JP2006329829A - Radar device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radar device capable of precisely estimating the position and the speed of a target, even if one or both of a monostatic radar station and a bistatic receiving station are placed on portable platform. <P>SOLUTION: The Doppler frequency A between an antenna 1 and the target 40 that is calculated by a calculating means 4 for the Doppler frequency A of the monostatic radar station 50, and a transmission frequency are transmitted via communication means 5, 9 to the bistatic receiving station 51, in real time. From these frequencies and frequency information that is received and measured by the station 51, the Doppler frequency B between an antenna 6 and the target 40 is calculated by a calculating means 10 for the Doppler frequency B. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a bistatic radar apparatus in which a signal transmission source and a signal reception source are arranged at different positions to estimate a target position, speed, and the like.

  A bistatic radar device is a radar device that detects a target by irradiating a signal from a signal transmission source toward the target and receiving a signal reflected from the target by a signal reception source that is spaced apart from the signal transmission source. . An example of a conventional bistatic radar device is disclosed in Patent Document 1.

  This bistatic radar device is separated from a monostatic radar station that performs transmission and reception of electromagnetic waves from a directional antenna and performs target ranging and angle measurement based on a time difference between a transmission wave and a reception wave and a directivity angle of an antenna beam. And a bistatic receiving station that receives a reflected wave from a target of a monostatic radar transmission wave, and the arrival time difference between the reception wave of the bistatic reception station and the reception wave of the monostatic radar station and the bistatic reception station The target position is measured from the signal arrival direction detected in step (1).

JP-A-4-29080

  The conventional bistatic radar apparatus calculates the position of the target based on the arrival time difference and the signal arrival direction of the reflected signal from the target received by the monostatic radar station and the bistatic receiving station, respectively. Therefore, in order to accurately calculate the target position, it is necessary that the relative positions of the monostatic radar station and the bistatic receiving station are known and the reference azimuth directions of the antennas of the two stations coincide with each other with high accuracy. is there.

  For this reason, it is difficult to know the relative positions of the two stations in real time, as in the case where one or both of the monostatic radar station and the bistatic receiving station are on different mobile platforms. When the alignment accuracy of the reference direction of the station is poor, there is a problem that position measurement is difficult or the measurement accuracy is remarkably deteriorated.

  The present invention has been made to solve the above-described problems, and accurately estimates the target position and velocity even when one or both of the monostatic radar station and the bistatic receiving station are on different mobile platforms. An object of the present invention is to obtain a radar device capable of performing the above.

  A radar apparatus according to the present invention outputs a transmission radio wave toward a target, and the transmission radio wave has a transmission / reception means for receiving a reflected radio wave reflected by the target, and is reflected at a position different from the monostatic radar station. A bistatic receiving station having a receiving means for receiving radio waves, a first frequency detecting means for measuring a frequency of a received radio wave by a transmission / reception means of a monostatic radar station, and a frequency of a received radio wave by a receiving means of the bistatic receiving station. Second frequency detection means for measuring, and first Doppler frequency for measuring the first Doppler frequency between the target and the reception position in the monostatic radar station from the frequency of the received radio wave measured by the first frequency detection means The calculation means, the frequency of the transmission radio wave, the frequency of the reception radio wave measured by the second frequency detection means, And second Doppler frequency calculating means for measuring a second Doppler frequency between the target and the reception position at the bistatic receiving station, using the first Doppler frequency calculated by the first Doppler frequency calculating means. Communication means for transmitting the first Doppler frequency and the frequency of the transmission radio wave of the measurement result to the second Doppler frequency calculation means in association with the measurement of the first Doppler frequency by the first Doppler frequency calculation means; A motion specification estimating means for estimating motion specifications relating to the position and speed of the target using the Doppler frequency.

  According to the present invention, the first Doppler frequency and the frequency of the transmission radio wave transmitted by the first Doppler frequency calculating means are transmitted to the second Doppler frequency calculating means by the communication means, so that the monostatic radar station and the bistatic receiving station Even when one or both of them are on different mobile platforms, the target position and speed can be estimated accurately in real time.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of a bistatic radar apparatus according to Embodiment 1 of the present invention. In FIG. 1, a monostatic radar station 50 includes an antenna 1, a transmission / reception unit 2, a frequency detection unit (first frequency detection unit) 3, a Doppler frequency A calculation unit (first Doppler frequency calculation unit) 4, and a communication unit 5. Is provided. The bistatic receiving station 51 includes an antenna 6, a receiving means 7, a frequency detecting means (second frequency detecting means) 8, a communication means 9, a Doppler frequency B calculating means (second Doppler frequency calculating means) 10, and an arrival. An angle measuring means 15 and a motion specification estimating means 52 by speed and angle are provided. The motion specification estimation means 52 based on speed and angle includes a speed prediction means 11, a speed error conversion means 12, a speed gain calculation means 13, a speed smoothing means 14, an angle prediction means 16, an angle error conversion means 17, and an angle gain calculation means 18. Angle smoothing means 19, delay circuit 20, and position / speed prediction means 21.

  The transmission / reception means 2 in the monostatic radar station 50 transmits a transmission signal as a transmission wave to the target 40 via the antenna 1, and receives a reflection signal by reflection of the transmission wave at the target 40 via the antenna 1. The frequency detection means 3 inputs the signal received by the transmission / reception means 2 as described above, and measures the frequency of this received signal. In the Doppler frequency A calculation means 4, the relative speed between the antenna 1 and the target 40 is handled based on the frequency of the signal measured by the frequency detection means 3 and the frequency of the signal transmitted from the transmission / reception means 2 toward the target 40. The Doppler frequency A (first Doppler frequency) to be calculated is calculated. The communication means 5 inputs the Doppler frequency A calculated by the Doppler frequency A calculation means 4 and the frequency of the transmission signal, and transmits them to the communication means 9 of the bistatic receiving station 51 by wireless communication.

  The reception means 7 in the bistatic reception station 51 receives the reflected signal from the transmission wave from the target 40 via the antenna 6. The frequency detecting means 8 inputs the signal received by the receiving means 7 as described above and measures the frequency. The communication unit 9 receives the Doppler frequency A information transmitted from the communication unit 5 and the frequency of the transmission signal. The Doppler frequency B calculating means 10 inputs the frequency of the received signal measured by the frequency detecting means 8 and the Doppler frequency A and the frequency of the transmitted signal received by the communication means 9, and uses these to input the target 40 and the antenna. The Doppler frequency B (second Doppler frequency) corresponding to the relative speed between 6 is calculated.

  The speed predicting means 11 in the motion specification estimating means 52 based on the speed and the angle is based on the predicted vector of the position and speed of the target 40 in the orthogonal coordinates output from the position / speed predicting means 21, and between the target 40 and the antenna 6. Calculate the predicted Doppler speed. The speed error conversion means 12 calculates an error conversion matrix for converting the error covariance matrix in the orthogonal coordinates to the error variance of the Doppler speed based on the position and speed prediction vector in the orthogonal coordinates input from the position / speed prediction means 21. .

  The speed gain calculation means 13 inputs the error conversion matrix calculated by the speed error conversion means 12 and the prediction error covariance matrix in the orthogonal coordinates calculated by the position speed prediction means 21, and uses these to calculate the orthogonal coordinates at the Doppler speed. A gain matrix for updating the smooth vector of the position and speed of the target 40 is calculated. The speed smoothing means 14 is a Doppler frequency B calculated by the Doppler frequency B calculating means 10, a predicted value of the Doppler speed calculated by the speed predicting means 11, an error conversion matrix calculated by the speed error converting means 12, and a speed gain calculation. The gain matrix calculated by the means 13 is inputted, and the smooth vector of the position and speed of the target 40 in the orthogonal coordinates is updated using these.

  The angle prediction means 16 receives the predicted vector of the position and speed of the target 40 in the orthogonal coordinates calculated by the position / position speed prediction means 21, and uses this to calculate the predicted value of the arrival angle of the reflected signal from the target 40. . The angle error conversion means 17 receives the position and speed prediction vector in the orthogonal coordinates calculated by the position / velocity prediction means 21, and uses this to convert the error covariance matrix in the orthogonal coordinates into an angle error variance. Is calculated. The angle gain calculation means 18 inputs the error conversion matrix calculated by the angle error conversion means 17 and the prediction error covariance matrix in the orthogonal coordinates calculated by the position / velocity prediction means 21, and uses these to calculate the angle in the orthogonal coordinates. A gain matrix for updating the smooth vector of the position and speed of the target 40 is calculated.

  The angle smoothing unit 19 includes a Doppler frequency B calculated by the Doppler frequency B calculating unit 10, an angle predicted value calculated by the angle predicting unit 16, an error conversion matrix calculated by the angle error converting unit 17, and an angle gain calculating unit. The gain matrix calculated by 18 and the predicted position and speed prediction vector and prediction error covariance matrix of the target 40 in the Cartesian coordinates calculated by the position / velocity prediction means 21 are input, and using these, the smooth vector and smooth error covariance matrix are input. Update the matrix.

  The delay circuit 20 inputs the smooth vector and the smooth error covariance matrix of the position and speed of the target 40 in the orthogonal coordinates output from the speed smoothing means 14 or the angle smoothing means 19, and uses these to delay the time by one sampling. Let The position / velocity prediction means 21 calculates the target 40 position / velocity prediction vector and prediction error covariance matrix at the next sample time based on the smooth vector and smooth error covariance matrix output from the delay circuit 20.

Next, various definition items for estimating the motion of the target 40 from the target information input to the bistatic receiving station 51 will be described.
FIG. 2 is a diagram showing the position and speed of the target 40 in the orthogonal coordinates 0-XYZ with the antenna 6 of the bistatic receiving station 51 as the origin. It is assumed that the three-dimensional motion of the target 40 is estimated. For the sake of simplicity, it is assumed that the constant velocity linear motion model shown in the following formula (1) is adopted as the motion model of the target 40.

The x _k underbar in the above equation (1) (indicated by reading for the purpose of electronic application) is a state vector that represents the true value of the motion specifications of the target 40 at the sampling time t _k . When the position vector of the target 40 in the reference coordinates is expressed by the following equation (2) and the velocity vector is expressed by the following equation (3), the state vector of the target 40 is expressed by the following equation (4). Here, the sampling time t _k (k = 1, 2,..., N) is a discrete time representing the timing at which the antenna 6 receives a signal. In the following, it referred to as the discrete time and time t _k.

Φ _k-1 is a state vector transition matrix from time t _k-1 to time t _k , and is expressed by the following equation (5). Further, w _k underbar (represented by reading for the purpose of electronic application) is a drive noise vector at time t _k , and Γ ₁ (k) is a conversion matrix of the drive noise vector at time t _k . For example, if the truncation error term due to the assumption that the motion model of the target 40 is constant-velocity linear motion is Γ ₁ (k−1) w _k-1 underbar (represented by reading for the purpose of electronic application), w _{The k} underbar is equivalent to the acceleration vector, and Γ ₁ (k−1) is expressed by the following equation (6). T is a sampling interval, and I is a 3 × 3 unit matrix.

If the symbol representing the average is E, w _k underbar is a three-dimensional normally distributed white noise with an average of 0 underbar (represented by reading for the purpose of electronic application), and the following formula (7) and the following formula ( 8). However, the 0 underbar is a zero vector, and Q _k is a drive noise covariance matrix at time t _k .

Next, an observation model when the Doppler frequency B with respect to the relative velocity between the target 40 and the antenna 6 is calculated by the Doppler frequency B calculating means 10 will be described.
When the Doppler frequency B based on the relative speed between the antenna 1 and the target 40 at time t _k is f _d ^B (k), the frequency of the reflected signal from the target 40 is f _C (k), and the speed of light is c, the Doppler speed The observed value r (k) dot (indicated by reading for the purpose of electronic application) is represented by the following formula (9). The Doppler velocity observation model is represented by the following formula (10). Here, R _k is the true value of the observed value of Doppler velocity, and h (x _k underbar) (indicated by reading for the purpose of electronic application) is the true value of Doppler velocity, which is expressed by the following equation (11). The ν _k is the Doppler velocity observation noise. The observation noise is assumed to follow a one-dimensional normal distribution white noise with an average of 0, and has the properties of the following formula (12) and the following formula (13). Note that S _k is the observation error variance of the Doppler velocity at time t _k .

The following equation (14) is obtained by Taylor expansion of the above equation (11) around the prediction vector x _k underbar (−) of the target 40 at the reference coordinates at time t _k (denoted by reading for the purpose of electronic application). Obtainable. Here, by using the matrix H (x _k hat underbar (−)) (indicated by reading for the purpose of electronic application), the error covariance matrix in the orthogonal coordinates can be approximately converted to the error variance of the Doppler velocity. it can.

Next, an observation model when the arrival angle of the reflected signal from the target 40 is measured by the arrival angle measuring means 15 will be described.
Represents an observation vector of the elevation E _k and azimuth angle Az _k of the target 40 at time t _k theta (k) by the following equation (24) represents the observation model of the elevation and azimuth by the following formula (25). Here, Θ _k is the true value of the observation vector of the elevation angle and the azimuth angle, and g (x _k underbar) (expressed by reading for the purpose of electronic application) is the true value of the elevation angle and the azimuth angle, (26) ω _k is an observation noise vector of elevation angle and azimuth angle. The observation noise vector is assumed to follow a two-dimensional normal distribution white noise with an average of 0, and has the properties of the following formulas (27) and (28). Λ _k is an observation error covariance matrix of elevation angle and azimuth angle at time t _k .

The following equation (29) can be obtained by Taylor expansion of the above equation (26) around the prediction vector x _k underbar (−) of the target 40 in the orthogonal coordinates at time t _k . Further, by using the matrix H (x _k hat underbar (−)), the error covariance matrix in the orthogonal coordinates can be approximately converted to the error variance of the Doppler velocity.

Next, the operation will be described.
The transmission / reception means 2 of the monostatic radar station 50 transmits a signal of frequency f ₀ toward the target 40 via the antenna 1 and receives the reflected signal from the target 40 via the antenna 1 again. The frequency detection means 3 receives the reception signal output from the transmission / reception means 2 and measures the frequency f _{A of the} reception signal. Here, since the frequency f _A of the received signal is affected by the Doppler frequency f _d ^A (Doppler frequency A) generated by the relative speed between the antenna 1 and the target 40, the following equation (38) It is represented by

The Doppler frequency A calculating means 4 inputs the frequency f _A of the signal output from the frequency detecting means 3 and calculates the Doppler frequency f _d ^A according to the following equation (39).

The communication unit 5 transmits information on the Doppler frequency f _d ^A and the transmission frequency f ₀ output from the Doppler frequency A calculation unit 4 to the communication unit 9.

On the other hand, the receiving means 7 receives the reflected signal from the target 40 via the antenna 6. The frequency detection means 8 inputs the reception signal output from the reception means 7 and measures its frequency. Here, the frequency f _B of the received signal, the influence of the Doppler frequency f _d ^A caused by the relative velocity between the antenna 1 and the target 40, a Doppler frequency caused by the relative velocity between the target 40 and the antenna 6 f _d ^Since it is affected by ^B (Doppler frequency B), it is expressed by the following formula (40).

Further, the communication unit 9 receives information on the Doppler frequency f _d ^A and the transmission frequency f ₀ from the communication unit 5. In the Doppler frequency B calculating means 10, the frequency f _{B of the} received signal output from the frequency detecting means 8, the Doppler frequency f _d ^A received from the communication means 9 and the transmission frequency f ₀ are input, and the Doppler frequency is calculated according to the following equation (41). f _d ^B is calculated. Here, the following equation (41) is derived by substituting the above equation (39) into the above equation (40).

The speed prediction means 11 receives the predicted position x of the target 40 in the orthogonal coordinates output by the position speed prediction means 21 and the predicted vector x _k hat underbar (−), and predicts the predicted value h (x _k hat underbar ( -)) Is calculated according to the following formula (42).

The speed error conversion means 12 receives the predicted vector x _k hat underbar (−) in the orthogonal coordinates output from the position / speed prediction means 21 and follows the relationship between the above formulas (15) to (23). An error conversion matrix H (x _k hat underbar (−)) for approximating the prediction error covariance matrix in FIG.

Further, the speed gain calculation means 13 includes an error conversion matrix H (x _k hat underbar (−)) output from the speed error conversion means 12 and a prediction error covariance matrix P _k in orthogonal coordinates output from the position speed prediction means 21. (−) Is input, and a gain matrix K _k for smoothing the state vector x _k underbar at the Doppler velocity is calculated according to the following equation (43) from the observation error variance S _k of the Doppler velocity set in advance. calculate.

In the speed smoothing means 14, the speed gain matrix K _k output from the speed gain calculating means 13, the predicted value h (x _k hat underbar (−)) output from the speed predicting means 11, and the speed error converting means 12 Output the error conversion matrix H (x _k hat underbar (−)), the position of the target in the orthogonal coordinates output by the position / velocity prediction means 21, the speed prediction error covariance matrix P _k (−), and the Doppler frequency. The Doppler frequency f _d ^A output from the B calculating means 10, the Doppler frequency f _d ^B and the transmission frequency f ₀ are input, and using these, the smooth vector of the position and speed of the target 40 in orthogonal coordinates and its error covariance. The smoothing error covariance matrix that is a matrix is calculated according to the following formula (44) and the following formula (45), respectively.

On the other hand, the arrival angle measurement means 15 inputs a reception signal from the reception means 7 and measures the arrival angle (elevation angle and azimuth angle). The angle predicting unit 16 inputs the predicted vector x _k hat underbar (−) of the target 40 in the orthogonal coordinates output from the position / velocity predicting unit 21 and inputs the predicted vector g (x _k hat underbar of the elevation angle and the azimuth angle). (−)) Is calculated according to the following formula (47).

In the angle error conversion means 17, the prediction vector x _k hat underbar (−) in the orthogonal coordinates output from the position / velocity prediction means 21 is input, and the orthogonal coordinates are expressed according to the relationship from the above expression (30) to the above expression (37). An error conversion matrix G (x _k hat underbar (−)) for approximating the prediction error covariance matrix in FIG.

The angle gain calculation means 18 includes an error conversion matrix G (x _k hat underbar (−)) output from the angle error conversion means 16 and a prediction error covariance matrix P _k (− in the orthogonal coordinates output from the position / velocity prediction means 21. ) And a preset elevation error and azimuth angle observation error covariance matrix Λ _k, and a gain matrix Ψ _k for smoothing the state vector x _k underbar at the elevation angle and azimuth angle is expressed by the following equation: Calculate according to (48).

The angle smoothing unit 19 includes an angle gain matrix Ψ _k output from the angle gain calculating unit 18, predicted elevation values g (x _k hat underbar (−)) output from the angle predicting unit 16, and angle error conversion. An error conversion matrix G (x _k hat underbar (−)) output by the means 17, a prediction error covariance matrix P _k (−) of the position and speed of the target 40 in the orthogonal coordinates output by the position / speed prediction means 21; The arrival angle (elevation angle and azimuth angle) of the reception signal output by the arrival angle measurement means 15 is input, and based on these, the smoothing vector of the position and velocity of the target 40 in orthogonal coordinates and the error covariance matrix thereof are used. The error covariance matrix is calculated according to the following formula (44) and the following formula (45), respectively.

In the delay circuit 20, the position 40 of the target 40 output from the speed smoothing means 14 or the angle smoothing means 19, the smoothing vector x _{k of the} hat underbar (+), and the smoothing error covariance matrix P _k (+) for one sample time. Delay.

The position / velocity prediction means 21 receives the smoothing vector x _k hat underbar (+) and the smoothing error covariance matrix P _k (+) of the position and speed of the target 40 one sampling before output from the delay circuit 20 and inputs the above-described smoothing error covariance matrix P _k (+). A prediction vector and a prediction error covariance matrix in orthogonal coordinates derived from the motion model of Expression (1) are calculated according to Expression (51) and Expression (52) below.

  By repeating the above process, the state vector of the position and speed of the target 40 can be accurately updated and tracking can be maintained. Here, the Doppler frequency B calculated by the Doppler frequency B calculating means 10 and the elevation angle and azimuth angle calculated by the arrival angle measuring means 15 are observation information at the same time. For this reason, after each processing from the speed prediction means 11 to the speed smoothing means 14 is performed first, the sampling speed T is set to 0, the processing of the position speed prediction means 21 is performed, and the angle prediction means 16 to the angle smoothing means 19 are performed. Each process according to the above is performed.

  As described above, according to the first embodiment, the Doppler frequency A and the transmission frequency between the antenna 1 and the target 40 calculated by the Doppler frequency A calculating unit 4 of the monostatic radar station 50 are set as the communication unit 5 and the communication frequency. The Doppler frequency B between the antenna 6 and the target 40 is calculated by the Doppler frequency B calculating means 10 from the frequency information sent to the bistatic receiving station 51 via the means 9 in real time and received and measured at the bistatic receiving station 51. Is calculated. The arrival angle measuring means 15 is configured to measure the arrival angle of the received signal.

  As a result, the condition that the relative positions of the monostatic radar station and the bistatic receiving station must be known and the reference directions of the antennas of the two stations must coincide with each other with high accuracy, as in a conventional radar device. It is unnecessary. That is, the position and speed of the target 40 can be accurately estimated even when one or both of the two stations are on different mobile platforms.

It is a block diagram which shows the structure of the bistatic radar apparatus by Embodiment 1 of this invention. It is a figure which shows the position and speed of the target in the orthogonal coordinate 0-XYZ which makes the origin the antenna of a bistatic receiving station.

Explanation of symbols

1 antenna 2 transmission / reception means 3 frequency detection means (first frequency detection means) 4 Doppler frequency A calculation means (first Doppler frequency calculation means) 5 communication means 6 antenna 7 reception means 8 frequency detection Means (second frequency detecting means), 9 communication means, 10 Doppler frequency B calculating means (second Doppler frequency calculating means), 11 speed predicting means, 12 speed error converting means, 13 speed gain calculating means, 14 speed smoothing Means, 15 arrival angle measurement means, 16 angle prediction means, 17 angle error conversion means, 18 angle gain calculation means, 19 angle smoothing means, 20 delay circuit, 21 position speed prediction means, 40 target, 50 monostatic radar station, 51 Bistatic receiving station, 52 Motion specification estimation means.

Claims (3)

A monostatic radar station having a transmission / reception means for outputting a transmission radio wave toward the target and receiving the reflected radio wave reflected by the target;
A bistatic receiving station having receiving means for receiving the reflected radio wave at a different position from the monostatic radar station;
First frequency detection means for measuring the frequency of a radio wave received by the transmission / reception means of the monostatic radar station;
Second frequency detecting means for measuring the frequency of the radio wave received by the receiving means of the bistatic receiving station;
First Doppler frequency calculating means for measuring a first Doppler frequency between the target and a reception position in the monostatic radar station from the frequency of the received radio wave measured by the first frequency detecting means;
Using the frequency of the transmission radio wave, the frequency of the reception radio wave measured by the second frequency detection means, and the first Doppler frequency calculated by the first Doppler frequency calculation means, the target and the bistatic reception Second Doppler frequency calculating means for measuring a second Doppler frequency between the receiving position and the station;
A communication means for transmitting the first Doppler frequency of the measurement result and the frequency of the transmission radio wave to the second Doppler frequency calculation means along with the measurement of the first Doppler frequency by the first Doppler frequency calculation means,
A radar apparatus comprising: motion specification estimating means for estimating a motion specification related to the position and speed of the target using the second Doppler frequency. An arrival angle measuring means for measuring the arrival angle of the received radio wave by the receiving means of the bistatic receiving station,
The motion specification estimation means uses the arrival angle of the received radio wave measured by the arrival angle measurement means and the second Doppler frequency calculated by the second Doppler frequency calculation means to determine the motion specifications related to the target position and velocity. The radar apparatus according to claim 1, wherein: The motion parameter estimation means is
Speed prediction means for calculating a prediction vector of Doppler speed using a prediction vector of a target position and speed in a reference orthogonal coordinate;
Speed error conversion means for calculating an error conversion matrix for approximating the prediction error covariance matrix in the orthogonal coordinates to the prediction error variance of the Doppler speed using the prediction vector of the target position and speed in the orthogonal coordinates;
Speed gain calculation means for calculating a speed gain matrix for Doppler speed using the prediction error covariance matrix and the error conversion matrix calculated by the speed error conversion means;
The second Doppler frequency calculated by the second Doppler frequency calculating means, the prediction vector of the Doppler speed calculated by the speed predicting means, the error conversion matrix calculated by the speed error converting means, and the speed calculated by the speed gain calculating means Speed smoothing means for calculating a smooth vector and a smoothing error covariance matrix of the target position and speed using a gain matrix, a prediction vector of the target position and speed and a prediction error covariance matrix;
An angle prediction unit that calculates a prediction vector of an arrival angle of a received radio wave by a reception unit of a bistatic reception station using a prediction vector of a target position and velocity in the orthogonal coordinates;
An angle error for calculating an error transformation matrix for approximating the prediction error covariance matrix in the orthogonal coordinates to the prediction error variance of the arrival angle of the received radio wave using the prediction vector of the target position and velocity in the orthogonal coordinates Conversion means;
Angle gain calculation means for calculating an angle gain matrix for the arrival angle of the received radio wave using the prediction error covariance matrix and the error conversion matrix calculated by the angle error conversion means;
The arrival angle of the received radio wave measured by the arrival angle measuring means, the prediction vector of the arrival angle of the received radio wave calculated by the angle prediction means, the error conversion matrix calculated by the angle error conversion means, and the angle gain calculation means Angle smoothing means for inputting the angle gain matrix, the target position and velocity prediction vector and the prediction error covariance matrix, and calculating the target position and velocity smooth vector and the smoothing error covariance matrix using these ,
A delay circuit that delays and outputs a smooth vector and a smoothing error covariance matrix of the target position and velocity calculated by the velocity smoothing unit or the angle smoothing unit by one sample time;
The smoothing vector and smoothing error covariance matrix of the target position and velocity before sampling outputted from the delay circuit are inputted, and using these, the predicted vector and prediction error covariance of the target position and velocity in the orthogonal coordinates are used. The radar apparatus according to claim 2, further comprising a position / velocity prediction unit that calculates a matrix and outputs the matrix to the velocity prediction unit and the angle prediction unit.

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