JP2014139581A - Target speed specification device and target speed specification program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To specify velocity in a range direction of a target with high accuracy and small computational complexity.SOLUTION: A velocity specification part 8 specifies range direction velocity of a target based on a predicted velocity in a plurality of range directions inputted by a predicted velocity input part 4 and an amplitude value calculated by an amplitude value calculation part 7 from each data after azimuth compression, using velocity v, distance R, and synthetic aperture time τ of an SAR-mounted machine, and a function of amplitude value Vexpressed using predicted velocity v' of the range direction of the target.

Description

  The present invention relates to a technique for identifying the speed of a target from, for example, a SAR (Synthetic Aperture Radar) image.

Patent Document 1 describes a refocus ISAR (Inverse SAR) that specifies the speed of a target from a SAR image after azimuth compression (data after azimuth compression).
In the refocus ISAR, the data after azimuth compression is decompressed using the reference function used for azimuth compression, and is returned to the data before azimuth compression. Then, the prediction speed of the target is changed to generate a plurality of reference functions, and the data before azimuth compression is again azimuth-compressed using each of the generated reference functions to generate a plurality of data after azimuth compression. Identify the reference function that was used to obtain the clearest (large amplitude value) image data among the multiple azimuth-compressed images that were generated, and predict the target that was used to generate the reference function The speed is identified as that of the target.

JP 2007-292532 A

C. Elachi and J.H. van Zyl, Introduction to the physics and techniques of remote sensing, Hoboken, NJ: John Wiley & Sons, 2006.

In the refocus ISAR, in order to specify the speed of the target with high accuracy, it is necessary to make a calculation based on a large number of predicted speeds by reducing the variation range of the predicted speed of the target. Therefore, when the speed of the target is specified with high accuracy, the amount of calculation increases.
An object of the present invention is to specify the speed of a target with high accuracy with a small amount of calculation.

The target speed specifying device according to the present invention is:
A target speed specifying device for specifying a speed of a target observed by the SAR;
Velocity v _p of the SAR mounting machine equipped with _SAR, enter the distance R _0, after range compression data range compression for the data of the target the SAR observed by the synthetic aperture time τ between the SAR and the target in the synthetic aperture center A data input section to
As predicted velocity in the range direction, the prediction speed input unit and a target speed slower and faster than the range direction of the velocity v _r of the input by at least one of each,
Velocity of the plurality of range-based prediction rate prediction speed input unit is inputted, based on the azimuth direction of the velocity of the target, for each predicted velocity of the range direction, velocity v _p and target of the SAR mounting machine A reference function generation unit that generates a plurality of reference functions by generating a reference function obtained from a relative distance between the SAR and the target represented based on
An azimuth compression processing unit that azimuth-compresses the range-compressed data input by the data input unit and generates a plurality of azimuth-compressed data by a processing device based on each reference function of the plurality of reference functions generated by the reference function generation unit When,
An amplitude value calculating unit that calculates an amplitude value of an image of a target in each azimuth-compressed data of the plurality of azimuth-compressed data generated by the azimuth compression processing unit;
Based on the predicted speeds in a plurality of ranges input by the predicted speed input unit and the amplitude values calculated from the azimuth-compressed data by the amplitude value calculation unit, the speed v _p and the distance R _{0 of the} SAR-equipped machine are combined. A speed specifying unit that specifies the speed in the range direction of the target using a function of the amplitude value V ₀ ^vrg expressed using the opening time τ and the predicted speed v _r ′ in the range of the target. Features.

The speed specifying unit specifies the speed in the range direction of the target using the function of the amplitude value V ₀ ^vrg shown in ^Formula 1.

The predicted speed input unit, a predicted velocity in the range direction, enter the slower rate than the range direction of the velocity v _r of the target v _{r1 'and} fast speed v _r2' and,
The speed specifying unit, wherein the predicted speed input unit is in the range direction input predicted velocity v _{r1 'and} v _r2', range direction of predicted velocity v _{r1 'based} on the generated post-azimuth compression generated by the reference function The amplitude value P ₁ of the target image in the data and the amplitude value P ₂ of the target image in the azimuth-compressed data generated by the reference function generated based on the predicted speed v _r2 ′ in the range direction By substituting into, the velocity v _r of the target in the range direction is specified.

The predicted speed input unit, a predicted velocity in the range direction, and a target range direction of the velocity v _r slower rate and a faster rate of type each at least two, respectively,
The speed specifying unit, and the predicted velocity in the range direction of the velocity v is slower than _r at least two range direction of the target, at least the generated azimuth compression by two range direction prediction speed reference function that has been generated based on the respective A linear function V ₀ ^vrg = a ₁ v _r + a ₂ (where a ₁ and a ₂ are constants) is calculated from the amplitude value of the image of the target in the subsequent data by the least square method, and the range of the target is calculated. A predicted speed in at least two range directions faster than the speed v _r, and an amplitude value of the target image in the azimuth-compressed data generated by a reference function generated based on each of the predicted speeds in the at least two range directions. A linear function V ₀ ^vrg = b ₁ v _r + b ₂ (where b ₁ and b ₂ are constants) is calculated by the least square method, and the linear function V ₀ ^{v _{rg = a 1 v r + a}} 2 and characterized by identifying a linear function ^{_{V 0 vrg = b 1 v r}} + b 2 Metropolitan from range direction velocity _{v r.}

The target speed specifying device according to the present invention is:
A target speed specifying device for specifying a speed of a target observed by the SAR;
A data input unit for inputting range-compressed data obtained by performing range compression on target data observed by the SAR;
As predicted velocity in the range direction, and predicted velocity input unit for inputting at least three predicted velocity and a target speed slower and faster than the range direction of the velocity v _r of each at least one of each,
Velocity of the plurality of range-based prediction rate prediction speed input unit is inputted, based on the azimuth direction of the velocity of the target, for each predicted velocity of the range direction, velocity v _p and target of the SAR mounting machine A reference function generation unit that generates a plurality of reference functions by generating a reference function obtained from a relative distance between the SAR and the target represented based on
An azimuth compression processing unit that azimuth-compresses the range-compressed data input by the data input unit and generates a plurality of azimuth-compressed data by a processing device based on each reference function of the plurality of reference functions generated by the reference function generation unit When,
An amplitude value calculating unit that calculates an amplitude value of an image of a target in each azimuth-compressed data of the plurality of azimuth-compressed data generated by the azimuth compression processing unit;
A quadratic function V ₀ ^vrg = c ₁ by a predetermined method from the predicted speeds in the at least three range directions input by the predicted speed input unit and the amplitude values calculated from the azimuth-compressed data by the amplitude value calculation unit. Calculate v _r ² + c ₂ v _r + c ₃ (where c ₁ , c ₂ , and c ₃ are constants) and process the speed in the range direction at the bottom of the quadratic curve as the speed v _{r in the} range direction And a speed specifying unit specified by the apparatus.

The target speed specifying program according to the present invention includes:
A target speed specifying program for specifying the speed of a target observed by the SAR;
Velocity v _p of the SAR mounting machine equipped with _SAR, enter the distance R _0, after range compression data range compression for the data of the target the SAR observed by the synthetic aperture time τ between the SAR and the target in the synthetic aperture center Data entry processing to
As predicted velocity in the range direction, the predicted speed input processing and target range direction of the velocity v _r slower rate and a faster rate of inputting one by at least one of each,
Velocity of the plurality of range-based prediction rate entered on predicted velocity input process, based on the azimuth direction of the velocity of the target, for each predicted velocity of the range direction, velocity v _p and target of the SAR mounting machine A reference function generation process for generating a plurality of reference functions by generating a reference function obtained from a relative distance between the SAR and the target represented based on
Based on each reference function of the plurality of reference functions generated in the reference function generation processing, azimuth compression processing to generate a plurality of azimuth compressed data by azimuth compressing the range-compressed data input in the data input processing,
An amplitude value calculation process for calculating an amplitude value of an image of a target in each azimuth-compressed data of the plurality of azimuth-compressed data generated by the azimuth compression process;
Based on the predicted speeds in the plurality of range directions input in the predicted speed input process and the amplitude values calculated from the respective azimuth-compressed data in the amplitude value calculation process, the speed v _p and the distance R _{0 of the} SAR-equipped machine are combined. ^Using a function of the amplitude value V ₀ ^vrg expressed using the opening time τ and the predicted speed v _r ′ of the target in the range direction, a speed specifying process for specifying the speed in the range direction of the target is executed on the computer It is characterized by making it.

In the speed specifying process, the range direction speed of the target is specified using a function of the amplitude value V ₀ ^vrg shown in ^Equation 3.

The predicted speed input processing, as the predicted rate in the range direction, enter the slower rate than the range direction of the velocity v _r of the target v _{r1 'and} fast speed v _r2' and,
Wherein a rate specific process, the a predicted velocity in the range direction inputted by the input processing predicted velocity v _{r1 'and} v _r2', range direction of predicted velocity v _{r1 'based} on the generated post-azimuth compression generated by the reference function The amplitude value P ₁ of the target image in the data and the amplitude value P ₂ of the target image in the azimuth-compressed data generated by the reference function generated based on the predicted speed v _r2 ′ in the range direction substituting the result, and identifies the range direction of the velocity v _r of the target.

The predictive speed input processing, as the predicted rate in the range direction, and a target range direction of the velocity v _r slower rate and a faster rate of type each at least two, respectively,
Wherein a rate specific process, and predicted velocity in the range direction of the velocity v is slower than _r at least two range direction of the target, at least the generated azimuth compression by two range direction prediction speed reference function that has been generated based on the respective A linear function V ₀ ^vrg = a ₁ v _r + a ₂ (where a ₁ and a ₂ are constants) is calculated from the amplitude value of the image of the target in the subsequent data by the least square method, and the range of the target is calculated. A predicted speed in at least two range directions faster than the speed v _r, and an amplitude value of the target image in the azimuth-compressed data generated by a reference function generated based on each of the predicted speeds in the at least two range directions. by the least squares method _(wherein, b 1, _{b 2} are constants) a linear function ^{_{V 0 vrg = b 1 v r}} + b 2 calculates a primary function V ^{_{vrg = a 1 v r + a}} 2 and characterized by identifying a linear function ^{_{V 0 vrg = b 1 v r}} + b 2 Metropolitan from range direction velocity _{v r.}

The target speed specifying program according to the present invention includes:
A target speed specifying program for specifying the speed of a target observed by the SAR;
A data input process for inputting range-compressed data obtained by subjecting the target data observed by the SAR to range compression;
A predicted speed input process for inputting at least three predicted speeds each including at least one of a speed slower than a speed v _r of the target in the range direction and a speed higher than the target speed in the range direction;
Velocity of the plurality of range-based prediction rate entered on predicted velocity input process, based on the azimuth direction of the velocity of the target, for each predicted velocity of the range direction, velocity v _p and target of the SAR mounting machine A reference function generation process for generating a plurality of reference functions by generating a reference function obtained from a relative distance between the SAR and the target represented based on
Based on each reference function of the plurality of reference functions generated in the reference function generation processing, azimuth compression processing to generate a plurality of azimuth compressed data by azimuth compressing the range-compressed data input in the data input processing,
An amplitude value calculation process for calculating an amplitude value of an image of a target in each azimuth-compressed data of the plurality of azimuth-compressed data generated by the azimuth compression process;
A quadratic function V ₀ ^vrg = c ₁ by a predetermined method from the predicted speed in the at least three range directions input in the predicted speed input process and the amplitude value calculated from each azimuth-compressed data in the amplitude value calculation process. Calculate v _r ² + c ₂ v _r + c ₃ (where c ₁ , c ₂ , and c ₃ are constants) and specify the speed in the range direction at the bottom of the quadratic curve as the speed v _{r in the} range direction And causing the computer to execute a speed specifying process.

In the target object speed specifying device according to the present invention, the speed of the target object in the range direction is specified using a function of the amplitude value V ₀ ^vrg . Thereby, the speed of the target in the range direction can be specified with a small amount of calculation.

Obtained from Expression 20, shown predicted velocity v _a of the azimuth direction of a target _'and the relationship between the amplitude V ₀ ^vaz FIG. FIG. 4 is a functional block diagram illustrating functions of a target speed identification device 1 according to a second embodiment. 9 is a flowchart showing the operation of the target speed identification device 1 according to the second embodiment. 9 is a flowchart showing the operation of the target speed identification device 1 according to the second embodiment. Obtained from Equation 22, shown predicted velocity v _r of the azimuth direction of a target _'and the relationship between the amplitude V ₀ ^VRG FIG. FIG. 6 is a functional block diagram showing functions of a target speed identification device 1 according to a third embodiment. 10 is a flowchart showing the operation of the target speed identification device 1 according to the third embodiment. The figure showing the state which plotted the amplitude value calculated from the estimated speed of a range direction. Explanatory drawing of the integration range of the integral part A (Formula 28) in Formula 27. FIG. Explanatory drawing of "τ- | t-t _R |". Explanatory drawing of the integration range of the integral part B (Formula 36) in Formula 35. FIG. The relative distance _R r of the equation 54 (t), shows the relative distance R (t), the relative distance _R s (t). The figure which shows an example of the hardware constitutions of the target object speed specific | specification apparatus 1. FIG.

Hereinafter, embodiments of the invention will be described with reference to the drawings.
In the following description, the processing device is a CPU 911 or the like which will be described later. The storage device is a storage device such as a ROM 913, a RAM 914, or a magnetic disk 920, which will be described later. The input device is a keyboard 902, a mouse 903, and the like which will be described later. That is, the processing device, the storage device, and the input device are hardware.

Embodiment 1 FIG.
In the first embodiment, a mathematical expression of a matched filter (a function of an amplitude value) at the time of azimuth compression assuming that the target is moving in the azimuth direction and the case where the target is moving in the range direction is briefly described. To do.

  In the SAR image reproduction process, generally, a received signal obtained by SAR is range-compressed and azimuth-compressed to generate image data. Range compression and azimuth compression are processes for calculating an amplitude value (voltage) by inputting a reference function and a received signal to a matched filter.

ここで、Ｖ_０は、振幅値である。ｔは、時刻である。Ｖは、参照関数である。^＊は、複素共役を示す。Ｖ_ｒは、受信信号である。ξは、積分のオペレータ（積分作用素）である。 The matched filter is expressed by Equation 11.

Here, V ₀ is an amplitude value. t is the time. V is a reference function. ^{* Indicates} a complex conjugate. _Vr is a received signal. ξ is an integration operator (integration operator).

ここで、Ｖ_０ ^ａｚは、振幅値である。ｔは、時刻である。Ａ（ｔ）は、−τ／２≦ｔ≦τ／２であれば１、他の場合には０となる関数である。なお、τは、合成開口時間である。ｊは、虚数単位である。λは、ＳＡＲから放射される電波の波長である。Ｒ（ｔ）は、時刻ｔにおけるＳＡＲと目標物との相対距離である。 The reference function for azimuth compression is generally expressed by Equation 12.

Here, V ₀ ^az is an amplitude value. t is the time. A (t) is a function that is 1 if −τ / 2 ≦ t ≦ τ / 2, and 0 in other cases. Note that τ is a synthetic aperture time. j is an imaginary unit. λ is the wavelength of the radio wave emitted from the SAR. R (t) is a relative distance between the SAR and the target at time t.

数１３では、簡単のため、各速度を定数成分のみ、すなわち等速直線運動と仮定している。一般に車両や船等の運動は等速直線運動が支配的であるため、車両や船等の速度を扱う場合に、この仮定は妥当である。なお、目標物のレンジ方向の速度には、地球の自転の速度等を含めて考えてもよい。また、ＳＡＲ搭載機の移動方向がアジマス方向であるため、ＳＡＲ搭載機の速度とは、ＳＡＲ搭載機のアジマス方向の速度である。
すると、ＳＡＲと目標物との相対距離Ｒ（ｔ）を数１４のように表すことができる。

ここで、Ｒ_０は、合成開口中心におけるＳＡＲと目標物との距離である。また、ａ_０，ａ_１，ａ_２は数１５に示す通りである。

The speed v _{r in} the range direction of the target, the speed v _{a in the} azimuth direction, and the speed v _P of the SAR-equipped machine can be defined as shown in Equation 13, respectively.

In Equation 13, for the sake of simplicity, each speed is assumed to be a constant component only, that is, a constant-velocity linear motion. In general, constant velocity linear motion is dominant in the movement of vehicles, ships, etc., so this assumption is valid when dealing with the speed of vehicles, ships, etc. Note that the speed of the target in the range direction may include the speed of rotation of the earth. Further, since the moving direction of the SAR-equipped machine is the azimuth direction, the speed of the SAR-equipped machine is the speed of the SAR-equipped machine in the azimuth direction.
Then, the relative distance R (t) between the SAR and the target can be expressed as in Expression 14.

Here, R ₀ is the distance between the SAR and the target at the center of the synthetic aperture. Further, a ₀ , a ₁ , and a ₂ are as shown in Equation 15.

By using Equation 14, the reference function for azimuth compression shown in Equation 12 is as shown in Equation 16 because only the term related to t in Equation 14 is important.

Similarly to the reference function for azimuth compression, the received signal V _r (t) can also be expressed as in Expression 17. Note that the received signal is an expression different from the reference function in that the received signal includes a scale factor α determined by signal attenuation, scattering intensity, and the like.

  Consider a case where a target imaged by SAR is moving. In this case, the target speed in the reference function may not match the target speed in the received signal. Therefore, the speed of the target in the reference function and the speed of the target in the received signal are expressed using different variables.

そして、参照関数における目標物のアジマス方向の速度は予測速度ｖ_ａ’であり、受信信号における目標物のアジマス方向の速度は真の速度ｖ_ａであるとする。すると、数１６に示す参照関数は、数１９のようになる。なお、受信信号は数１７に示すままである。

First, consider a case where the speed of the target in the azimuth direction is different. Here, for simplicity, it is assumed that the speed of the target in the range direction is the same.
As shown in Equation 15, the speed _{v a} azimuth direction of the _target, of _{a 0, a 1, a 2} , it contained only in _{a 2.} Therefore, the true azimuth direction of velocity of the target to v _{a, 'as} predicted velocity azimuth direction of target, as in equation 18 a _2' v a to define.

Then, it is assumed that the speed of the target in the azimuth direction in the reference function is the predicted speed v _a ′, and the speed of the target in the azimuth direction in the received signal is the true speed v _a . Then, the reference function shown in Equation 16 is as shown in Equation 19. The received signal remains as shown in Equation 17.

ここで、ｊは、虚数単位である。ｐは、積分のオペレータである。 The reference function _V ^{0 az} complex conjugate of of the equation 19 and ^{V *,} as a received signal _{V r} received signal _{V r} of the equation 17 and by substituting the matched filter indicated in Formula 11 to Formula deformation, the number 20 is obtained It is done. A method for deriving Equation 20 will be described in a later embodiment.

Here, j is an imaginary unit. p is an operator of integration.

Next, consider a case where the speeds of the targets in the range direction are different. Here, for the sake of simplicity, it is assumed that the speed of the target in the azimuth direction is the same.
As shown in Formula 15, the range direction of the velocity _{v r} of the _target, of _{a 0, a 1, a 2} , contained only in _{a 1.} Therefore, a ₁ ′ = v _r ′ is defined where v _r is the speed of the target in the true range direction and v _r ′ is the predicted speed of the target in the range direction.
Then, it is assumed that the speed in the range direction of the target in the reference function is the predicted speed v _r ′, and the speed in the range direction of the target in the received signal is the true speed v _r . Then, the reference function shown in Equation 16 is as shown in Equation 21. The received signal remains as shown in Equation 17.

The reference function _V ^{0 az} complex conjugate of of the equation 21 and ^{V *,} as a received signal _{V r} received signal _{V r} of the equation 17 and by substituting the matched filter indicated in Formula 11 to Formula deformation, the number 22 is obtained It is done. A method for deriving Equation 22 will be described in a later embodiment.

  By obtaining Equations 20 and 22, it is possible to specify the speed of the target with high accuracy with a small amount of calculation.

Embodiment 2. FIG.
In the second embodiment, a method for efficiently specifying the speed of the target in the azimuth direction with a small amount of calculation based on Equation 20 will be described.

In the refocus ISAR, the speed of the target can be specified with higher accuracy as the change width of the predicted speed of the target when generating a plurality of reference functions for azimuth compression is reduced. On the other hand, the amount of calculation increases as the range of change in the predicted speed of the target decreases.
Heretofore, when specifying the speed of a target using the refocus ISAR, it has not been possible to obtain a guideline indicating how much the range of change in the predicted speed of the target should be. However, by using Equation 20, it is possible to determine the amount of change in the predicted speed of the target when the target speed is identified using the refocus ISAR.

Figure 1 is obtained from the number 20 is a diagram showing the relationship between the azimuth direction and the predicted velocity v _{a 'and} the amplitude value V ₀ ^vaz of the target. In Figure 1, taking the predicted velocity of the azimuth direction of a target v _{a 'on} the horizontal axis, taking the amplitude value V ₀ ^vaz vertical axis.
In FIG. 1, the maximum value of the amplitude value V ₀ ^vaz is normalized to 1. Moreover, the true velocity v _a of the azimuth direction of a target is set to 0. In FIG. 1, the speed V _p of the SAR-equipped machine on which the SAR is mounted, the distance R ₀ between the SAR and the target at the center of the synthetic aperture, the wavelength λ of the radio wave emitted from the SAR, and the synthetic aperture time τ Value.
In the following description, the positive azimuth direction speed is the speed in the traveling direction of the SAR-equipped machine, and the negative azimuth direction speed is the speed in the direction opposite to the traveling direction of the SAR-equipped machine. The positive range direction speed is a speed in the range direction away from the SAR, and the negative range direction speed is a speed in the range direction approaching the SAR.

Here, also the true velocity v _a of the azimuth direction of a target as any value other than 0, the shape of the graph shown in FIG. 1 does not change, only the graph is parallel moved in the horizontal direction. That is, the shape of the graph is determined if the speed V _p , the distance R ₀ , the radio wave wavelength λ, and the synthetic aperture time τ are determined. The speed V _p , distance R ₀ , radio wave wavelength λ, and synthetic aperture time τ of the SAR-equipped machine are SAR image observation conditions, and are information that is determined at the time of capturing the SAR image. Therefore, as shown in FIG. 1, a graph of the true velocity v _a of the azimuth direction of a target as an arbitrary value, showed predicted velocity v _a of the azimuth direction of a target _'and the relationship between the amplitude V ₀ ^vaz Draw.
Then, arbitrarily selecting a large amplitude V _a than the amplitude value V ₂ of the maximum amplitude value is high mountain M ₂ to the second top T ₂ in graph depicting. For example, here, to select the amplitude value of 0.5 is half of the maximum value as _{V a.} In graph depicting, to identify the range of expected velocity v _{a 'of} the amplitude values becomes equal to or greater than the amplitude value V _a selected, identifying the velocity width Delta] v _a.
When the reference function is generated by changing the predicted speed of the target with the speed width Δva as _a step size (change width), the azimuth compression is performed based on at least one (at most two) reference functions. The amplitude value is V _a or more.
Here, for example, an amplitude value is equal to or greater than V _a at the predicted velocity v _x. Then, it can be seen that the speed of the target is in the speed range of Δv _a / 2 before and after the predicted speed v _x . In other words, by generating the reference functions by changing the predicted velocity of the target as the stride the velocity width Delta] v _a, it is possible to narrow the speed range of the target to the speed width Delta] v _a.
Then, with respect to the narrowed speed range, the predicted speed is changed with a fine step size, a reference function is generated, and the speed of the target is specified with high accuracy.

FIG. 2 is a functional block diagram illustrating functions of the target velocity specifying apparatus 1 according to the second embodiment.
The target speed specifying device 1 includes a data input unit 2, a step size specifying unit 3, a predicted speed input unit 4, a reference function generating unit 5, an azimuth compression processing unit 6, an amplitude value calculating unit 7, and a speed specifying unit 8. The predicted speed input unit 4, the reference function generation unit 5, the azimuth compression processing unit 6, the amplitude value calculation unit 7, and the speed specification unit 8 are referred to as a specific process execution unit.

  3 and 4 are flowcharts showing the operation of the target velocity specifying apparatus 1 according to the second embodiment. The operation of the target speed identification device 1 is roughly divided into two stages. The first stage is the process shown in FIG. 3, which is a range limiting process for narrowing down the speed range of the target. The second stage is the process shown in FIG. 4, which is a speed determination process for determining the speed of the target in the narrowed speed range.

The range limiting process will be described.
(S1: Data input process)
The data input unit 2 inputs range-compressed data (image information after range compression) obtained by performing range compression on the target data observed by the SAR, and stores the data in the storage device.
Here, the data input unit 2 is the observation information when the target is imaged, from the speed V _p of the SAR-equipped machine equipped with the SAR, the distance R ₀ between the SAR and the target at the center of the synthetic aperture, and the SAR. The wavelength λ of the emitted radio wave and the synthetic aperture time τ are also input.
The range-compressed data may be data generated by azimuth decompression (inverse calculation of azimuth compression) using the reference function used when azimuth compression is performed on the data after azimuth compression.

(S2: step size specifying process)
Stride specifying unit 3, the speed _{V p} of the SAR mounting machine entered on (S1), the distance _{R 0,} the wavelength of the radio wave lambda, and synthetic aperture time tau, several 20., speed width as described above Delta] v _a ( Hereinafter, Δv _a1 ) is calculated by the processing device as a step size.
Stride specifying unit 3, the speed V _p of the SAR mounting _machine, the distance R _0, the wavelength of the radio wave lambda, and synthetic aperture time tau, by substituting the number 20 and a velocity v _a of any azimuth direction, step size May be calculated. Further, the step size specifying unit 3 may draw a graph and calculate the step size from the drawn graph as described with reference to FIG.

(S3: Predictive speed input process)
The predicted speed input unit 4 inputs the predicted speed in the range direction and the predicted speeds in the plurality of azimuth directions for the target by the processing device and stores them in the storage device.
The predicted speed input unit 4 arbitrarily inputs one of the predicted speeds in the range direction that can be taken by the target. On the other hand, predicted velocity input unit 4, the prediction rate azimuthal inputs the predicted speed at specified every stride Delta] v _a1 has the velocity range considered target is possible by (S2).
In addition, what is necessary is just to determine the speed range considered that a target can take by target targets, such as a ship and a vehicle. For example, if the target has a speed of 100 km / h, the speed range that the target can take is ± 100 km / h. Therefore, in this case, the predicted speed input unit 4 inputs one appropriate speed within the range of ± 100 km / h as the predicted speed in the range direction. For example, if the step size is 20 km / h, the predicted speed input unit 4 inputs a speed within a range of ± 100 km / h as a predicted speed in the azimuth direction every 20 km / h. That is, for example, the predicted speed input unit 4 inputs −100, −80, −60,..., +60, +80, +100 km / h as the predicted speed in the azimuth direction.

(S4: Reference function generation process)
The reference function generation unit 5 uses the processing device to generate a reference function (see, for example, Equation 16) for each predicted speed in the azimuth direction based on the predicted speed in the range direction and the predicted speed in the plurality of azimuth directions input in (S3). Generate. Thereby, a plurality of reference functions are generated.

(S5: Azimuth compression processing)
The azimuth compression processing unit 6 performs azimuth compression on the range-compressed data input in (S1) based on each reference function generated in (S4), and generates a plurality of azimuth-compressed data by the processing device.

(S6: Amplitude value calculation processing)
The amplitude value calculator 7 calculates the amplitude value of the target image in each post-compression data generated in (S5) by the processing device.

(S7: Speed specifying process)
The speed specifying unit 8 specifies the reference function used for generating the azimuth-compressed data having the maximum amplitude value of the target image calculated in (S6) by the processing device. Furthermore, the speed specifying unit 8 specifies the predicted speed in the azimuth direction used when generating the specified reference function by the processing device. Then, the speed specifying unit 8 specifies the range of Δv _a1 / 2 before and after the specified predicted speed as the speed range of the target in the azimuth direction.

The speed determination process will be described.
(S8: Predictive speed input process)
Predicted velocity input unit 4 stores the specified speed range, the input to the storage device by the input device a predicted velocity of a plurality of azimuth directions every narrower stride Delta] v _a2 than step size Delta] v _a1 in (S7).
Stride Delta] v _a2 may be determined depending on whether you want to identify the speed of the target at any degree of accuracy. For example, step width Δv _a2 is a 1km / h and 0.1km / h or the like.

(S9: Reference function generation process)
Based on the predicted speed in the range direction input in (S3) and the predicted speed in the plurality of azimuth directions input in (S8), a processing function is used for each predicted speed in the azimuth direction (see, for example, Expression 16). Generate by. Thereby, a plurality of reference functions are generated.
(S10: Azimuth compression processing)
The azimuth compression processing unit 6 performs azimuth compression on the range-compressed data input in (S1) based on each reference function generated in (S9), and generates a plurality of azimuth-compressed data by the processing device.

(S11: Amplitude value calculation process)
The amplitude value calculator 7 calculates the amplitude value of the image of the target in each post-compression data generated in (S10) by the processing device.

(S12: Speed specifying process)
The speed specifying unit 8 specifies the reference function used for generating the azimuth-compressed data having the maximum amplitude value of the target image calculated in (S11) by the processing device. And the speed specific | specification part 8 specifies the predicted speed of the azimuth direction used when producing | generating the specified reference function as a speed of the target in the azimuth direction by a processing apparatus.

As described above, in the target speed specifying apparatus 1 according to the second embodiment, by using Equation 20, the predicted target speed is used to specify the target speed using the refocus ISAR. The width can be determined.
In particular, the target velocity specifying apparatus 1 according to the second embodiment narrows down the velocity range of the target in the azimuth direction by performing a coarse-accurate search using the coarse step width determined based on Equation 20. Then, only the narrowed range is searched with high precision and with a small step size, and the speed of the target in the azimuth direction is specified with the same level of accuracy as when high-precision search is performed for the entire range. be able to. That is, it is possible to specify the speed with high accuracy with a small amount of calculation.

In the above description, the predicted speed in the range direction input in (S3) is one. This is because the shape of the graph drawn by Equation 20 is not affected by the speed in the range direction, and it is sufficient for the predicted speed in the range direction to be one arbitrary speed.
However, due to the influence of noise or the like, it may be impossible to specify an accurate speed depending on the predicted speed in the direction of the direction input in (S3). Therefore, predicted speeds in a plurality of range directions may be input in (S3), and a reference function may be generated for each speed in each azimuth direction and in each range direction in (S4) and (S9). In (S6) and (S11), the amplitude value of the target in the image data after azimuth compression generated based on each reference function is calculated, and the average value is calculated for each predicted velocity in the azimuth direction for the calculated amplitude value. You may calculate.
As a result, the influence of noise or the like that has an influence on a signal in a part of the range direction speed is reduced, and the speed specifying accuracy can be increased.

Embodiment 3 FIG.
In the third embodiment, a method for efficiently specifying the range-direction speed of the target with a small amount of calculation will be described based on Equation 22.

Figure 5 is obtained from Equation 22 is a diagram showing the relationship between the azimuth direction and the predicted velocity v _{r 'and} the amplitude value V ₀ ^VRG of the target. In FIG. 5, the horizontal axis represents the predicted speed v _r ′ of the target in the range direction, and the vertical axis represents the amplitude value V ₀ ^vrg .
In FIG. 5, the maximum value of the amplitude value V ₀ ^vrg is normalized to 1. Moreover, the true velocity v _r in the range direction of a target is set to 0. In FIG. 1, the speed V _p of the SAR-equipped machine on which the SAR is mounted, the distance R ₀ between the SAR and the target at the center of the synthetic aperture, the wavelength λ of the radio wave emitted from the SAR, and the synthetic aperture time τ Value.

そして、数２３から数２４が得られる。

数２４において、αは、任意に設定される値であり、ＳＡＲ搭載機の速度ｖ_Ｐと距離Ｒ_０と合成開口時間τとは、ＳＡＲ画像の観測条件であるため、予め分かっている。そのため、予測速度ｖ_ｒ１’、振幅値をＰ_１、予測速度ｖ_ｒ２’、振幅値Ｐ_２が分かれば、数２４に基づき、目標物の真のレンジ方向速度ｖ_ｒを計算することができる。 As can be seen from Equation 22, and FIG. 5, the number 22 is the amplitude value V ₀ ^VRG is the maximum value when the predicted velocity of the target v _{r 'is} the true range direction velocity v _r of the target, the absolute value Is a linear function including
Therefore, (in FIG. 5, the predicted velocity v _{r 'is} negative side) true range direction velocity v slow side linear function than _r of the target in the fast side linear function (Fig. 5, predicted velocity v r _'by simultaneous equations become side) and positive, determine the true range direction velocity v _r of the target amplitude value V ₀ ^VRG is maximized. For example, if the amplitude value of the predicted speed v _r1 ′ in FIG. 5 is P ₁ and the amplitude value P ₂ of the predicted speed v _r2 ′, the amplitude values P ₁ and P ₂ can be expressed as shown in Equation 23. It should be _noted that v _r1 '<v _r <v _r2 '.

Then, Expression 23 to Expression 24 are obtained.

In Expression 24, α is a value that is arbitrarily set, and the speed v _P , the distance R _0, and the synthetic aperture time τ of the SAR-equipped device are known in advance because they are SAR image observation conditions. Therefore, if the predicted speed v _r1 ′, the amplitude value P ₁ , the predicted speed v _r2 ′, and the amplitude value P ₂ are known, the true range-direction speed v _r of the target can be calculated based on Expression 24.

  FIG. 6 is a functional block diagram showing functions of the target velocity specifying apparatus 1 according to the third embodiment. The target speed specifying device 1 shown in FIG. 6 has the same configuration as the target speed specifying device 1 shown in FIG. 2 except that the step size specifying unit 3 is not provided.

FIG. 7 is a flowchart showing the operation of the target velocity specifying apparatus 1 according to the third embodiment.
(S21: Data input process)
As in (S1) of FIG. 3, the data input unit 2 inputs the range-compressed data obtained by performing range compression on the target data observed by the SAR, and stores the data in the storage device.

(S22: Predictive speed input process)
The predicted speed input unit 4 inputs the predicted speed in the two range directions and the speed in the azimuth direction of the target by the processing device and stores them in the storage device.
The predicted speed input unit 4 inputs a speed v _r1 ′ that is slower than the true speed v _r and a higher speed v _r2 ′ one by one for the predicted speed in the range direction. Note that the slower speed than the true velocity v _r, is that the value of speed is smaller speed than the true velocity v _r. For example, if the true velocity _{v r} is 0 km / h, a small -10km / h and -50km / h or the like than 0. On the other hand, the speed higher than the true velocity v _r, is the value of the rate of speed greater than the true velocity v _r. For example, if the true velocity _{v r} is 0km / h, it is a great 10km / h and 50km / h, etc. than 0. The slow speed and a faster rate than the true velocity _{v r,} for example, the rate of possible target is if ± 100km / h, it once as a ± 150 km / h.
The predicted speed input unit 4 inputs the speed specified by the method of the second embodiment or the like for the speed in the azimuth direction. As for the speed in the azimuth direction, one arbitrary predicted speed may be input, but it is preferable to input an accurate speed.

(S23: Reference function generation process)
The reference function generation unit 5 generates a reference function (see, for example, Equation 16) for each predicted speed in the range direction based on the two predicted speeds in the range direction and the speed in the azimuth direction input in (S22). To do. As a result, two reference functions are generated.

(S24: Azimuth compression processing)
The azimuth compression processing unit 6 performs azimuth compression on the range-compressed data input in (S21) based on each reference function generated in (S23), and generates two azimuth-compressed data by the processing device.

(S25: Amplitude value calculation process)
The amplitude value calculation unit 7 calculates the amplitude value of the target image in each of the two azimuth-compressed data generated in (S24) by the processing device. Thereby, the amplitude values P ₁ and P ₂ are calculated.

(S26: Speed specifying process)
The speed specifying unit 8 calculates the speed v _p , the distance R ₀ and the synthetic opening time τ input in (S21), the speed v _r1 ′ and the speed v _r2 ′ input in (S22), and (S25). Substituting the amplitude values P ₁ and P ₂ calculated in ( ₁ ) above, the true velocity v _r is calculated by the processing device.

  As described above, in the target velocity specifying apparatus 1 according to the third embodiment, by using Equation 22, only the image data after azimuth compression is generated based on the two predicted velocities, and the range of the target is determined. The speed can be specified. That is, the speed can be specified with a small amount of calculation.

In the above description, the prediction rate in the range direction at (S22), and enter one and slow speed and a faster rate than the true velocity v _r, a linear function of the slower side than the true velocity v _r and by coalition a primary function of the fast side than the true velocity v _r to determine the true velocity v _r.
However, when the predicted speed in the range direction and the amplitude value calculated from the predicted speed are plotted due to the influence of noise or the like, it does not become a clean linear function as shown in FIG. 5, but as shown in FIG. May vary. Therefore, it may be input and the true velocity v 2 or more speed slower than _r and fast two or more speeds as predicted speed (S22). Then, the true velocity v _r 2 or more speed slower than from an amplitude value calculated from each of these speeds, the true velocity v a linear function of slower than _r side ^V ₀ vrg ⁼ a ₁ v _r + A ₂ (where a ₁ and a ₂ are constants) is calculated by the least square method or the like. Similarly, from two or more speeds faster than the true speed v _r and the amplitude value calculated from each of these speeds, a linear function V ₀ ^vrg = b ₁ v on the faster side than the true speed v _r is ^obtained. _r + b ₂ (where b ₁ and b ₂ are constants) is calculated by the least square method or the like. Thereby, each linear function can be specified more accurately. The true velocity v _r may be calculated by combining the two specified linear functions.

It is also possible to input at least one comprises one by three or more predicted speed and slow speed and a faster rate than the true velocity v _r in (S22). Then, a quadratic function V ₀ ^vrg = c ₁ v _r ² + c ₂ v _r + c ₃ (where c ₁ , c ₂ , and c ₃ are constants) by least square method or spline interpolation from three or more predicted speeds. And the predicted speed at the bottom of the calculated quadratic function may be specified as the true speed v _r .

Incidentally, when obtaining the true velocity v _r, as the difference between the amplitude value in the possible speed range of the target is large, it is possible to reduce the error due to the influence of noise or the like. For example, in FIG. 5, the amplitude value in the speed range ± 100 km / h is approximately 0.84 to 1, that is, the difference between the amplitude values is 0.16. A small difference in amplitude value in the speed range means that the slope of the linear function is gentle. Therefore, a large error occurs in the specified speed just by including a little error in the amplitude value due to noise or the like.
Therefore, the SAR-equipped machine may be designed so that the difference between the amplitude values in the speed range is large, that is, the slope of the linear function is steep. Specifically, in order to make the slope of the linear function steep, R ₀ may be designed to be large and v _P to be small so that the value of R ₀ / v _P ² in Equation 22 is large.

Embodiment 4 FIG.
In the fourth embodiment, a method for deriving Equation 20 and Equation 22 will be described.

Equations 20 and 22 are both equations for azimuth compression. Here, the range compression and the azimuth compression are the same in that the amplitude value (voltage) is calculated by inputting the reference function and the received signal to the matched filter.
Therefore, in the fourth embodiment, first, as a reference, first, range compression will be described (see Non-Patent Document 1). Second, azimuth compression, which is the main subject, will be described. In particular, as 2-1 will be described a case where there is no difference between the true speed of the target and the predicted speed. As 2-2, the case where there is a difference between the true speed of the target in the azimuth direction and the predicted speed will be described. As a 2-3, a case where there is a difference between the true speed in the range direction of the target and the predicted speed will be described. Thirdly, as a summary, Equation 20 is derived from the result 2-2, and Equation 22 is derived from the result 2-3.

ここで、Ｖは、振幅値である。ｔは、時刻である。Ａ（ｔ）は、−τ／２≦ｔ≦τ／２であれば１、他の場合には０となる関数である。なお、τは、合成開口時間である。ｊは、虚数単位である。ｆ_ｃは、中心周波数である。Ｋは、チャープ率である。αは、スケールファクタである。ｔ_Ｒは、ＳＡＲから送信された信号が目標物で反射して戻るまでの遅延時間である。 <First. Range compression>
As described in the first embodiment, the matched filter is expressed by Equation 11. Further, the reference function V (t) for range compression is expressed as in Expression 25, and the received signal V _r (t) is expressed as in Expression 26.

Here, V is an amplitude value. t is the time. A (t) is a function that is 1 if −τ / 2 ≦ t ≦ τ / 2, and 0 in other cases. Note that τ is a synthetic aperture time. j is an imaginary unit. f _c is the center frequency. K is the chirp rate. α is a scale factor. t _R is a delay time until the signal transmitted from the SAR is reflected by the target and returned.

The complex conjugate of the reference function V indicating the number 25 and V ^*, as a received signal V _r received signal V _r of the equation 26 and substituting the matched filter shown in Expression 11, the number 27.

ｔ_Ｒ≧ｔの場合、数２８は数２９のように計算される。

一方、ｔ_Ｒ＜ｔの場合、数２８は数３０のように計算される。

つまり、ｔ_Ｒ≧ｔとｔ_Ｒ＜ｔとのどちらの場合も結果は同じになる。したがって、数２７を数３１のように変換できる。なお、数３１はｓｉｎｃ関数である。

FIG. 9 is an explanatory diagram of the integration range of the integration part A (Equation 28) in Equation 27. As shown in FIG. 9, Equation 28 is calculated in two cases of t _R ≧ t and t _R <t.

When t _R ≧ t, Equation 28 is calculated as Equation 29.

On the other hand, when t _R <t, Equation 28 is calculated as Equation 30.

That is, the result is the same in both cases of t _R ≧ t and t _R <t. Therefore, Expression 27 can be converted into Expression 31. Equation 31 is a sinc function.

そして、一般的なＳＡＲシステムでは、参照関数と受信信号とは大部分で相関するため、｜ｔ_０−ｔ_Ｒ｜はτに比べて非常に小さい（｜ｔ_０−ｔ_Ｒ｜＜＜τ）。そのため、数３２を数３３のように変換できる。

The physical interpretation of “τ− | t−t _R |” will be described.
FIG. 10 is an explanatory diagram of “τ− | t−t _R |”. As shown in FIG. 10, τ− | t−t _R | represents the degree of correlation between the reference function and the received signal. Unlike a received signal that is an observation amount, the reference function can arbitrarily determine its start and end times. Therefore, once the correlation amount of the SAR system is set, the correlation amount does not change depending on the position of the focal point t at “| t−t _R |”, so “τ− | t−t _R |” is treated as a constant. Can do. That is, “t” in “τ− | t−t _R |” can be considered separately from time t.
Therefore, by setting “t” in “τ− | t−t _R |” to “t ₀ ”, the equation 31 can be converted into the equation 32.

In a general SAR system, since the reference function and the received signal are mostly correlated, | t ₀ -t _R | is very small compared to τ (| t ₀ -t _R | << τ). . Therefore, Expression 32 can be converted into Expression 33.

なお、受信信号にはａ_０の項の成分が含まれるため、数１７に示す受信信号からはａ_０の項を除かず、そのままとする。 <Second. Azimuth compression>
<2-1. When there is no difference between the true speed of the target and the predicted speed>
The calculation proceeds in the same flow as in the first description.
As described in the first embodiment, the matched filter is expressed by Equation 11. Further, the reference function for azimuth compression is expressed as in Expression 16, and the received signal is expressed as in Expression 17.
Here, the term a _{0 in} the reference function shown in Expression 16 is independent from the time t, and is not important in the matched filter. Therefore, by removing the section a ₀ in the reference function shown in Equation 16, the number 34 is obtained.

Note that the received signal for which the component is included in the term of a _0, from the received signal shown in Equation 17 without removing the section a _0, and it is.

The complex conjugate of the reference function ^{V az} shown in formula 34 and ^{V *,} as a received signal _{V r} received signal _{V r} of the equation 17 and substituting the matched filter shown in Expression 11, the number 35.

０≧ｔの場合、数３６は数３７のように計算される。

一方、０＜ｔの場合、数３６は数３８のように計算される。

つまり、０≧ｔと０＜ｔとのどちらの場合も結果は同じになる。したがって、数３５を数３９のように変換できる。

FIG. 11 is an explanatory diagram of the integration range of the integration portion B (Equation 36) in Equation 35. As shown in FIG. 11, Equation 36 is calculated separately for two cases of 0 ≧ t and 0 <t.

When 0 ≧ t, Expression 36 is calculated as Expression 37.

On the other hand, when 0 <t, Expression 36 is calculated as Expression 38.

That is, the result is the same in both cases of 0 ≧ t and 0 <t. Therefore, Expression 35 can be converted into Expression 39.

そして、一般的なＳＡＲシステムでは、参照関数と受信信号とは大部分で相関するため、｜ｔ_０｜はτに比べて非常に小さい（｜ｔ_０｜＜＜τ）。そのため、数４０を数４１のように変換できる。

“Τ− | t |” can be physically interpreted in the same manner as “τ− | t−t _R |” described in the first description. Therefore, by setting “t” in “τ− | t |” to “t ₀ ”, Equation 39 can be converted into Equation 40.

In a general SAR system, since the reference function and the received signal are mostly correlated, | t ₀ | is very small compared to τ (| t ₀ | << τ). Therefore, Formula 40 can be converted into Formula 41.

<2-2. When there is a difference between the true speed of the target in the azimuth direction and the predicted speed>
As described in the first embodiment, the speed _{v a} azimuth direction of the _target, of a _0, a 1, _{a 2,} contained only _{a 2, v a} the true azimuth direction of a target The speed, v _a ′ is defined as the predicted speed of the target in the azimuth direction, and a ₂ ′ is defined as shown in Equation 18. Then, it is assumed that the speed of the target in the azimuth direction in the reference function is the predicted speed v _a ′, and the speed of the target in the azimuth direction in the received signal is the true speed v _a .
Then, the reference function V ^az shown in ^{Expression 34} can be converted into the reference function V ^vaz shown in ^Expression 42.

Henceforth, calculation is advanced in the same flow as the description of 2-1.
First, ^when the complex conjugate of the reference function V ^vaz shown in ^Equation 42 is set as the reference function V ^* and the received signal V _r shown in Equation 17 is substituted as the received signal V _r into the matched filter shown in Equation 11, Equation 43 is obtained.

Δ＝ａ_２−ａ_２’とし、０≧ｔの場合、数４４は数４５のように計算される。

これは、Δ＜０に対応するものであり、Δ≧０の場合は、数４６のように計算される。

一方、０＜ｔの場合、数４４はΔの符号に応じて数４７、および数４８のように計算される。

次に、ｔの符号に注意すると、数４５と数４７を数４９のように変換できる。

これは、Δ＜０の場合に相当し、Δ≧０の場合は、数４６と数４８を数５０のように変換できる。

ここで、数４９と数５０とそれぞれを数４３の積分値に代入すると、それぞれ数５１と数５２のように変換できる。

As described with reference to FIG. 11, the integral part C (Equation 44) in Equation 43 is calculated in two cases of 0 ≧ t and 0 <t.

When Δ = a ₂ −a ₂ ′ and 0 ≧ t, Equation 44 is calculated as Equation 45.

This corresponds to Δ <0. When Δ ≧ 0, the calculation is performed as shown in Equation 46.

On the other hand, when 0 <t, Equation 44 is calculated as Equation 47 and Equation 48 according to the sign of Δ.

Next, if attention is paid to the sign of t, Equations 45 and 47 can be converted into Equation 49.

This corresponds to the case of Δ <0, and when Δ ≧ 0, Expressions 46 and 48 can be converted into Expression 50.

Here, by substituting Equation 49 and Equation 50 into the integral value of Equation 43, conversion can be performed as Equation 51 and Equation 52, respectively.

If t = 0 and an absolute value is taken, Equations 53 and 52 are obtained.

なお、ここでは、アジマス方向の速度は同じであるとする。特に、ここでは、簡単のため、目標物のアジマス方向の速度は０であるとし、数１５に示すａ_２は、ａ_２＝ｖ_Ｐ ^２／Ｒ_０とする。 <2-3. When there is a difference between the true speed in the range direction of the target and the predicted speed>
As described in the first embodiment, the range direction of the velocity _{v a} of the _target, of a _0, a 1, _{a 2,} contained only _{a 1, v r} and the true range direction of a target The speed, v _r ′ is defined as a predicted speed of the target in the range direction, and a ₁ ′ = v _r ′ is defined. Then, it is assumed that the speed in the range direction of the target in the reference function is the predicted speed v _r ′, and the speed in the range direction of the target in the received signal is the true speed v _r .
Then, the relative distance R _r (t) in the received signal, the relative distance R (t) in the reference function, and the relative distance R _s (t) between the SAR and the target when the target is not moving in the range direction, Can be expressed as Equation 54.

Here, the speed in the azimuth direction is the same. In particular, here, for the sake of simplicity, it is assumed that the speed of the target in the azimuth direction is 0, and a ₂ shown in Equation 15 is a ₂ = v _P ² / R ₀ .

FIG. 12 is a diagram illustrating the relative distance R _r (t), the relative distance R (t), and the relative distance R _s (t) shown in Equation 54.
As shown in FIG. 12, the bottom positions of the relative distance R _r (t), the relative distance R (t), and the relative distance R _s (t) are shifted. Note that the deviation in the R (t) axis between the relative distance R _r (t) and the relative distance R (t), that is, the deviation in the range direction is a constant and is not important because it is independent of the time t. Therefore, here, the difference between the true speed of the target in the range direction and the predicted speed is only the shift in the time axis between the relative distance R _r (t) and the relative distance R (t), that is, the shift in the azimuth direction. Think of it as causing something. Then, the shift amount Δt on the time axis is expressed by Equation 55.

すると、数５５に示す相対距離Ｒ（ｔ）から、数３４に示す参照関数Ｖ^ａｚは、数５７に示す参照関数Ｖ^ｖｒｇに変換できる。

By substituting a ₁ ′ shown in Equation 55 for the relative distance R (t), Equation 56 is obtained.

Then, the relative distance is shown in the number 55 R (t), the reference function ^{V az} shown in Formula 34 can be converted into the reference function ^{V VRG} shown in Formula 57.

Henceforth, calculation is advanced in the same flow as the description of 2-1.
First, the complex conjugate of the reference function ^{V VRG} shown in several 57 and reference function ^{V *,} as a received signal _{V r} received signal _{V r} of the equation 17 and substituting the matched filter shown in Expression 11, the number 58.

０≧ｔ＋Δｔの場合、数５９は数６０のように計算される。

一方、０＜ｔ＋Δｔの場合、数５９は数６１のように計算される。

つまり、０≧ｔ＋Δｔと０＜ｔ＋Δｔとのどちらの場合も結果は同じになる。したがって、数５８を数６２のように変換できる。

For the same reason as the integration parts A, B, and C, the integration part D (Equation 59) in Expression 58 is calculated separately in two cases of 0 ≧ t + Δt and 0 <t + Δt.

When 0 ≧ t + Δt, Expression 59 is calculated as Expression 60.

On the other hand, when 0 <t + Δt, Equation 59 is calculated as Equation 61.

That is, the result is the same in both cases of 0 ≧ t + Δt and 0 <t + Δt. Therefore, Formula 58 can be converted into Formula 62.

さらに、絶対値をとると数６３を数６４のように変換できる。

そして、ｔ_０＝０とすると、数６４を数６５のように変換できる。

“Τ− | t + Δt |” can be interpreted in the same physical manner as “τ− | t−t _R |” described in the description of the range compression. Therefore, by setting “t” in “τ− | t + Δt |” to “t ₀ ”, the equation 62 can be converted into the equation 63.

Furthermore, when the absolute value is taken, the equation 63 can be converted into the equation 64.

Then, when t ₀ = 0, Expression 64 can be converted into Expression 65.

In Expression 65, the position of the maximum value of the amplitude value is determined by the portion (E) shown in Expression 66. However, the position of the maximum value of the amplitude value is not important here. Therefore, when (E) is set to 1 and Expression 65 is simplified, Expression 67 is obtained.

<3. Summary>
Since it is Expression 68, Expressions 48 to 20 which are the results of the 2-2 are obtained.

Moreover, since it is Formula 69, Formula 67 to Formula 22 which are the results of 2-3 are obtained.

Next, the hardware configuration of the target speed identification device 1 in the embodiment will be described.
FIG. 13 is a diagram illustrating an example of a hardware configuration of the target speed identification device 1.
As shown in FIG. 13, the target velocity specifying apparatus 1 includes a CPU 911 (also referred to as a central processing unit, a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, and a processor) that executes a program. Yes. The CPU 911 is connected to the ROM 913, the RAM 914, the LCD 901 (Liquid Crystal Display), the keyboard 902 (K / B), the communication board 915, and the magnetic disk device 920 via the bus 912, and controls these hardware devices. Instead of the magnetic disk device 920 (fixed disk device), a storage device such as an optical disk device or a memory card read / write device may be used. The magnetic disk device 920 is connected via a predetermined fixed disk interface.

  An operating system 921 (OS), a window system 922, a program group 923, and a file group 924 are stored in the magnetic disk device 920 or the ROM 913. The programs in the program group 923 are executed by the CPU 911, the operating system 921, and the window system 922.

The program group 923 includes “data input unit 2”, “step size identification unit 3”, “predicted speed input unit 4”, “reference function generation unit 5”, “azimuth compression processing unit 6”, “ Software, programs, and other programs that execute the functions described as the “amplitude value calculating unit 7”, “speed specifying unit 8”, and the like are stored. The program is read and executed by the CPU 911.
The file group 924 includes information, data and signal values such as “data after range compression”, “step size”, “predicted speed”, “reference function”, “data after azimuth compression”, “amplitude value” in the above description. And variable values and parameters are stored as items in the “database”. The “database” is stored in a recording medium such as a disk or a memory. Information, data, signal values, variable values, and parameters stored in a storage medium such as a disk or memory are read out to the main memory or cache memory by the CPU 911 via a read / write circuit, and extracted, searched, referenced, compared, and calculated. Used for the operation of the CPU 911 such as calculation / processing / output / printing / display. Information, data, signal values, variable values, and parameters are temporarily stored in the main memory, cache memory, and buffer memory during the operation of the CPU 911 for extraction, search, reference, comparison, calculation, calculation, processing, output, printing, and display. Is remembered.

In the above description, the arrows in the flowchart mainly indicate input / output of data and signals, and the data and signal values are recorded in a memory of the RAM 914, other recording media such as an optical disk, and an IC chip. Data and signals are transmitted online by a bus 912, signal lines, cables, other transmission media, and radio waves.
In addition, what is described as “to part” in the above description may be “to circuit”, “to device”, “to device”, “to means”, and “to function”. It may be “step”, “˜procedure”, “˜processing”. In addition, what is described as “˜device” may be “˜circuit”, “˜device”, “˜means”, “˜function”, and “˜step”, “˜procedure”, “ ~ Process ". Furthermore, what is described as “to process” may be “to step”. That is, what is described as “˜unit” may be realized by firmware stored in the ROM 913. Alternatively, it may be implemented only by software, or only by hardware such as elements, devices, substrates, and wirings, by a combination of software and hardware, or by a combination of firmware. Firmware and software are stored in a recording medium such as ROM 913 as a program. The program is read by the CPU 911 and executed by the CPU 911. That is, the program causes a computer or the like to function as the “˜unit” described above. Alternatively, the computer or the like is caused to execute the procedures and methods of “to part” described above.

The target speed identification device according to this embodiment is
A target speed specifying device for specifying a speed of a target observed by the SAR;
Velocity v _p of the SAR mounting machine equipped with _SAR, distance R ₀ between the SAR and the target in the synthetic aperture _center, wavelength radio wave radiated from the SAR lambda, target the SAR observed in the observation conditions of the synthetic aperture time τ A data input part for inputting the data of the object,
The velocity v _p and the distance R ₀ and Telecommunications of predicted velocity v _{a 'and} a function of amplitude V ₀ ^vaz represented using azimuthal wavelength λ and a synthetic aperture time τ and the target of the SAR mounting machine, wherein enter the speed of the SAR mounting machine v _p and the distance R ₀ and radio wavelength λ and a synthetic aperture time τ is the observation condition data the data input unit inputs an amplitude value V ₀ corresponding to the predicted velocity v _{a '} ^By calculating ^vaz , the range of the predicted velocity v _a ′ in the azimuth direction in which the amplitude value V ₀ ^vaz is greater than or ^equal to a predetermined value is identified by the processing device, and the velocity width below the velocity width of the identified range is ^stepped Δv a step width specifying part _a1 ;
With step size Delta] v _a1 of the step size specifying unit is identified, characterized by comprising a specifying process execution unit which identifies the processing unit azimuth direction of the velocity of the target.

The step size specifying unit, and a function of amplitude V ₀ ^vaz shown in Formula 70, the data input unit of the speed v _p and the distance R ₀ and Telecommunications of SAR mounting machine is an observation condition data input wavelength λ with inputs the synthetic aperture time tau, enter a value that is the velocity v _a of the target, and calculates an amplitude value V ₀ ^vaz corresponding to the predicted velocity v _{a '.}

In the graph obtained by plotting the amplitude value V ₀ ^vaz for each predicted speed in the azimuth direction based on the function shown in ^Equation 70, the step size specifying unit has the second largest amplitude value V ₀ ^{vaz at the} top. A value larger than the amplitude value V ₀ ^{vaz at the} top of the peak is defined as the predetermined value.

The data input unit inputs range-compressed data that is range-compressed as target data,
The specific process execution unit
For target inputs the predicted velocity in the range direction, and predicted velocity input unit for inputting the predicted velocity of the azimuth direction for each step size Delta] v _a1 of the step size specifying unit has identified,
A reference function obtained from the relative distance between the SAR and the target is processed for each predicted speed in the azimuth direction based on the predicted speed in the range direction and the predicted speed in a plurality of azimuth directions input by the predicted speed input unit. A reference function generation unit that generates a plurality of reference functions by generating by the device;
An azimuth compression processing unit that azimuth-compresses the range-compressed data input by the data input unit and generates a plurality of azimuth-compressed data by a processing device based on each reference function of the plurality of reference functions generated by the reference function generation unit When,
An amplitude value calculating unit that calculates an amplitude value of an image of a target in each azimuth-compressed data of the plurality of azimuth-compressed data generated by the azimuth compression processing unit;
Prediction of the azimuth direction used when the reference function generator generates the reference function used to generate the azimuth-compressed data with the maximum amplitude value of the target image calculated by the amplitude value calculator. And a speed specifying unit that specifies by the processing device when the speed of the target in the azimuth direction falls within the range of Δv _a1 / 2 before and after the speed.

The predicted velocity input unit, front and rear speed where the velocity identifying unit has identified, for the speed range of the step width Delta] v _{a1 /} 2, the predicted velocity azimuthal narrow every stride Delta] v _a2 than the step width Delta] v _a1 Newly enter
The reference function generation unit is obtained from the relative distance for each predicted speed in the azimuth direction based on the predicted speed in the range direction and a plurality of predicted speeds in the azimuth direction newly input by the predicted speed input unit. By creating a reference function, you can create multiple new reference functions,
The azimuth compression processing unit generates a plurality of azimuth-compressed data by azimuth-compressing the range-compressed data based on each reference function of a plurality of reference functions newly generated by the reference function generation unit,
The amplitude value calculation unit newly calculates the amplitude value of the image of the target in each azimuth-compressed data of the plurality of azimuth-compressed data newly generated by the azimuth compression processing unit,
The speed specifying unit uses a reference function used to generate azimuth-compressed data with the maximum amplitude value of the target image newly calculated by the amplitude value calculating unit as a reference function, and the reference function generating unit. The predicted speed in the azimuth direction used when the is generated is specified as the speed of the target in the azimuth direction.

The predicted speed input unit, a predicted velocity in the range direction, and a target range direction of the velocity v _r slower rate and a faster rate of newly entered one by at least one of each,
The reference function generation unit is based on the predicted speeds in the range direction newly input by the predicted speed input unit and the speeds in the azimuth direction of the target specified by the speed specification unit. A plurality of reference functions are newly generated by generating a reference function obtained from the relative distance every time,
The azimuth compression processing unit generates a plurality of azimuth-compressed data by azimuth-compressing the range-compressed data based on each reference function of a plurality of reference functions newly generated by the reference function generation unit,
The amplitude value calculating unit calculates an amplitude value of an image of the target in each azimuth-compressed data of the plurality of azimuth-compressed data newly generated by the azimuth compression processing unit,
The speed specifying unit is configured to determine the speed v _{p of the} SAR-equipped machine based on the predicted speeds in a plurality of ranges direction input by the predicted speed input unit and the amplitude values calculated from the azimuth-compressed data by the amplitude value calculation unit. The range direction velocity of the target is determined using a function of the amplitude value V ₀ ^vrg expressed using the distance R ₀ , the synthetic aperture time τ, and the predicted velocity v _r ′ of the target in the range direction. Features.

The speed specifying unit specifies the range direction speed of the target using a function of the amplitude value V ₀ ^vrg shown in ^Formula 71.

The predicted speed input unit, a predicted velocity in the range direction, enter the slower rate than the range direction of the velocity v _r of the target v _{r1 'and} fast speed v _r2' and,
The speed specifying unit, wherein the predicted speed input unit is in the range direction input predicted velocity v _{r1 'and} v _r2', range direction of predicted velocity v _{r1 'based} on the generated post-azimuth compression generated by the reference function The amplitude value P ₁ of the target image in the data and the amplitude value P ₂ of the target image in the azimuth-compressed data generated by the reference function generated based on the predicted speed v _r2 ′ in the range direction are expressed by Equation 72 substituting the result, and identifies the range direction of the velocity v _r of the target.

The predicted speed input unit, a predicted velocity in the range direction, and a target range direction of the velocity v _r slower rate and a faster rate of type each at least two, respectively,
The speed specifying unit, and the predicted velocity in the range direction of the velocity v is slower than _r at least two range direction of the target, at least the generated azimuth compression by two range direction prediction speed reference function that has been generated based on the respective A linear function V ₀ ^vrg = a ₁ v _r + a ₂ (where a ₁ and a ₂ are constants) is calculated from the amplitude value of the image of the target in the subsequent data by the least square method, and the range of the target is calculated. A predicted speed in at least two range directions faster than the speed v _r, and an amplitude value of the target image in the azimuth-compressed data generated by a reference function generated based on each of the predicted speeds in the at least two range directions. A linear function V ₀ ^vrg = b ₁ v _r + b ₂ (where b ₁ and b ₂ are constants) is calculated by the least square method, and the linear function V ₀ ^{v _{rg = a 1 v r + a}} 2 and characterized by identifying a linear function ^{_{V 0 vrg = b 1 v r}} + b 2 Metropolitan from range direction velocity _{v r.}

The predicted speed input unit, a predicted velocity in the range direction, newly enter the predicted rate of at least three range direction and a target range direction of the velocity v _r slower rate and a faster rate of one by at least one of each ,
The reference function generation unit is based on the predicted speeds in the range direction newly input by the predicted speed input unit and the speeds in the azimuth direction of the target specified by the speed specification unit. A plurality of reference functions are newly generated by generating a reference function obtained from the relative distance every time,
The azimuth compression processing unit generates a plurality of azimuth-compressed data by azimuth-compressing the range-compressed data based on each reference function of a plurality of reference functions newly generated by the reference function generation unit,
The amplitude value calculating unit calculates an amplitude value of an image of the target in each azimuth-compressed data of the plurality of azimuth-compressed data newly generated by the azimuth compression processing unit,
The speed specifying unit is a quadratic function V ₀ ^vrg = c ₁ v _r by a predetermined method from the predicted speeds in the at least three range directions and the amplitude values calculated from the azimuth-compressed data by the amplitude value calculation unit. Calculating ² + c ₂ v _r + c ₃ (where c ₁ , c ₂ , and c ₃ are constants) and specifying the speed in the range direction at the bottom of the quadratic curve as the speed v _{r in the} range direction It is characterized by.

The target speed specifying program according to the present invention includes:
A target speed specifying program for specifying the speed of a target observed by the SAR;
Velocity v _p of the SAR mounting machine equipped with _SAR, distance R ₀ between the SAR and the target in the synthetic aperture _center, wavelength radio wave radiated from the SAR lambda, target the SAR observed in the observation conditions of the synthetic aperture time τ Data input processing to input data of things,
The velocity v _p and the distance R ₀ and Telecommunications of predicted velocity v _{a 'and} a function of amplitude V ₀ ^vaz represented using azimuthal wavelength λ and a synthetic aperture time τ and the target of the SAR mounting machine, wherein SAR-equipped machine speed v _p , distance R ₀ , radio wave wavelength λ, and synthetic aperture time τ, which are observation conditions for data input in the data input process, are input, and amplitude value V ₀ corresponding to predicted speed v _a ′. ^By calculating ^vaz , a range of the predicted velocity v _a ′ in the azimuth direction in which the amplitude value V ₀ ^vaz is equal to or greater than a predetermined value is identified, and a velocity width equal to or smaller than the velocity width of the identified range is set as a step width Δv _a1 . Step size identification processing,
With step size Delta] v _a1 specified in the step size specifying process, characterized in that to execute a specific process execution on a computer for identifying the azimuth direction of the velocity of the target.

In the step size specifying process, the function of the amplitude value V ₀ ^vaz shown in ^Expression 73 is ^added to the speed v _p of the SAR-equipped machine, the distance R _0, and the wavelength λ of the radio wave, which are the observation conditions for the data input in the data input process. with inputs the synthetic aperture time tau, enter a value that is the velocity v _a of the target, and calculates an amplitude value V ₀ ^vaz corresponding to the predicted velocity v _{a '.}

In the step size specific process, based on the function shown in several 73, in a graph obtained by plotting the values of the amplitude values V ₀ ^vaz each predicted velocity azimuthal amplitude value V ₀ ^vaz at the top is the second largest A value larger than the amplitude value V ₀ ^{vaz at the} top of the peak is defined as the predetermined value.

In the data input process, as the target data, the range-compressed data that is range-compressed is input,
In the specific process execution process,
A predicted speed input process for inputting a predicted speed in the range direction and inputting a predicted speed in the azimuth direction for each step width Δv _a1 specified in the step size specifying process for the target;
A reference function obtained from a relative distance between the SAR and the target is generated for each predicted speed in the azimuth direction based on the predicted speed in the range direction and the predicted speed in a plurality of azimuth directions input in the predicted speed input process. A reference function generation process for generating a plurality of reference functions,
Based on each reference function of the plurality of reference functions generated in the reference function generation processing, azimuth compression processing to generate a plurality of azimuth compressed data by azimuth compressing the range-compressed data input in the data input processing,
An amplitude value calculation process for calculating an amplitude value of an image of a target in each azimuth-compressed data of the plurality of azimuth-compressed data generated by the azimuth compression process;
Prediction of the azimuth direction used when the reference function used to generate the azimuth-compressed data having the maximum amplitude value of the target image calculated in the amplitude value calculation process is generated in the reference function generation process It is characterized by causing a computer to execute a speed specifying process that specifies that the speed of the target in the azimuth direction falls within the range of Δv _a1 / 2 before and after the speed.

The predictive speed input processing, before and after the rate specified in the speed identification processing, the speed range of the step width Delta] v _{a1 / 2,} the predicted velocity azimuthal narrow every stride Delta] v _a2 than the step width Delta] v _a1 Newly enter
In the reference function generation process, based on the predicted speed in the range direction and the predicted speeds in the azimuth direction newly input in the predicted speed input process, the reference function generation process is obtained from the relative distance for each predicted speed in the azimuth direction. By creating a reference function, you can create multiple new reference functions,
In the azimuth compression processing, based on each reference function of a plurality of reference functions newly generated in the reference function generation processing, the range-compressed data is azimuth-compressed to newly generate a plurality of azimuth-compressed data,
In the amplitude value calculation process, a new amplitude value of the target image in each azimuth-compressed data of the plurality of azimuth-compressed data newly generated in the azimuth compression process is calculated,
In the speed specifying process, the reference function used to generate the azimuth-compressed data having the maximum amplitude value of the target image newly calculated in the amplitude value calculation process is used as the reference function, and the reference function generation process. The predicted speed in the azimuth direction used when generated in step (2) is specified as the speed of the target in the azimuth direction.

The predictive speed input processing, as the predicted rate in the range direction, and a target range direction of the velocity v _r slower rate and a faster rate of newly entered one by at least one of each,
In the reference function generation process, the predicted speed in the range direction based on the predicted speed in the plurality of range directions newly input in the predicted speed input process and the speed in the azimuth direction of the target specified in the speed specifying process A plurality of reference functions are newly generated by generating a reference function obtained from the relative distance every time,
In the azimuth compression processing, based on each reference function of a plurality of reference functions newly generated in the reference function generation processing, the range-compressed data is azimuth-compressed to newly generate a plurality of azimuth-compressed data,
In the amplitude value calculation process, the amplitude value of the image of the target in each azimuth-compressed data of the plurality of azimuth-compressed data newly generated by the azimuth compression process is calculated,
Wherein a rate specific process, a plurality of range-based prediction speed input by the predicted rate input process, based on the amplitude value calculated from the azimuth data after compression by the amplitude value calculation process, the speed of the SAR mounting machine v _p The range direction velocity of the target is determined using a function of the amplitude value V ₀ ^vrg expressed using the distance R ₀ , the synthetic aperture time τ, and the predicted velocity v _r ′ of the target in the range direction. Features.

In the speed specifying process, the range direction speed of the target is specified using a function of the amplitude value V ₀ ^vrg shown in ^Formula 74.

The predicted speed input processing, as the predicted rate in the range direction, enter the slower rate than the range direction of the velocity v _r of the target v _{r1 'and} fast speed v _r2' and,
Wherein a rate specific process, the a predicted velocity in the range direction inputted by the input processing predicted velocity v _{r1 'and} v _r2', range direction of predicted velocity v _{r1 'based} on the generated post-azimuth compression generated by the reference function The amplitude value P ₁ of the target image in the data and the amplitude value P ₂ of the target image in the azimuth-compressed data generated by the reference function generated based on the predicted speed v _r2 ′ in the range direction are expressed in Expression 75. substituting the result, and identifies the range direction of the velocity v _r of the target.

The predictive speed input processing, as the predicted rate in the range direction, and a target range direction of the velocity v _r slower rate and a faster rate of type each at least two, respectively,
Wherein a rate specific process, and predicted velocity in the range direction of the velocity v is slower than _r at least two range direction of the target, at least the generated azimuth compression by two range direction prediction speed reference function that has been generated based on the respective A linear function V ₀ ^vrg = a ₁ v _r + a ₂ (where a ₁ and a ₂ are constants) is calculated from the amplitude value of the image of the target in the subsequent data by the least square method, and the range of the target is calculated. A predicted speed in at least two range directions faster than the speed v _r, and an amplitude value of the target image in the azimuth-compressed data generated by a reference function generated based on each of the predicted speeds in the at least two range directions. by the least squares method _(wherein, b 1, _{b 2} are constants) a linear function ^{_{V 0 vrg = b 1 v r}} + b 2 calculates a primary function V ^{_{vrg = a 1 v r + a}} 2 and characterized by identifying a linear function ^{_{V 0 vrg = b 1 v r}} + b 2 Metropolitan from range direction velocity _{v r.}

The predictive speed input processing, as the predicted rate in the range direction, newly enter the predicted rate of at least three range direction and a target range direction of the velocity v _r slower rate and a faster rate of one by at least one of each ,
In the reference function generation process, the predicted speed in the range direction based on the predicted speed in the plurality of range directions newly input in the predicted speed input process and the speed in the azimuth direction of the target specified in the speed specifying process A plurality of reference functions are newly generated by generating a reference function obtained from the relative distance every time,
In the azimuth compression processing, based on each reference function of a plurality of reference functions newly generated in the reference function generation processing, the range-compressed data is azimuth-compressed to newly generate a plurality of azimuth-compressed data,
In the amplitude value calculation process, the amplitude value of the image of the target in each azimuth-compressed data of the plurality of azimuth-compressed data newly generated by the azimuth compression process is calculated,
In the speed specifying process, a quadratic function V ₀ ^vrg = c ₁ v _{r is} ^obtained by a predetermined method from the predicted speed in the at least three range directions and the amplitude value calculated from each azimuth-compressed data in the amplitude value calculation process. Calculating ² + c ₂ v _r + c ₃ (where c ₁ , c ₂ , and c ₃ are constants) and specifying the speed in the range direction at the bottom of the quadratic curve as the speed v _{r in the} range direction It is characterized by.

The target velocity specifying method according to this embodiment is:
A target speed specifying method for specifying the speed of a target observed by the SAR.
Velocity v _p of the SAR mounting machine equipped with _SAR, distance R ₀ between the SAR and the target in the synthetic aperture _center, wavelength radio wave radiated from the SAR lambda, target the SAR observed in the observation conditions of the synthetic aperture time τ A data input process for inputting data of objects;
The velocity v _p and the distance R ₀ and Telecommunications of predicted velocity v _{a 'and} a function of amplitude V ₀ ^vaz represented using azimuthal wavelength λ and a synthetic aperture time τ and the target of the SAR mounting machine, wherein enter the speed of the SAR mounting machine v _p and the distance R ₀ and radio wavelength λ and synthetic aperture time τ is the observation condition data input in the data input step, the amplitude value V ₀ corresponding to the predicted velocity v _{a '} ^By calculating ^vaz , the range of the predicted velocity v _a ′ in the azimuth direction in which the amplitude value V ₀ ^vaz is greater than or ^equal to a predetermined value is identified by the processing device, and the velocity width below the velocity width of the identified range is ^stepped Δv a step size specifying step _a1 ;
With step size Delta] v _a1 specified in the step size specification step, characterized in that it comprises a specific process execution step of specifying by the processor the azimuth direction of the velocity of the target.

  DESCRIPTION OF SYMBOLS 1 Target speed specific apparatus, 2 Data input part, 3 Step width specific part, 4 Predicted speed input part, 5 Reference function production | generation part, 6 Azimuth compression process part, 7 Amplitude value calculation part, 8 Speed specific part

Claims (10)

A target speed specifying device for specifying a speed of a target observed by a SAR (Synthetic Aperture Radar),
Velocity v _p of the SAR mounting machine equipped with _SAR, enter the distance R _0, after range compression data range compression for the data of the target the SAR observed by the synthetic aperture time τ between the SAR and the target in the synthetic aperture center A data input section to
As predicted velocity in the range direction, the prediction speed input unit and a target speed slower and faster than the range direction of the velocity v _r of the input by at least one of each,
Velocity of the plurality of range-based prediction rate prediction speed input unit is inputted, based on the azimuth direction of the velocity of the target, for each predicted velocity of the range direction, velocity v _p and target of the SAR mounting machine A reference function generation unit that generates a plurality of reference functions by generating a reference function obtained from a relative distance between the SAR and the target represented based on
An azimuth compression processing unit that azimuth-compresses the range-compressed data input by the data input unit and generates a plurality of azimuth-compressed data by a processing device based on each reference function of the plurality of reference functions generated by the reference function generation unit When,
An amplitude value calculating unit that calculates an amplitude value of an image of a target in each azimuth-compressed data of the plurality of azimuth-compressed data generated by the azimuth compression processing unit;
Based on the predicted speeds in a plurality of ranges input by the predicted speed input unit and the amplitude values calculated from the azimuth-compressed data by the amplitude value calculation unit, the speed v _p and the distance R _{0 of the} SAR-equipped machine are combined. A speed specifying unit that specifies the speed in the range direction of the target using a function of the amplitude value V ₀ ^vrg expressed using the opening time τ and the predicted speed v _r ′ in the range of the target. Feature target velocity identification device. The target speed specifying device according to claim 1, wherein the speed specifying unit specifies a speed in the range direction of the target using a function of the amplitude value V ₀ ^vrg shown in ^Formula 1.

The predicted speed input unit, a predicted velocity in the range direction, enter the slower rate than the range direction of the velocity v _r of the target v _{r1 'and} fast speed v _r2' and,
The speed specifying unit, wherein the predicted speed input unit is in the range direction input predicted velocity v _{r1 'and} v _r2', range direction of predicted velocity v _{r1 'based} on the generated post-azimuth compression generated by the reference function The amplitude value P ₁ of the target image in the data and the amplitude value P ₂ of the target image in the azimuth-compressed data generated by the reference function generated based on the predicted speed v _r2 ′ in the range direction The target speed specifying device according to claim 1, wherein the target speed specifying device determines a speed v _r of the target in the range direction.

The predicted speed input unit, a predicted velocity in the range direction, and a target range direction of the velocity v _r slower rate and a faster rate of type each at least two, respectively,
The speed specifying unit, and the predicted velocity in the range direction of the velocity v is slower than _r at least two range direction of the target, at least the generated azimuth compression by two range direction prediction speed reference function that has been generated based on the respective A linear function V ₀ ^vrg = a ₁ v _r + a ₂ (where a ₁ and a ₂ are constants) is calculated from the amplitude value of the image of the target in the subsequent data by the least square method, and the range of the target is calculated. A predicted speed in at least two range directions faster than the speed v _r, and an amplitude value of the target image in the azimuth-compressed data generated by a reference function generated based on each of the predicted speeds in the at least two range directions. A linear function V ₀ ^vrg = b ₁ v _r + b ₂ (where b ₁ and b ₂ are constants) is calculated by the least square method, and the linear function V ₀ ^{v _{rg = a 1 v r + a}} 2 a linear function ^{_{V 0 vrg = b 1 v r}} + b 2 Metropolitan target speed specifying device according to claim 1 or 2, characterized in that identifying the velocity _{v r} in the range direction from . A target speed specifying device for specifying a speed of a target observed by a SAR (Synthetic Aperture Radar),
A data input unit for inputting range-compressed data obtained by performing range compression on target data observed by the SAR;
As predicted velocity in the range direction, and predicted velocity input unit for inputting at least three predicted velocity and a target speed slower and faster than the range direction of the velocity v _r of each at least one of each,
Velocity of the plurality of range-based prediction rate prediction speed input unit is inputted, based on the azimuth direction of the velocity of the target, for each predicted velocity of the range direction, velocity v _p and target of the SAR mounting machine A reference function generation unit that generates a plurality of reference functions by generating a reference function obtained from a relative distance between the SAR and the target represented based on
An azimuth compression processing unit that azimuth-compresses the range-compressed data input by the data input unit and generates a plurality of azimuth-compressed data by a processing device based on each reference function of the plurality of reference functions generated by the reference function generation unit When,
An amplitude value calculating unit that calculates an amplitude value of an image of a target in each azimuth-compressed data of the plurality of azimuth-compressed data generated by the azimuth compression processing unit;
A quadratic function V ₀ ^vrg = c ₁ by a predetermined method from the predicted speeds in the at least three range directions input by the predicted speed input unit and the amplitude values calculated from the azimuth-compressed data by the amplitude value calculation unit. Calculate v _r ² + c ₂ v _r + c ₃ (where c ₁ , c ₂ , and c ₃ are constants) and process the speed in the range direction at the bottom of the quadratic curve as the speed v _{r in the} range direction A target speed specifying device comprising: a speed specifying unit specified by the device. A target speed specifying program for specifying a speed of a target observed by SAR (Synthetic Aperture Radar),
Velocity v _p of the SAR mounting machine equipped with _SAR, enter the distance R _0, after range compression data range compression for the data of the target the SAR observed by the synthetic aperture time τ between the SAR and the target in the synthetic aperture center Data entry processing to
As predicted velocity in the range direction, the predicted speed input processing and target range direction of the velocity v _r slower rate and a faster rate of inputting one by at least one of each,
Velocity of the plurality of range-based prediction rate entered on predicted velocity input process, based on the azimuth direction of the velocity of the target, for each predicted velocity of the range direction, velocity v _p and target of the SAR mounting machine A reference function generation process for generating a plurality of reference functions by generating a reference function obtained from a relative distance between the SAR and the target represented based on
Based on each reference function of the plurality of reference functions generated in the reference function generation processing, azimuth compression processing to generate a plurality of azimuth compressed data by azimuth compressing the range-compressed data input in the data input processing,
An amplitude value calculation process for calculating an amplitude value of an image of a target in each azimuth-compressed data of the plurality of azimuth-compressed data generated by the azimuth compression process;
Based on the predicted speeds in the plurality of range directions input in the predicted speed input process and the amplitude values calculated from the respective azimuth-compressed data in the amplitude value calculation process, the speed v _p and the distance R _{0 of the} SAR-equipped machine are combined. ^Using a function of the amplitude value V ₀ ^vrg expressed using the opening time τ and the predicted speed v _r ′ of the target in the range direction, a speed specifying process for specifying the speed in the range direction of the target is executed on the computer A target speed specifying program characterized in that The target speed specifying program according to claim 6, wherein in the speed specifying process, the range direction speed of the target is specified using a function of the amplitude value V ₀ ^vrg shown in ^Formula 3.

The predicted speed input processing, as the predicted rate in the range direction, enter the slower rate than the range direction of the velocity v _r of the target v _{r1 'and} fast speed v _r2' and,
Wherein a rate specific process, the a predicted velocity in the range direction inputted by the input processing predicted velocity v _{r1 'and} v _r2', range direction of predicted velocity v _{r1 'based} on the generated post-azimuth compression generated by the reference function The amplitude value P ₁ of the target image in the data and the amplitude value P ₂ of the target image in the azimuth-compressed data generated by the reference function generated based on the predicted speed v _r2 ′ in the range direction substituted by, target speed determining program according to claim 6 or 7, characterized in that identifying the range direction of the velocity v _r of the target to.

The predictive speed input processing, as the predicted rate in the range direction, and a target range direction of the velocity v _r slower rate and a faster rate of type each at least two, respectively,
Wherein a rate specific process, and predicted velocity in the range direction of the velocity v is slower than _r at least two range direction of the target, at least the generated azimuth compression by two range direction prediction speed reference function that has been generated based on the respective A linear function V ₀ ^vrg = a ₁ v _r + a ₂ (where a ₁ and a ₂ are constants) is calculated from the amplitude value of the image of the target in the subsequent data by the least square method, and the range of the target is calculated. A predicted speed in at least two range directions faster than the speed v _r, and an amplitude value of the target image in the azimuth-compressed data generated by a reference function generated based on each of the predicted speeds in the at least two range directions. by the least squares method _(wherein, b 1, _{b 2} are constants) a linear function ^{_{V 0 vrg = b 1 v r}} + b 2 calculates a primary function V ^{_{vrg = a 1 v r + a}} 2 a linear function ^{_{V 0 vrg = b 1 v r}} + b 2 Metropolitan from according to claim 6 or 7, characterized in that identifying the velocity _{v r} of the range direction target speed determining program . A target speed specifying program for specifying a speed of a target observed by SAR (Synthetic Aperture Radar),
A data input process for inputting range-compressed data obtained by subjecting the target data observed by the SAR to range compression;
A predicted speed input process for inputting at least three predicted speeds each including at least one of a speed slower than a speed v _r of the target in the range direction and a speed higher than the target speed in the range direction;
Velocity of the plurality of range-based prediction rate entered on predicted velocity input process, based on the azimuth direction of the velocity of the target, for each predicted velocity of the range direction, velocity v _p and target of the SAR mounting machine A reference function generation process for generating a plurality of reference functions by generating a reference function obtained from a relative distance between the SAR and the target represented based on
Based on each reference function of the plurality of reference functions generated in the reference function generation processing, azimuth compression processing to generate a plurality of azimuth compressed data by azimuth compressing the range-compressed data input in the data input processing,
An amplitude value calculation process for calculating an amplitude value of an image of a target in each azimuth-compressed data of the plurality of azimuth-compressed data generated by the azimuth compression process;
A quadratic function V ₀ ^vrg = c ₁ by a predetermined method from the predicted speed in the at least three range directions input in the predicted speed input process and the amplitude value calculated from each azimuth-compressed data in the amplitude value calculation process. Calculate v _r ² + c ₂ v _r + c ₃ (where c ₁ , c ₂ , and c ₃ are constants) and specify the speed in the range direction at the bottom of the quadratic curve as the speed v _{r in the} range direction A target speed specifying program that causes a computer to execute speed specifying processing.

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