JPH0530230B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a moving target tracker using a split gate method.

[Technical background of the invention]

FIG. 1 shows a moving target tracker using a conventional split gate method. In Fig. 1, the received signal a _x , t (Fig. 2 a) is supplied to an AGC amplifier 1, which outputs a signal a _x1 , t (Fig. 2 b) with a constant amplitude. MTI processor 2
supply to. The MTI processor 2 extracts a signal corresponding to the moving target and supplies it to the distance tracking processor 3.

This distance tracking processor 3 is constructed as shown in FIG. Signal processed by MTI processor 2
a _x1 and t are introduced into the multiplication circuit 3a. This multiplier circuit 3a receives a split gate signal h1, which includes positive and negative pulses generated by the split gate generation circuit 3b at the same timing as the distance pulses h and _t .
By multiplying t (Fig. 2 d) by the signal a _x1 and t, we get
The multiplication results a _x1 , t·h ₁ , and t are output to the integrating circuit 3c. The integrating circuit 3c integrates a _x1 , t·h ₁ , and t over time and outputs a signal.

The output ε (Fig. 2 e) of this integrating circuit 3c is called a distance error, and the magnitude of this signal is the same as the central time t _b of the distance pulses h, t (Fig. 2 c) and the received signal a _x ,
It is proportional to the time difference between t and the central time t _a . The larger this time difference, the larger the distance error ε ,
There is a large difference between the generation timing of the distance pulses h and t as AGC gates and the reception timing of the received signals a _x and t. Therefore, the distance correction circuit 3d operates so that the processing error ε becomes zero, and outputs the distance pulses h and t in accordance with the reception timing of the received signals a _x and t.

That is, first, the distance error ε is added to the adder 3e. Further, the distance information output from the distance correction circuit 3d is added to the memory 3f, and the distance information output from the distance correction circuit 3d is added to the memory 3f.
The current distance information R is stored as the current distance information R. Current distance information R from this memory 3f is also added to the adder 3e. The adder 3e adds this distance error ε and the current distance information R, and applies the addition output (corrected distance information) to the distance correction circuit 3d.

The distance correction circuit 3d is composed of, for example, a counter and a pulse generator, receives distance information from the adder 3e, counts the time position corresponding to the distance information by the counter, and outputs the counted output from the pulse generator. and outputs distance pulses h and t at time positions corresponding to the distance information. These distance pulses h and t are supplied to the split gate generator 3b and also to the AGC amplifier 1, which functions as an AGC gate. This makes it possible to track moving targets.

[Problems with background technology]

The tracking status of this conventional moving target tracker is servo, and in order to stably track the target, the distance error ε is proportional only to the time difference between the distance pulses h, t and the received signals a _x , t, for example, the received signal a It must be ensured that it is not affected by the strength or weakness of the levels of _x and t. For this reason, the AGC amplifier 1 is used to keep the amplitude constant.

However, it is difficult to keep the amplitudes of the received signals a _x and t constant due to the relationship between the AGC time constants and the target scintillation. Furthermore, in the region of the received signal level where AGC does not operate, the equivalent gain of the servo decreases and the tracking response deteriorates.

[Purpose of the invention]

This invention was made to eliminate the above-mentioned conventional drawbacks, and provides a moving target tracker that can stably track high-speed targets by eliminating the burden of AGC and the inaccuracy of distance errors caused by scintillation. The purpose is to provide.

[Summary of the invention]

The moving target tracker of the present invention includes a first means for extracting a signal corresponding to the target from a received signal gated by an external distance pulse signal, and an output signal of the first means and an externally supplied signal. a split gate signal that includes positive and negative pulse signals and is generated at the same timing as the distance pulse signal; a third means for integrating the output multiplied by the output signal of the means on the time axis; and a fourth means for dividing the output of the third means by the output of the second means and outputting a distance correction signal.
correcting the distance information by adding the output signal of the fourth means and the signal representing the current distance information, generating a pulse signal based on the corrected distance information, and outputting the pulse signal as the distance pulse signal. It is characterized by comprising a fifth means for.

[Embodiments of the invention]

Embodiments of the moving target split gate distance tracker of the present invention will be described below with reference to the drawings. FIG. 4 is a block diagram showing the overall configuration of one embodiment. If the overall configuration of the present invention is shown in a block diagram, it is the same as that in FIG. 1, and the same parts as in FIG. 1 are given the same reference numerals and their explanation will be omitted.

In this invention, the configuration of the distance tracking processor 3 is different from the conventional one, and the configuration is shown in a block diagram in FIG. This FIG. 5 corresponds to FIG. 3, and the same parts as in FIG. 3 will be described with the same reference numerals.

That is, the signals a _x1 and t corresponding to the moving target from the MTI processor 2 are sent to the multiplication circuit 3a and the multiplication circuit 3.
g. As in the case of FIG. 3, the multiplication circuit 3a combines the split gate signals h ₁ and t output from the split gate generation circuit 3b and the above signal
Multiply by a _x1 and t and send the result to the integrator circuit 3
Output to c. This integrating circuit 3c outputs a multiplication
A distance error Δ obtained by integrating a _x1 , t·h ₁ , and t over time is output, and this distance error Δ is supplied to the division circuit 3h.

Furthermore, the multiplication circuit 3g multiplies the signals a _x1 and t by the distance pulses h and t from the distance correction circuit 3d, and supplies the multiplication result to the integration circuit 3i. The integrating circuit 3i integrates the multiplication results a _x1 , t・h, t over time, and the integrated output ε is sent to the dividing circuit 3
supply h.

The dividing circuit 3h divides (Δ/ε) the output of the integrating circuit 3c, that is, the distance error Δ, by the integral output ε of the integrating circuit 3i, and outputs a distance correction signal. This division result is supplied to adder 3e.

The adder 3e adds the current distance information R from the memory 3f and this division result, and supplies the added output to the distance correction circuit 3d. This distance correction circuit 3d
As in the case of Fig. 3, the distance information is stored in memory 3.
f, and distance pulses h and t are supplied to the split gate generating circuit 3b and the AGC amplifier 1 of FIG.

In this invention, a multiplication circuit 3g, an integration circuit 3i, and a division circuit 3h are added to the configuration shown in FIG. 3, and the multiplication circuit 3h performs division Δ/ε between the integral outputs Δ and ε. This division output Δ/ε is then supplied to the adder 3e as a distance error. The division output Δ/ε is a normalized integral output Δ (conventional distance error), and the distance error and the division output Δ/ε have a linear proportional relationship.

Therefore, by adding this division output Δ/ε and the current distance information R, and supplying this addition output to the distance correction circuit 3d to perform distance correction in the same manner as in the case of FIG. Distance correction is possible even in non-operating areas, and target tracking is possible. That is, distance correction can be performed even in areas where AGC is not applied because the distance is large and the reception level is small. Therefore, the distance that can be tracked increases and a stable tracking operation can be performed. Furthermore, even if the reception level fluctuates for some reason in the AGC region, stable tracking is possible because the division output as the error output is normalized.

〔Effect of the invention〕

As described above, according to the moving target tracker of the present invention, it is possible to stably track a target by eliminating the burden of AGC and the inaccuracy of distance errors caused by scintillation, and it is also possible to increase the tracking distance.

[Brief explanation of drawings]

Figure 1 is a block diagram of a conventional moving target tracker.
FIG. 2 is a diagram illustrating the operation of the moving target tracker same as above, FIG. 3 is a block diagram showing the configuration of the distance tracking processor in the same moving target tracker as above, and FIG. 4 is a diagram of the moving target tracker of the present invention. FIG. 5 is a block diagram showing the structure of an embodiment of the present invention. FIG. 5 is a block diagram showing the structure of a distance tracking processor in the same moving target tracker as above. 1...AGC amplifier, 2...MTI processor, 3...
...Distance tracking processor, 3a, 3g...Multiplication circuit, 3
b...Split gate generation circuit, 3c, 3i...
...Integrator circuit, 3d...Distance correction circuit, 3e...Adder, 3f...Memory, 3h...Divide circuit.

Claims (1)

[Claims] 1. A first means for extracting a signal corresponding to the target from the received signal by gated by an external distance pulse signal, and multiplication of the output signal of this first means by the distance pulse signal supplied from the outside. a second means for integrating the output on a time axis; and a multiplication output of the output signal of the first means and a split gate signal that includes positive and negative pulse signals and is generated at the same timing as the distance pulse signal. a third means for integrating on the time axis; a fourth means for dividing the output of the third means by the output of the second means and outputting a distance correction signal; and fifth means for correcting distance information by adding the output signal of the means and a signal representing current distance information, generating a pulse signal based on the corrected distance information, and outputting the pulse signal as the distance pulse signal. A moving target tracker.