JPH05142336A - Target distance detecting device - Google Patents

Abstract

PURPOSE:To provide range detecting precision which is equal to and under the range bin width, in a target range sensor of a radar. CONSTITUTION:An interpolation 8 detects target range with precision under the range bin width which is obtained with a range detector 7. By solving Gaussian ternary simultaneous equation with the interpolator 8 providing as a solution the three points in all which are the nth range cell with maximum and its front and back range cells by 1 each out of discrete amplitude values of a range bin unit of SIGMA detecting signal 3 at each pulse, by calculating the maximum amplitude value of an interpolating curve, and by providing the range under the range bin width, interpolating range data 9 is output.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a target distance of a radar device, and more particularly to an apparatus for detecting a highly accurate target distance by interpolating between range bins.

[0002]

2. Description of the Related Art For example, FIG. 5 is a diagram for explaining a conventional target distance detecting apparatus described in P280, Institute of Electronics, Information and Communication Engineers, P280. In the figure, 1 is a Σ signal pulse, Z
Is a Σ received signal, 3 is a Σ detected signal, 4 is distance data, 5 is a receiver, 6 is a detector, and 7 is a distance detector.

6 and 7 are views for explaining a conventional target distance detecting device. In the figure, 10 is a range bin.

First, the operation of FIG. 5 will be described.

A Σ signal pulse 1 which is a radar echo from a target is input to a signal processing circuit by a receiver 5.
The received Σ received signal 2 becomes the Σ detected signal 3 in the intermediate frequency band by the detector 6, and the distance detector 7 shows the distance to the nth range bin having the largest Σ signal amplitude in the Σ detected signal 3 as shown in FIG. As shown, the distance data 4 is output.

Next, the target distance detecting device will be described with reference to FIG. When the target moves, each range bin 1
The target distance data 4 is detected at intervals quantized by 0 unit. However, the distance data 4 has a step-like range bin width as shown in FIG. 7, and has a drawback that the target distance is the same both before and after the range bin width is the same.

[0007]

Since the conventional target distance detecting device is constructed as described above, the target distance can be detected only in units of range bins. There was a problem that it became stairs.

The present invention has been made to solve the above problems, and an object thereof is to obtain highly accurate target distance data without the target distance being quantized in range bin units.

[0009]

A target distance detecting device according to the present invention obtains continuous target distances by interpolating discrete range bin intervals without defining the minimum change width of the target distance by the range bin width. It has the following elements. (A) a receiver for receiving a signal from the target, (b) a detector for detecting the received signal,
(C) A distance detector that outputs distance data from the detected signal to the target, and (d) an interpolator that interpolates between the distance data using the output distance data and outputs continuous distance data.

[0010]

The interpolator according to the present invention interpolates the discrete distance change width of the distance data sequentially output from the distance detector and converts it into continuous distance data, thereby improving the accuracy of distance data collection.

[0011]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 8 is an interpolator and 9 is interpolation distance data. In FIG. 1, up to the distance data 4 output from the distance detector 7, the same operation as the conventional target distance detecting device described in FIG. 5 is performed.

FIG. 2 is a diagram for explaining an embodiment of the present invention. As shown in FIG. 2, a Gaussian three-dimensional system of equations whose solution is the maximum value of the discrete amplitude value in the range bin unit of the Σ-detected signal 3 for each pulse and the total of three points for one range cell before and after Is calculated by the interpolator 8, the maximum amplitude value 12 of the interpolation curve 11 is calculated, the distance of the range bin width 10 or less at that time is calculated, and the interpolation distance data 9 is output. The formula of the Gaussian distribution curve is, for example, as shown in FIG. _{y i = y o · exp {} -P (x i -x o) 2} ····· Formula (1) x _i in this application: i-th range cell number y _i: i-th range cell number of the I / Q The amplitude value of the video signal is shown.

Embodiment 2. Although the distance data output from the distance detector 7 is directly input to the interpolator 8 in the above-described embodiment, as shown in FIG.
It is also possible to provide a determiner 13 for substituting into the Gaussian curve formula to determine the case where it cannot be solved algebraically. The cases where Gaussian curve interpolation is applicable and cases where it is not applicable are as follows. In the above equation (1), x _i , y _i ,
When calculating x _o and y _o from, the unknowns are 3 including P
Therefore, a simultaneous three-dimensional linear equation is set up and solved, so that (x _i-1 , y _i-1 ), (x _i , y _i ), (x _{i + 1} , y
It is applicable when the three values of _{i + 1} ) are known. Other than that is not applicable.

As shown in FIG. 4, when the Gaussian curve which is a three-dimensional simultaneous linear equation cannot be solved, the distance data 4 is directly output without passing through the interpolator 8. Other operations are similar to those of the first embodiment described with reference to FIG.

As described above, in this embodiment, when the distance to the target object is detected in the radar device, the Gaussian curve interpolation function is added, and the range bin interval between the range bins of the I / Q video signal discretely exists. The target distance detecting apparatus has been described, which is characterized in that the distance to the target object is detected with high accuracy by interpolating. Further, the target distance detecting apparatus has been described in which a judging device is added in order to cope with the case where the waveform shape of the I / Q video signal is inappropriate for interpolation. Although the Gaussian curve is used in the above embodiment,
The interpolation processing may be performed using other normal distribution curves.

[0016]

As described above, according to the target distance detecting apparatus of the present invention, since the interpolator is provided, it is possible to detect the target distance with accuracy less than the range bin width.

[Brief description of drawings]

FIG. 1 is a functional block diagram of an embodiment of the present invention.

FIG. 2 is a diagram for explaining the principle of an embodiment of the present invention.

FIG. 3 is a diagram for explaining a Gaussian distribution curve.

FIG. 4 is a functional block diagram of another embodiment of the present invention.

FIG. 5 is a functional block diagram of a conventional target distance detection device.

FIG. 6 is a diagram for explaining the principle of a conventional target distance detection device.

FIG. 7 is a diagram for explaining a defect of a conventional target distance detection device.

[Explanation of symbols]

 1 Σ signal pulse 2 Σ received signal 3 Σ detected signal 4 distance data 5 receiver 6 detector 7 distance detector 8 interpolator 9 interpolated distance data 10 range bin width 11 interpolation curve 12 maximum amplitude value 13 discriminator 14 post-judgment Σ detection signal

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[Procedure amendment]

[Submission date] April 2, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

Claims (1)

[Claims] 1. A target distance detecting device having the above elements (a) a receiver for receiving a signal from a target, (b) a detector for detecting a received signal, and (c) a detector to a target. A distance detector that outputs distance data, and (d) an interpolator that interpolates between the distance data using the output distance data and outputs continuous distance data.