JPH042986A - Detecting system of radio wave - Google Patents

Abstract

PURPOSE:To reduce an effect of lobbing sharply and to improve the precision in calculation of distance by calculating the distance to a target on the basis of the average value of a reception signal power at each prescribed number of hits and a known value of an effective radiant power. CONSTITUTION:A series circuit of an integrating circuit 10 and an average reception power calculating circuit 11 is interposed between a reception peak power measuring circuit 8 and a distance calculating circuit 9, and pulse repetition interval (PRI) data are outputted from a data processing system 6 to the calculating circuit 11. In other words, a reception peak power at each hit obtained by the reception peak power measuring circuit 8 is integrated by the integrating circuit 10. The result of integration is subjected to an average value processing in the following calculating circuit 11 by using the PRI data thereby an effect of lobbing is removed. Consequently, highly-precise calculation of distance can be executed in the distance calculating circuit 9 on the basis of effective radiant power (ERP) data and a average reception power.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a radio wave detection system, and particularly relates to a signal processing method for calculating the distance to a target. There are those that do not emit radio waves but detect and receive radio waves emitted by the target, and those that detect and receive radio waves that are reflected by the target among the radio waves that they themselves emit. The distance calculation processing system in this radio wave detection system has conventionally been configured as shown in FIG. 2, for example.

In FIG. 2, radio waves from the target received by the detection/measurement antenna are received and processed by the detection and reception system 2, and from there are transmitted to the detection processing system 3, measurement reception system 4, and reception peak power measurement port li! The detection processing system 3 and the measurement processing system 5, which are output in three branches to the 88, output the frequency, direction, pulse width, pulse repetition interval
It analyzes and measures radio wave specifications such as rval: P RI ) and outputs them to the data processing system 6.

The data processing system 6 analyzes and identifies the target based on the input radio wave specifications, and tracks the target's movement. In addition, the data processing system 6 compares the input radio wave specifications with the library data 7 prepared in advance, and if they match, the data processing system 6 compares the input radio wave specifications with the library data 7 prepared in advance. Specifically identify the effective radiation power of the identified radio wave emission source.
er:E RP) data from the library Cheetah, and the ERP data of the specific target is sent to the distance calculation circuit 9.
Output to.

The distance calculation circuit 9 determines that the target is emitting radio waves according to the ERP data inputted from the data processing system, that is, the known ERP data, and that the radio wave propagation loss from the target to the radio wave detection system is as follows. Assuming that it is as predicted based on the past performance, calculate the distance to the target from the peak power of the received signal input from the received peak power J1 measuring circuit 8 using the known ERP data as a reference. , and outputs the result to the data processing system 6.

As a result, the data processing system 6 outputs the target data to a display system outside the country.

(Invention or problem to be solved) As mentioned above, radio wave detection systems either calculate the distance to the target from the power of the received signal, or the calculation process involves several prerequisites. There is a problem with accuracy. Since the data obtained is valuable for system operation, increasing its accuracy is an important technical issue.

In particular, in radio wave propagation paths, roving occurs due to the influence of multipaths, and this greatly fluctuates the level of the received signal, making it difficult to measure the power of the received signal.

Regarding the phenomenon of low pink, for example, McGRA
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The general outline of the radio wave detection system is as follows.

In other words, in a radio wave detection system, the radio waves from the target arrive in two parts: direct waves and reflected waves reflected from the ground, sea surface, etc.
These amplitudes and phases are received in a combined state.

The degree of influence of both waves depends on factors such as antenna installation height, target altitude, distance to target, frequency of radio waves used, reflection coefficient of reflective surface, etc.
Although it differs depending on various conditions, overall it is accompanied by significant fluctuations in reception level.

Normally, radio wave detection systems target long distances for early warning and are often installed on coastlines. In this case, the influence of roving is large, and as the target moves, the received power increases by 200%. 6 As a result, the distance calculation varies considerably, which causes a practical problem.

The present invention was made in view of such problems, and its purpose is to provide a radio wave detection system that significantly reduces the influence of roving and has high accuracy in distance calculation.

(Means for Solving the Problems) In order to achieve the above object, the radio wave detection system of the present invention has the following configuration.

That is, the radio wave detection system of the present invention detects and receives radio waves emitted from a target or radio waves reflected from the target to determine the distance to the target.
The present invention is characterized by comprising means for determining an average value of received signal power for a predetermined number of hits; and means for calculating a distance to a target based on a known effective radiated power value and the average value.

Function) Next, the function of the radio wave detection system of the present invention configured as described above will be explained.

In the present invention, the average value of the received signal power for each predetermined number of hits is determined, that is, the received signal power with the influence of roving reduced is determined, and the distance to the target is calculated based on this.

As a result, distance calculation accuracy can be significantly improved.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a radio wave detection system according to an embodiment of the present invention. In the system of this embodiment, as shown in FIG. 6 to average received power calculation port f? L11
The PRT data is output at the same time. Others are
This system is similar to the conventional system shown in FIG. 2, and is designated by the same reference numerals. Hereinafter, parts related to the present invention will be mainly explained.

Received peak power f (received peak power for each angle t obtained by measuring circuit 8 is integrated by an integrating circuit 10.

This integration result is PR at the next average received power calculation port ill.
The average value is processed using ITA to remove the influence of low pink.

As a result, the distance calculation circuit 9 performs highly accurate distance calculation based on the ERP data and the average received power.

Note that the time for performing the averaging operation is determined to be an optimum value using parameters such as antenna installation height, frequency, and target speed, and is also variably set.

In FIG. 1, an integrating circuit 10 and an average received power calculating circuit 11
Although the average value processing is performed at the reception peak power measurement port FI! ! There is also a practical method in which the measurement results of 8 are digitized and recorded for each hit, and the average value for a predetermined number of hits is calculated digitally.

(Effects of the Invention) As explained above, according to the radio wave detection system of the present invention, since the average value of a predetermined number of hits is used as the received signal power necessary for distance calculation, the influence of roving is significantly reduced. 9, which has the effect of significantly improving distance calculation accuracy.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a radio wave detection system according to an embodiment of the present invention, and Fig. 2 is a block diagram of a conventional radio wave detection system. ...detection and reception system, 3..detection processing system, 4..measurement reception system, 5..measurement processing system, 6..data processing system, 7..library. Data, 8...
Received peak power measurement circuit, 9... Distance calculation circuit,
10...Integrator circuit, 11...Average received power calculation circuit. Agent Patent Attorney Yoshihiro Yahata L. Shu's ultimate knowledge Systemdem's 14 precepts 82 diagrams

Claims (1)

[Claims] In a radio wave detection system that detects and receives radio waves emitted from a target or radio waves reflected by the target to determine the distance to the target; means for determining the average value of received signal power for each predetermined number of hits; and known effective A radio wave detection system comprising: means for calculating a distance to a target based on a radiation power value and the average value.