JPS58103677A - Radar device - Google Patents

Abstract

PURPOSE:To measure easily and with high accuracy a distance of a target which is farther than 1 transmission period, by rearranging the signals from plural range gate circuits provided with range gates corresponding to different combinations of different transmission periods, and executing the integration processing, etc. CONSTITUTION:On each range gate circuit 2a, 2b, 9 pieces of range gates, for instance, arranging each start point of each different transmission period T1, T2 to be a start point are provided. Receiving outpus by these gates are rearranged in order of a small distance to store them in a memory 6. Subsequently, an output of the memory 6 is processed by an integration circuit 3 at every range, and in accordance with detection of the maximum value of an integral output, an output of the range gate of corresponding number to a true target is fetched by a distance detector 7. According to this constitution, an integration effect is not reduced, also a distance calculating circuit becomes unnecessary, and a distance of a target which is farther than 1 transmission period is measured easily and with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides transmission repetition frequency #k (PulsejLep
@tit! on Frequency 7 hereinafter referred to as PRF)
This invention relates to a radar FI device that can distinguish the distance of a target that is far away from a distance corresponding to a transmission repetition period with a high vsv-dicg.

A conventional device of this type is shown in FIG. In the figure, 11) Fi radar receiver, +2) is a range gate circuit that samples the received signal with multiple clocks according to the detection distance, and (2) is a range gate circuit that integrates the output of the range gate circuit (2) for each range. Integral circuit.

(4) is a detector that detects a signal by comparing the output of the integrating circuit (3) with a predetermined value, and (5) is a distance calculation circuit that calculates the distance of the detected signal.

FIG. 2 shows an explanatory diagram of the production of the above-mentioned conventional device. Transmission is performed using two Ps, PiLF + and PRF t, as shown in the same figure.
Switch RF and transmit. In the same figure, +tb) +e) shows the transmission signals when PILFI and PjLFffi are respectively, and +C) +fl in the same figure is PILFI and 1"1L, respectively.
Shows the range gate when Ftt. Here, in this example, the range gate conditions for PILFI and PRFg are each 5.4, and Figure 1 (C) shows five range gates with period TI numbered 1 to 5 together. 6#) and front figure tf) collectively illustrate four range gates numbered 1 to 4 and having nine periods Tg. In the same cIAtd), - indicates the received signal when PILF+ and i''RF are full, respectively.

Next, regarding the movement, is the signal from the target the 8th? An example will be explained in which there is a range gate number ζ.

The nine received signals received by the radar receiver (1) in Fig. 1 enter the range gate circuit (2), where the PRF is connected to the PiLF.
When PJLF is PRFffi, it is sampled by five clocks -ζ of period rl numbered 1 to 5 shown in Figure 2-C), and similarly, when PJLF is PRFffi, it is sampled by t of period T2. sampled by two clocks.

And the output of Jin's range gate circuit (2) is the integral circuit @
13), the signal is divided for each range, and as a result, only those that are correlated among the received signals grow and their S/N ratio improves, and the output signal of this integrating circuit (3) becomes one peak. Vessel (4)
At a predetermined darkness value and the north wall, the signal is detected.

As a result, a signal appears at the third range gate as shown in Fig. d) lζ, and a signal appears at the third range gate, as shown in Fig. d). If a signal is captured by the four gates of iLFg, the signal will appear at the fourth range gate. That is, in this case, since the transmission repetition period is high, the received signal exceeds each transmission period rl and I'1, and the third and fourth range gate signals of the next transmission period appear. And distance calculation time Wit t
51 performs the following calculation using the above two signals to calculate the true range gate.

RC! ! ! [ClAltenCtomiAgJmodulo(
m and mg) lilHowever, Rc is ml in [ ]
This is the residue from cutting with '-tH. Also here.

m+ (mg) :PRF I(PiLFg) (
D time gate late Al (At): PiLF+ (PILFg) (D Toki (8m9f): / Digate number C+ = tz -m hawk! (1) snodu
l o (m t ) cl = b to mta (1) m
odulo (m-tomi) bI (b-tomi): m fable bt/m+
Minimum natural number such that the remainder of (m+bm/mx) is 1 Now, if we perform calculations using the case in Figure 2 as an example, m+(m
Proverb) = 5 (4) AI (AI) = 3 (4) Therefore, if n is any natural number, it is 1! ! ! -A b s ==Ma1) l=1+1ml5
5 - b t = ib t = Kano Yu m to 4 4 When we find bI and b taka, we get 6 When bl = 4, m = 3 Toka, 5 When bl = 1, 5 == 1 + 14 and Nuru force. et bl=4. bs=l and CI==su+@mg=16 t】g=bl −011=5 mc=[16X3+5X4Jmodulo(5X4)=
[6g 1 modul o(20) = 8, and the true range gate number 8 is obtained.

Since the conventional radar device is configured as described above,
Integration must be performed for each PRF to detect the signal, and since the integral factor is half the pulse factor of the received signal, S
The disadvantage is that the effect of improving the /N ratio cannot be sufficiently obtained, and the true distance must be calculated by a distance calculation circuit.

This invention has been made to eliminate the drawbacks of the conventional ones as described above, and it changes the transmission cycle for each transmission, provides a plurality of range gate circuits correspondingly, and changes the output of the range gate circuit. The purpose of the present invention is to provide a radar device that can integrate all of the received signals by matching and overlapping the start timings of each transmission cycle using memory, and which eliminates the need for a distance calculation circuit. .

Hereinafter, one embodiment of the present invention will be explained with reference to the drawings.

FIG. 3 shows a radar device according to an embodiment of the present invention. In figure number ζ, (1) indicates the transmission period rl and Tg for every l transmission.
Radar receiver that transmits by switching with = (2a) t
;f From the start of transmission period TI to the end of transmission narg r
The first range gate circuit (2b) has 9 range gates arranged in order from 1st to 9th.
A second range gate circuit having 9 range gates arranged in order from ti-th to 9th, +6) Fi above 2
memory for rearranging the outputs from the two range gate circuits (21) (2b) in the order of the outputs of the circuits (2m) (21)) and in order of distance from each range gate, +3)
(71) is an integration circuit that integrates the output of the memory +2), and (71) is a distance detector that detects the maximum output of this integration circuit +,3 to detect the distance to the target.

4. An explanatory diagram of the operation of the above-mentioned chastity device is shown.

In this example, we will show the case where the range gates in the period Tl 8 and Ts are 5# and 4 respectively.
and #I are alternately turned off and transmitted. Figure 1b) is Figure t
This is an enlarged view of the time axis of 1), and (C) is the 1st
The range gate of the range gate circuit (21) is shown, and IdJ in the figure shows the range gate of the second range gate circuit M (2b).

Next, the previous work will be explained using an example where the target is at the 8th range gate.

The nine received signals received by the third CIA radar receiver (1) are the first. Second range gate circuit (2λ), (2b)
gated with. This range gate circuit (2a), (
The range gate in 2b) spans two transmission periods rl and rt as shown in Figure 4+c)td), and now -
For example, if the target is on the 8th range gate, the 4th
As shown in Figures tel and lf), the transmission period 'rl
and the 98th and 4th, which are delayed by 8 range gates with respect to the starting time of the quake and the emitted transmission signal, respectively;
And signals appear at the 3rd and 8th range gates.

This signal is stored in the memory (6) of FIG. 3 in the first range gate circuit @ (21k)! m of the second range gate circuit (2b) next to the signal corresponding to the 8th to 9th range gates.
The output of the memory (6) is as shown in FIG. 4(g).
It becomes as shown in . The output of this memory (6) is then integrated by the integrating circuit (3) for each range, and the output is n
4m becomes -, and in this output, the signal of the 3.4th range gate is inputted every other time by 6ζ, but the signal of the 8th range gate is inputted every time, and the signal of the 8th range gate is inputted every other time. The signal is the loudest. and distance S
By detecting the maximum output of the integrating circuit +31, the detector (7) can extract the signal of the 8th range gate, which is the true target, as shown in Fig. 14.

In addition, in the above embodiment, the true distance is obtained by switching between two transmission cycles, but by switching the transmission cycles of n(≧3)l, it is possible to obtain a range dart that exceeds the total number of n transmission cycles. n1m may be provided.

As described above, according to this invention number ζ, a plurality of transmission cycles are cut off for each transmission, a plurality of range gate circuits are provided according to the transmission cycle number ζ, and the range gate start timing of the range gate circuit is is different for each circuit, the outputs of the range gate circuits are rearranged in the order of output of each circuit, and each range gate -ζ is rearranged in order of distance h,
Since the output is integrated and the maximum value of the 6ζ integrated output is detected, it is possible to determine the distance of a target that is farther than the distance equivalent to one transmission cycle without reducing the integration effect. There are effects that can be omitted.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a conventional device, FIG. 2 is an explanatory diagram of a previous version of the conventional device, FIG. 3 is a block diagram showing the configuration of a radar device according to an embodiment of the present invention, and FIG. 4 is a block diagram showing the configuration of a radar device according to an embodiment of the present invention. This is an explanatory diagram of the operation of the device of this embodiment)...Radar receiver, (2a) (2b)...Range gate. (6)...Memory, -3)...Integrator circuit, (7)...
...Distance detector. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Makoto Kuzuno - Figure 4 (i)

Claims (1)

[Claims] (1) A radar receiver that performs transmission by switching the transmission period for each transmission, and each of the plurality of range gates each having a plurality of range gates and each circuit having a different start timing for receiving signals received by the radar receiver. a plurality of range gate circuits for sampling, and a memory for rearranging the outputs of the plurality of range gate circuits in the order of output of each range gate circuit and in order of distance i for each range gate;
By detecting the horizontal branch circuit that integrates the output of this memory and the maximum output of these multiple integrating circuits, the
Distance si to detect distance! A radar device characterized by being equipped with a detector-0