JPH01304374A - Radar signal processor - Google Patents

Abstract

PURPOSE:To always monitor the operation of an elevation angle detection circuit so as to discover a malfunction of the circuit in an early stage by providing an elevation angle inspection circuit. CONSTITUTION:In the first place, data are inputted 5 from an SR/SIF synthesization circuit 3 and whether the input data are response data to the altitude of an aircraft or those to SIF mode C is discriminated. When the data are the target data of SR/SIF synthesization, an elevation angle is calculated from the altitude and distance of the SIF mode C responding data and used as a real elevation angle. Then the real elevation angle and the receiving level ratio DELTA/SIGMA of amplitude monopulses are stored in a paired state. Then whether or not the stored data are higher than a specific value is discriminated. Then an elevation angle inspection circuit 4 finds the least square approximation line from the stored data by plotting the real elevation angle on the Y-axis and receiving level ratio DELTA/SIGMA on the X-axis. Namely, whether the elevation angle is normal or not can be discriminated from the A and B of the following expression: elevation angle = A.DELTA/SIGMA+B, where A: an inclination indicating the relation between the elevation angle and receiving level ratio, B: elevation angle when DELTA/SIGMA=0.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a radar signal processing device that can constantly monitor the elevation angle detection operation of a radar device and detect malfunctions at an early stage6. [Prior Art] FIG. 7 is a block diagram of a conventional radar signal processing device. In the figure, 1 is an SR buffer circuit, 2 is an SIF buffer circuit, and 3 is an SR/SIF combining circuit.

Next, the operation will be explained. The primary radar echo is received and processed, converted into a digital signal, and the data detected as a target is sent to the SR buffer circuit 1 as SR data a.
is input.

In addition, secondary radar echoes are also received and processed, and after being converted into digital signals, the data detected as a target is transmitted to the SI.
It is input to the SIF7177 circuit 2 as F data b.

Both the SR buffer circuit 1 and the SIF7177 circuit 2 store data in the order of input.

The SR/S IF combining circuit 3 includes the SR buffer circuit 1,
Data is read from the SIF7177 circuit 2 in the order of storage.

Then, the elevation angle of the SR data is detected using the amplitude monopulse method. In other words, the signal Σ received by the antenna sum pattern and the signal Δ received by the difference pattern
Find the elevation angle using the received level ratio.

Angle detection using the amplitude monopulse method is also described in "Radar Technology" published by the Institute of Electronics and Communication Engineers.

If the distance difference between the SR data and SIF data read by the S R/S IF combining circuit 3 is within γh and the azimuth difference is within α degrees, the echoes are considered to be from the same target and are combined into one target data C. and output it.

Also, if the distance difference is outside the γ range or the orientation difference is outside the α range, the SR data and SIF data will be treated as echoes of different targets.
Output each target data.

[Problem to be solved by the invention]

Conventional radar signal processing equipment is configured as described above, so to check whether the amplitude monopulse elevation angle detection function is working properly, the radar operator must check the altitude determined from the elevation angle and distance of the target. Look, 1 of the secondary radar response data.
The difference between the altitude and the mode C response data (hereinafter referred to as SIF mode C response data) indicating the altitude of the aircraft is small.

Ma/+ focused on one target and relied on the operator's sense that there was little change in altitude.

Therefore, there is a problem in that the judgment of whether the amplitude monopulse elevation angle detection circuit is malfunctioning or normal varies depending on the operator, resulting in a delay in finding the fault.

This invention was made to solve the above-mentioned problems, and it is possible to constantly monitor the operation of the amplitude monopulse elevation angle detection circuit, and does not require the judgment of a radar operator.
The object of the present invention is to obtain a radar signal processing device that can detect malfunctions at an early stage.

[Means to solve the problem]

The radar signal processing device according to the present invention includes SR data and S
After synthesis with IF data, an elevation angle verification circuit using a microcomputer that monitors the amplitude monopulse elevation angle detection operation is provided.

[Effect]

The elevation angle verification circuit according to the present invention monitors whether the relationship between the Σ reception level and the Δ reception level of the SR data of the same target as the SIF data is normal based on the altitude obtained from the response code of the SIF data.

〔Example〕

An embodiment of the present invention will be described below.

In FIG. 1, 1 to 3 indicate the same parts as in FIG. 7. 4
is a microcomputer as an elevation angle verification circuit, and has an input circuit 5, a CPU 6, a memory 7, and an output circuit 8.

Next, the operation will be explained. FIG. 2 is a flowchart showing the elevation angle verification process stored in the memory 7 of the micro φ computer 4.

First, in step ST1, data is input from the SR/SIF synthesis circuit 3. The input data is the target data,
The data may be SR data only, SIF data only, or SR/SIF composite data.

In step ST2, it is determined whether the input data contains SIF mode C response data, which is response data on the altitude of the aircraft. If SIP'mode C'response data is held, proceed to step ST3, and SIF mode C
If the response data is not held, the process advances to step ST8.

In step ST3, the input data is S R/S I F
It is determined whether the data is the target data for combination, and if it is the target data for SR/SIF' combination, the process proceeds to step ST4.

The data that has proceeded to step ST4 has angle data based on the amplitude monopulse method, and also has SIF' mode C
It also holds aircraft altitude information based on response data.

In step ST4, the elevation angle is calculated from the altitude and distance of the SIF mode C response data, and this is set as the true elevation angle. The received level ratio ~Σ of the true elevation angle and the amplitude monopulse is stored as 182'j.

In step ST5, it is determined whether the number of stored data is equal to or greater than a specified value N. If it is less than the specified number N, the process proceeds to step ST8, and if it is greater than or equal to the specified number N, the process proceeds to step ST6.

The prescribed number N is a variable parameter.

In step ST6, the relationship between the true elevation angle and the reception level ratio Σ is determined from the stored data by Δmaximal square approximation. In other words, the true elevation angle is received on the Y axis, and Δ elevation angle - A - Σ 1 B ...... (1)
In this equation (1), A is the slope indicating the relationship between the elevation angle, the reception level ratio, and Δ, and B is the “reception level ratio Σ=0”.
This is the elevation angle when .

In step ST7, all stored data is erased and preparations are made for the next least squares approximation calculation. In step ST8, the target data input in step ST is output.

As a result of the above processing, it can be determined whether the amplitude monopulse elevation angle detection is normal or not by A and B of Equation 11 obtained in step ST6. In other words, both A and B are within the specified values (A
If O<A<AI) and (IBI<BO), amplitude monopulse elevation angle detection is normal. AO+A, , B0 is a parameter indicating the permissible error range of amplitude monopulse elevation angle detection.

FIG. 3 shows a block diagram of a radar device using an amplitude comparison verification method as an example of application of the present invention to other uses. In FIG. 3, the same reference numerals as in FIG. 1 indicate the same or corresponding parts.

There is an amplitude comparison method as an elevation angle detection method in a radar device. This transmits multiple beams in the elevation direction. When reflected echoes from a target are received in multiple beams, each received beam is received at a level corresponding to the antenna beam pattern. Therefore, the elevation angle of the target can be detected by comparing the reception levels of two adjacent beams.

In FIG. 4, the level received by the beam having an elevation angle of φ1 degree is assumed to be Σ1, and the level received by the beam having an elevation angle of φ2 degrees is assumed to be Σ2. The amplitude comparison elevation angle detection method detects the elevation angle of the target from the level ratio of Σ1 and Σ2, and the relationship between the angle and the angle is shown in FIG.

FIG. 6 is a flow chart showing the amplitude comparison elevation angle verification process stored in the memory 7 of the elevation angle verification circuit 4 by the microcomputer. In FIG. 6, the same step numbers as in FIG. 2 indicate the same or corresponding parts.

In step ST9, the SR data is the adjacent elevation beam 2.
It is determined whether or not more than one book has been received.

If only one elevation angle beam is received, the elevation angle cannot be detected by the amplitude comparison method, so the process proceeds to step ST8.

In step 5T10, the elevation angle is calculated from the altitude and distance of the SIF mode C response, and is set as the true elevation angle.

The reception level ratio of the two beams of true elevation angle and SR data is stored as a pair as data on the high elevation angle side of the two beams.

In step 5T11, a least squares approximation straight line is obtained from the true elevation angle and the reception level ratio of the two beams by least squares approximation from the stored data in the same way as step ST6 in FIG.

In step 5T12, all stored data of the elevation angle beam corresponding to the data stored in step 5TIO is erased,
Initialize for the next least squares approximation calculation.

As a result of the above processing, it can be determined whether the amplitude comparison elevation angle detection is normal or not based on A and H of equation (2) obtained in step 5T11.

〔Effect of the invention〕

As described above, according to the present invention, the elevation angle verification circuit calculates the SIF value based on the altitude obtained from the response code of the SIF data.
Since the configuration is configured to monitor whether the relationship between the Σ reception level and the Δ reception level of the SR data of the same target as the data is normal, it is possible to easily determine whether or not the elevation angle detection in the radar device is normal.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a radar signal processing device according to an embodiment of the present invention, FIG. 2 is a flowchart showing the operation of the same embodiment, and FIG. 3 is a block diagram showing the configuration of a radar signal processing device according to an embodiment of the invention. 4 and 5 are explanatory diagrams showing the relationship between the reception level and elevation angle of a radar device for amplitude comparison elevation angle verification, which is an example of application of FIG. 3 to other uses. FIG. 6 is a flowchart showing the amplitude comparison elevation angle verification process stored in the memory of the microcomputer in FIG. 3, and FIG. 7 is a block diagram showing the configuration of a conventional radar device. 1 is an SR7177 circuit, 2 is an SIF buffer circuit, 3 is an SR/SIF synthesis circuit, and 4 is a microcomputer (elevation angle verification circuit). In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] In a radar device for amplitude monopulse elevation angle detection, an SR buffer circuit in which detected targets of the primary radar are sequentially written, an SIF buffer circuit in which detected targets of the secondary radar are sequentially written, the targets detected by the primary radar, and the above. 2
Operation details of the amplitude monopulse elevation angle detection described above using an SR/SIF synthesis circuit that synthesizes the target detected by the secondary radar and mode C response data indicating the altitude of the aircraft, which is a type of response data of the secondary radar. A radar signal processing device comprising: an elevation angle verification circuit for verifying the angle of elevation.