JPS62170867A - Data analyzing device - Google Patents

Abstract

PURPOSE:To discriminate a size of a target by providing a pulse repeat frequency (PRF) discriminating circuit in a measuring instrument, and calculating an effective reflecting area of the target in not only a tracking state but also a detecting state. CONSTITUTION:A data analyzing device 13 is connected to a pulse Doppler radar equipment 1. In the data analyzing device 13, a PRF discriminating circuit 10 is provided, a high speed Fourier transform (FFT) output data containing a PRF reference signal existing in a digital bus 8 and a target existing in a digital signal processing bus line 9 is inputted, detecting information, namely, a range gate which is considered to be a target and the time are extracted, a PRF synchronized with it is extracted, and the PRF decided definitely is sent to a measuring device 11. The measuring device 11 decides definitely the target, and its data is recorded. The recorded data is reproduced and analyzed by an analyzing device 12, and in a detecting state, an effective reflecting area of the target is calculated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data analysis device that measures and analyzes the target detection, tracking, and other functions and performance of an aircraft-mounted pulse Doppler radar.

[Conventional technology]

A conventional device of this type is shown in FIG. In Fig. 2, (1) is a pulse Doppler radar device, (2
) is a transmitter that amplifies and transmits the radar transmission signal, (3) is an antenna that radiates the transmission signal into free space and receives the reflected signal from the target, and (4) is the output of the above transmitter (3). A transmitting/receiving switch that sends the signal to the antenna (4) and sends the reflected signal from the target received by the antenna (4) to the receiving circuit, (5) is a highly stable high frequency signal generation circuit for pulsed Doppler and the reflected signal from the target. an excitation/receiver having a receiving circuit that receives, amplifies, and converts into a digital signal;
(61H) The radar computer (7) performs overall control of the pulse Doppler radar device (1) and target tracking using a Kalman filter; A digital signal processor that performs all processing and detects targets, (811-1
, command signal and transmission mf from the radar computer (6)
21. The antenna (31° excitation/digital bus line (hereinafter referred to as Digi Bus line) through which the response signal from the receiver (5) passes
i9) is a digital signal processing bus line (hereinafter referred to as DSP Bus) through which digital processing data and processing results pass between the radar computer (6) and the digital signal processor (7), and αυ is the digital signal processing bus line (hereinafter referred to as DSP Bus).
Bus (data of 81, DSPBus (data of 91), a measurement device that measures and records fast Fourier transform (hereinafter referred to as FFT) and target detection data in the digital signal processor (7) at high speed and high density, (L2 reproduces various in-flight data recorded by the measurement device 0υ, and determines the functions and functions of the pulse Doppler radar device (1).
An analysis device that analyzes and evaluates performance (f3 is a measurement device aυ
This is a data analysis device consisting of an analysis device α2 and an analysis device α2.

Next, the operation will be explained. Data analysis device θJ is the operation of pulse Doppler radar equipment #(1) during flight.

Data etc. are transferred to a digital signal processor (71, Digi Bus T81.DSP Bu
s (9).

Analyzer 0z selects arbitrary data from the measurement data and outputs the time and distance as parameters.

Analyze and evaluate the functions and performance of the Doppler radar device (1). Medium pulse repetition frequency (hereinafter referred to as PRF)
The radar equation for the pulsed Doppler radar is as follows.

In formula (1), RO is the simple detection distance that does not take into account atmospheric attenuation*
PAV is the average transmitted power, G is the antenna gain, λ is the wavelength,
σ is the target effective reflection area, and LA is the transmission system loss.

LB is receiving system loss + LR is radome loss, KT,
is the noise power per unit bandwidth, and B is the equivalent noise bandwidth.

NF is the noise figure and S is the system loss.

The pulse Doppler radar device (1) captures the target, and in the tracking state, the analysis device 0 is included in the data of the DSP Bus (9).
2 is used and output, as shown in Figure 3, there is FFT output data (14) represented by the number of filters on the horizontal axis and the number of range gates on the vertical axis, and from the above FFT output data α4, it is determined that the target exists Tracking target data called track matrix (to) extracted from nearby data (includes FFT data near where IO exists).

In equation (1), the values other than distance RO and target effective reflection area are values specific to the pulsed Doppler radar device and are known, so each data is given to radar equation (1) from the above FFT output data I. This allows the received power from the target to be calculated. (1) is the received signal F
Expressed as FT output.

becomes. In equation (2), L is a loss, which is the S/N ratio required to detect the target with the warning probability of equation fl), excluding a certain detection coefficient. As mentioned above (1
) Similarly, in equation (2), the values other than the distance Ro and the target effective reflection area σ are values specific to the pulse Doppler radar device.If they are replaced by 1jKo, equation (2) can be expressed as follows.

(8/N) FFT out” KO2(3’(3
), the target effective reflection area σ is expressed as O.

As mentioned above, in the tracking state, data regarding the target is FFT-converted in the digital signal processor (7)
It is output in the form of a Doppler matrix, that is, in the form of a 4-y dibin The size of - that is, the target effective reflection area σ is the distance R from the DSPBus (9).As shown in FIG. ) by determining the amplitude of the FFT output point (S/N)'i as a voltage value, and by substituting various values into equation (4) and calculating in the analyzer path, the target effective reflection can be calculated. The area σ can be calculated.

[Problem that the invention seeks to solve]

As described above, when the radar device is in the tracking state, the conventional data analysis device calculates the received power from the target from the FFT data called the track matrix included in the data on the DSP bus, substitutes it into the radar equation, and calculates the received power from the target. In the detection state where the track matrix does not exist in the DSP bus data, it is unclear which PRF was used to detect the information, so there was a problem that the effective reflection area of the target could not be calculated.

This invention was made to solve the above problems, and provides a data analysis device that can calculate the effective reflection area of a target and identify the size of the target not only in the tracking state but also in the detection state. The purpose is to

[Means for solving problems]

The data analysis device according to the present invention measures the radar transmission PRF synchronized with signal processing data from the reference signal in the Digi Bus, and adds a PRF identification circuit that identifies the size of the target not only in the tracking state but also in the detection state. This is what I did.

[Effect]

In the detection state, the PRF identification circuit in this invention:
Reference transmission PRF that measures target data included in FF'T data measured from DSPBus from DigiBus
By extracting the range gate and time at which what appears to be a target exists, and calculating from FFT data in the vicinity, it is possible to measure the target effective reflection area without tracking.

〔Example〕

Figure 1? An embodiment of the present invention will be described using the following.

In Fig. 1, 11) is a pulse Doppler radar device, (
2) is a transmitter that amplifies and transmits the radar transmission signal, (3I
(4) is the transmitter (31
The output signal of the antenna (4) is transmitted to the antenna (4).
) is a transmitting/receiving switch that transmits the reflected signal from the target received by the target to the receiving circuit, and (5) is a highly stable high-frequency signal generation circuit for pulsed Doppler and a receiver that receives the reflected signal from the target, amplifies it, and converts it into a digital signal. An excitation/receiver circuit (6) is a radar computer that controls the entire pulse Doppler radar device (1) and performs target tracking using a Kalman filter.

(7) is a digital signal processor that performs signal processing on the digitized received signal output from the excitation/receiver (5) and detects a target; command signal and transmitter (2:, antenna (
3), Dig through which the response signal from the excitation/receiver (5) passes
t Bus e (91 is DSPBus (1 (I is D
i g iBu a (Inputs the PRF reference signal from 81 and the FFT data of DSP Bus (9), and transmits the radar's transmission PRF in synchronization with the signal processing data.
i meter side, pulse repetition frequency identification circuit (hereinafter referred to as PRF identification circuit), aυ is the above-mentioned Digi Bus
f8) data, DSPB u s (9) data,
A measurement device that measures all FFT and target detection data in the digital signal processor (7) and records it at high speed and high density;
tlZ reproduces various in-flight data recorded in the measuring device αυ.

An analysis device for analyzing and evaluating the function and performance of the pulse Doppler radar device (II) (131 is a data analysis device consisting of a PRF identification circuit measurement device αυ and an analysis device O3.

Next, the operation will be explained. To fully identify the size of the target, as explained in the prior art section above.

Itj, D S P Bus (9
) The data includes FFT data in the vicinity of the target, called track matrix α9, which is obtained by extracting data in the vicinity of the target from the FFT data.

The total received power from the target can be calculated by giving each data to the 0FFT data relay equation (Equation 21), and then the target effective reflection area σ can be determined using equation (4). But in detection state its
D S P Bus (Track matrix 0 in 91)
9 does not exist. The target Doppler obtained from the zero track matrix in the tracking state is used to calculate the PRF'i that matches the filter number with the highest detection sensitivity.

Therefore, even in the detection state, the tracked target data (the same target data as IO exists in the FFT output output data α section) in D S P Bus f91. However, since tracking is not being performed, the track matrix (15) is not formed.
S P Bus (exists in the 91 in a flowing state. Therefore, a PRF identification circuit full'i is provided in the data analysis device 03 + Digi Bus (PRF reference signal existing in the 81 and D S P Bus f9) Input FFT output data fi4e including targets existing in
The PRFt-
The extracted and confirmed PRF'i is sent to the measuring device αυ. Measuring device αυFl D S P Bus (Determine the target using the FFT data among the 91 data and the determined PRF, and record the data. The recorded data is played back and analyzed by the analysis device α, and the state is similar to the tracking state. The target effective reflection area σ is calculated in the detection state.

In the above embodiment, the data analysis device α31CPRF identification circuit 0 was shown, but a sequencer is provided in the measurement device αD to extract the range gate corresponding to one time and identify the target that matches the range gate. By doing so, the same effects as in the above embodiment can be achieved.

〔Effect of the invention〕

As described above, the data analysis device according to the present invention provides the DSPBus by providing the P”RF identification circuit in the measurement device.
Since the target effective reflection area is calculated from the FFT signal in the data in the detection state, it is possible to calculate how the target effective reflection area changes depending on the distance, and what is the relationship with the detection probability. It has the effect of obtaining evaluations of radar equipment such as.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing a data analysis device according to an embodiment of the present invention, Fig. 2 is a block diagram showing a conventional data analysis device, and Fig. 3 shows an output example of FFT output data existing in the DSPBus. figure. FIG. 4 is a diagram showing an output example of a track matrix existing in FFT output data in a tracking state. In the figure, (1) is a pulse Doppler radar device. (2) is a transmitter, (3) is an antenna, (41 is a transmit/receive switch, (5) is an excitation/receiver, (6) is a radar computer, (
7) is a digital signal processor, (8) is Digi Bu
s+ (91 is DSPBus+I) α is the pulse repetition frequency identification circuit, 0υ is the measurement device, ag is the analysis device,
H is a data analysis device. a4 is FFT output data, 05 is track matrix, and tiS is tracking target data. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] a transmitter that generates a radar transmission signal; an antenna that radiates the output transmission signal of the transmitter into free space and receives a reflected signal from a target; and an antenna that transmits the output signal of the transmitter to the antenna; A transmitting/receiving switch that transmits the reflected signal from the target received by the above-mentioned antenna to the receiving circuit, a highly stable high frequency signal generation circuit for pulse Doppler, and a receiving circuit that receives the reflected signal from the target, amplifies it, and converts it into a digital signal. a radar computer that sends command signals to the transmitter, antenna, and excitation/receiver and performs control and calculations based on the response signals;
A digital bus line that connects the receiver and the radar computer, a digital signal processor that performs signal processing on the digitized reception signal output from the excitation/receiver and detects a target, and the radar computer. A digital signal processing bus line connects the above-mentioned digital signal processor and transmits digital processing data and processing results, and various signal processing data on the tracking status of the pulse Doppler radar that detects and tracks a target are connected to the above digital bus line. A measurement device that continuously measures during flight using the digital signal processing bus line and the output of the digital signal processor, and an analysis device that reproduces and analyzes and evaluates the data measured by the measurement device on the ground. In the data analysis device, the transmission pulse repetition frequency of the pulse Doppler radar synchronized with the in-flight signal processing data of the pulse Doppler radar is measured from the digital bus line, and the fast Fourier transform and target detection data are processed by the digital signal processing. A data analysis device comprising a pulse repetition frequency identification circuit that measures from a bus line, identifies a transmission repetition frequency of the pulse Doppler radar, and supplies its output to the measurement device.