KR20190136850A - Method for mitigation of topographic effect in infrared images taken from geostationary orbit imaging system and Apparatus Thereof - Google Patents

Abstract

The present invention relates to a reduction method of an altitude impact from a geostationary orbit infrared image and a device thereof. More specifically, the present invention relates to the reduction method of the altitude impact from the geostationary orbit infrared image and the device thereof, wherein a surface temperature image is estimated on the basis of an infrared channel image photographed by a satellite operating in a geostationary orbit, and minimizes an effect caused by an altitude change displayed on the estimated surface temperature image. The present invention comprises: an acquiring part; a surface temperature image producing part; a land surface temperature lapse rate estimating part; and an altitude impact reduction part.

Description

Method for mitigation of topographic effect in infrared images taken from geostationary orbit imaging system and Apparatus Thereof}

The present invention relates to a method and apparatus for reducing altitude effects in a geostationary infrared image, and more particularly, to obtain a surface temperature image from an infrared channel image captured by a satellite operating in a geostationary orbit, and to change the elevation in the surface temperature image. A method and apparatus for minimizing the effects of the present invention.

The earth observation satellite, which observes the earth from space, has the advantage of monitoring human activity and changes in the natural environment by periodically obtaining information about the earth's surface by excluding the earth's surroundings along the satellite orbit.

Of the various satellite orbits, the geostationary orbit is a circular orbit of 35,786 km in the air. A geostationary satellite is a satellite that photographs the earth's surface on a geostationary orbit. Since the satellite's revolution speed and the earth's rotation speed are the same, the geostationary satellite can continuously photograph the same area. Therefore, it is possible to respond rapidly to the weather field, ocean currents, and natural disasters that change in real time. Therefore, advanced countries utilizing satellite imagery such as the US, Japan, and Taiwan are operating geostationary satellites, and Korea is also planning to operate geostationary satellites. Is in.

Unlike the polar orbit satellite, the geostationary orbit satellite has a relatively low spatial resolution because of the high altitude of the orbit, and has the advantage of providing a channel image of various wavelength bands.

Just as the ratio of temperature decreasing with altitude is defined as the air temperature lapse rate, the ratio of surface temperature decreasing with altitude is defined as the land surface temperature lapse rate, The researches and methods utilized have been continuously made. Related patents include Korean Patent No. 10-1404430 "Method of Estimating Surface Temperature Reduction Using Infrared Image" and Korean Patent No. 10-1378774 "Method of Monitoring Time Series Surface Temperature Using Thermal Infrared Image". Has come true.

However, the method for estimating the altitude effect in the satellite image system developed to date is suitable for the high resolution polar orbit satellite image system, and it is effective to estimate the altitude effect in the local area. However, there is a limitation in estimating the altitude effect in the local area due to the low resolution geostationary satellite image system photographing the whole earth. This is because most of the regions shown in the geostationary satellite imagery belong to the lowlands, and when the low temperature is emphasized, the surface temperature rate is estimated to converge close to 0 K / km.

Therefore, in order to reduce altitude effects in geostationary satellite image systems, a method for estimating surface temperature decrement suitable for satellite images of geostationary orbits is required, and a technique for reducing altitude effects from estimated surface temperature deceleration is needed.

An object of the present invention is to reduce the altitude effect appearing in the stationary orbit infrared image.

An object of the present invention is to reduce the altitude effect by effectively estimating the altitude effect shown in the geostationary infrared image.

An object of the present invention is to estimate the surface temperature reduction rate at the time of image capturing and to reduce the altitude effect.

An object of the present invention is to reduce the altitude effect shown in the geostationary infrared image by using the estimated surface temperature reduction rate.

An object of the present invention is to produce a surface temperature image of which the altitude effect is reduced rather than the actual surface temperature image by reducing the altitude effect using the estimated surface temperature reduction rate.

An object of the present invention is to contribute to the field of infrared satellite image application including forest fire detection, volcanic eruption monitoring, and urban heat island phenomenon monitoring by producing surface temperature images with reduced altitude.

An object of the present invention is to improve the performance of algorithmic techniques that can monitor forest fires, volcanic eruptions, etc. by producing surface temperature images with reduced altitude effects.

The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned above will be clearly understood by those skilled in the art from the following description. Could be.

According to an embodiment of the present invention, it is possible to provide an apparatus for reducing the altitude effect in a geostationary satellite. At this time, the altitude impact reduction device in the geostationary satellite has a geostationary satellite image acquisition unit, digital elevation model acquisition unit, cloud area removal unit, surface temperature image production unit, sample data selection unit, surface temperature reduction estimation unit and altitude impact reduction It may include wealth.

In addition, the following embodiments may be commonly applied to the altitude reduction device in the geostationary satellite and the altitude impact reduction method in the geostationary satellite.

According to an embodiment of the present invention, the image acquisition unit may acquire a geostationary satellite image taken by the geostationary satellite system.

According to an embodiment of the present invention, the digital elevation model acquisition unit may acquire a digital elevation model having the same coordinate system as the geostationary satellite image.

According to an embodiment of the present invention, the cloud region removal unit may detect and remove the cloud region existing in the image using the satellite image acquired by the geostationary satellite image acquisition unit.

According to an embodiment of the present invention, the surface temperature image production unit produces the surface temperature image using the infrared satellite image acquired by the geostationary satellite image acquisition unit.

According to an embodiment of the present invention, the sample data selection unit is a sample surface temperature and altitude information for estimating the surface temperature reduction rate in the surface temperature image produced by the surface temperature image production unit and the digital elevation model acquisition unit Can be obtained.

According to an embodiment of the present invention, the surface temperature reduction rate estimating unit estimates the surface temperature reduction rate using the surface temperature and the altitude information sample selected by the sample data selection unit.

According to an embodiment of the present invention, the altitude reduction unit may reduce the altitude effect displayed on the surface temperature image produced by the surface temperature image production unit by using the surface temperature reduction rate estimated by the surface temperature reduction estimation unit.

According to the present invention, there is an effect of estimating the surface temperature reduction rate corresponding to the image capturing time from the surface temperature image provided in the stationary orbit infrared image.

The present invention has the effect of estimating the global surface temperature reduction rate corresponding to the image capturing time from the global surface temperature image that can be provided in the geostationary infrared image.

The present invention has an effect of reducing the influence of the terrain altitude appearing in the surface temperature image that can be provided in the geostationary orbit infrared image using the surface temperature reduction rate.

The present invention has an effect that can be applied to the application of land surface temperature image, such as forest fire detection, volcanic eruption monitoring by reducing the effect of topographical altitude appearing on the surface temperature image.

The present invention has the effect of improving the performance of the surface temperature image using algorithms such as forest fire detection, volcanic eruption monitoring by reducing the influence of the terrain altitude appearing on the surface temperature image.

The present invention is a technology that can be widely applied to various fields for observing surface temperature information, and has an effect that can be applied to civilian fields such as military field such as image classification, target detection, vegetation monitoring, and object recognition including soil water extraction. have.

Among the commercial satellite image processing software of foreign countries, the method for reducing the high impact of geostationary infrared satellite image is lacking as a module of the software. Therefore, the original technology of the present invention can be installed in the satellite image processing software developed in Korea. Therefore, the present invention has the effect of contributing to the increased utilization of satellite imagery and the national satellite industry through the commercialization of the original technology.

The present invention can be applied to domestic geostationary satellites, including communication oceanic satellites and next-generation geostationary satellites, which can acquire infrared images, thereby maximizing the utilization of domestic satellite image data.

The effects obtainable in the present invention are not limited to the above-mentioned effects, and other effects not mentioned above may be clearly understood by those skilled in the art from the following description. will be.

FIG. 1 is a diagram illustrating a configuration of an apparatus for reducing an altitude effect in a geostationary infrared image.
2 is a diagram showing an example of a geostationary satellite image and a digital elevation model.
3 is a diagram illustrating an example of the surface temperature image.
4 is a diagram illustrating an example of a sample data selection method.
5 is a diagram illustrating an example of the estimated surface temperature reduction rate.
6 is an image showing an example before and after the correction of the altitude impact.
7 is a diagram illustrating an application example of the surface temperature image.
8 is a flowchart illustrating a method for reducing altitude effects in a geostationary infrared image.

The terms or words used in this specification and claims are not to be construed as limiting in their usual or dictionary meanings, and the inventors may appropriately define the concept of terms in order to best explain their invention in the best way possible. Based on the principle that the present invention should be interpreted as meaning and concept corresponding to the technical idea of the present invention.

Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

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 "have" are intended to indicate that there is a feature, number, step, action, 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, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, in describing the embodiments of the present invention, specific numerical values are merely examples.

The present invention relates to a method and apparatus for reducing altitude effects in a geostationary infrared image. More specifically, the surface temperature image is estimated based on the infrared channel image captured by the satellite operating in the geostationary track, and the altitude effect on the geostationary infrared image to minimize the effect of the elevation change in the estimated surface temperature image It relates to a reduction method and an apparatus thereof.

The invention will be described below in the order of the drawings.

1 is a view showing a configuration of an apparatus for reducing the high impact in a geostationary infrared image.

2 to 7 are diagrams showing embodiments of image processing according to the apparatus and method for reducing the high impact in the geostationary infrared image of the present invention. When the embodiment of FIGS. 2 to 7 corresponds to the embodiment of the corresponding configuration of the apparatus of FIG. 1, the configuration of the apparatus of FIG. 1 will be described with reference to FIGS. 2 to 7.

Referring to FIG. 1, the method and apparatus for reducing the altitude effect in the geostationary infrared image of the present invention include a geostationary satellite image acquisition unit 110, a digital elevation model acquisition unit 120, a cloud region removal unit 130, Surface temperature image production unit 140, sample data selection unit 150, surface temperature reduction rate estimator 160 and altitude impact reduction unit 170.

The geostationary satellite image acquisition unit 110 acquires the geostationary satellite image taken by the geostationary satellite system. In more detail, the geostationary satellite image acquisition unit 110 acquires a satellite image photographed by the geostationary satellite system. In general, geostationary orbit satellite systems, unlike polar orbit satellite systems, have a small spatial resolution because they observe the Earth's surface from a very high 35,786 km.

On the other hand, geostationary satellite system has the advantage of being able to collect radiation of various wavelength bands. The channel images provided by most geostationary satellite systems range from visible wavelength bands to near-infrared, mid-infrared and thermal-infrared wavelengths. Among them, the mid-infrared and thermal-infrared channel images record the radiated energy emitted from the surface of the sensor as an image. The geostationary satellite image acquisition unit 110 acquires geostationary channel images of various wavelength bands, including the infrared channel image, which is the object of the present invention.

In the field of the present invention, infrared image refers to an image related to the surface emission radiant energy such as mid-infrared and thermal infrared. Infrared image has the advantage of obtaining the surface temperature information from the surface emission radiant energy recorded in the infrared image, so there is an advantage that it can be used for monitoring volcanic activity, forest fire and urban heat island phenomenon that require temperature information of the earth's surface. do.

In this case, in order to perform time series monitoring by using a geostationary satellite system capable of acquiring images in near real time, it is effective to reduce the effects that may occur depending on the shooting time and regional characteristics. In general, regional influences appearing in infrared images include latitude change, terrain slope change, and terrain altitude. This is because the surface radiation energy is released differently according to latitude, slope and altitude. The most local characteristic of the infrared channel image is the surface emission radiation which varies according to the terrain altitude. That is, the low-land surface radiation energy and the high-land surface radiation energy are different at the same latitude and slope. As the altitude rises, the amount of radiant energy emitted from the surface decreases, so that it has a small surface temperature, and the very high mountain peak shows a very low surface temperature, which causes a natural phenomenon that snow does not melt easily in winter. do.

The digital elevation model acquisition unit 120 acquires a digital elevation model having the same coordinate system as the geostationary satellite image. In more detail, the digital elevation model acquired by the digital elevation model acquisition unit 120 is an image representing height information on an index, and the digital elevation model acquisition unit 120 is obtained by the geostationary satellite image acquisition unit 110. A digital elevation model with the same coordinate system as the geostationary satellite image is obtained.

In this case, the digital elevation model acquired by the digital elevation model acquisition unit 120 should have the same coordinate system as the geostationary satellite image acquired by the geostationary satellite image acquisition unit 110, and the spatial resolution is also determined by the geostationary satellite image. It is desirable to use a numerical elevation model with the same spatial resolution.

If the acquired digital elevation model has a coordinate system different from the acquired geostationary satellite image, it must be converted to have the same coordinate system through coordinate transformation. In addition, if the acquired digital elevation model differs from the acquired geostationary satellite imagery, the digital elevation model must be converted to have the same spatial resolution using interpolation. Coordinate transformations and interpolation techniques can use existing techniques.

2 is a diagram showing an example of a geostationary satellite image and a digital elevation model.

More specifically, FIG. 2 illustrates an example of a geostationary satellite image acquired by the geostationary satellite image acquisition unit 110 and a digital elevation model acquired by the digital elevation model acquisition unit 120 according to an embodiment of the present invention. will be.

2 (a) shows a geostationary satellite image taken from the HIMAWARI-8 satellite, and FIG. 2 (b) is a digital elevation model having the same coordinate system and spatial resolution as the geostationary satellite image.

According to FIG. 2A, the entire earth is represented by a geostationary satellite image.

At this time, since the whole earth is photographed, one of the biggest features of geostationary satellite imagery is that some regions show daytime time zones and some regions show night time zones according to the relationship between the sun and the earth. Since the image of the visible wavelength band can be obtained only in the daytime time and the image of the infrared wavelength band can be obtained without affecting the day and night, (a) of FIG. 2 illustrates the characteristics of the geostationary satellite image. have.

Figure 2 (b) is a numerical elevation model produced from the SRTM DEM. In FIG. 2 (b), coordinate transformation was performed to provide surface elevation information for the same region as that of the HIMAWARI-8 satellite image, and interpolation was applied to have the same spatial resolution.

The cloud region removal unit 130 detects and removes a cloud region existing in the image using the satellite image acquired by the geostationary satellite image acquisition unit 110. The cloud region removal unit 130 may detect and remove a cloud region that may affect the surface temperature reduction estimation and the altitude impact reduction. In more detail, since the cloud area removal unit 130 is for the purpose of removing the cloud area, the user can freely remove the cloud area at the discretion of the user, and remove the cloud area using the cloud area detection technique developed to date. You may.

Most cloud detection techniques developed to date carry out detection using features of cloud zones. In the cloud area, it has very high reflectivity information and very low surface temperature information. Using this feature, techniques have been developed to remove the cloud area by using the reflectance information of visible light image in daytime area and to remove the cloud area by using surface temperature information of infrared image only in night time area. Recently, in addition to reflectance information of visible light images and surface temperature information of infrared images, techniques for removing a cloud region using various information such as image capturing time, satellite sensor photographing angle, and zenith angle of the sun have been developed. Therefore, the cloud region removal unit 130 preferably removes the cloud region by applying the cloud detection technique developed to date, rather than the user directly removes the cloud region. Such cloud area detection and removal methods can utilize existing techniques.

The surface temperature image producing unit 140 manufactures the surface temperature image using the infrared satellite image acquired by the geostationary satellite image acquisition unit 110. In more detail, the surface temperature image producing unit 140 converts the surface emission radiant energy acquired by the geostationary satellite image acquisition unit 110 to the surface temperature.

A commonly used conversion method is the radiative transfer equation (RTE) based on Planck's function. The Earth Radiation Model model based on the flank function converts the surface emission radiant energy into surface temperature information using wavelength band information of the radiant energy, upstream and downstream radiation levels, atmospheric transmittance information and flank coefficients. Since the respective coefficients are provided in the sensor calibration process, the infrared images may be converted into the surface temperature image using the respective coefficients. The method for producing the surface temperature image may use existing technology.

3 is a diagram illustrating an example of the surface temperature image.

More specifically, Figure 3 shows an example of the surface temperature image produced by the surface temperature image production unit 140 in one embodiment of the present invention.

In the case of Figure 3 is an example of the six-hour interval surface temperature image from 0 o'clock to 18 o'clock on May 6, 2017. (A) of FIG. 3 is 0 o'clock on May 6, 2017, FIG. 3 (b) is 6 o'clock on May 6, 2017, and (c) of FIG. 3 is May 6, 2017. 12 (d) of FIG. 3 and FIG. 3 (d) are surface temperature images of 18 o'clock on May 6, 2017. According to FIG. 3, the produced surface temperature image uses an absolute temperature unit as a unit of pixel value. The surface temperature image provides various information according to the image capturing time and the characteristics of the surface.

According to FIG. 3, the continental continent of the southern hemisphere shows a large deviation of the surface temperature with time because most of the surface is composed of deserts, whereas the sea region shows a small surface temperature variation because of high specific heat. It also shows very low surface temperatures in highlands such as the cloud and Himalayan mountains. Therefore, it can be seen that the removal of the cloud area is necessary when estimating the surface temperature reduction rate through FIG.

Sample data selection unit 150 is a sample surface temperature and altitude information for estimating the surface temperature reduction rate from the surface temperature image produced by the surface temperature image production unit 140 and the digital elevation model obtained by the digital elevation model acquisition unit 120 Acquire.

In more detail, the sample data selection unit 150 obtains the surface temperature information and the surface elevation information at the same location. The surface temperature information at the same location is obtained from the surface temperature image, and the surface elevation information is obtained from the digital elevation model. Here, the same position means the same position coordinate in the image coordinate system. For example, the meaning of the position (400,500) in the image coordinate means the position corresponding to the 400th in the line direction (vertical direction) and the 500th in the pixel direction (horizontal direction) with the upper left corner of the image as the origin (0,0). it means. In other words, when the location information is set to (400,500), the sample data includes the pixel value (index temperature) corresponding to the (400,500) position in the surface temperature image and the pixel value (index elevation) corresponding to (400,500) in the numerical elevation model. it means.

In more detail, the sample data selection unit 150 obtains sample data for the surface temperature and the surface elevation suitable for estimating the surface temperature reduction rate. Here, the surface temperature decrease means the ratio of the surface temperature that decreases when the altitude rises. Therefore, it is appropriate to select the data showing the surface temperature decrease well. In other words, the sample data suitable for estimating the surface temperature deterioration rate is suitable for the regions with high elevation change, and the mountain region is representative.

In more detail, the sample data selector 150 obtains sample data on the surface temperature and the surface altitude for estimating the surface temperature decrease based on the mountainous region. In this case, it is appropriate that the sample data not only acquire the surface temperature information and the surface elevation information, but also obtain the “difference” information of the surface temperature and the “difference” information of the surface elevation. Because surface temperature decay is defined as the ratio of surface temperature that changes as altitude changes, it is more appropriate to use relative information about surface temperature and surface altitude than to use absolute information about surface temperature and surface altitude. Corresponds to the method of estimating.

To do this, select one reference point, select a target point in the area around the reference point, and obtain the difference information of the relative altitude difference and the relative surface temperature of the selected pair (reference point and target point) as sample data. It is preferable to select. In this case, when the selected pair of positional differences is small, the difference between the altitude difference and the surface temperature also appears very small. Therefore, when the positional difference is small, it is preferable to reselect the target point. In addition, if any of the reference point and target point exist within the cloud area, it should be excluded from the sample data.

In more detail, the sample data selector 150 obtains a large amount of sample data about the surface temperature and the surface altitude for estimating the surface temperature reduction rate based on the mountainous region. Multiple target points can be selected from one reference point to obtain a large sample of altitude and surface temperature differences.

For example, by selecting 100 target points per reference point, the altitude difference and the surface temperature difference information for 100 pairs may be obtained. If the base point is 100 points in total, the number of sample data for estimating the surface temperature reduction rate is 10,000. In order to estimate global surface temperature decay, it is desirable to have more than 5,000 sample data from about 500 reference points.

On the other hand, Figure 4 is a view showing an example of a sample data selection method.

More specifically, Figure 4 shows an example of a sample data selection method of the sample data selection unit 150 as an embodiment of the present invention.

4A illustrates a method of selecting the reference point 410 as a part of the numerical elevation model, and FIG. 4B illustrates an enlarged view of the red box region 420 of FIG. 4A. One method of selecting the target point 440 is shown.

Referring to (a) of FIG. 4, reference points 410 for estimating the surface temperature reduction rate are expressed as white dots, and it can be seen that they are located in a mountainous region where the surface elevation is severely changed on the digital elevation model. According to FIG. 4B, the target points 440 represented by the red points are selected in the target points area 450, and the target points area 450 is represented by the red box in the drawing. . The target points area 450 means an area away from the reference point 430 by a predetermined distance, and the target points 440 may be selected within the corresponding area.

The surface temperature reduction estimation unit 160 estimates the surface temperature reduction rate by using the surface temperature and altitude information samples selected by the sample data selection unit 150. At this time, the surface temperature reduction rate estimator 160 estimates the global surface temperature decrease rate by using the surface temperature difference and the altitude difference information of the samples obtained by the sample data selection unit 150. Surface temperature reduction estimation unit 160 performs a linear regression analysis using a large amount of sample data.

을 추정한다. To describe in more detail, the surface temperature reduction rate estimator 160 is the surface temperature reduction rate through Equation 1 below.

Estimate

는 표본자료에서의 지표온도를 의미하며,

은 표본자료에서의 지표고도를 나타내며,

는 지표고도와 지표온도간 관계를 설명할 수 있는 지표온도감율을 나타낸다. At this time,

Means surface temperature in the sample data,

Represents the surface elevation in the sample data,

Represents the surface temperature reduction rate that explains the relationship between surface elevation and surface temperature.

을 독립변수로,

를 독립변수로 하는 원점을 지나는 선형회귀모델과 동일하다. 즉, 지표온도감율 추정은 원점을 지나는 선형회귀모델에서 기울기를 추정하는 방법과 동일하며, 잔차의 제곱합이 최소가 되는 기울기를 지표온도감율로 정의할 수 있다.According to Equation 1,

As an independent variable,

It is the same as the linear regression model that passes through the origin with. That is, the surface temperature reduction estimation is the same as the method of estimating the slope in the linear regression model passing through the origin, and the slope at which the sum of the squares of the residuals is minimum may be defined as the surface temperature reduction.

5 is a diagram illustrating an example of the estimated surface temperature reduction rate.

In more detail, FIG. 5 is an example of the surface temperature reduction rate estimated by the surface temperature reduction rate estimator 160. 5 is the surface temperature reduction estimated from the mid-infrared and thermal infrared surface temperature images taken at 18 o'clock on May 6, 2017. FIG. 5A shows the surface temperature reduction estimated from the mid-infrared surface temperature image, and FIG. 5B shows the surface temperature reduction estimated from the thermal infrared surface temperature image. As can be seen in Figure 5, the surface temperature reduction rate can be estimated in the mid-infrared and thermal infrared surface temperature images, respectively.

In FIG. 5, the x-axis represents altitude difference information in the sample data, and the y-axis represents surface temperature difference information in the sample data. As can be seen in Figure 5, each sample data shows a very wide distribution, the surface temperature reduction rate that can represent the entire earth by estimating the slope by applying the optimal linear model between the two variables through the equation (1) Can be estimated.

According to (a) of FIG. 5, the surface temperature changes by 4.21 K when the 1 km altitude increases in the mid-infrared surface temperature image, and according to FIG. 5 (b), the 1 km altitude increases in the thermal infrared surface temperature image. As you can see, the surface temperature changes by 3.26K.

The altitude impact reduction unit 170 reduces the altitude impact on the surface temperature image produced by the surface temperature image production unit 140 using the surface temperature reduction rate estimated by the surface temperature reduction estimation unit 160.

In more detail, the altitude reduction unit 170 obtains the surface temperature image of which the altitude effect is reduced by applying the estimated surface temperature reduction to the original surface temperature image. By reducing the altitude effect, the low surface temperature in the highlands has the effect of increasing, the high surface temperature in the lowlands has the effect of decreasing.

를 획득한다. In more detail, the altitude impact reduction unit 170 is a surface temperature image of the altitude effect is reduced through the following equation (2)

Acquire.

는 고도영향이 저감된 지표온도영상을 나타내며,

와

는 각각 라인방향과 픽셀방향의 영상좌표를 나타낸다.

는 상기 지표온도영상 제작부에서 제작한 지표온도영상을 나타내며,

는 상기 수치표고모델 획득부에서 획득한 수치표고모델을 나타낸다.

는 상기 지표온도감율 추정부에서 추정한 지표온감율을 나타내며,

는 기준고도를 의미한다. 여기서 기준고도는 사용자가 자유로이 설정할 수 있다. At this time,

Represents the surface temperature image with reduced altitude effect,

Wow

Denote image coordinates in line and pixel directions, respectively.

Represents the surface temperature image produced by the surface temperature image production unit,

Denotes a digital elevation model obtained by the digital elevation model acquisition unit.

Denotes the surface temperature reduction rate estimated by the surface temperature reduction rate estimating unit,

Means the reference altitude. Here, the reference altitude can be freely set by the user.

값이 0이라면, 고도영향이 저감된 지표온도 영상은 해발고도 0m에서의 지표온도영상을 나타낸다. 반면

값이 500이라면, 고도영향이 저감된 지표온도 영상은 해발고도 500m에서의 지표온도영상을 나타낸다. if

If the value is 0, the surface temperature image with reduced altitude effect indicates the surface temperature image at altitude of 0 m. On the other hand

If the value is 500, the surface temperature image with reduced altitude influences shows the surface temperature image at an altitude of 500m above sea level.

On the other hand, Figure 6 is an image showing an example before and after the high-impact correction.

FIG. 6 is an index temperature image produced from a mid-infrared channel image, and FIG. 6 is an altitude effect of the surface temperature image at 18 o'clock on May 6, 2017, using the surface temperature reduction ratio of FIG. 5.

6 (a) shows the surface temperature image before the reduction of altitude, and FIG. 6 (b) shows the surface temperature image after the reduction of altitude. According to (a) of FIG. 6, it can be seen that the Baekdusan and Gaemae Highlands 610 in the northern part of the Korean peninsula exhibit low surface temperature. In addition, it can be confirmed that the vicinity of Seoraksan 620 in Gangwon-do also shows a low surface temperature. These areas are mountainous and high altitudes, and thus exhibit low surface temperatures. At this time, it can be seen that the altitude of the Baekdusan region is lower than that of Gangwon-do, indicating a lower surface temperature. FIG. 6B is a surface temperature image obtained by reducing the altitude effect on the surface temperature image using the estimated surface temperature reduction rate of 4.21 K / km.

When comparing (a) of FIG. 6 and (b) of FIG. 6, it can be seen that the surface temperature in the high-altitude region is increased to have similar information to the surroundings as a result of the altitude reduction. In particular, the area of the northern part of the Korean peninsula (610) of the northern part of the Korean peninsula (610) and the Seoraksan mountain 620 in Gangwon-do and the area of the Baekdu and the Gamma Highlands (630) of the northern part of the Korean peninsula of FIG. 640), it can be seen that the surface temperature 630 of the Baekdusan and Gaemae Highlands in the northern part of the Korean Peninsula is further increased to have a surface temperature similar to that of the Gangwon-do region 640.

On the other hand, Figure 7 is a view showing an example of the utilization of the surface temperature image.

In more detail, FIG. 7 is an image showing an enlarged image before and after correction of altitude impact, and shows an example of an improvement in the possibility of detecting a fire, which is one of the applications of the surface temperature image. FIG. 7 is a surface temperature image near Samcheok, Gangwon-do, 18 o'clock on May 6, 2017.

7 (a) shows before the high impact reduction, Figure 7 (b) shows after the high impact reduction. According to FIG. 7, the pixels 710 and 730, which are represented in yellow in the middle of the image, exhibit a very high surface temperature of about 300K even though the local time is 3:00 am, and the fire is actually burned in Samcheok, Gangwon-do, during the image capture. It is very likely that it is a forest fire pixel. Most forest fire detection techniques use the surface temperature information of pixels near forest fire pixels to determine whether the suspect pixels are forest fire pixels.As a key indicator, the difference in the surface temperature between forest fire pixels and surrounding pixels and the surface temperatures of the surrounding pixels Use At this time, as the volatility of the surrounding pixels decreases, the possibility of identifying the deep fire pixels as wild fluoride pixels is improved.

When comparing (a) of FIG. 7 and (b) of FIG. 7, the indexes of the peripheral pixels of FIG. 7 (b) having a lower altitude effect than the surface temperature 720 of the peripheral pixels of FIG. It can be seen that the temperature 740 has a more uniform surface temperature, therefore, the possibility of detecting a fire can be improved by reducing the altitude effect through the present invention.

The method and apparatus for reducing altitude effects in a geostationary infrared image according to an embodiment of the present invention may be implemented in a program instruction form that can be executed by various computer means and recorded in a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and ROMs, RAMs. Hardware devices specifically configured to store and execute programs audfudd, such as flash memory, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

8 is a flowchart illustrating a method for reducing altitude effects in a geostationary infrared image.

First, a geostationary satellite image and a digital elevation model having the same coordinate system and resolution are obtained (S810). And the cloud region appearing in the geostationary satellite image is removed (S820). The surface temperature image is produced from the infrared image (S830), and the sample data for estimating the surface temperature decrease is obtained by obtaining the surface temperature information and the altitude information at the same location (S840). The surface temperature reduction rate at the image capturing time is estimated using the surface temperature information and the altitude information constructed as sample data (S850). Finally, by using the estimated surface temperature reduction rate, it is possible to reduce the altitude effect displayed on the infrared satellite image (S860).

In the present invention as described above has been described by the specific embodiments, such as specific components and limited embodiments and drawings, but this is only provided to help a more general understanding of the present invention, the present invention is not limited to the above embodiments. For those skilled in the art, various modifications and variations are possible from these descriptions.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and all of the equivalents and equivalents of the claims as well as the claims to be described later belong to the scope of the present invention. .

110: geostationary satellite image acquisition unit
120: digital elevation model acquisition unit
130: cloud area removal unit
140: surface temperature image production unit
150: sample data selection unit
160: surface temperature reduction rate estimator
170: high impact reduction unit

Claims (1)

Altitude Effect Reduction Device for Shooting Geostationary Infrared Image in Geostationary Satellite System
A geostationary satellite image acquisition unit for acquiring a captured geostationary infrared image;
A surface temperature image production unit for producing a surface temperature image using the obtained geostationary satellite image;
A surface temperature reduction rate estimating unit for estimating the surface temperature rate reduction of the acquired geostationary satellite image;
And
An altitude impact reduction unit for reducing an altitude effect shown in the surface temperature image produced by the surface temperature image production unit;
Including,
The high impact reduction unit
The apparatus for reducing altitude effects in a geostationary infrared image, characterized in that to reduce the altitude effect by using the surface temperature decrement estimated by the surface temperature deceleration estimator.

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