JP2005291816A - Radar equipment - Google Patents

Abstract

Provided is a radar apparatus that accurately identifies an arrival target using a high-resolution reflection intensity distribution even when the number of radars is small.
A radar apparatus for identifying a target and estimating a posture of the target using a high-resolution reflection intensity distribution of the target obtained by observing the same target with a plurality of radar devices installed at a plurality of points, The target position estimation unit 2 that estimates the target position using distance information to the target measured by the radar device 1, the database 4 that stores the observation angle characteristics of the high-resolution reflection intensity distribution of the candidate target in advance, and the estimation Assuming the attitude of the candidate target at the target position, prepare a set of high-resolution reflection intensity distributions obtained by each radar device, and estimate the model and attitude of the arrival target by comparing with the reflection intensity distribution of the arrival target And an identification processing unit 3.
[Selection] Figure 1

Description

  The present invention relates to a radar apparatus that uses a reflection intensity distribution obtained by observing the same target with a plurality of radars installed at a plurality of points to identify the target and estimate the posture of the target.

  Conventionally, as this type of radar apparatus, there is one that estimates a target identification and a target attitude using a target RCS (Radar Cross Section) value obtained by observing the same target with radars installed at a plurality of points ( For example, see Patent Document 1).

JP 2002-267747 A

  However, the conventional radar device described above has a problem that the identification performance is lowered when the number of radars is small.

  The present invention has been made to solve such a conventional problem, and an object thereof is to provide a radar apparatus that can accurately identify an arrival target even when the number of radars is small.

  A radar apparatus according to the present invention uses a reflection intensity distribution having a spatial resolution capable of separating a target scattering point, which is obtained by observing the same target with a plurality of radar devices installed at a plurality of points. A radar device for estimating the attitude of a target, and a target position estimator that estimates the position of the target using distance information to the target measured by each radar device, and the observation angle characteristics of the reflection intensity distribution of the candidate target are stored in advance Assuming the attitude of the candidate target at the estimated target position and the estimated target position, a set of reflection intensity distributions obtained by each radar device based on the data accumulated in the database is prepared, and the observation result of the arrival target It comprises an identification processing unit for estimating the arrival target model and posture by comparing with the reflection intensity distribution.

  According to the present invention, even when the number of radars is small, an arrival target can be accurately identified using a reflection intensity distribution having a spatial resolution capable of separating a target scattering point.

Embodiment 1 FIG.
(Range profile)
The first embodiment of the present invention will be described below with reference to FIGS.
1 is a block diagram showing a configuration of a radar apparatus according to Embodiment 1 of the present invention. The radar apparatus shown in FIG. 1 uses a range profile as a high-resolution reflection intensity distribution of a target obtained by observing the same target with radar devices installed at a plurality of points, and uses a range profile to estimate the target attitude and target attitude. The radar devices 1 (1-1, 1-2,..., 1-M are collectively referred to) installed at a plurality of points and the distance information to the target measured by each radar device 1 are used as targets. Target position estimator 2 for estimating the position of the target, a range profile database 4 as a database for storing observation angle characteristics of the high resolution reflection intensity distribution of the candidate target in advance, and a high resolution reflection intensity distribution by processing the received signal Assuming the attitude of the candidate target at the estimated target position, a set of high-resolution reflection intensity distributions obtained by each radar device 1 is prepared and compared with the reflection intensity distribution of the arrival target And a range profile identification processor 3 as an identification processing unit for estimating the model and the posture of the incoming target by the. Here, the “high resolution reflection intensity distribution” referred to in this specification is a reflection intensity distribution having a spatial resolution high enough to separate a target scattering point from a target shape.

  Here, the range profile database 4 stores in advance the observation angle characteristics of the candidate target's range profile as the observation angle characteristics of the candidate target's high-resolution reflection intensity distribution, and the range profile identification processing unit 3 at the estimated target position. Assuming various attitudes of candidate targets, a set of range profiles obtained by each radar device 1 is prepared, and the model and attitude of the arrival target are estimated by comparing with the range profile of the arrival target.

  FIG. 2 is a block diagram showing an internal configuration of the range profile identification processing unit 3. As shown in FIG. 2, the range profile identification processing unit 3 assumes the posture of the candidate target at various target positions estimated by the target position estimation unit 2 and determines the observation angle of each radar device between the target and each radar device. Observation angle calculation unit 3a that is calculated from the positional relationship, range profile reading unit 3b that reads the range profile of the candidate target corresponding to the observation angle from the range profile database 4, and the estimation result of the model and posture of the arrival target based on the range profile And a determination unit 3c for outputting.

Next, the operation of the radar apparatus according to Embodiment 1 having the above configuration will be described.
(1) Radar devices 1-m (m = 1, 2,..., M) are assumed to be arranged at a plurality of points as shown in FIG. The position (x _m , y _m , z _m ) (m = 1, 2,..., M) of each radar device 1-m is known. Each radar device 1-m transmits and receives pulses to and from the same target. From the obtained received signals, the target range profiles s _m (m = 1, 2,..., M) observed by each radar device 1-m and the distance R _m from each radar device 1-m to the target. (M = 1, 2,..., M) is obtained. Here, range profile s _m is a vector defined by the following equation. Here, s (r) is an RCS observation amount in the r-th range bin. K is the number of range bins.

The target range profile s _m obtained by each radar device 1 _-m and the distance R _m to the target are sent to the target position estimation unit 2.

(2) The target position estimation unit 2 includes the distance R _m to the target measured by each radar device 1-m and the position (x _m , y _m , z _m ) of each radar device 1-m that is known information. From this, the target position is estimated. If the target position is P _t (x _p , y _p , z _p ), the distance R _m between each radar device 1-m and the target position P _t is expressed by the following equation.

The target position P _t is determined by solving the nonlinear simultaneous equations of Expression (1) by the least square method. And the target position P _t estimated by the target position estimation unit 2, range profile s _m of the target is transmitted to the range profile identification processor 3.

(3) The observation angle calculation unit 3a assumes various attitudes (i _x , i _y , i _z ) of the candidate target N (N = 1, 2,..., N) at the target position P _t . The observation angle (θ _m , φ _m ) (m = 1, 2,..., M) of each radar device 1-m is calculated from the positional relationship between the target and each radar device 1-m. Here, (i _x , i _y , i _z ) represents a target posture, and represents unit vectors in the target nose direction, lateral direction, and height direction, respectively. (Θ _m , φ _m ) is an observation angle of each radar device 1-m, and is represented by an elevation angle φ _m and an azimuth angle θ _m . The observation angle (θ _m , φ _m ) is the direction of each radar device 1-m with respect to the target, and as shown in FIG. 4, (i _x , i _y , i _z ) in the coordinate system (i _{x, i y)} azimuth angle measured counterclockwise from the _{i x} axis in the plane phi _m, and _is defined by _(i x, i _y) elevation angle measured in the _{i z} axis from the plane theta _m.

(4) Then, the range profile reading unit 3b _displays the range profile s _{N, (θm, φm)} of the candidate target N corresponding to the observation angle (θ _m , φ _m ) for various observation angles for each candidate target N. Is read out from the database 4 that stores the range profile for and is prepared as a vector of the following equation.

S (N, (i _x , i _y , i _z ), P _t ) in the expression (3) is obtained when the candidate target N is in the posture (i _x , i _y , i _z ) at the target position P _t . This is a vector having the range profile _{sN, (θm, φm)} obtained by the radar device 1-m as an element.

(5) determining unit 3c, first, providing a vector S _obs to a range profile s _m of the target observed by the radar device 1-m transmitted from the target position estimation unit 2 and the element by the following equation.

(6) Next, when the candidate target N coincides with the arrival target and the postures (i _x , i _y , i _z ) are equal, S _obs and S (N, (i _x , i _y , i _z) ), P _t) is given that ideally matches the following equation candidate target N that minimizes the evaluation function, posture (i _{x, i} y, set the type of incoming targets each _{i z)} and orientation It is assumed that

(Other examples)
(Correlation value)
In the first embodiment, the evaluation function of Expression (5) is introduced, and the candidate target and the target target are minimized so as to minimize the error between S _obs and S (N, (i _x , i _y , i _z ), P _t ). Although the attitude is determined, an evaluation function of the following equation may be introduced to identify the correlation value as an evaluation index.

Here, Xcoll, as expressed by the following _{equation, S obs} and _{S (N, (i x,} i y, i z), P t) corresponding element _{(s 1} and s _{n of, (.theta.1,} It is an operator that calculates a maximum correlation value for each of _φ1) , s ₂ and s _{n, (θ2, φ2)} , s _M and s _{n, (θM, φM)} ), and returns a sum of these values.

  At this time, candidate targets and postures that maximize the evaluation function of Expression (6) are output as identification results.

(Other examples)
(Database)
In the first embodiment, the range profile database 4 that stores the observation angle characteristics of the range profile of the candidate target in advance is provided. However, the shape of the candidate target is prepared and a GTD (Geometrical Theory of Diffraction) or the like is prepared. A similar effect can be obtained even if the range profile is calculated sequentially by numerical calculation.

(Other examples)
(Multi-static)
In Embodiment 1 described above, an example of a monostatic radar system that transmits and receives pulses with a plurality of radar devices and observes the same target has been described. However, as shown in FIG. It can be easily estimated that the same effect can be obtained even in a multi-static radar system that simultaneously receives signals with the radar apparatus.

(effect)
As described above, according to Embodiment 1 of the present invention, even when the number of radars is small, an arrival target can be accurately identified using a high-resolution range profile. In addition, since the target position is estimated using the distance information to the target measured by each radar device, the target position can be estimated accurately even when a radar device with a low angular resolution is used, and the identification rate is high. improves.

Embodiment 2. FIG.
(Cross range profile)
The second embodiment of the present invention will be described below with reference to FIGS.
FIG. 6 is a block diagram showing the configuration of the radar apparatus according to Embodiment 2 of the present invention. FIG. 7 is a block diagram showing an internal configuration of the cross range profile identification processing unit 13 according to Embodiment 2 of the present invention. 6 and 7, the same reference numerals are given to the portions corresponding to those in FIGS. 1 and 2, and the detailed description thereof is omitted.

  The radar apparatus shown in FIG. 6 uses a cross-range profile as a high-resolution reflection intensity distribution of a target obtained by observing the same target with radar devices installed at a plurality of points, and uses a cross-range profile to estimate the target posture. A radar device 11 (11-1, 11-2,..., 11-M collectively) installed at a plurality of points, and a target position estimation unit similar to the first embodiment shown in FIG. 2, an RCS (Radar Cross Section) database 14 as a database, and a cross range profile generation unit 12 and a cross range profile identification processing unit 13 as identification processing units.

  Here, the database 14 stores in advance the observation angle characteristics of the candidate target RCS as the observation angle characteristics of the high-resolution reflection intensity distribution, and the cross range profile generation unit 12 processes the received signal to obtain the cross range profile. The cross range profile identification processing unit 13 generates a set of cross range profiles obtained by each radar device 11 assuming the posture of the candidate target at the estimated target position, and compares it with the cross range profile of the arrival target. To estimate the model and attitude of the arrival target.

  Further, as shown in FIG. 7, the cross range profile identification processing unit 13 includes an observation angle calculation unit 3a and a determination unit 3c similar to those in the first embodiment shown in FIG. 2, and instead of the range profile reading unit 3b. In addition, an RCS reading unit 13 a that reads the observation angle characteristics of the candidate target RCS corresponding to the observation angle from the RCS database 14 is provided.

  In the first embodiment described above, a target range profile is observed by using a radar with a high range resolution, but a range profile cannot be obtained with a radar with a low range resolution. However, when the target moves, the reflection intensity distribution (cross range profile) with respect to the length in the cross range direction orthogonal to the range can be observed by transmitting and receiving a plurality of pulses and observing the Doppler frequency. See the literature High-Resolution Radar Second Edition (author Donald R. Wehner, publisher Artech House Publishers, pp. 341-433) for cross-range profile observation methods.

Next, the operation of the radar apparatus according to the second embodiment having the above configuration will be described.
(1) The radar devices 11-m (m = 1, 2,..., M) arranged at a plurality of points have the same target during t = 0 (s) to t = T (s). On the other hand, the process of irradiating the pulse and receiving the reflected wave is repeated H times. Accordingly, the received signal g _m (h) (h = 1, 2,..., H) collected by each radar device 11-m and the distance R _m (h) from each radar device 11-m to the target. (M = 1, 2,..., M, h = 1, 2,..., H). Here, T is called the synthetic opening time, H is the number of hits, and h is the hit number. The position of the radar unit _{11-m (x m, y} m, z m) (m = 1,2, ···, M) is assumed to be known. The received signal g _m (h) obtained by each radar device 11-m and the distance R _m (h) to the target are sent to the target position estimation unit 2.

(2) The target position estimation unit 2 performs the same processing as in the first embodiment for H transmission / reception, and estimates the target position P _t (h) (h = 1, 2,..., H). . The target position _P t (h), so represents an estimate of the trajectory of the target has moved between t = 0 from the (s) t = T (s ), in the subsequent description and the trajectory _P t (h) I will call it. The trajectory P _t (h) estimated by the target position estimation unit 2 and the received signal g _m (h) are sent to the cross range profile generation unit 12.

(3) The cross range profile generator 12 processes the received signal g _m (h) based on the trajectory P _t (h) estimated by the target position estimator 2 and observes it with each radar device 11-m. cross range profile _{Cp m (m = 1,2, ···} , M) to generate a. Cross-range profile Cp _m is a vector defined by the following equation. However, Cp (r) is an RCS observation amount in the r-th cross-range cell. D is the number of cross-range cells.

And cross-range profile Cp _m Goal observed generated by cross-range profile generator 12, the target position P _{t (h)} is sent to the cross-range profile identification processor 13.

(4) In the cross-range profile identification processing unit 13, the observation angle calculation unit 3a determines the posture (i _x ) of the candidate target N (N = 1, 2,..., N) in the estimated trajectory P _t (h). , I _y , i _z ) are variously assumed, and an observation angle in each transmission / reception when each radar device 11-m transmits / receives H times of pulses to / from the candidate target N is calculated.

(5) Then, the RCS reading unit 13a reads the RCS of the candidate target N for this observation angle from the RCS database 14 that accumulates RCS for various observation angles for each candidate target N, and each radar device 11-m Prepares a received signal obtained by transmitting and receiving H pulses. Then, processes the received signal based on the estimated trajectory _P t (h), the radar device 11-m cross-range profile obtained by _{Cp m (N, (i x} , i y, i z), P _t (h)) (m = 1, 2,..., M, N = 1, 2,..., H) is generated and summarized as the following equation.

(6) determination portion 3c, first, providing a vector S _obs to the cross-range profile Cp _m targets observed by the radar unit 11-m transmitted from the cross range profile 12 as elements by the following equation.

Next, when the candidate target N matches the incoming target and the postures (i _x , i _y , i _z ) are equal, S _obs and S (N, ((i _x , i _y , i _z ), _Pt (h)) is ideally matched, and a set of candidate target N and attitude (i _x , i _y , i _z ) that minimizes the evaluation function of Assume the result of posture estimation.

(Other examples)
(Correlation value)
In the second embodiment, the evaluation function of Expression (12) is introduced, and S _obs and S (N, (i _x , i
_The candidate target and the posture are determined so as to minimize the error of _{y 1} , i _z ), P _t (h)), but the evaluation function of the following equation is introduced and the correlation value is used as the evaluation index. Also good.

  At this time, candidate targets and postures that maximize the evaluation function of Expression (13) are output as identification results.

(Other examples)
(Trajectory)
In the second embodiment, a set of cross-range profiles obtained by each radar device is prepared by assuming various attitudes of candidate targets in the estimated trajectory, and identification is performed. However, in the estimated trajectory, Considering the fact that observation errors are included, a certain area including the estimated trajectory is provided, various trajectories are assumed within that area, and each target radar is assumed in the assumed trajectory variously. Identification may be performed by preparing a set of cross-range profiles obtained by a vessel.

(Other examples)
(Multi-static)
In the second embodiment, the example of the monostatic radar system that transmits and receives pulses with a plurality of radar devices and observes the same target has been described. However, transmission is performed with one radar device and reception is simultaneously performed with all radar devices. It can be easily estimated that the same effect can be obtained in the multistatic radar system to be performed.

(effect)
As described above, according to the second embodiment of the present invention, even when the number of radars is small, an arrival target can be accurately identified using a high-resolution cross-range profile. Further, the arrival target can be accurately identified even when a radar having a low range resolution is used.

Embodiment 3 FIG.
(Radar image)
The third embodiment of the present invention will be described below with reference to FIGS.
FIG. 8 is a block diagram showing the configuration of the radar apparatus according to Embodiment 3 of the present invention. FIG. 9 is a block diagram showing an internal configuration of the radar image identification processing unit 22 according to the third embodiment of the present invention. 8 and 9, parts corresponding to those in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The radar apparatus shown in FIG. 8 uses a radar image as a high-resolution reflection intensity distribution of a target obtained by observing the same target with radar devices installed at a plurality of points to estimate the target's identification and target posture. In addition, radar devices 11 (11-1, 11-2,..., 11-M are collectively referred to) installed at a plurality of points, and a target position estimation unit 2 similar to the first embodiment shown in FIG. And a partial RCS (Radar Cross Section) database 23 as a database, and an image reproduction unit 21 and a radar image identification processing unit 22 as an identification processing unit.

  Here, the partial RCS database 14 stores in advance the observation angle characteristics of the candidate target partial RCS (Radar Cross Section) as the observation angle characteristics of the high-resolution reflection intensity distribution, and the radar image identification processing unit 22 estimates Assuming the attitude of the candidate target at the target position, a set of radar images obtained by each radar device is prepared, and the model and attitude of the arrival target are estimated by comparing with the radar image of the arrival target.

  As shown in FIG. 9, the radar image identification processing unit 22 includes an observation angle calculation unit 3a and a determination unit 3c similar to those in the first and second embodiments shown in FIGS. Instead of the unit 3b, a partial RCS reading unit 22a that reads the observation angle characteristics of the candidate target partial RCS corresponding to the observation angle from the partial RCS database 23 is provided.

  In the second embodiment described above, a radar with a low range resolution is used to identify the reflection intensity distribution (cross range profile) with respect to the length in the cross range direction orthogonal to the range. However, a radar with a high range resolution is used. Thus, the reflection intensity distribution on the target can be obtained as a high-resolution image with the range and the cross range as axes. See the literature High-Resolution Radar Second Edition (author Donald R. Wehner, publisher Artech House Publishers, pp. 341-433) for the method of generating target radar images with ranges and cross ranges as axes.

Next, the operation of the radar apparatus according to Embodiment 3 having the above configuration will be described.
(1) The processing up to the radar device 11-m and the target position estimation unit 2 is the same as that in the second embodiment.

(2) The image reproduction unit 21 that has received the target position P _t (h) and the received signal g _m (h) from the target position estimating unit 2 processes the received signal and uses the range and cross range as axes. The radar image I _m (m = 1, 2,..., M) is reproduced, and the obtained radar image I _m and the target position P _t (h) are sent to the radar image identification processing unit 22.

  In the second embodiment, the radar image identification processing unit 22 replaces what the cross range profile identification processing unit 12 compares the observed target cross range profile with the candidate target cross range profile with a radar image. Since this is a process, a description thereof will be omitted. Since the radar image is used for identification instead of the cross range profile, the partial RCS readout unit 22a generates a candidate target radar image with the range and the cross range as axes instead of the cross range profile. . At this time, the radar image of the candidate target is generated by reading out the partial RCS from the partial RCS database storing the partial RCS for various observation angles for each candidate target N. Here, the partial RCS is the RCS of each scattering center on the target.

(Other examples)
(Multi-static)
In the third embodiment, the example of the monostatic radar system in which each radar device 11-m independently transmits and receives has been described. However, a multi-device that transmits by one radar device and receives simultaneously by all the radar devices is described. It can be easily estimated that the same effect can be obtained in the static radar system.

(effect)
As described above, according to the third embodiment of the present invention, by using a high-resolution radar image, the parameters for target identification processing further increase, and even when the number of radars is small, an incoming target can be accurately identified. Can do.

Embodiment 4 FIG.
(Feature value)
The fourth embodiment of the present invention will be described below with reference to FIGS.
FIG. 10 is a block diagram showing a configuration of a radar apparatus according to Embodiment 4 of the present invention.
The radar apparatus shown in FIG. 10 is a radar apparatus that estimates the target identification and the target posture using the feature amount of the high-resolution reflection intensity distribution of the target obtained by observing the same target with radar devices installed at a plurality of points. In addition, radar devices 1 (1-1, 1-2,..., 1-M are collectively referred to) installed at a plurality of points, and a target position estimation unit 2 similar to the first embodiment shown in FIG. And a feature quantity database 33 as a database, and a feature quantity calculation section 31 and a feature quantity identification processing section 32 as identification processing sections.

  Here, the feature quantity database 33 stores in advance the observation angle characteristics of the feature quantity of the high resolution reflection intensity distribution of the candidate target as the observation angle characteristics of the high resolution reflection intensity distribution, and the feature quantity identification processing unit 32 Assuming the posture of the candidate target at the estimated target position, prepare a set of high-resolution reflection intensity distribution features obtained by each radar device and compare them with the high-resolution reflection intensity distribution features of the arrival target. Thus, the model and posture of the arrival target are estimated.

Next, the operation of the radar apparatus according to Embodiment 4 having the above configuration will be described.
The fourth embodiment is different from the first embodiment in that identification is performed by comparing the feature amount obtained from the observed target range profile with the feature amount obtained from the candidate target range profile.

The feature quantity calculation unit 31 that receives the target position P _t and the target range profile s _m from the target position estimation unit 2 uses the following target as the feature quantity from the range profile s _m observed by each radar device 1-m. And the average power is calculated.

(Target size)
As shown in FIG. 11, a threshold T _amp of the received signal strength is set for the range profile s _m observed by each radar device 1-m, and the target size L _m is estimated from the range cell exceeding the threshold T _amp. .

(Average power)
To range profile s _m observed by the radar device 1-m, by setting a threshold T _{# 038} of received signal strength, averaging the received signal strength of the range cells that exceed the threshold T _{# 038,} the average power P _m.

Feature amount calculation unit 31 sends the target position P _t, the feature amount calculated as described above from the range profile s _m observed by the radar device 1-m to the feature amount identification processing unit 32.

  The feature quantity identification processing unit 32 performs discrimination by comparing the feature quantity obtained from the target range profile with the feature quantity obtained from the candidate target range profile. In other words, assuming the attitude of the candidate target at the observed position in various ways, the feature amount calculated from the range profile obtained by each radar device is set in advance as the observation angle characteristic of the feature amount calculated from the range profile of the candidate target. Candidate targets and postures that are prepared by reading out from the stored feature amount database 33 and minimize the difference from the observed target feature amounts are set as estimated values of the arrival target model and posture, respectively.

(effect)
As described above, according to the fourth embodiment of the present invention, identification is performed by comparing the feature amount obtained from the target range profile with the feature amount calculated from the candidate target range profile. For example, even when the observed range profile is changed due to noise, it is possible to prevent the identification accuracy from being lowered.

  In the fourth embodiment, the contents have been described as a development of the first embodiment, but needless to say, it can be realized as a development of the second and third embodiments. That is, in addition to the range profile of the candidate target, identification can be performed by comparing a feature amount calculated from either a cross range profile or a radar image with the range and the cross range as an axis.

Embodiment 5 FIG.
(frequency)
The fifth embodiment of the present invention will be described below with reference to FIGS.
FIG. 12 is a block diagram showing a configuration of a radar apparatus according to Embodiment 5 of the present invention.
The radar apparatus shown in FIG. 12 is a radar apparatus that uses a high-resolution reflection intensity distribution of a target obtained by observing the same target with radar devices installed at a plurality of points to estimate the target and the attitude of the target. , Radar devices 41 (41-1, 41-2,..., 41-M collectively) installed at a plurality of points, a target position estimation unit 2 similar to that of the first embodiment shown in FIG. As a multi-frequency feature quantity database 43 and a frequency-considered identification processing unit 42 as an identification processing unit.

  Here, the multi-frequency database 43 accumulates the high-resolution reflection intensity distribution corresponding to the frequency of the candidate target radar signal and the observation angle characteristic of the feature amount as the observation angle characteristic of the high-resolution reflection intensity distribution, The consideration type identification processing unit 42 performs identification of the target model and estimation of the attitude in consideration that each radar device transmits and receives radar signals having different frequencies.

  That is, the fifth embodiment is different from the first embodiment in that the radar device 1 is replaced with the radar device 41, the identification processing unit 1 is replaced with the frequency-considering type identification processing unit 42, and the database 1 is replaced with the multi-frequency database 43. Different.

Next, the operation of the radar apparatus according to Embodiment 5 having the above configuration will be described.
(1) As shown in FIG. 13, the radar device 41-m are different frequencies _{f m (m = 1,2, ···} , M) transmitted and received in, to obtain the distance to the range profile and the target of the target .

  (2) The frequency-considered identification processing unit 42 assumes a variety of candidate target postures at the target position, and obtains a plurality of range profiles obtained by transmitting and receiving radar signals of the frequency fm with each radar device 41-m. Candidate targets and attitudes that minimize the difference from the observed target range profile are prepared by reading from the multi-frequency database 43 that stores the observation angle characteristics of candidate target range profiles in advance. Use the target model and posture estimation results.

  As described above, in the fifth embodiment, each radar device transmits and receives radar signals having different frequencies so that target identification can be performed. Therefore, a radar device that can perform transmission and reception by switching frequencies is used as necessary. Can be selected. In addition, it is possible to identify a single radar device having different transmission / reception signal frequencies by networking.

  In the fifth embodiment, the contents have been described as a development of the first embodiment, but it is needless to say that the present embodiment can be realized as a development of the second and third embodiments.

Embodiment 6 FIG.
(Polarization)
The sixth embodiment of the present invention will be described below with reference to FIGS.
FIG. 14 is a block diagram showing a configuration of a radar apparatus according to Embodiment 6 of the present invention.
The radar apparatus shown in FIG. 14 is a radar apparatus that uses a high-resolution reflection intensity distribution of a target obtained by observing the same target with radar devices installed at a plurality of points to estimate the target and the attitude of the target. , Radar devices 51 (51-1, 51-2,..., 51-M collectively) installed at a plurality of points, a target position estimation unit 2 similar to that of the first embodiment shown in FIG. And a polarization-considered identification processing unit 52 as an identification processing unit.

  Here, the scattering matrix database 53 accumulates the observation angle characteristics of the candidate target's scattering matrix range profile as the observation angle characteristics of the high-resolution reflection intensity distribution and the observation angle characteristics of the candidate target's scattering matrix range profile. The consideration type identification processing unit 52 performs identification of the target model and estimation of the attitude in consideration that each radar device transmits and receives radar signals having different polarizations.

  That is, the sixth embodiment is different from the first embodiment in that the radar device 1 is replaced with the radar device 51, the identification processing unit 1 is replaced with the polarization-considered identification processing unit 52, and the database 1 is replaced with the scattering matrix database 53. Is different.

Next, the operation of the radar apparatus according to Embodiment 6 having the above configuration will be described.
(1) As shown in FIG. 15, each radar device 51-m transmits and receives with different polarizations P _m (m = 1, 2,..., M), and sets the target range profile and the distance to the target. obtain.

(2) The scattering matrix database 53 stores the observation angle characteristics of the scattering matrix range profile in advance, and by using this information, it is possible to calculate a range profile for an arbitrary transmission / reception polarization by polarization synthesis. For example, it is assumed that the scattering matrix database 53 stores the scattering matrix range profile z _{N, (θm, φm)} of the candidate target N corresponding to the observation angle (θ _m , φ _m ).

  Here, z (r) is a scattering matrix in the rth range bin.

  The polarization-considered identification processing unit 52 assumes the attitude of the candidate target at the target position in various ways, and obtains the range profile obtained by transmitting and receiving the radar signal of the polarization Pm with each radar device 51-m as the candidate target. The observation angle characteristics of the scatter matrix range profile are read out and generated from the scatter matrix database 53 stored in advance, and the candidate target and attitude that minimize the difference from the observed target range profile are set as the arrival target model and attitude, respectively. It is assumed that For polarization synthesis, refer to the document Radar Polarimetry for Geoscience Applications (author Fawwaz T. Ulaby, Charles Elachi, publisher Artech House, pp. 27-32).

(effect)
As described above, according to the sixth embodiment, each radar device transmits and receives different polarizations so that target identification can be performed. Therefore, a radar device that can perform transmission and reception by switching polarizations transmits and receives as necessary. Signal polarization can be selected. Further, radar devices having different polarizations of transmission / reception signals can be identified by networking. Further, since the candidate target scattering matrix range profile is stored in the database, it is not necessary to store the range profile for every polarization, and the capacity of the database can be reduced.

  In the sixth embodiment, the contents have been described as the development of the first embodiment, but it is needless to say that the present embodiment can be realized as the development of the second and third embodiments.

Embodiment 7 FIG.
(Multiple observations, majority decision)
Hereinafter, a seventh embodiment of the present invention will be described with reference to FIGS.
FIG. 16 is a block diagram showing a configuration of a radar apparatus according to Embodiment 7 of the present invention.
The radar apparatus shown in FIG. 16 is a radar apparatus that uses the high-resolution reflection intensity distribution of a target obtained by observing the same target with radar devices installed at a plurality of points to estimate the target and the attitude of the target. 1, the radar apparatus 1 (1-1, 1-2,..., 1-M collectively) installed at a plurality of points and the implementation shown in FIG. A target position estimation unit 2 similar to that of the first embodiment, a range profile database 4 as a database, and a range profile identification processing unit 32 as an identification processing unit. A multiple-time observation determination unit 61 that outputs the candidate target determined as the most target model among the plurality of identification results obtained by repeating the process up to the identification multiple times is further provided as the final arrival target model. To have.

  That is, the seventh embodiment is different from the first embodiment in that a plurality of observation determination units 61 are added.

Next, the operation of the radar apparatus according to Embodiment 7 having the above configuration will be described.
(1) As shown in FIG. 17, the processes from the transmission / reception at each radar device 1-m to the identification at the range profile identification processing unit 3 are repeated a plurality of times, and a plurality of identification results obtained are observed and determined a plurality of times. The unit 61 accumulates.

  (2) The multiple-time observation determination unit 61 uses the candidate target and posture selected as the most frequent identification result among the obtained identification results as the identification result of the arrival target model and posture.

(effect)
As described above, according to the seventh embodiment, since a plurality of identification results obtained by a plurality of observations are combined to obtain an identification result, misidentification can be reduced.

  In the seventh embodiment, the contents have been described as an expanded form of the first embodiment, but it is needless to say that the present invention can be realized as an expanded form of the second to sixth embodiments.

It is a block diagram which shows the structure of the radar apparatus which concerns on Embodiment 1 of this invention. It is a block diagram which shows the internal structure of the range profile identification process part 3 of FIG. It is a figure explaining operation | movement of the radar apparatus which concerns on Embodiment 1 of this invention. It is a figure explaining operation | movement of the radar apparatus which concerns on Embodiment 1 of this invention. It is a figure explaining operation | movement of the radar apparatus which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structure of the radar apparatus which concerns on Embodiment 2 of this invention. It is a block diagram which shows the internal structure of the cross range profile identification process part 13 of FIG. It is a block diagram which shows the structure of the radar apparatus which concerns on Embodiment 3 of this invention. It is a block diagram which shows the internal structure of the radar image identification process part 22 of FIG. It is a block diagram which shows the structure of the radar apparatus concerning Embodiment 4 of this invention. It is a figure explaining operation | movement of the radar apparatus which concerns on Embodiment 4 of this invention. It is a block diagram which shows the structure of the radar apparatus which concerns on Embodiment 5 of this invention. It is a figure explaining operation | movement of the radar apparatus which concerns on Embodiment 5 of this invention. It is a block diagram which shows the structure of the radar apparatus based on Embodiment 6 of this invention. It is a figure explaining operation | movement of the radar apparatus based on Embodiment 6 of this invention. It is a block diagram which shows the structure of the radar apparatus based on Embodiment 7 of this invention. It is a figure explaining operation | movement of the radar apparatus based on Embodiment 7 of this invention.

Explanation of symbols

  1, 1-1, 1-2, ..., 1-M, 11, 11-1, 11-2, ..., 11-M, 41, 41-1, 41-2, ..., 41-M, 51, 51-1, 51-2,..., 51-M Radar unit, 2 target position estimation unit, 3 range profile identification processing unit, 3a observation angle calculation unit, 3b range profile readout unit, 3c Determination unit, 4 range profile database, 12 cross range profile generation unit, 13 cross range profile identification processing unit, 13a RCS readout unit, 14 RCS database, 12 image reproduction unit, 22 radar image identification processing unit, 22a partial RCS readout unit, 33 partial RCS database, 31 feature quantity calculation unit, 32 feature quantity identification processing unit, 33 feature quantity database, 42 frequency consideration type identification processing unit, 4 Multi-frequency database 52 polarization considered type identification processor, 53 scattering matrix database, 61 a plurality of times observed determination unit.

Claims (9)

A radar device that uses a reflection intensity distribution with spatial resolution that can separate target scattering points obtained by observing the same target with multiple radar devices installed at multiple locations, and that estimates the target posture and target posture. There,
A target position estimator that estimates the position of the target using distance information to the target measured by each radar device;
A database that stores in advance the observation angle characteristics of the reflection intensity distribution of the candidate target;
Assuming the posture of the candidate target at the estimated target position, a set of reflection intensity distributions obtained by each radar device based on the data accumulated in the database is prepared, and the reflection intensity distribution that is the observation result of the arrival target is prepared. A radar apparatus comprising: an identification processing unit that estimates a model of an arrival target and a posture by comparison. The radar apparatus according to claim 1, wherein
The database previously stores the observation angle characteristics of the range profile of the candidate target as the observation angle characteristics of the reflection intensity distribution,
The identification processing unit assumes the posture of the candidate target at the estimated target position, prepares a set of range profiles obtained by each radar device, and compares it with the range profile of the incoming target, thereby comparing the model and posture of the incoming target A radar apparatus characterized by estimating The radar apparatus according to claim 1, wherein
The database previously stores observation angle characteristics of candidate target RCS (Radar Cross Section) as observation angle characteristics of the reflection intensity distribution,
The identification processing unit assumes the posture of the candidate target at the estimated target position, prepares a set of cross-range profiles obtained by each radar device, and compares it with the cross-range profile of the arrival target, thereby making the model of the arrival target A radar device characterized by estimating the attitude. The radar apparatus according to claim 1, wherein
The database previously stores the observation angle characteristics of the candidate target partial RCS (Radar Cross Section) as the observation angle characteristics of the reflection intensity distribution,
The identification processing unit assumes the posture of the candidate target at the estimated target position, prepares a set of radar images obtained by each radar device, and compares it with the radar image of the arrival target, thereby comparing the model and posture of the arrival target. A radar apparatus characterized by estimating The radar apparatus according to claim 1, wherein
The database stores in advance the observation angle characteristics of the feature quantity of the reflection intensity distribution of the candidate target as the observation angle characteristics of the reflection intensity distribution,
The identification processing unit assumes a posture of the candidate target at the estimated target position, prepares a set of feature values of the reflection intensity distribution obtained by each radar device, and compares it with the feature value of the reflection intensity distribution of the arrival target A radar device characterized by estimating the model and attitude of the arrival target. The radar apparatus according to claim 1, wherein
The plurality of radar devices transmit and receive radar signals having different frequencies,
The database accumulates the observation angle characteristic of the reflection intensity distribution corresponding to the frequency of the candidate target radar signal and the characteristic amount thereof as the observation angle characteristic of the reflection intensity distribution,
The radar apparatus according to claim 1, wherein the identification processing unit identifies a target model and estimates a posture in consideration that each radar device transmits and receives radar signals having different frequencies. The radar apparatus according to claim 1, wherein
The plurality of radar devices transmit and receive radar signals having different polarizations,
The database stores the observation angle characteristics of the scattering matrix range profile of the candidate target as the observation angle characteristics of the reflection intensity distribution,
The radar apparatus according to claim 1, wherein the identification processing unit identifies a target model and estimates a posture in consideration that each radar device transmits and receives radar signals having different polarizations. The radar device according to any one of claims 5 to 7,
The radar apparatus according to claim 1, wherein the reflection intensity distribution is any one of a range profile, a cross range profile, or a radar image having a range and a cross range as axes. The radar apparatus according to any one of claims 1 to 8,
Among the multiple identification results obtained by repeating the processes from transmission / reception at each radar device to identification at the identification processing unit multiple times, the candidate target judged as the most targeted model is the final target model A radar device, further comprising: a multiple-time observation determination unit that outputs as

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