Communications: directive radio wave systems and devices (e.g. – Ship collision avoidance
Patent
1995-10-06
1997-09-02
Sotomayor, John B.
Communications: directive radio wave systems and devices (e.g.,
Ship collision avoidance
342197, G01S 1393
Patent
active
056637306
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a radar system. The invention relates to an improvement of the radar systems as they are known today. More particularly, the invention relates to a radar system for transmitting and receiving radar signals via a common aerial.
The navigational radar of today has not changed essentially for many years. Taking into account that the clarity of the picture has the greatest significance in bad weather, one might be tempted to say that the majority of radar sets are of relatively poorer quality than they were earlier.
Some of the background for this is that when the radar has a specification for a given purpose, one must compromise, i.e. that by providing radar systems one can obtain the required information with the necessary precision, assuming that one is willing to renounce other information, and to accept higher weights, need of space and costs.
It is a known fact that shipping has increased considerably in recent years. Moreover the speed of certain types of vessels, and particularly passenger vessels (catamarans and pleasure crafts etc) has greatly increased. Many of these vessels can reach a speed of up to 60 knots. Taking these facts into consideration, and the increase of speed boats in recent years presents a corresponding need for further development and improvement of radar sets.
During the last ten years there have been many accidents, or near accidents, which can partly be blamed on poor radar systems onboard. This is even more serious, as it is well known that the weather conditions at times may make certain types of radar sets almost unusable. A radar set can therefore represent a security risk in itself.
If we summarize the various factors influencing the radar, the prementioned increase in the number of vessels, and their speed, it is clearly necessary to stipulate more stringent requirements for the main function of the radar, i.e. to furnish the pilot of a vessel, for example, with the possibility to see what has importance for safe navigation, particularly in bad weather conditions, such as rain, fog, heavy sea, and so forth, and in narrow waters.
Thus there is a considerable need for further technical development of the radar with the object of improving the picture (video) quality.
A number of parameters exist determining the quality of a radar picture. These parameters include the transmitting effect, the length of the pulse, the pulse repetition frequency (PRF), the sensitivity and dynamics of the receiver, the signal processing in the receiver, the signal processing in the display, the type of aerial and its size and rotation speed. These are known conditions which on a technological basis determine the quality of the radar picture.
With reference to the previously known techniques, and problems encumbering todays radar, one shall refer to an article written by Bjorn Hansen and published in "Norsk Nautisk Almanakk for 1993", pages 552-561, entitled "90-arenes navigasjonsradar", and to the U.S. Pat. Nos. 2,817,832, and 4,197,540.
U.S. Pat. No. 2,817,832 describes a radar set in which the sequences between the transmitters (TX1-TX2-TX3) and the gated amplifiers 10, 11, 12 and the receiver 16 with which the radar set is constructed are shown in FIG. 1 wherein the upper portion of the figure indicates the order and distance between the transmitter pulses. It will be apparent that the transmitter fires pulses in the mentioned order (TX1-TX2-TX3). The lower portion of the diagram shows the situation of the receiver 16, that is to say the periods of time wherein the receivers are active (open) or closed.
It is evident that the certain receiver (RX) is cut off (i.e. open) during the entire sequence cycle. As mentioned in said patent the individual receiver opens for a limited sequence time only, in that the sequence in the given occasion is only 1/3 of the sequence time of the respective TX. Furthermore it is stated that the segments are divided into 0-25 NM. It follows therefore that the radar set, according to U.S. Pat. No. 2,817,832, can only see one segment
REFERENCES:
patent: 2817832 (1957-12-01), Mathes
patent: 4197540 (1980-04-01), Riggs, et al.
patent: 4206461 (1980-06-01), Pease et al.
patent: 4890112 (1989-12-01), Petito et al.
patent: 5191343 (1993-03-01), Danzer et al.
patent: 5254999 (1993-10-01), Lee
patent: 5583511 (1996-12-01), Hulderman
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