Radar apparatus

• US 5,351,055 A
• Filed: 05/26/1993
• Issued: 09/27/1994
• Est. Priority Date: 11/21/1989
• Status: Expired due to Term

• Current Assignee: Furuno Electric Co, Ltd
• Original Assignee: Furuno Electric Co, Ltd
• Inventors: Kondo, Motoji, Fujikawa, Takumi
• Primary Examiner(s): Sotomayor, John B.
• Application Number:
  US08/067,165
• Time in Patent Office: 489 Days
• Field of Search: 342/184, 342/176, 342/179, 342/189, 342/195, 342/159
• US Class Current: 342/184
• CPC Class Codes: G01S 7/064 using a display memory for image processing G01S7/298 takes precedence
• CPC Class Codes: G01S 7/12 Plan-position indicators, i.e. P.P.I.

Abstract

A radar apparatus displays echo signals in a manner that desired echo signals can be easily distinguished from unwanted echo signals such as sea clutter and the like and eliminated, when any one of display modes is selected. The radar apparatus includes a receiving unit for receiving echo signals, a buffer memory for storing echo signals resulting from one search signal and produced by the receiving unit, a first memory for storing echo signals coming from a wide range of directions in memory elements corresponding to points on the surface of the search at which the echo signals are generated respectively, signal process device for applying a signal process on the signals outputted from the buffer memory and the signals read out from the first memory and supplying resultant output signals to the first memory, a second memory for storing the output signals of the correlation means in corresponding memory elements thereof determined in compliance with a display mode selected, and an indicator for displaying the signals read out from the second memory.

Claims

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

a receiving unit for receiving echo signals;

a buffer memory for storing the received echo signals based on one search signal, said echo signals being supplied from the receiving unit;

a first memory for storing echo signals coming from a wide range of directions in memory elements thereof, the memory elements being determined with respect to a bearing;

correlation means for performing a correlation process upon signals supplied by said buffer memory and signals read from said first memory and for outputting resultant processed signals;

said first memory storing said resultant processed signals;

a second memory for storing said resultant processed signals outputted by said correlation means in memory elements thereof, said memory elements being determined by a selected display mode; and

an indicator for displaying signals read from said second memory;

said first and second memories functioning in combination to remove unwanted sea clutter.

2. The radar apparatus as claimed in claim 1 wherein said first memory stores echo signals coming from a wide range of directions in memory elements thereof determined with respect to North.

3. The radar apparatus as claimed in claim 1 wherein said first memory stores echo signals coming from a wide range of directions in memory elements thereof determined with respect to an advancing bearing of the ship.

4. The radar apparatus as claimed in claim 1 wherein said resultant processed signals outputted by said correlation means are written into corresponding memory elements of said second memory determined by a head-up display mode.

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

a receiving unit for receiving echo signals;

a buffer memory for storing the received echo signals based on one search signal, said echo signals being supplied from the receiving unit;

a first memory for storing echo signals coming from a wide range of directions in memory elements thereof, the memory elements being determined with respect to a bearing;

signal process means for implementing a signal process upon signals produced by said buffer memory and signals read from said first memory and for outputting resultant signals representative of a track of another ship;

said first memory storing said resultant signals;

a second memory for storing said resultant signals outputted by said signal process means representative of the track of another ship in corresponding memory elements determined in compliance with a selected display mode; and

an indicator for displaying signals read from said second memory;

said first and second memories functioning in combination to remove unwanted sea clutter.

6. A radar apparatus comprising:

a rotating antenna;

a gyro compass;

detection means for detecting a bearing of said rotating antenna;

display setting means for setting a helm-perspective display mode;

receiving means for receiving echo signals resulting from each search signal radiated in different directions by said rotating antenna;

a buffer memory for storing echo signals coming from a direction, said echo signals being produced by said receiving means;

write data generating means for generating data for picture indication based on output data from said buffer memory;

a frame memory for storing data generated by said write data generating means;

first write address generating means for generating write addresses for writing data into said frame memory based on data supplied from said gyro compass, said detection means and said display mode setting means;

read address generating means for providing said frame memory with read addresses;

an indicator for displaying data read from said frame memory;

a process memory for storing data read from said write data generating means;

said process memory being provided independently of said frame memory; and

second write address generating means for producing write addresses determined with respect to a bearing based on output data of said gyro compass and said detection means, said write addresses being supplied to said process memory;

said frame memory and said process memory functioning in combination to remove unwanted sea clutter.

7. The radar apparatus as claimed in claim 6 wherein said read address generating means provides said frame memory with read addresses produced in accordance with a raster scanning method.

8. The radar apparatus as claimed in claim 6 wherein said read address generating means provides said frame memory with read addresses produced in accordance with a spiral scanning method.

9. The radar apparatus as claimed in claim 7 wherein said second write address generating means produces write addresses determined with respect to North, with said write addresses being supplied to said process memory.

10. The radar apparatus as claimed in claim 7 wherein said second write address generating means produces write addresses determined with respect to an advancing bearing of the ship, with said write addresses being supplied to said process memory.

37. The radar apparatus as claimed in claim 8 wherein said second write address generating means produces write addresses determined with respect to North, with said write addresses being supplied to said process memory.

38. The radar apparatus as claimed in claim 8 wherein said second write address generating means produces write addresses determined with respect to an advancing bearing of the ship, with said write addresses being supplied to said process memory.

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

receiving means for receiving echo signals;

a buffer memory for storing the received echo signals resulting from one search signal, said echo signals being produced by said receiving means;

a first memory for storing echo signals coming from a wide range of directions in memory elements corresponding to points on a surface of the Earth at which said echo signals are generated respectively;

correlation means for performing a correlation process upon signals outputted from said buffer memory and signals read from said first memory;

a second memory for storing signals outputted from said correlation means in corresponding memory elements determined in compliance with a display mode; and

an indicator for displaying signals read from said second memory;

said first and second memories functioning in combination to remove unwanted sea clutter.

12. A radar apparatus comprising:

a gyro compass;

detection means for detecting a bearing of an antenna;

mode setting means for setting a usage mode obtained by appropriately combining one of a relative motion mode and a true motion mode and one of a north-up display mode, a helm-perspective display mode and a course-up display mode;

receiving means for receiving echo signals resulting from each search signal radiated in different directions by the antenna;

a buffer memory for storing echo signals coming from a direction, said echo signals being produced by said receiving means;

write data generating means for generating data for picture indication based on output data from said buffer memory;

a frame memory for storing data generated by said write data generating means;

first write address generating means for generating write addresses for writing data into said frame memory based on data supplied from said gyro compass, said detection means and said mode setting means;

read address generating means for providing an address corresponding to a fixed point in said frame memory as a start address for a reading operation;

an indicator for displaying the data read from said frame memory;

a process memory for storing data outputted from said write data generating means;

said process memory being provided independently of said frame memory; and

second write address generating means for producing a continuous series of write addresses in compliance with a true north-up mode to write data which go beyond a boundary of said process memory into a portion in said process memory based on data outputted from both said gyro compass and said detection means and data representative of a distance from a center of a radial radar sweep when one of a true-motion north-up mode and a relative-motion helm-perspective mode is selected.

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

receiving means for receiving echo signals;

first memory means for storing echo signals coming from a wide range of directions in memory elements thereof, the memory elements being determined by a relative motion mode combined with one of a north-up and a course-up mode;

correlation means for performing a correlation process upon signals supplied by said receiving means and signals read from said first memory means and for outputting resultant processed signals;

second memory means for storing the resultant processed signals outputted by said correlation means in memory elements thereof, said memory elements being determined by a combination of a relative motion mode and a helm-perspective mode; and

indicator means for displaying signals read from said second memory means.

14. The radar apparatus as claimed in claim 13 wherein said first memory means stores echo signals coming from a wide range of directions in memory elements thereof determined with respect to North.

15. The radar apparatus as claimed in claim 13 wherein said first memory means stores echo signals coming from a wide range of directions in memory elements thereof determined with respect to an advancing bearing of the ship.

16. The radar apparatus as claimed in claim 13 wherein said resultant processed signals outputted by said correlation means are written into corresponding memory elements of said second memory means determined by a helm-perspective display mode.

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

receiving means for receiving echo signals;

first memory means for storing echo signals coming from a wide range of directions in memory elements thereof, the memory elements being determined by a combination of a relative motion made and one of a north-up or a course-up mode;

signal process means for implementing a signal process on signals produced by said receiving means and signals read from said first memory means and for outputting resultant signals representative of a track of another ship;

said first memory means storing said resultant signals;

second memory means for storing the processed signals outputted by said signal process means representative of the track of another ship in corresponding memory elements determined by a combination of a relative motion mode and a helm-perspective mode; and

indicator means for displaying signals read from said second memory means.

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

receiving means for receiving echo signals;

buffer memory means for storing the received echo signals based on one search signal, said echo signals being supplied from said receiving means;

first memory means for storing echo signals coming from a wide range of directions in memory elements thereof, the memory elements being determined with respect to a bearing;

signal process means for implementing a signal process on signals produced by said buffer memory means and signals read from said first memory means and for outputting resultant signals representative of a track of another ship;

said first memory means storing said resultant signals;

second memory means for storing the processed signals outputted by said signal process means representative of the track of another ship in corresponding memory elements determined in compliance with a selected display mode; and

indicator means for displaying signals read from said second memory means;

said first and second memory means functioning in combination to remove unwanted sea clutter.

19. The radar apparatus as claimed in claim 18 wherein said read address generating means provides said frame memory means with read addresses produced in accordance with a raster scanning method.

20. The radar apparatus as claimed in claim 18 wherein said read address generating means provides said frame memory means with read addresses produced in accordance with a spiral scanning method.

21. The radar apparatus as claimed in claim 19 wherein said second write address generating means produces write addresses determined with respect to North, with said write addresses being supplied to said process memory means.

22. The radar apparatus as claimed in claim 19 wherein said second write address generating means produces write addresses determined with respect to an advancing bearing of the ship, with said write addresses being supplied to said process memory means.

39. The radar apparatus as claimed in claim 20 wherein said second write address generating means produces write addresses determined with respect to North, with said write addresses being supplied to said process memory means.

40. The radar apparatus as claimed in claim 20 wherein said second write address generating means produces write addresses determined with respect to an advancing bearing of the ship, with said write addresses being supplied to said process memory means.

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

receiving means for receiving echo signals;

first memory means for storing echo signals coming from a wide range of directions in memory elements respectively determined by a combination of a true motion mode and one of a north-up or a course-up mode;

correlation means for performing a correlation process upon signals outputted from said receiving means and signals read from said first memory means;

second memory means for storing signals outputted from said correlation means in corresponding memory elements determined by a combination of a relative motion mode and a helm-perspective mode; and

indicator means for displaying signals read form said second memory means.

24. A radar apparatus comprising:

a gyro compass;

detection means for detecting a bearing of an antenna;

mode setting means for setting a usage mode obtained by appropriately combining one of a relative motion mode and a true motion mode and one of a north-up display mode, a helm-perspective display mode and a course-up display mode;

receiving means for receiving echo signals resulting from each search signal radiated in different directions by the antenna;

buffer memory means for storing echo signals coming from a direction, said echo signals being produced by said receiving means;

write data generating means for generating data for picture indication based on output data from said buffer memory;

frame memory means for storing data generated by said write data generating means;

first write address generating means for generating write addresses for writing data into said frame memory means based on data supplied from said gyro compass, said detection means and said mode setting means;

read address generating means for providing an address corresponding to a fixed point in said frame memory means as a start address for a reading operation;

indicator means for displaying the data read from said frame memory means;

process memory means for storing data outputted from said write data generating means;

said process memory means being provided independently of said frame memory means; and

second write address generating means for producing a continuous series of write addresses in compliance with a true north-up mode to write data which go beyond a boundary of said process memory means into a portion in said process memory means based on data outputted from both said gyro compass and said detection means and data representative of a distance from a center of a radial radar sweep when one of a true-motion north-up mode and a relative-motion helm-perspective mode is selected.

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

(a) receiving echo signals;

(b) storing the received echo signals based on one search signal in a first memory the echo signals being supplied from said step (a);

(c) storing echo signals coming from a wide range of directions in memory elements of a second memory, the memory elements being determined with respect to a bearing;

(d) performing a correlation process upon signals supplied by the first memory and signals read from the second memory and outputting resultant processed signals;

(e) storing the resultant processed signals in the second memory;

(f) storing the resultant processed signals in memory elements of a third memory, the memory elements being determined by a selected display mode; and

(g) displaying signals read from the third memory;

said steps (e) and (f) functioning in combination to remove unwanted sea clutter.

26. The method as claimed in claim 25 wherein the second memory stores echo signals coming from a wide range of directions in memory elements thereof determined with respect to North.

27. The method as claimed in claim 25 wherein the second memory stores echo signals coming from a wide range of directions in memory elements thereof determined with respect to an advancing bearing of the ship.

28. The method as claimed in claim 25 wherein the resultant processed signals are written into corresponding memory elements of the third memory determined by a helm-perspective display mode.

29. A method for successively radiating search signals in different directions, receiving echo signals and displaying the signals so that surrounding conditions in a wide range of directions are indicated, comprising the steps of:

(a) receiving echo signals;

(b) storing the received echo signals based on one search signal in a first memory, the echo signals being supplied by said step (a);

(c) storing echo signals coming from a wide range of directions in memory elements of a second memory, the memory elements being determined with respect to a bearing;

(d) implementing a signal process on signals produced by the first memory and signals read from the second memory and outputting resultant signals representative of a track of another ship;

(e) storing the resultant signals in the second memory;

(f) storing the resultant signals representative of the track of another ship in corresponding memory elements of a third memory determined in compliance with a selected display mode; and

(g) displaying signals read from the third memory;

said steps (e) and (f) functioning in combination to remove unwanted sea clutter.

30. A method for detecting objects around a ship, comprising the steps of:

(a) transmitting search signals;

(b) determining a bearing of the ship;

(c) detecting a bearing of the search signals;

(d) setting a helm-perspective display mode;

(e) receiving echo signals resulting from each search signal radiated in different directions;

(f) storing echo signals coming from a direction in a first memory, the echo signals being produced by said step (e);

(g) generating data for picture indication based on output data from the first memory;

(h) storing data generated in said step (g) in a frame memory;

(i) generating write addresses for writing data into the frame memory based on data supplied from said step (b), said step (c), and said step (d);

(j) providing the frame memory with read addresses;

(k) displaying data read from the frame memory;

(l) storing data generated in said step (g) in a process memory, the process memory being provided independently of the frame memory; and

(m) producing write addresses determined with respect to a bearing based on output data of said step (b) and said step (c), the write addresses being supplied to the process memory.

31. The method as claimed in claim 30 wherein said step (j) provides the frame memory with read addresses produced in accordance with a raster scanning method.

32. The method as claimed in claim 30 wherein said step (j) provides the frame memory with read addresses produced in accordance with a spiral scanning method.

33. The method as claimed in claim 31 wherein said step (m) produces write addresses determined with respect to North, with the write addresses being supplied to the process memory.

34. The method as claimed in claim 31 wherein said step (m) produces write addresses determined with respect to an advancing bearing of the ship, with the write addresses being supplied to the process memory.

41. The method as claimed in claim 32 wherein said step (m) produces write addresses determined with respect to North, with the write addresses being supplied to the process memory.

42. The method as claimed in claim 32 wherein said step (m) produces write addresses determined with respect to an advancing bearing of the ship, with the write addresses being supplied to the process memory.

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

(a) receiving echo signals;

(b) storing the received echo signals resulting from one search signal in a first memory, the echo signals being produced by said step (a);

(c) storing echo signals coming from a wide range of directions in memory elements of a second memory corresponding to points on a surface of the Earth at which the echo signals are generated respectively;

(d) performing a correlation process upon signals outputted from the first memory and signals read from the second memory;

(e) storing signals generated in said step (d) in corresponding memory elements of a third memory determined in compliance with a display mode; and

(f) displaying signals read from the third memory;

said steps (c) and (e) functioning in combination to remove unwanted sea clutter.

36. A method for detecting objects around a ship, comprising the steps of:

(a) determining a bearing of the ship;

(b) detecting a bearing of an antenna;

(c) setting a usage mode obtained by appropriately combining one of a relative motion mode and a true motion mode and one of a north-up display mode, a helm-perspective display mode and a course-up display mode;

(d) receiving echo signals resulting from each search signal radiated in different directions by the antenna;

(e) storing echo signals coming from a direction in a buffer memory, the echo signals being produced by said step (d);

(f) generating data for picture indication based on output data from the buffer memory;

(g) storing data generated in said step (f) in a frame memory;

(h) generating write addresses for writing data into the frame memory based on data supplied from said step (a), said step (b) and said step (c);

(i) providing an address corresponding to a fixed point in the frame memory as a start address for a reading operation;

(j) displaying the data read from the frame memory;

(k) storing data generated in said step (f) in a process memory, the process memory being provided independently of the frame memory; and

(l) producing a continuous series of write addresses in compliance with a true north-up mode to write data which go beyond a boundary of the process memory into a portion in the process memory based on data outputted from both said step (a) and said step (b) and data representative of a distance from a center of a radial radar sweep when one of a true-motion north-up mode and a relative-motion helm-perspective mode is selected.

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

receiving means for receiving echo signals;

a buffer memory for storing the received echo signals resulting from one search signal, said echo signals being produced by said receiving means;

a first memory for storing echo signals coming from a wide range of directions in memory elements corresponding to points on a surface of the Earth at which said echo signals are generated respectively;

correlation means for performing a correlation process upon signals outputting from said buffer memory and signals read from said first memory;

said first memory storing the processed signals produced by said correlation means;

a second memory for storing signals outputted from said correlation means in corresponding memory elements determined by a helm-perspective display mode; and

an indicator for displaying signals read from said second memory;

the first and second memories functioning in combination to remove unwanted sea clutter.

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

receiving means for receiving echo signals;

buffer memory means for storing the received echo signals based on one search signal, said echo signals being supplied from said receiving means;

first memory means for storing echo signals coming from a wide range of directions in memory elements thereof corresponding to points on a surface of the Earth at which said echo signals are generated respectively;

signal process means for implementing a signal process on signals produced by said buffer memory means and signals read from said first memory means and for outputting resultant signals representative of a track of another ship;

said first memory means storing said resultant signals;

second memory means for storing the processed signals outputted by said signal process means representative of the track of another ship in corresponding memory elements determined by a helm-perspective display mode; and

an indicator for displaying signals read from said second memory means.

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

receiving means for receiving echo signals;

buffer memory means for storing the received echo signals resulting from one search signal, said echo signals being produced by said receiving means;

first memory means for storing echo signals coming from a wide range of directions in memory elements thereof corresponding to points on a surface of the Earth at which said echo signals are generated respectively;

correlation means for performing a correlation process upon signals outputted from said buffer memory and signals read from said first memory means;

said first memory means storing the processed signals produced by said correlation means;

second memory means for storing echo signals coming from the wide range of directions in memory elements thereof corresponding to points on a surface of the Earth at which said echo signals are generated respectively;

signal process means for implementing a signal process on signals produced by said buffer memory means and signals read from said second memory means and for outputting resultant signals representative of a track of another ship;

said second memory means storing said resultant signals;

third memory means for storing signals outputted from said correlation means and said signal process means in corresponding memory elements thereof determined by a selected display mode; and

an indicator for displaying signals read from said third memory means.

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

receiving means for receiving echo signals;

buffer memory means for storing the received echo signal resulting from one search signal, said echo signals being produced by said receiving means;

first memory means for storing echo signals coming from a wide range of directions in memory elements thereof corresponding to points on a surface of the Earth at which said echo signals are generated respectively;

correlation means for performing a correlation process upon signals outputted from said buffer memory and signals read from said first memory means;

said first memory means storing the processed signals produced by said correlation means;

second memory means for storing echo signals coming from the wide range of directions in memory elements thereof corresponding to points on a surface of the Earth at which said echo signals are generated respectively;

signal process means for implementing a signal process on signals produced by said buffer memory means and signals read from said second memory means and for outputting resultant signals representative of a track of another ship;

said second memory means storing said resultant signals;

third memory means for storing signals outputted from said correlation means and said signal process means in corresponding memory elements thereof determined by a helm-perspective display mode; and

an indicator for displaying signals read from said third memory means.

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

receiving means for receiving echo signals;

first memory means for storing echo signals coming from a wide range of directions in memory elements thereof, the memory elements being determined with respect to a bearing;

correlation means for performing a correlation process upon signals outputted from said receiving means and signals read from said first memory means;

said first memory means storing the processed signals produced by said correlation means;

second memory means for storing signals outputted from said correlation means in corresponding memory elements thereof determined by a helm-perspective display mode; and

an indicator for displaying signals read from said second memory means.

48. A display system comprising:

signal generating means for generating signals for indication;

a first memory for storing the signals from said signal generating means in memory elements thereof, the memory elements being determined with respect to a bearing;

a second memory for storing the signals outputted from said first memory in corresponding memory elements determined by a helm-perspective display mode; and

an indicator for displaying signals read from said second memory.

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

receiving means for receiving echo signals;

first memory means for storing echo signals coming from a wide range of directions in memory elements thereof, respectively, determined by a combination of a true motion mode and one of a north-up mode and a course-up mode;

signal process means for implementing a signal process on signals from said receiving means and signals read from said first memory and for outputting resultant signals representative of a track of another ship;

said first memory means storing said resultant signals;

second memory means for storing signals outputted from said signal process means in corresponding memory elements thereof determined by a combination of a relative motion mode and a head-up mode; and

an indicator for displaying signals read from said second memory means.