KR20110060626A - The method for measurign object's velocity using synthetic aperture radar image and the apparatus thereof - Google Patents

Abstract

PURPOSE: A method and an apparatus for measuring the speed of an object using synthetic aperture radar images are provided to determine two dimensional speed of the object by observing the speeds of the surface observing direction and the aviating direction of the object. CONSTITUTION: A first interference diagram forming part(110) forms an along track SAR interferometry(ATI) interference diagram based on synthetic aperture radar images. A second interference diagram forming part(120) forms a multiple aperture SAR interferometry(MAI) interference diagram based on the synthetic aperture radar images. A first speed measuring part(130) measures the speed of the surface observing direction with respect to an object based on the ATI interference diagram. A second speed measuring part(140) measures the speed of the aviating direction with respect to the object based on the MAI interference diagram. A speed determining part(150) combines the speed of the surface observing direction and the aviating direction to determine the two dimensional speed of the object.

Description

TECHNICAL FIELD METHOD AND DEVICE MEASUREMENT USING A Synthetic Aperture Radar Image {THE METHOD FOR MEASURIGN OBJECT'S VELOCITY USING SYNTHETIC APERTURE RADAR IMAGE AND THE APPARATUS THEREOF}

The present invention relates to a method and apparatus for measuring the speed of an object, and more particularly, to a method and apparatus for measuring the speed of an object using a synthetic aperture radar image.

The ATI technique acquires a pair of synthetic aperture radar image data from an airplane or satellite equipped with two radar antennas in the direction of flight, produces radar interference images from these data, and visualizes the phase values of radar interference images. After converting to the velocity in the direction of-sight (LOS), the velocity of the moving object in the surface observation direction is finally observed. Here, one of the two radar antennas has a transceiver function, and the other has only the function of a receiver.

The ATI technique can accurately observe the speed of a moving object in the surface observation direction and is used in various fields such as automobile, ship speed observation, sea wave speed observation and glacier speed observation.

However, this ATI technique has the disadvantage of observing only the moving speed of the radar in the surface observation direction (the vertical direction of the flight direction). Therefore, the speed of the moving object moving in the flight direction could not be observed. In order to overcome the biggest drawback, the vehicle is measured using the direction of the road because it moves along the road, but this method has a problem that the error increases exponentially as the road is closer to the flight direction. Moreover, it remains an unresolved assignment on the movement of seawater, the movement of ships, and the movement of glaciers, which show free movement.

In order to solve the above problems, the present invention observes the velocity of the surface observation direction from the ATI interference using synthetic aperture radar image data, extracts the two-dimensional velocity by observing the velocity of the flight direction from the MAI interference and combines them. The purpose is to provide a way to.

According to an aspect of the present invention, there is provided a method of measuring velocity of an object using a synthetic aperture radar image, comprising: a first manufacturing step of producing an ATI (along-track SAR interferometry) interference using the synthetic aperture radar image; A first observation step of observing a velocity in a surface observation direction with respect to a moving object from the ATI interference degree; A second manufacturing step of manufacturing multiple aperture SAR interferometry (MAI) coherence using the synthesized aperture radar image data; A second observation step of observing a velocity of a flying direction with respect to the moving object from the MAI interference degree; And determining the two-dimensional velocity of the moving object by combining the velocity in the surface observation direction and the velocity in the flight direction.

And, in the first manufacturing step, it is preferable to produce the ATI interference degree using a pair of front observation SLC image and a pair of rear observation SLC image in a pair of sensor mounting body having a radar sensor in front and rear. .

In addition, the ATI interference degree is preferably determined by multiplying the complex complex number of the front observation SLC image and the rear observation SLC image.

The first observation may include determining a phase of an ATI interference degree from the ATI interference degree; Determining a speed in the visual direction with respect to the moving object using the phase of the ATI interference degree, the wavelength of the radar, the wavelength of the sensor mounting body, and the distance between the front radar sensor and the rear radar sensor; And observing the speed in the surface observation direction with respect to the moving object using the speed in the eye direction and the incident angle of the radar.

In the second manufacturing step, a pair of forward-looking SLC images and a pair of backward-looking SLC images are fabricated from a pair of sensor mounting bodies equipped with radar sensors in front and behind. And producing a front view InSAR interference from the front view SLC image pair and a rear view InSAR interference from the rear view SLC image pair, and producing a MAI interference from the front view InSAR interference and the rear view InSAR interference. It is preferable.

One of the pair of forward-viewing SLC images is determined as the main image and the rest as sub-pictures, and one of the pair of backward-viewing SLC images is set as the main-image and the rest as sub-pictures, and the color complex number of the sub-images is determined. Multiplying the main image corresponding to the sub-image to produce the front-view InSAR interference and the back-view InSAR interference, and multiply the COLE complex number of the back-view InSAR interference by the front-view InSAR interference. It is desirable to produce an interference degree.

In addition, determining the phase of the MAI interference from the MAI interference; And the phase of the MAI interference, the time interval for the two radar sensor payloads to photograph the same area, the radar antenna length in the flight direction, and the normalized squint adjustment parameter. Determining a speed; preferably.

The determining of the phase of the MAI interference may include: a correction value for correcting the phase of the MAI interference using the speed in the surface observation direction when the moving object moves in the surface observation direction. Determining; And determining the difference between the correction values in the MAI interference degree as a final MAI interference degree.

Further, the correction value may include the radar antenna length in the flight direction, the speed in the surface observation direction, the normalized squint adjustment parameter, the length projected on the horizontal plane of the base line, and the speed of the radar sensor payload. It is preferable to determine using.

On the other hand, according to the present invention for achieving the above object, the apparatus for measuring the velocity of an object using a synthetic aperture radar image, the first interference to produce the ATI (along-track SAR interferometry) interference using the synthetic aperture radar image data Road production unit 110; A first speed observing unit for observing the speed in the surface observation direction with respect to a moving object from the ATI interference degree; A second interference producing unit configured to manufacture multiple aperture SAR interferometry (MAI) interference using the synthesized aperture radar image data; A second speed observing unit for observing the speed of the flying direction with respect to the moving object from the MAI interference degree; And a speed determiner configured to determine the two-dimensional speed of the moving object by combining the speed in the surface observation direction and the speed in the flight direction.

In addition, the first interference manufacturing unit, it is preferable to produce an ATI interference degree using a pair of front observation SLC image and a pair of rear observation SLC image in a pair of sensor mounting body having the radar sensor front and back. Do.

In addition, the ATI interference degree is preferably determined by multiplying the complex complex number of the front observation SLC image and the rear observation SLC image.

The first velocity observation unit determines the phase of the ATI interference degree from the ATI interference degree, and determines the phase of the ATI interference degree, the wavelength of the radar, the wavelength of the sensor mounting body, the front radar sensor and the rear radar. It is preferable to determine the speed in the eye direction with respect to the moving object using the distance between the sensors, and to observe the speed in the surface observation direction with respect to the moving object using the speed in the eye direction and the incident angle of the radar.

In addition, the second interference degree production unit, a pair of forward-looking SLC image and a pair of backward-looking SLC image in a pair of sensor mounting body having the radar sensor front and back Fabricate and produce a front view InSAR interference from the front view SLC image pair and a rear view InSAR interference from the rear view SLC image pair, and produce a MAI interference from the front view InSAR interference and the rear view InSAR interference. It is desirable to.

The second interference degree producing unit may determine one of the pair of forward-viewing SLC images as a main image and the other as a sub-image, and one of the pair of backward-viewing SLC images as a main image and the rest as a sub-image. Set the color complex number of the sub-image to the main image corresponding to the sub-image to produce the front observation InSAR interference degree and the rear observation InSAR interference degree, and the front complex observation of the rear complex InSAR interference degree. It is preferable to produce the MAI interference level by multiplying the InSAR interference degree.

In addition, the second speed observation unit, the phase of the MAI interference from the MAI interference degree, the phase of the MAI interference degree, the time interval between the two radar sensor payload to shoot the same area, the radar antenna length in the flight direction And using the normalized squint adjustment parameter to observe the velocity of the flight direction.

And, when the moving object is moving in the surface observation direction, the second speed observation unit determines a correction value for correcting the phase for the MAI interference degree using the speed in the surface observation direction, It is preferable to determine the difference of the correction value in the MAI interference degree as the final MAI interference degree, and to observe the speed of the flight direction with respect to the moving object from the final MAI interference degree.

Further, the correction value may include the radar antenna length in the flight direction, the speed in the surface observation direction, the normalized squint adjustment parameter, the length projected on the horizontal plane of the base line, and the speed of the radar sensor payload. It is preferable to determine using.

According to the present invention, it is possible to determine the two-dimensional speed by observing the surface observation speed and the flight direction speed of the moving object using the ATI interference and the MAI interference.

This can be used for traffic observations, car speed observations, glacier movements and sea level movements.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. A singular expression includes a plural expression unless the context clearly indicates otherwise. In this application, the terms "comprise" or "having" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other It is to be understood that the present invention does not exclude the possibility of the presence or the addition of features, numbers, steps, operations, components, parts, or a combination thereof.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a block diagram of an apparatus for measuring object velocity using a synthetic aperture radar image according to an embodiment of the present invention, and FIG. 2 is a method of measuring object velocity using a composite aperture radar image according to an embodiment of the present invention. This is a flow chart showing the process of performing.

As shown in FIG. 1 and FIG. 2, the first interference canceling unit removes the ATI (along-track SAR interferometry) interference using the synthetic aperture radar image data (S210), and the second interference manufacturing unit 120. In operation S220, multiple aperture SAR interferometry (MAI) coherence is produced using the synthetic aperture radar image data. In addition, the first speed observer 130 observes the moving object speed in the ground range direction from the ATI interference degree (S230), and the second speed observer 140 measures the flight direction from the MAI interference degree (S230). The moving object velocity in the along-track direction is observed (S240). Finally, the speed determination unit 150 determines the two-dimensional speed of the moving object by combining the speed in the surface observation direction and the speed in the flight direction (S250).

Hereinafter, each step will be described in more detail with reference to the accompanying drawings.

First, the process of determining the velocity in the surface observation direction with respect to the moving object will be described.

3 is a view showing the geometry of the sensor mounting body for observing the speed of the two-dimensional moving object. Each of the front and rear sensors is mounted on the sensor tower body at a certain distance (), and the sensor mounting body 1 and the sensor mounting body 2 obtain radar images of the same area with a certain time interval ().

At this time, the velocity of the surface observation direction with respect to the moving object on the ground surface is calculated from the ATI images made from the SLC images after the SLC images are produced from the front and rear sensors of each sensor mounting body. On the other hand, the velocity of the flight direction is a MAI image obtained by using one of the SLC images obtained from the front and rear sensors of the sensor mounting body 1 as a main image, and one of the SLC images obtained from the front and rear sensors of the sensor mounting body 2 as a sub image. Is calculated from The distance between the front and rear sensors is 1.2m, and the time interval between the sensor mounting body 1 and the sensor mounting body 2 is preferably at most about 0.08 seconds.

)는 앞의 레이더 센서에 의해 촬영된 전방관측 SLC 영상 자료(

)와 뒤의 합성 개구 레이더 영상 센서에 의해 촬영된 후방 관측 SLC 영상 자료(

)에 의하여 하기 수학식 1과 같이 결정된다.Specifically, the first interference manufacturing unit 110 produces the ATI interference degree from the SLC image pairs obtained from the front and rear sensors provided on the sensor mounting body 1 and the sensor mounting body 2, respectively.

) Is the front view SLC image data (

And rearview SLC image data captured by the composite aperture radar image sensor behind

Is determined by Equation 1 below.

Where * is a complex conjugate.

In addition, the first speed observation unit 130 determines the phase of the ATI interference degree as shown in Equation 2 below.

Where is the angle of the complex number.

)를 결정한다.On the other hand, in the case of a radar system having one of the two radar antennas only the transceiver function, the other only the receiver function, the first speed observer 130 is the speed from the ATI phase to the visual direction (Equation 3 below)

Is determined.

는 레이더 파장(radar's wavelength)이고,

는 레이더 센서 탑재체(예를 들어, 위성, 비행기 등)의 속도이며,

는 앞 및 뒤 센서간의 거리이다. here,

Is the radar's wavelength,

Is the speed of the radar sensor payload (e.g., satellite, airplane, etc.)

Is the distance between the front and rear sensors.

)로 변환한다.In addition, the first speed observer 130 may measure the visual direction speed of Equation 3 as shown in Equation 4 below.

To.

는 레이더파의 입사각을 의미한다.here,

Denotes the incident angle of the radar wave.

4 is a diagram illustrating an example of determining the speed of the surface observation direction with respect to a moving object using the ATI interference degree according to one embodiment of the present invention. In order to determine the speed of the surface observation direction with respect to the moving object as shown in FIG. 4, after simulating the synthetic aperture radar image data photographing the four moving objects on the surface, an ATI interference degree was produced, and the surface observation speed was measured. Is calculated.

)로 변환한 값을 나타낸 도면이고, 도 4의 (d)는 수학식 4를 이용하여 시선방향속도를 지표관 측방향 속도(

)로 변환한 값을 나타낸 도면이다. FIG. 4 (a) shows the velocity and direction vectors for four moving objects used in the simulation, and shows the velocity in the surface observation direction. Figure 4 (b) is a diagram showing the phase value of the ATI interference degree for each moving object using the equation (2). 4 (c) shows the ATI phase by using the equation 3,

Figure 4 is a diagram showing the value converted to, Figure 4 (d) is a surface direction lateral velocity (

The figure which converted the value into ().

The actual surface observation velocities of the four moving objects were -5, 14.14, 0, and 10 m / s, respectively, and the surface observation velocities measured from the ATI coherence were -4.94, 14.21, 0.05, and 10.09 m / s, respectively. Therefore, the simulated four moving objects are 0.06, 0.07, 0.05, 0.09 m / s, and the average of about 0.068 m / s (0.25 km / h) can be used to confirm that the moving objects on the surface can be observed from the ATI interference degree. Can be. However, this value uses a simulated image. Of course, when using an actual image, it may have a larger error. In FIG. 4, the position of the moving object in FIG. 4A and the position of the moving object in FIG. 4B (c) and (d) is due to the Doppler effect of the moving object.

The following describes how to determine the velocity of the flight direction for the moving object.

On the other hand, the second interference producing unit 120 is a pair of forward-looking SLC image and a pair of backward-looking from a pair of composite aperture radar image data having a short vertical baseline (perpendicular baseline) A SLC image is produced, and a front-side InSAR interference from the front-side SLC image pair and a rear-side InSAR interference from the rear-view SLC image pair are produced, and MAI interference is obtained from the two inter-SAR (interferometric SAR) interference. To make.

When using a composite aperture radar image pair having a baseline, the MAI interference is influenced by an object moving in the visual direction, and thus the moving object velocity in the flight direction can be determined from the MAI interference. On the other hand, since the composite aperture radar image pairs are actually located at different positions, it is necessary to correct the moving object velocity in the flight direction from the surface observation direction velocity.

Hereinafter, a detailed description will be given with reference to FIG. 5. 5 is a diagram showing the MAI phase geometry for the moving object in the flight direction.

), 평균 도플러 중심주파수(

), 서브어퍼쳐 도플러 대역폭(Subaperture Doppler bandwidth;

)을 이용하여 제작되며, 일반적인 영상압축과정을 이용하여 제작되지만, 하기 두 가지 점에서 일반적인 영상압축과정과 다르다.The second interference degree producing unit 120 is a master image of one of the SLC images obtained from the front and rear sensors of the sensor mounting body 1 illustrated in FIG. 5, and among the SLC images obtained from the front and rear sensors of the sensor mounting body 2. One pair of front-view SLC images and one pair of rear-view SLC images are produced as slave images. In this case, the first image captured for the same region is used as the main image, and the image captured afterwards is the sub image. Then, the front observation InSAR interference from the front observation SLC image pair and the rear observation InSAR interference from the rear observation SLC image pair are produced, and the MAI interference is produced from the two InSAR interferences. Here, the front and rear observation SLC images are the front and rear observation Doppler center frequencies (

), Average Doppler center frequency (

), Subaperture Doppler bandwidth;

It is produced by using) and is produced by using a general image compression process, but is different from the general image compression process in the following two points.

)와 서브어퍼쳐 도플러 대역폭(

)을 이용하여 처리되며, 후방관측 SLC자료를 위한 영상압축처리는 후방관측 도플러 중심주파수(

)와 서브어퍼쳐 도플러 대역폭(

)를 이용하여 처리된다.First, image compression is generally performed using the Doppler center frequency and the Doppler bandwidth of the radar sensor. However, the image compression processing for forward observation SLC data does

) And subaperture Doppler bandwidth (

Image compression processing for the posterior observation SLC data.

) And subaperture Doppler bandwidth (

Is processed using).

)를 이용하여 RCMC를 적용한다.Second, the synthetic aperture radar image is obtained through the process of compressing the object thousands of times to obtain the SLC image. However, the information about an object in the synthetic aperture radar image data does not appear in the form of a straight line due to the change of the distance between the sensor and the object. It is called range cell migration. In addition, the process of straightening this phenomenon is called range cell migration correction (RCMC). In general, RCMC linearizes using the Doppler center frequency. However, since the different Doppler center frequencies are used in the production of front and rear observation SLC data, they have a positional difference in the horizontal direction of the image. Therefore, the average Doppler is used to make the same object in the front and rear observation SLC data. Center frequency

Apply RCMC using).

)과 후방관측 SLC 부영상(slave image,

)을 이용하여 전방관측 InSAR간섭도(

)를 제작한다. 특히, 전방관측 InSAR간섭도는 하기 수학식 5와 같이 제작되는 것이 바람직하다. The second interference producing unit 120 is a front view SLC main image (master image,

) And posterior observation SLC sub-images

InSAR coherence using

). In particular, the front observation InSAR interference is preferably produced as shown in Equation 5.

)과 후방관측 SLC 부영상(

)를 이용하여 하기 수학식 6와 같은 후방관측 InSAR간섭도(

)를 제작한다. And, the second interference degree production unit 120 is the rear view SLC main image (

) And posterior observation SLC sub-image (

BackSurveillance InSAR interference (

).

)를 제작한다.In addition, the second interference degree manufacturing unit 120 uses the MAI interference (Equation 7) using the front observation InSAR interference and the rear observation InSAR interference degree (

).

The second speed observing unit 140 determines the phase of the MAI interference degree from the MAI interference degree as shown in Equation 8 below.

On the other hand, the second speed observation unit 140 observes the flight direction speed based on the phase of the MAI interference, it will be described in more detail below.

6 is a view showing the MAI phase up and down for the moving object in the flight direction according to an embodiment of the present invention.

은 비행방향으로의 레이더 안테나 길이(Effective antenna length in azimuth direction)이고,

는 레이다 파장(radar wavelength)이며,

은 정규화된 스퀸트 조정 변수(normalized squint adjustment parameter)이다. 그리고,

는 각각 레이더 센서 탑재체와 비행방향으로의 이동물체속도를 나타낸다. 여기서, 정규화된 스퀸트 조정변수는 안테나 어퍼쳐(aperture)의 크기를 전기적으로 조정하는 변수이다. In Figure 6

Is the effective antenna length in azimuth direction,

Is the radar wavelength,

Is a normalized squint adjustment parameter. And,

Are the radar sensor payloads and the moving object velocity in the flight direction, respectively. Here, the normalized squint adjustment variable is a variable for electrically adjusting the size of the antenna aperture.

In general, synthetic aperture radar image data is compressed by photographing an object on the ground thousands of times to produce a high resolution image. In this case, the front observation composite aperture radar image data is produced by using the data corresponding to the size of the aperture observed forward among the size of the antenna aperture, and the rear observation composite aperture radar image data is observed backward. It was produced using the data. Normally, the normalized squind adjustment variable uses 0.5 (exactly dividing the antenna aperture in half).

는 각각 전방관측과 후방관측 주영상에 대한 경사거리(slant range distance)를 의미하며,

는 각각 전방관측과 후방관측 부영상에 대한 경사거리를 의미하고,

는 센서탑재체와 지표면간의 최단경사거리를 의미한다.

는 각각 전방관측과 후방관측영상을 촬영할 때의 센서탐재체의 위치를 나타낸다. 또한,

은 주영상의 전방관측시 이동물체의 위치,

는 주영상의 후방관측시 이동물체의 위치,

는 부영상의 전방관측시 이동물체의 위치 및

는 부영상의 후방관측시 이동물체의 위치를 보인다.Also,

Denotes the slant range distance for the front and rear main images, respectively.

Are the inclination distances for the anterior and posterior subimages, respectively.

Means the shortest inclination distance between the sensor mounting body and the ground surface.

Indicates the positions of the sensor probes when the front and rear observation images are taken, respectively. Also,

Is the position of the moving object in front view of the main image,

Is the position of the moving object in the rear view of the main image,

Is the position of the moving object in front view of the sub-image and

Shows the position of the moving object in the rear view of the sub-image.

)는 전방관측 주영상의 경사거리(

)와 전방관측 부영상의 경사거리(

)의 차에 의해서 하기 수학식 9와 같이 결정된다. In Fig. 6 the inclination distance of the front observation InSAR interference degree (

) Is the inclination distance (

) And the inclination distance of the anterior subview

Is determined as shown in Equation 9 below.

)와 전방관측 부영상의 경사거리(

)는 각각 하기 수학식 10 및 수학식 11과 같이 결정된다. Where the inclination distance of the main observation image (

) And the inclination distance of the anterior subview

) Are determined as in Equations 10 and 11, respectively.

)도 후방관측 주영상의 경사거리(

)와 후방관측 부영상의 경사거리(

)의 차에 의해서 하기 수학식 12와 같이 결정된다.On the other hand, the inclination distance of the rearview InSAR interference degree (

Degrees of inclination of the posterior main image

) And the oblique distance of the posterior subimage

Is determined as shown in Equation 12 below.

)와 후방관측 부영상의 경사거리(

)는 각각 하기 수학식 13 및 수학식 14와 같이 결정된다.Where the oblique distance of the posterior main image (

) And the oblique distance of the posterior subimage

) Are determined as in Equations 13 and 14, respectively.

)는 수학식 9와 수학식 12를 이용하여 하기 수학식 15와 같이 결정된다.The slope distance of MAI interference

) Is determined as in Equation 15 using Equations 9 and 12.

인 것과 탑재체에 비해 이동물체의 속도가 일반적으로 매우 작기 때문에

이므로 하기 수학식 16과 같이 단순화 할 수 있다.here,

Because the speed of the moving object is generally very small compared to

Therefore, it can be simplified as shown in Equation 16 below.

The second speed observation unit 140 determines the phase of the MAI interference degree using Equation 16 as shown in Equation 17 below.

)를수학식 17에 정의된 MAI간섭도 위상(

)를 이용하여 하기 수학식 18와 같이 결 정한다. As a result, the second speed observer 140 measures the speed of the object moving in the flight direction (

MAI coherence phase (

) Is determined as in Equation 18 below.

Therefore, the flight direction velocity is obtained by calculating the phase of MAI interference using Equation 8 and converting the phase by using Equation 18 from the prepared MAI interference.

On the other hand, the phase of the MAI interference should be corrected because it changes not only by the speed of the moving object moving in the flight direction but also by the speed of the moving object moving in the surface observation direction (that is, the cross direction with the flying direction).

Flight direction speed correction includes a step of correcting the phase by the speed of the moving object moving in the surface observation direction from the phase of the MAI interference produced by the second interference producing unit 120.

7 is a view showing the MAI phase up and down for the moving object in the surface observation direction according to an embodiment of the present invention.

는 지표관측방향으로의 이동물체속도를 나타내고,

는 각각 주영상과 부영상에서 센서탑재체와 지표면간의 최단경사거리를 의미한다.

과

는 각각 주영 상과 부영상에서

의 지표면 상의 거리를 나타내며,

는 각각 주영상과 부영상의 위성고도이다.

는 주영상에 대한 전방관측과 후방관측영상을 촬영할 때의 센서탐재체의 위치이며,

과 는 부영상에 대한 전방관측과 후방관측영상을 촬영할 때의 센서탑재체의 위치를 나타낸다.Description of each symbol in FIG. 7 is the same as FIG. 5, and additionally

Represents the moving object velocity in the surface observation direction,

Denotes the shortest inclination distance between the sensor mounting body and the ground surface in the main and sub-images, respectively.

and

In the main and sub-images

Represents the distance on Earth's surface,

Are the altitudes of the main and sub images respectively.

Is the position of the sensor probe when the front and rear observation images of the main image are taken.

and Indicates the position of the sensor mounting body when photographing the front and rear observation images for the sub-image.

)는 전방관측 주영상의 경사거리(

)와 전방관측 부영상의 경사거리(

)의 차에 의해서 결정된다.The inclination distance of the forward observation InSAR interference degree in FIG.

) Is the inclination distance (

) And the inclination distance of the anterior subview

) Is determined by the difference.

)와 전방관측 부영상의 경사거리(

)는 각각 하기 수학식으로 정의될 수 있다.Where the inclination distance of the main observation image (

) And the inclination distance of the anterior subview

) May be defined by the following equations, respectively.

)는 후방관측 주영상의 경사거리(

)와 후방관측 부영상의 경사거리(

)의 차에 의해서 결정된다.Also, the inclination distance of the rearview InSAR interference degree (

) Is the inclination distance (

) And the oblique distance of the posterior subimage

) Is determined by the difference.

는 각각 하기 수학식으로 정의될 수 있다.here

Each can be defined by the following equation.

)는 수학식 19와 수학식 22를 이용하여 하기 수학식으로 정의할 수 있다.The slope distance of MAI interference

) Can be defined by the following equation (19) and (22).

인 것을 이용하면 하기 수학식과 같이 단순화할 수 있다.here,

Using can be simplified as in the following equation.

와 수평면과 기선이 이루는 각

를 이용하면

으로 대체할 수 있고, 상기 값에 비하여

는 매우 작은 값이므로 무시할 수 있다. 이와 같은 단순화를 통하여 수학식 26은 하기와 같이 표현된다.Also, baseline from FIG. 7.

Angle between the horizontal plane and the base line

If you use

Can be replaced with

Is a very small value and can be ignored. Through this simplification, Equation 26 is expressed as follows.

The phase of the MAI interference is defined by the following equation (27).

)에 의하여 MAI 간섭도의 위상은 수학식 28과 같이 변환된다. Eventually, the velocity of the object moving in the surface observation direction (

), The phase of the MAI interference is converted as shown in Equation 28.

That is, the phase of MAI interference is used to calculate the velocity in the flight direction. The phase of MAI interference according to the movement speed in the surface observation direction should be corrected.

)로부터 변형된 MAI 위상값을 수학식 28로부터 계산한다. 그리고, 수학식 8에 의하여 제작된 MAI 간섭도에서 변형된 MAI 위상값을 뺀 값을 최종 MAI 간섭도의 위상으로 결정하고, 이를 수학식 18을 적용하여 비행방향의 물체 속도(

)를 계산한다.This correction process is performed by the speed of the object moving in the surface observation direction extracted by the surface observation direction observation step (S1).

The MAI phase value modified from) is calculated from Equation 28. Then, the value obtained by subtracting the modified MAI phase value from the MAI interference degree produced by Equation 8 is determined as the phase of the final MAI interference degree, and the equation 18 is applied to the object velocity in the flight direction (

Calculate

FIG. 8 illustrates simulation results of the front and rear composite aperture radar image data of four moving objects existing on the ground according to an embodiment of the present invention, and then a MAI interference calculation and flight direction velocity calculations. Figure is shown.

)로 변환한 값을 나타낸다. 도9의 (d)는 수학식 28를 이용하여 지표관측방향 속도(

)에 의하여 변형된 MAI 위상을 보정한 비행방향속도(

)를 나타낸다. FIG. 9 (a) shows the velocity and direction vector for the four moving objects used in the simulation, shows the speed in the flight direction, and FIG. 9 (b) shows the phase value of the MAI interference degree of each moving object. . 9 (c) shows the MAI phase in flight direction velocity (Equation 18).

) Is converted to). 9 (d) shows the surface observation direction velocity (Equation 28).

Flight direction velocity corrected MAI phase modified by

).

The actual flight speeds of the four moving objects were 0, 14.14, 10 and 0m / s, respectively, and the final flight speeds measured from MAI interference were 0.01, 14.51, 9.90 and -0.18m / s. Therefore, the simulated error of the four moving objects is 0.01, 0.37, 0.1, -0.18m / s, and the average velocity of the moving object on the ground can be observed with an error of about 0.11m / s (0.39km / h). Able to know. However, this value uses a simulated image. Of course, when using an actual image, it may have a larger error. The position of the moving object in FIG. 8 (a) and the position of the moving object in FIGS. 8 (b), (c) and (d) is indicated by the Doppler effect of the moving object.

In addition, although the preferred embodiment of the present invention has been shown and described above, the present invention is not limited to the specific embodiments described above, but the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Of course, various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

1 is a block diagram of an apparatus for measuring an object velocity using a composite aperture radar image according to an embodiment of the present invention;

2 is a flowchart illustrating a process of performing an object velocity measuring method using a composite aperture radar image according to an embodiment of the present invention;

3 is a view showing the geometry of the sensor mounting body for observing the speed of the two-dimensional moving object,

4 is a view showing an example of determining the speed of the surface observation direction for a moving object using the ATI interference degree according to an embodiment of the present invention,

5 is a diagram showing the MAI phase geometry for the moving object in the flight direction,

6 is a view showing the MAI phase upper and lower for the moving object in the flight direction according to an embodiment of the present invention,

7 is a view showing the MAI phase up and down for the moving object in the surface observation direction according to an embodiment of the present invention, and

FIG. 8 illustrates simulation results of the front and rear composite aperture radar image data of four moving objects existing on the ground according to an embodiment of the present invention, and then a MAI interference calculation and flight direction velocity calculations. Figure is shown.

Explanation of symbols on the main parts of the drawings

110: first interference degree production unit 120: second interference degree production unit

130: first speed observing unit 140: second speed observing unit

150: speed determination unit

Claims (18)

A first manufacturing step of producing an ATI (along-track SAR interferometry) interference using a synthetic aperture radar image; A second manufacturing step of manufacturing multiple aperture SAR interferometry (MAI) coherence using the synthesized aperture radar image data; A first observation step of observing a velocity in a surface observation direction with respect to a moving object from the ATI interference degree; A second observation step of observing a velocity of a flying direction with respect to the moving object from the MAI interference degree; And And determining a two-dimensional velocity of the moving object by combining the velocity in the surface observation direction and the velocity in the flight direction. The method of claim 1, The first production step, An ATI interference degree is produced by using a pair of front-view SLC images and a pair of rear-view SLC images in a pair of sensor mounting bodies equipped with the front and rear of the radar sensor. How to measure speed. 3. The method of claim 2, The ATI interference degree is The object velocity measuring method using a composite aperture radar image, characterized in that determined by multiplying the Cull complex number of the front observation SLC image and the rear observation SLC image. The method of claim 1, The first observation step, Determining a phase of an ATI interference degree from the ATI interference degree; Determining a speed in the visual direction with respect to the moving object using the phase of the ATI interference degree, the wavelength of the radar, the wavelength of the sensor mounting body, and the distance between the front radar sensor and the rear radar sensor; And And observing the speed in the surface observation direction with respect to the moving object by using the speed in the eye direction and the incident angle of the radar. The method of claim 1, The second production step, A pair of forward-looking SLC images and a pair of backward-looking SLC images are produced from a pair of sensor mounting bodies equipped with radar sensors at the front and the rear, and from the pair of front-view SLC images A composite aperture radar image is generated from the front observation InSAR interference and the rear observation SLC image pair. Method of measuring the speed of the object used. The method of claim 5, One of the pair of forward-viewing SLC images is determined as a main image and the rest as sub-pictures, and one of the pair of backward-viewing SLC images is set as a main-image and the rest as sub-pictures, Producing the front observation InSAR interference and the rear observation InSAR interference by multiplying the color complex number of the sub-image by the main image corresponding to the sub-image, And producing the MAI interference by multiplying the front complex InSAR interference degree by the COLE complex number of the rear observation InSAR interference degree. The method of claim 1, Determining a phase of the MAI interference from the MAI interference; And The velocity of the flight direction is determined using the phase of the MAI interference, the time interval between the two radar sensor payloads photographing the same area, the length of the radar antenna in the direction of flight, and a normalized squint adjustment parameter. Determining the velocity of the object using the composite aperture radar image. The method of claim 7, wherein Determining the phase of the MAI interference degree, Determining a correction value for correcting a phase with respect to the MAI interference degree using the speed in the surface observation direction when the moving object is moving in the surface observation direction; And And determining a difference between the correction values in the MAI interference degree as a final MAI interference degree. The method of claim 7, wherein The correction value is, Radar antenna length in the direction of flight, speed in the surface observation direction, normalized squint adjustment parameter, length projected on the horizontal plane of the baseline, and speed of the radar sensor payload. An object velocity measurement method using a composite aperture radar image. A first interference producing unit for producing an ATI (along-track SAR interferometry) interference using synthetic aperture radar image data; A second interference producing unit configured to manufacture multiple aperture SAR interferometry (MAI) interference using the synthesized aperture radar image data; A first speed observing unit for observing the speed in the surface observation direction with respect to a moving object from the ATI interference degree; A second speed observing unit for observing the speed of the flying direction with respect to the moving object from the MAI interference degree; And And a speed determiner configured to determine the two-dimensional speed of the moving object by combining the speed in the surface observation direction and the speed in the flight direction. The method of claim 10, The first interference degree production unit, An ATI interference degree is produced by using a pair of front-view SLC images and a pair of rear-view SLC images in a pair of sensor mounting bodies equipped with the front and rear of the radar sensor. Speed measuring device. The method of claim 11, The ATI interference degree is The apparatus for measuring the velocity of an object using a composite aperture radar image, which is determined by multiplying the COLE complex number of the front observation SLC image and the rear observation SLC image. The method of claim 11, The first speed observation unit, The phase of the ATI interference degree is determined from the ATI interference degree, and the moving object is determined using the phase of the ATI interference degree, the wavelength of the radar, the wavelength of the sensor mounting body, and the distance between the front radar sensor and the rear radar sensor. The speed of the object is determined using a composite aperture radar image, the speed of which is determined in the visual direction, and the speed of the surface observation direction with respect to the moving object is observed using the speed in the eye direction and the incident angle of the radar. Device. The method of claim 10, The second interference degree production unit, A pair of forward-looking SLC images and a pair of backward-looking SLC images are produced from a pair of sensor mounting bodies equipped with radar sensors at the front and the rear, and from the pair of front-view SLC images A composite aperture radar image is produced from a front observation InSAR interference map and a rear view InSAR interference map from the rear view SLC image pair, and a MAI interference from the front view InSAR interference map and the rear view InSAR interference map. Speed measuring device of the used object. 15. The method of claim 14, The second interference degree production unit, One of the pair of forward-viewing SLC images is determined as a main image and the rest as sub-pictures, and one of the pair of backward-viewing SLC images is set as a main-image and the rest as sub-pictures, Producing the front observation InSAR interference and the rear observation InSAR interference by multiplying the color complex number of the sub-image by the main image corresponding to the sub-image, And the MAI interference level is produced by multiplying the front complex InSAR interference degree by the COLE complex number of the rearview InSAR interference degree. The method of claim 10, The second speed observation unit, The phase of the MAI interference is determined from the MAI interference degree, the phase of the MAI interference degree, the time interval at which the two radar sensor payloads photograph the same region, the radar antenna length in the flight direction, and the normalized sequence adjustment parameter (normalized) and a squint adjustment parameter to observe the velocity of the flight direction. The method of claim 10, The second speed observation unit, When the moving object is moving in the surface observation direction, a correction value for correcting a phase with respect to the MAI interference degree is determined using the speed in the surface observation direction, The speed difference of the object using the composite aperture radar image is determined by determining the difference between the correction values in the MAI interference degree as the final MAI interference degree and observing the velocity of the flight direction with respect to the moving object from the final MAI interference degree. Device. The method of claim 17, The correction value is, Radar antenna length in the direction of flight, speed in the surface observation direction, normalized squint adjustment parameter, length projected on the horizontal plane of the baseline, and speed of the radar sensor payload. An apparatus for measuring the velocity of an object using a synthetic aperture radar image.

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