JPH01262492A - Radar equipment - Google Patents

Abstract

PURPOSE:To not only suppress an increase in search frame time, but also maintain necessary tracking accuracy by adding a machine which calculates the number of zoom spots to be deleted correspondingly to the generation number of tracking targets and a machine which calculates coordinates. CONSTITUTION:A zoom spot quantity calculating circuit 9 calculates the number of zoom spots which are not searched for in a search time deleted from tracking information from a target tracking circuit 6 and the priority of a search area and inputs them a search beam coordinate calculating circuit 10. The circuit 10 assigns the position coordinates of a search beam spot to a search beam spot with low priority, and calculates a search pattern except the coordinate position coordinates and outputs it to a beam scanning sequence circuit 7. In this constitution, the circuit 9 calculates the time required for the search and the number of search beam spots from a target which is detected nearly by a target detecting circuit 5 and a target which is already controlled by a target tracking circuit 6 by using a prescribed expression. The found number of search beam spots is inputted to a search beam coordinate calculating circuit 10 to easily generate a search beam array corresponding to the number of tracking targets.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a radar device that can simultaneously perform a search function and a tracking function.

[Conventional technology]

Figure 3 shows a functional block diagram of a typical conventional radar device. (5) is the target detection circuit, (61Fi target tracking circuit.

(7) is a beam scanning sequence circuit (81Fi, beam orientation?Iil controller).

A conventional radar device is configured as described above.

The transmitting/receiving antenna [1] radiates microwave power into space, receives reflected waves from the target, and inputs them to the receiver (4) via the transmitting/receiving switch (2). Receiver (4)
converts the received signal into a video signal and sends it to the target detection circuit (
5). The target detection circuit (5) determines the presence or absence of a target from the supplied video signal, converts the target f%F information such as the target distance, azimuth, and elevation angle into a digital signal and sends it to the target tracking circuit (6). Output.

The target tracking circuit C61 classifies and stores the input target information, establishes the track and speed of the target from the position information, predicts and calculates the future position of the target at the secondary target tracking time, and calculates the predicted position. Beam scanning sequence circuit (7) for tracking requests
supply to.

In addition, the beam scanning sequence circuit (7) forms a preliminary search sequence for searching the search coverage area, and at the same time performs interrupt processing in response to a tracking request from the target tracking circuit (6) to control the beam position. output to the device (8),
At the same time, transmission information (pulse width, PRT.

number of hints, etc.) is output to the transmitter (3). A beam directing controller (8) directs the beam to a designated beam position. The transmitter (3) generates the microwave power necessary for searching and tracking the target, and turns on the transmitter/receiver switch (2).

It is supplied to the transmitting/receiving antenna fl).

In addition, the search frame time (time period required to search a predetermined spatial coverage area) of such a radar device TF
is the sum of the time Ts required for searching and the time Tt required for target tracking, as shown in the following equation.

TF = TS + Ttfl) Tt is also determined by the product of the number of pulse hits ni required for tracking, the number of tracking targets N, and the pulse repetition period (hereinafter referred to as PRT1.) required for target tracking, as in zero-order.

Tt= N*ntaPRTtf21 T8 is! (1) Beam detection area of the search area as follows: a)
NB, the number of pulse hints n6 required for searching, and the pulse repetition period required for searching (hereinafter referred to as PRT).

) is determined by the product of

TB = NB @ng ・PRTB (
31 Here, NB is determined by the search coverage area Ω and the search beam θBFC in a zero-order manner.

NB = η・Ω/θB2 f41 However,
η is the arrangement coefficient determined by the beam arrangement.

[Problem to be solved by the invention]

In the radar device described above, since the search coverage area Ω is constant, the number of pulse hints ni is required to improve tracking accuracy.
(The tracking accuracy is inversely proportional to n1/2) or when the number of tracking targets N increases, the tracking time Tt increases, and the search coverage area near the tracking target occurrence position disappears. . Alternatively, if the search time 7 days is kept constant, the search frame time TF will increase in VC. If Tt is kept constant, the tracking pulse hint ant decreases due to an increase in H, which causes a problem in that tracking accuracy deteriorates.

This invention has been made to improve this problem, and the tracking time TtIC increased according to the tracking target NK.
By correspondingly reducing the search time T8 and reducing the search coverage area (reducing the number of search beam spots NB) in accordance with the amount of reduction in the search time Te, it is possible to secure Tj, that is, maintain the required tracking accuracy and reduce the search frame. The purpose is to prevent time increase and simultaneously realize busyness.

[Means to solve the problem]

The radar device according to the present invention includes a "beam spot number calculation circuit" that calculates the number of beam spots that have missed the search from the search time that is reduced according to the number of targets to be tracked, and a search beam that calculates the number of beam spots that have missed the search based on the search time that is reduced according to the number of targets to be tracked. It is equipped with a ``search beam coordinate calculation circuit'' that calculates the spatial coordinates of the beam.

[Effect]

This invention differs from conventional radar systems in which searching and tracking are performed using a fixed beam spot array.

Target search is performed using a search beam spot array that maintains the desired search frame time and changes depending on the number of targets being tracked, which not only prevents increase in search frame time due to tracking, but also improves tracking accuracy. It can be done.

〔Example〕 FIG. 1 shows one embodiment of the present invention.

(1) to 18) are exactly the same as the conventional inversion described above.

(9) is a beam spot number calculation circuit, and O(I is a search beam coordinate calculation circuit. The beam spot number calculation circuit (9) can complete the search with a search time reduced from the tracking information from the target tracking circuit +61. The number of beam spots and the priority of the search coverage area are calculated and input to the search beam coordinate calculation circuit.The search beam coordinate calculation circuit αa assigns the position coordinates of the search beam bond to the search beam spot of low priority, Calculate the entire search pattern excluding the position target and repeat the beam scanning sequence jug f7) K /fl
Strengthen.

In a radar device configured as described above.

From the target newly detected by the target detection circuit (5) and the target already managed by the target tracking circuit (6), the beam spot number calculation circuit (9) k calculates Calculate the time required for the search using the following formula.

TB = TF-Tt==TP-41ent*pRT1
．． (51 Also. From equations (31 and 5), calculate the number of search beam spots as shown in the following equation.

NB 1li16 *pR'rt= T7- N#nt
#PRTtHowever, in formula C6) TF, nt,
Since PRTt, n6, and PBr3 are determined by the radar device, once N is determined, NB is determined.

By inputting NB calculated using Equation 161 into the search beam coordinate calculation circuit diagram, it becomes possible to easily form a search beam array according to the number of targets to be tracked.

Therefore, compared to the conventional method in which the search coverage area is fixed and the beam is irradiated, it is possible to greatly improve the problems such as an increase in the search frame time due to an increase in the time Tt required for target tracking, and a deterioration in t or tracking accuracy. becomes.

This situation is shown in Fig. 2, taking as an example the case where a beam is scanned in a living sphere space.

In Fig. 2, (A) is a search coverage diagram when the tracking target is the moon, (B) is its time chart, (C is a search coverage diagram in the present invention when the tracking target is increased to 4, (D) is the time chart), (K) is the search coverage diagram of the conventional method when the number of tracking targets is 4. 6 (P) is the time chart), (
at is the search beam spot, (b) is the search time per beam spot, (C) is the tracking beam bond, (d
J is the tracking time of the target, and (θ) is the increase time of the search frame time due to occurrence of tracking in the conventional method.

FIG. 2 also explains how to suppress an increase in search frame time due to an increase in the number of targets to be tracked in the conventional method.

〔Effect of the invention〕

As explained above, the present invention adds a mechanism for calculating the beam spot to be deleted in accordance with the number of targets to be tracked and a mechanism for calculating the coordinates of the beam spot to search for target tracking. Not only does it suppress the increase in frame time.

This has the effect of maintaining the required tracking accuracy.

[Brief explanation of the drawing]

Fig. 1 is a system block diagram showing an embodiment of the present invention, Fig. 2) to (F) are diagrams for explaining the operation and effects of the present invention, and Fig. 3 is a system block diagram of a conventional radar device. It is. In the figure, [l] is the transmitting and receiving antenna, (2) is the transmitting/receiving switch 2, (3) is the transmitter, (4) is the receiver, (5) is the target detection circuit, CG) is the target tracking circuit, and (7) is the transmitter/receiver antenna. ) is the beam scanning sequence circuit, (8) is the beam direction controller, (9)
is a beam spot number calculation circuit, (11 is a search beam coordinate calculation circuit. (a) Search beam spot, (b) Search time per beam spot, (C) Tracking beam spot, (
dl is the tracking time per target, and (e) is the increase in search frame time due to occurrence of tracking in the conventional method. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] A transmitting/receiving antenna that emits and receives radio waves, a receiver that receives waves from the transmitting/receiving antenna, a target detection circuit that detects a target using the receiver, and a target detection circuit that detects a target by using the receiver. a target tracking circuit for managing target information, a means for calculating search time from the target information from the target tracking circuit, a means for calculating the priority of the search coverage area from the target information, and a means for calculating the priority of the search coverage area from the target information, A radar device comprising means for extracting a beam spot and re-forming a search pattern, and means for directing a beam to a beam position according to the search pattern.