Communications: directive radio wave systems and devices (e.g. – With particular circuit – Display
Patent
1991-02-05
1992-10-20
Hellner, Mark
Communications: directive radio wave systems and devices (e.g.,
With particular circuit
Display
H03I 1324
Patent
active
051574063
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a radar apparatus which radiates search signals successively in different directions and receives echo signals coming from the respective directions by means of a rotating antenna, writes the echo signals coming from a wide range of directions into a display memory to store the signals therein, and reads the signals therefrom to supply them to an indicator so that surrounding conditions around the radar antenna are indicated on the display surface of the indicator. Particularly, the invention relates to a radar apparatus which writes echo signals caught by an antenna into a display memory in accordance with a novel method, thereby improving the conveyance of information relating to conditions around the vicinity of the own ship on the display surface of an indicator.
BACKGROUND ART
A conventional raster scanning radar is constructed as illustrated in FIG. 16. An antenna 901 rotates at a constant speed, radiates radar search signals successively in different directions and receives echo signals. A radar transmitting and receiving unit 907 receives echo signals; an A/D converter 902 converts the echo signals to digital data; and a primary memory 903 stores the resultant converted digital data therein. The primary memory has a memory capacity to store all the echo signals based on one radar search signal corresponding to one radar sweep. A coordinates converter 904 converts the polar coordinates of information in relation to surroundings about the radar antenna to corresponding Cartesian coordinates based on bearing signals produced by the radar transmitting and receiving unit 907 and generates signals representative of the addresses of corresponding memory elements of a display memory. The echo signals read from the primary memory are written into respective memory elements of a display memory 905 which are disposed along an imaginary sweep drawn in correspondence to a direction in which echo signals come, the addresses of the memory elements are identified by output signals of the coordinates converter 904. FIG. 17 shows a relationship between imaginary sweeps traced in the display memory 905 and some memory elements of the display memory when signals read from of the primary memory are written into the memory elements of the display memory 905. Every time the pointing bearing of the antenna 901 varies, relevant contents are refreshed in the display memory 905. Referring to FIG. 17, when a sweep SW1 is traced, echo signals based on one radar search signal and read from the primary memory are successively written into memory elements M00, M01, M11, M12 . . . disposed along the sweep. When a next sweep SW2 is drawn, echo signals supplied by the primary memory are written into memory elements M00, M01, M11, M12, M22 . . . scanned by the sweep. When another sweep SW3 is traced, echo signals are written into memory elements M00, M01, M11, M12, M22 . . . disposed along the sweep. In the same way, when another sweep SW4 is run, echo signals are written into memory elements M00, M10, M11, M21, M22 . . . disposed along the sweep. When another sweep SW5 is drawn, echo signals in response to a following radar search signal and stored in the primary memory and read from the memory are successively written into memory elements M00, M10, M11, M21, M22 disposed along the sweep. When a further sweep SW6 is run, echo signals read from the primary memory are successively written into memory elements M00, M10, M11, M21 . . . disposed along the sweep. In the same way, every time the pointing direction of the radar antenna is varied, an imaginary sweep is drawn in the display memory 905, echo signals read from the primary memory are written into the display memory. An indicating device 906 comprises, for example, a raster-scanned cathode-ray tube, respective picture elements of which correspond to respective memory elements of the display memory 905 and indicates echo signals having come from a wide range of directions, read from the display memory and applied at the input te
REFERENCES:
patent: 4387365 (1983-06-01), Berry et al.
patent: 4697185 (1987-09-01), Thomas et al.
patent: 4745475 (1988-05-01), Bicknell
Fujikawa Takumi
Kondo Motoji
Furuno Electric Company Ltd.
Hellner Mark
LandOfFree
Radar apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Radar apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Radar apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-195212