawn into a pixel adjacent in an azimuth direction (sweep moving direction) to a pixel into which previous detected image data has been drawn and is located at the same distance in a sweep distance direction, the delayed detected image data is compared with new detected image data, and the greater data is drawn into the new pixel. Here, when the delayed detected image data is greater, this detected image data is eventually enlarged in the azimuth direction.

Claims

1. A radar apparatus or like comprising:

a coordinate converter for converting detected data at each sample point obtained in a polar coordinate system into a rectangular coordinate system;

a detected image data generator for generating detected image data corresponding to each pixel in an image memory based on the detected data; and

an image memory for storing detected image data output from the detected image data generator,

wherein the apparatus comprises data shifter for shifting detected image data input from the detected image data generator with predetermined timing and outputting the detected image data, and azimuth direction detected image data corrector for comparing detected image data of a current sweep from the detected image data generator with detected image data of a previous sweep from the data shifter at the same position in a sweep distance direction, and outputting a maximum value of the pieces of detected image data as detected image data of the current sweep.

2. A radar apparatus or like according to claim 1, wherein the azimuth direction detected image data corrector comprises a correction stopper for, when a predetermined number or more of consecutive pieces of detected image data greater than or equal to a predetermined threshold value are present over a plurality of sweeps at the same position in a distance direction, stopping replacement of detected image data of a current sweep with detected image data of a previous sweep based on a sweep on which detected image data at the same position in the distance direction has a value less than the threshold value.

3. A radar apparatus or like according to claim 1 or 2, comprising a distance direction detected image data corrector for comparing a predetermined number of consecutive pieces of detected image data in the distance direction on the same sweep, and outputting most peripheral detected image data of the pieces of detected image data as a maximum value of the consecutive pieces of detected image data.

4. A radar apparatus or like according to any of claims 1 to 3, comprising a selector for selecting the number of sweeps to be shifted by the data shifter.

5. A radar apparatus or like according to claim 4, wherein the selector selects the number of pieces of detected image data to be compared by the distance direction detected image data corrector.