Communications: directive radio wave systems and devices (e.g. – With particular circuit – Display
Patent
1989-11-06
1991-07-30
Sotomayor, John B.
Communications: directive radio wave systems and devices (e.g.,
With particular circuit
Display
342179, G01S 756
Patent
active
050363263
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention concerns the display of radar images and, more particularly, a case where one and the same geographical zone is covered by several radars and where it is desired to obtain a single resultant image, formed by a mosaic of the images given by the different radars.
The need to make a mosaic arises notably when the position of a radar is such that it cannot cover the entire zone it is entrusted with monitoring, owing to obstacles such as mountains or tall buildings creating a shadow in the zone under surveillance, namely a sector without echo. This, for example, is often the case with airport surveillance radars.
To cover the entire zone, one or more additional radars are then needed, and are arranged so as to reach the shaded sectors of the first radar.
To enable an operator to have a comprehensive image of the zone on a single screen, it is then necessary to make a mosaic of images given by the different radars.
There are known ways to make this mosaic by taking, for each of the pixels of the resultant image, a video signal equal to a function (mean, maximum etc.) of each of the pixels given by the different radars. Since, in general, the images given by the different radars overlap one another, two types of zones are then distinguished on the single screen:
In the second type of zone, the echos of the detected objects (aircraft for example) processed by each of the radars should, of course, be superimposed on the screen and, to a given aircraft, there should therefore. This requiremement may not necessarily be achieved due to the asynchronism of the rotation of the radars. There may be movement by the aircraft between the instant when it is detected by the first radar and the instant when it is detected by the second one.
Furthermore, the radar video signal always contains a certain degree of noise and, with this type of system, the noises get added together in the zones common to several radars.
SUMMARY OF THE INVENTION
The present invention is aimed at forming a mosaic from a plurality of radar images, which avoids the previous drawbacks through the use of means for the mutual exclusion of the radar images. To a given point of the resultant image, there thus corresponds the display of one and only one radar.
Other objects, particular features and results of the invention will emerge from the following description, illustrated by the appended figures.
DESCRIPTION OF THE FIGURES
FIG. 1, the block diagram of a standard digital converter of images;
FIG. 2, a first embodiment of the mosaic according to the invention;
FIG. 3, a second embodiment of the mosaic according to the invention;
FIG. 4, the block diagram of a digital converter of images comprising an ancillary memory called a block memory;
FIG. 5, a third embodiment of the mosaic according to the invention;
FIG. 6, the detail of one of the elements of the previous figure;
FIG. 7, a fourth embodiment according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In these different figures, the same references pertain to the same elements.
FIG. 1 represents a standard digital converter of images.
It will be recalled that a converter of this type, also called an IDC, has the essential role of converting a radar image, given in polar coordinates and having relatively slow refreshing, into a television type light image, enabling it to be exploited in an illuminated environment.
The IDC thus receives, firstly, video signals from the radar receiver and, secondly, the radar antenna rotation signals.
The video signals are formed, firstly, by a synchronization signal indicating that a pulse has been emitted by the radar and, secondly, by the video proper, consisting of all the responses to (echos from) this pulse. These video signals are received by an input interface 1 comprising chiefly circuits for sampling the input analog information and a memory enabling the memorizing of the video information corresponding to each radar pulse.
The rotation signals are formed, firstly, by a North signal which i
REFERENCES:
patent: 3160881 (1964-12-01), Pederzani et al.
patent: 3378835 (1968-04-01), Mooney, Jr. et al.
patent: 3872474 (1975-03-01), Levine
patent: 4224669 (1980-09-01), Brame
patent: 4434422 (1984-02-01), Kenol et al.
patent: 4580164 (1986-04-01), Andrieu et al.
patent: 4601001 (1986-07-01), Guiglini
patent: 4612544 (1986-09-01), DaSilva et al.
patent: 4660043 (1987-04-01), Lachaize et al.
patent: 4688046 (1987-08-01), Schwab
patent: 4729029 (1988-03-01), Henri et al.
patent: 4754279 (1988-06-01), Cribbs
patent: 4757317 (1988-07-01), Henri et al.
patent: 4774516 (1988-09-01), Henri et al.
patent: 4777489 (1989-10-01), Allan
Andrieu Jean-Pierre
Gault Dominique
Henri Jean-Claude
"Thomson-CSF"
Sotomayor John B.
LandOfFree
Method and device for the display of several radar images in a s does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and device for the display of several radar images in a s, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and device for the display of several radar images in a s will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1545049