Radar apparatus

• US 5,278,566 A
• Filed: 09/29/1992
• Issued: 01/11/1994
• Est. Priority Date: 02/01/1991
• Status: Expired due to Fees

• Current Assignee: Furuno Electric Co, Ltd
• Original Assignee: Furuno Electric Co, Ltd
• Inventors: Fujikawa, Takumi, Aridome, Nishinomiya, Kiya, Yoshiyuki
• Primary Examiner(s): TUBBESING, THEODORE
• Application Number:
  US07/927,495
• Time in Patent Office: 469 Days
• Field of Search: 342/174, 342/176, 342/185
• US Class Current: 342/174
• CPC Class Codes: G01S 13/89 for mapping or imaging
• CPC Class Codes: G01S 7/295 Means for transforming co-ordinates or for evaluating data, e.g. using computers
• CPC Class Codes: G01S 7/4004 of parts of a radar system

Abstract

A radar apparatus radiates search signals successively in different directions, receives echo signals and displays the signals so that surrounding conditions in a wide range of directions are displayed. The radar apparatus comprises a buffer memory for temporarily storing echo signals resulting from single search signals, a memory for storing echo signals supplied from the buffer memory and corresponding to single scans at corresponding memory elements, a timing adjusting amount setter for determining a timing adjusting amount in a distance direction, and a control arrangement for causing the buffer memory to write received echo signals thereinto based on the determined timing adjustment amount.

Claims

1. A radar apparatus for radiating search signals successively in different directions, receiving echo signals and displaying the signals so that surrounding conditions in a wide range of directions are displayed, comprising:

an input for receiving echo signals;

a first memory for storing received echo signal data corresponding to one sweep and supplied from said input;

a second memory for storing received signal data corresponding to one scan and supplied from said first memory;

a indicator for displaying the signals read out from said second memory;

main bang detection means for detecting a main bang included in the received echo signals; and

start signal generating means for generating a start pulse for initiating to write echo signals into said first memory based on the main bang detected by said main bang detection means.

2. A radar apparatus fur radiating search signals successively in different directions, receiving echo signals and displaying the signals so that surrounding conditions in a wide range of directions are displayed, comprising:

an input for receiving echo signals;

a buffer memory for storing echo signals resulting from one search signal;

a memory for storing at corresponding memory elements echo signals corresponding to one scan and supplied from said buffer memory;

main bang detection means for detecting a main bang included in the echo signals supplied from said buffer memory; and

start signal generating means for generating a start pulse for initiating writing of echo signals from said buffer memory into said memory based on the main bang detected by said main bang detection means.

3. A radar apparatus in which a transmitting pulse is transmitted in response to a trigger signal, comprising:

a source of said trigger signal and an input for receiving echo signals from objects;

a primary memory for storing received signal data from said input and corresponding to one sweep;

a secondary memory for storing received signal data corresponding to one scan;

reception data transfer means comprising means for sequentially reading signals stored in said primary memory, starting from a predetermined location in said primary memory, and writing the read signals into memory elements of said secondary memory corresponding to a pointing direction of an antenna;

timing amount determining means for determining a time delay corresponding to a distance in a direction from said apparatus; and

read reference point varying means for shifting the predetermined location corresponding to an antenna position in said primary memory by an amount corresponding to said time delay.

4. A radar apparatus claimed in claim 3 wherein the means for shifting comprises a counter and signal generating means for generating a start signal in response to the output signal of said counter.

5. A radar apparatus comprising:

transmission trigger pulse generating means for generating a trigger pulse for determining the transmission timing of search signals from an antenna;

a sampling circuit for sampling at a predetermined sampling period received signals resulting from the search signal, reflected by objects and caught by the antenna;

a buffer memory for storing the reception signals sampled by said sampling circuit and corresponding to a plurality of beams;

a display memory for storing as image data the received signal data transferred from said buffer memory;

an address signal generating circuit for generating write/read address signals for the image data written into and read from said display memory;

an indicator for displaying the image data read out from said display memory;

an A/D converter for converting the reception signals obtained by the antenna to digital signals at a predetermined sampling period in response to a transmission trigger pulse from said transmission trigger pulse generating unit;

a main bang detection memory for storing the reception signals corresponding to a plurality of beams and digitized by said A/D converter;

a main bang detection circuit for detecting a main bang included in the reception signal data by performing a sweep correlation on the reception signal data corresponding to a plurality of beams and stored in said main bang detection memory and;

start pulse generating means for producing a start pulse for initiating a sampling operation in said sampling circuit in response to a main bang detected by said main bang detection circuit.

6. A radar apparatus comprising:

transmission trigger pulse generating means for generating a trigger pulse for determining the transmission timing of search signals from an antenna;

a sampling circuit for sampling at a predetermined sampling period reception signals resulting from the search signal, reflected by objects and caught by the antenna;

a buffer memory for storing the reception signals sampled by said sampling circuit and corresponding to a plurality of beams;

a display memory for storing as image data the reception signal data transferred from said buffer memory;

an address signal generating circuit for generating write/read address signals for the image data written into and read from said display memory;

an indicator for displaying the image data read out from said display memory;

a main bang detection circuit for detecting a main bang included in the reception signal data by performing a sweep correlation on the reception signal data stored in said buffer memory and corresponding to a plurality of beams; and

start pulse generating means for producing a start pulse for causing said address signal generating circuit to produce write address signals in response to a main bang detected by said main bang detection circuit.