KR101969863B1 - Method and apparatus for simulating of GPS receiver observation environment based on DSM - Google Patents

Abstract

Provided are an observation environment simulation method of a DSM-based navigation satellite and an apparatus thereof. A method for simulating an observation environment of a navigation satellite based on a DSM of an electronic apparatus comprises the following steps: the electronic apparatus obtains a grid-based DSM for a target area and a grid-based DSM for a road region in the target area; and the electronic apparatus uses altitude values provided by the DSM of the target area and the road region provided by a road network DSM to determine an area in which a signal from a navigation satellite is shielded by obstacles located within the target area at a specific inspection point located on the road area of the road network DSM.

Description

Method and apparatus for simulating the observation environment of DSM-based navigation satellites {Method and apparatus for simulating of GPS receiver observation environment based on DSM}

The present invention relates to a method and apparatus for simulating the observation environment of a DSM-based navigation satellite. More specifically, the present invention relates to a DSM-based simulation of a navigation environment in a road area using a grid-based DSM constructed for a target area. The present invention relates to a method and apparatus for simulating the observation environment of navigation satellites.

The autonomous vehicle system is composed of body control that reflects the judgment of artificial intelligence according to the exact recognition of the driving environment and the situation and the result of the determination. Precise mobile positioning technology is the core technology of autonomous vehicle system because it is necessary to accurately express the position of the vehicle on the road precision map for accurate recognition and judgment of the driving environment.

The methods used for the positioning of the vehicle include satellite navigation system and inertial navigation system. In the positioning of autonomous vehicles, integrated positioning method in which satellite navigation system and inertial navigation system are combined is applied. This is a way to complement the strengths and weaknesses of the two sensors. Besides, RADAR, LiDAR, camera, and ultrasonic sensors have been developed and applied to complement the vehicle positioning and situational awareness in autonomous vehicles.

The satellite navigation system can be used to determine the user's absolute position, but positioning is impossible in areas where minimum visibility is not observed, such as tunnels, and positioning accuracy is degraded in areas where signals are shielded by obstacles such as urban areas. .

 Other sensors such as inertial navigation system when positioning in the section where the observation environment of satellite navigation system is not good if it can recognize future satellite observation environment of driving route in autonomous vehicle system with sensor fusion positioning technology Increasing the weighting of, improves the positioning accuracy and enhances the stability of autonomous driving. Therefore, the development of a plan that can support the situational awareness of satellite navigation system users such as autonomous vehicles through the satellite observation environment simulation.

In general, in order to simulate the observation environment of a GPS (Global Positioning System) receiver, methods of analyzing the line of sight (LOS) between the observation point and the satellite have been utilized.A method of analyzing the LOS is a linear-polygon collision test (Akenine-). Moller et al., 1999) is a representative example of a vector-based satellite visibility analysis method.

However, in order to apply this method to mobile positioning, the receiver must have 3D vector information of the surrounding area, and additionally, a device that can perform vector-based operations is required. There is a difficulty in identifying the complex geometric relationships of obstacle information such as buildings and buildings.

In addition, when 3D vector information is used for visibility analysis, a 3D building model is used or a value obtained by substituting 3D elevation information into 2D information of a building area in a digital map is used. However, when this data is used, the 3D building model of the city does not represent all ground objects, so signal shielding by all objects in the real world such as trees, roadside trees, and telephone poles may be omitted. .

Domestic Patent No. 10-1221931 (registered on Jan. 8, 2013)

The technical problem to be solved by the present invention is to observe the DSM-based navigation satellite to observe the signal shielding area of the navigation satellite in consideration of all obstacles such as buildings or trees by using the DSM of the road area. To present a method and apparatus for environmental simulation.

The problem of the present invention is not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

As a means for solving the above technical problem, according to an embodiment of the present invention, a method for simulating the observation environment of the navigation satellite based on the Digital Surface Model (DSM) of the electronic device, (A) the Obtaining, by the electronic device, a DSM for a target region (hereinafter referred to as a 'target region DSM') and a DSM for a road region within the target region (hereinafter referred to as a 'road network DSM'); And (B) the electronic device is located in the target area at a specific inspection point located in the road area of the road network DSM by using the altitude values provided by the target area DSM and the road area provided by the road network DSM. Determining an area in which the signal from the navigation satellite is shielded by obstacles.

In the step (A), the first method of obtaining the road network DSM by overlapping layers of the numerical map representing the target area DSM and the road network for the target area, and an orthoimage of the target area DSM and the target area Obtaining the road network DSM by one of a second method of obtaining the road network DSM by superimposing a vector-based layer generated by digitizing.

In the step (B), the altitude angles for all directions are calculated at intervals of n ° (where n is a constant) from a specific inspection point located in the road area from 0 ° to 360 ° in all directions. Calculating elevation angles for the plurality of inspection target pixels located between the specific inspection point and each orientation; And (B2) determining the position of the inspection target pixel whose maximum altitude is calculated among the plurality of altitudes calculated for each azimuth based on the specific inspection point in step (B1) as an area where the signal is shielded at each azimuth. It comprises; a.

In the step (B1), for each azimuth angle of n ° intervals from 0 ° to 360 ° in the total azimuth, (B11) pixel coordinates of the selected specific check point are selected when a specific check point located in a road area in the road network DSM is selected. Setting a rotation angle; (B12) calculating a normal orthogonal to a straight line passing through the specific inspection point while having the rotation angle; (B13) determining an inspection range with respect to the r (row) axis of the pixels to be examined by considering the pixel coordinates of the specific inspection point and the slope of the straight line; (B14) calculating c (column) column coordinates of the inspection target pixels using the rotation angle, a normal line calculated for the rotation angle, and r-axis coordinates of inspection target pixels included in the inspection range. ; (B15) if the coordinates of the inspection target pixels are determined by the c-axis coordinates calculated in the operation (B14), calculating a straight line distance between the inspection target pixels from the specific inspection point; (B16) calculating an altitude difference between the specific inspection point and the inspection pixel with reference to the target area DSM; And (B17) calculating an altitude angle for each of the pixels to be inspected using the linear distance calculated in step (B15) and the altitude difference calculated in step (B16).

On the other hand, according to another embodiment of the present invention, the device for simulating the observation environment of the navigation satellite based on the Digital Surface Model (DSM), DSM of the target area for simulating the observation environment of the navigation satellite (Hereinafter referred to as a 'target area DSM') and a storage unit for storing a DSM (hereinafter referred to as a 'road network DSM') for a road area in the target area; And the obstacles located in the target area at a specific inspection point located in the road area of the road network DSM using the altitude values provided by the target area DSM and the road area altitude values provided by the road network DSM. And a shielding area determiner configured to determine an area in which a signal from the navigation satellite is shielded.

A first method of obtaining the road network DSM by overlapping layers of the numerical map representing the target area DSM and the road network for the target area, and a vector based generated by digitizing the orthoimage of the target area DSM and the target area And a road network DSM obtaining unit for obtaining the road network DSM by one of a second method of obtaining the road network DSM by overlapping layers.

The shielding area determiner is configured to calculate altitude angles for all azimuths at an interval of n ° from a specific inspection point located in the road area to all directions 0 ° to 360 °, and is located between the specific inspection point and each bearing. A total azimuth elevation calculator for calculating elevation angles for the plurality of pixels to be inspected; And determining the location of the inspection target pixel whose maximum altitude is calculated among the plurality of altitudes calculated for each azimuth based on the specific inspection point as the area where the signal is shielded at each azimuth. It includes; shielding area determination unit.

According to the present invention, by simulating the observation environment of the navigation satellite by using the DSM of the target area and the DSM of the road area located in the target area, it is possible to simulate in consideration of all obstacles such as buildings and trees. It is possible to detect a signal shielding area caused by spatial characteristics such as.

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

1 is a flowchart illustrating a method for simulating an observation environment of a DSM-based navigation satellite in an electronic device according to an embodiment of the present invention;
2 is a view showing an example of a result of digitizing a road area and a building area of a target area in an orthoimage according to an embodiment of the present invention;
3 is a view for explaining the relationship between the image coordinate system and a specific inspection point (i), rotation angle (θ), azimuth angle (AZ),
4 is a diagram illustrating a process of determining an inspection section of a straight line for each azimuth from a specific inspection point;
FIG. 5 is a flowchart illustrating step S130 of FIG. 1 in detail;
FIG. 6 is a flowchart for describing operation S530 of FIG. 5 in detail;
7 is a view for explaining the EMP determination process by comparing the elevation angle,
8 is a block diagram illustrating an apparatus for simulating a viewing environment of a DSM-based navigation satellite according to an embodiment of the present invention;
9 is a view showing skyplot results of EMP generation at a first specific check point according to an embodiment of the present invention;
FIG. 10 is a skyplot representation of EMP generation results at a second specific checkpoint.

Objects, other objects, features and advantages of the present invention will be readily understood through the following preferred embodiments associated with the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosure may be made thorough and complete, and to fully convey the spirit of the present invention to those skilled in the art.

It is to be understood that an element (or component) may be implemented in software, hardware, or any form of software and hardware, unless otherwise specified in the present specification.

Also, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, the words 'comprises' and / or 'comprising' do not exclude the presence or addition of one or more other components.

Hereinafter, specific technical contents to be implemented in the present invention will be described in detail with reference to the accompanying drawings. In describing the following specific embodiments, various specific details are set forth in order to explain and understand the invention in more detail. However, those skilled in the art can understand that the present invention can be used without these various specific details.

In addition, each configuration shown in Figure 8 represents a functional and / or logically separate, and does not necessarily mean that each configuration is divided into separate physical devices or written in a separate code. The average expert in the art will be able to reason easily.

In addition, the DSM-based navigation satellite observation environment simulation apparatus 800 according to an embodiment of the present invention is capable of installing and executing a program such as a microprocessor, a memory, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), and the like. It may be implemented using an electronic device.

According to an embodiment of the present invention, a method and apparatus for simulating a navigation environment of a navigation satellite based on a digital surface model (DSM) 800 uses a DSM constructed based on image data obtained from a drone. We propose an algorithm that can simulate the observation environment of navigation satellites in road area. As an example, any device that provides an image of a target area for generating a digital surface model may be used.

In addition, the embodiment of the present invention describes a method for simulating the observation environment of the navigation satellite from the DSM, but is not limited to the DSM, and may be implemented as grid-type obstacle representation data based on the planar rectangular coordinate system.

When the DSM acquisition of the target area is described, it is possible to construct geospatial information such as orthoimages, point clouds, and DSMs for a small area by using a mapping technique using a drone. According to the present invention, three-dimensional spatial information can be extracted from a series of aerial photographs in the form of a point cloud, and the DSM generated based on this can express the obstacle information on the ground without data. In this way, the DSM of the target area can be used to simulate the observation environment of the navigation satellite in the road area located in the target area.

Using this method, the GPS signal shielding area due to the surrounding obstacles can be determined and DBized at a specific grid point on the road (i.e., a specific location on the road). When the same vehicle is approached, shielding elevation angle information of all azimuths is provided based on the current position, so that the vehicle or a device in the vehicle can quickly determine the visibility satellite. In an embodiment of the present invention, an area where a signal is shielded by a peripheral obstacle is called an Elevation Mask Profile (EMP).

1 is a flowchart illustrating a method for simulating an observation environment of a DSM-based navigation satellite in an electronic device according to an embodiment of the present invention.

An electronic device that performs the DSM-based navigation satellite observation environment simulation method of FIG. 1 may be the device 800 described below with reference to FIG. 8.

Referring to FIG. 1, the electronic device obtains a grid-based DSM for a target area (hereinafter referred to as a 'target area DSM') and a grid-based DSM for a road area within the target area (hereinafter referred to as a 'road network DSM'). It may be (S110, S120).

Referring to steps S110 and S120, an embodiment of the present invention requires a target area DSM and a road network DSM to simulate a DSM-based navigation satellite observation environment.

Target Area DSM provides grid-based surface elevation data for the target area. The target area is the area to simulate the observation environment of the navigation satellite. Surface altitude information data may be generated using DSM or gridized urban three-dimensional model generated by drone aerial data processing.

Road network DSM is grid-based surface elevation data for road areas within the target area. Road area altitude information data, that is, road network DSM, provides altitude data for road boundaries in the same area as the target area.

If the road network DSM has a target area DSM or a gridized three-dimensional model, and there is a numerical map representing the road network for the same target area, the road network DSM can be obtained by extracting the road area through layer overlap.

If there is no digital map representing the road network, the digital map may be substituted with a vector based layer generated by digitizing the orthoimage for the target area. The reason for creating this layer separately is that the target area DSM cannot determine which location is the road position in two dimensions. As a result, in the present invention, the road area altitude information data, that is, the road network DSM, may be obtained by overlapping the road area numerical map and the DSM for the entire target area.

2 is a diagram illustrating an example of a result of digitizing a road area and a building area of a target area in an orthoimage according to an exemplary embodiment of the present invention.

Referring to FIG. 2, the electronic device may set a site where a specific institution is located as a target area and implement an algorithm by utilizing spatial information constructed by using a drone. The electronic device photographs a target area with a drone to acquire a point cloud, an orthogonal image, and a DSM for a three-dimensional space. Here, the spatial resolution of the DSM is 5cm / pixel, and the coordinate system of the DSM consists of planar rectangular coordinates with the top of the image facing north.

In the case of the road network required to determine the road area within the target area, since the national numerical map does not describe the internal roads of specific organizations in detail, the electronic device digitizes the road area in the orthoimage to determine the internal road area. To create a vector-based layer. The electronic device extracts the DSM for the road area by overlapping the road area layer and the entire target area DSM among the generated vector based layers.

In the image of FIG. 2, a blue area represents a road area that a vehicle can carry, such as a road or a parking lot, and a red area represents a boundary of a building. In practice, the building area DSM may not be needed in the implementation of the algorithm, but the building area is separately expressed to describe the area where the signal is shielded according to the azimuth and elevation angles.

The operation described with reference to FIG. 2 is a data production process for testing, and may be omitted if the grid data represents a road. However, in general, DSM does not reflect the information on the land use, etc., so it may be necessary to set up the zone as described above.

Referring back to FIG. 1, the electronic device uses obstacles located in the target area at a specific inspection point located in the road area of the road network DSM by using the altitude values provided by the target area DSM and the road area provided by the road network DSM. By using the azimuth, the area EMP in which the signal from the navigation satellite is shielded can be determined for each azimuth angle (S130, S140).

In detail, the electronic device may sequentially calculate altitude angles of the inspection target pixels positioned in the azimuth (AZ) direction for all azimuths from a specific inspection point for inspecting the shielding area in the road area (S130). Some of the pixels to be inspected may be obstacles (buildings, trees, etc.) where the signal from the GPS is shielded.

In step S130, the electronic device calculates elevation angles for all directions at n ° intervals (where n is a constant) from a specific inspection point located in the road area from 0 ° to 360 ° in the all directions, respectively. Elevation angles may be calculated for a plurality of pixels to be inspected positioned between the azimuths. n may be various numbers, for example, 0.1, 0.5, 1, 10, etc. The electronic device may set the resolution by adjusting n. In other words, as n is set smaller, the electronic device may obtain high resolution EMP.

The electronic device may determine the location of the inspection target pixel whose maximum altitude is calculated among the plurality of altitudes calculated for each azimuth based on a specific inspection point as an area (EMP) where the signal is shielded at each azimuth in step S130. There is (S140). That is, the electronic device may determine the area where the maximum altitude angle for each bearing is calculated as the EMP in operation S130.

Hereinafter, the step S130 will be described in detail with reference to FIGS. 3 to 7.

3 is a diagram for explaining a relationship between an image coordinate system, a specific inspection point i, a rotation angle θ, and an azimuth angle AZ.

In FIG. 3, the c axis represents a column of the image and the r axis represents a row of the image. When a specific inspection point is selected in the road area of the road network DSM, the electronic device may perform an altitude shielding inspection for all azimuths at an interval of n ° from the entire azimuth angle of 0 ° to 360 ° based on the specific inspection point. For this purpose, when a certain inspection point in the image, that is, a specific pixel coordinate is given, it should be possible to express a straight line for the whole orientation from this point.

를 선택했을 때, 점 i로부터 시작하여 θ 방향으로 나아가는 직선

는 도 3과 같이 표현될 수 있다. 도 3에서, ρ는 영상좌표 원점에서 시작하여 직선

에 직교하는 법선이다. 이를 특정 검사점 i의 측면에서 보면 회전각(θ)의 시작은 영상의 동쪽(E) 방향 축에서부터 반시계방향으로 시작되므로, 회전각(θ)의 체계는 북쪽(N) 방향 축으로부터 시계방향으로 시작되는 방위각(AZ)의 체계와는 다르다.That is, a specific check point in the image coordinate as shown in FIG.

When you select, the straight line starting from point i and moving in the θ direction

May be expressed as shown in FIG. 3. In Figure 3, ρ is a straight line starting from the image coordinate origin

Is normal to orthogonal to. When viewed from the side of a specific check point i, the start of the rotation angle θ starts counterclockwise from the east (E) axis of the image, so the system of rotation angle (θ) is clockwise from the north (N) axis. This is different from the system of azimuth (AZ) starting with.

On the other hand, since the signal shielding test for the azimuth angle is performed to the end of a given image, the electronic device can set the inspection range of the r-axis or the c-axis by applying to the characteristics of each quadrant having a specific test point as the origin. For example, when an angle on one quadrant is given as shown in FIG. 4, the electronic device may set up to an uppermost pixel or an image rightmost pixel as an inspection range according to a position of a specific inspection point and a slope of a straight line. That is, the electronic device may set r _i to 0 as the inspection range of the r-axis, and thus c _j to c _k may be set to the inspection range of the c-axis.

If the inspection range for the r-axis is set from r _i where the specific inspection point is located to the uppermost range of the image, each c-axis coordinate (c _j ) for this is used to determine the range of the DSM image according to the position and rotation angle θ of the specific inspection point. It may escape (shown by the dashed line in FIG. 3). When the c _j result calculated by Equation 2 to be described later is out of the range of the DSM image, the electronic device excludes the corresponding section from the analysis target pixel. The electronic device can determine the inspection range by applying this method to the characteristics of each quadrant originating from a specific inspection point.

4 is a diagram illustrating a process of determining an inspection section of a straight line for each azimuth from a specific inspection point.

Referring to FIG. 4, a process of determining a visibility determination test section for a straight line in a specific azimuth direction from a specific test point is illustrated, and this is represented by an interval of 0 ° to 45 °. In FIG. 4, blue represents a building area and red represents a road area, and a green straight line represents a direction extending when each azimuth is given from a specific inspection point. As shown in FIG. 4, the pixels to be inspected in the line and the inspection range for each azimuth angle may be determined to analyze the elevation angle between the specific inspection point and the pixels to be inspected on the straight line, and the maximum elevation angle may be returned as a shielding area.

FIG. 5 is a detailed flowchart illustrating step S130 of FIG. 1.

와 초기 회전각으로서 θ=0도를 설정한다(S510).3 to 5, when a specific checkpoint is selected, the electronic device determines pixel coordinates of the specific checkpoint.

And θ = 0 degrees as the initial rotation angle (S510).

The electronic device sets the initial elevation angle EL (θ) = 0 degrees (S520).

상에 위치하는 픽셀일 수 있다.The electronic device sequentially calculates altitude angles of the inspection target pixels positioned in the azimuth (AZ) direction from the specific inspection point set in operation S510 (S530). The pixels to be inspected are for example straight lines of FIG. 3.

It may be a pixel located on the top.

In operation S530, the electronic device may output the azimuth angle AZ in which the altitude angle is calculated for each pixel to be inspected, and the coordinates of the inspection pixel in which the maximum altitude angle is calculated among the altitude angles calculated for each pixel to be inspected ( S540). The coordinates of the inspection target pixel calculated at the maximum altitude angle output in step S540 may be determined as an area where the navigation satellite observation signal is shielded when looking at the azimuth (AZ) direction from a specific inspection point, that is, EMP (AZ). have.

If the current rotation angle is not 360 degrees, the electronic device enters step S520 after adding n ° to the initial rotation angle set in step S510 (S560).

When the rotation angle θ = n °, the azimuth angle decreases n ° as before, so that when the rotation angle θ = n °, the electronic device has an altitude angle of the inspection target pixels located in the azimuth direction by n ° decrease at a specific inspection point. Can be calculated. That is, the electronic device repeatedly performs steps S520 to S560 for azimuths of n ° intervals until the rotation angle becomes 360 degrees from the initial 0 degree based on a specific inspection point, and the maximum altitude angle is calculated for each azimuth angle. The coordinates of the target pixel can be output.

FIG. 6 is a flowchart for describing operation S530 of FIG. 5 in detail, and illustrates a process of calculating an elevation angle between inspection target pixels and a specific inspection point in one arbitrary orientation.

3 to 6, the electronic device calculates an altitude angle for each bearing based on a specific inspection point by dividing the case where the rotation angle is 0 degrees and the case where the rotation angle is not.

을 지나는 직선

이 통과하는 검사대상 픽셀을 결정하기 위해, 영상좌표 원점에서 시작하여 직선

에 직교하는 법선(ρ)을 [수학식 1]을 이용하여 산출한다(S610).First, when the rotation angle is not 0 degrees (S600-No), the electronic device has a specific inspection point while having the rotation angles (θ, θ> 0).

Straight through

In order to determine the pixel to be inspected, a straight line starting from the image coordinate origin

The normal ρ orthogonal to is calculated using Equation 1 (S610).

Equation 1 is a normal equation obtained by using a polar coordinate-based equation (for example, Gonzalez et. Al., 2004). Here, the pixel coordinates of a specific checkpoint are given as initial input values, and θ is given sequentially at intervals of n ° from 0 ° to 360 °, and is given every time iteration is performed. Therefore, it is possible to determine the p value according to the θ value through this.

Meanwhile, as described with reference to FIG. 3, since the signal shielding test for the azimuth angle is performed to the end of a given image, the electronic device sets an inspection range for the r-axis by applying the characteristic to each quadrant having a specific test point as the origin. (S620). In, step S620 in the case 3, the electronic device may be set to _i from the r point in a particular test in the first quadrant to the top range of the image, that is, r _i a ~~ 0 r-axis scan range.

When the inspection range of the r-axis is set, each c-axis coordinate is calculated using the current rotation angle, normals calculated in step S610, and coordinates of inspection target pixels located in the inspection range of the r-axis (S630).

Referring to [Equation 2], r _j is the r-axis coordinates of the inspection target pixels located in the inspection range of the r-axis set in step S620, and does not mean one fixed coordinate. Therefore, r _j substituted into Equation 2 may be changed whenever the position of the pixel to be inspected is changed.

C-axis coordinate calculated by the [Equation 2] c _j, the position (r _i, c _i) and rotated according to the angle θ _j c values of the specific checkpoint may be out of range of DSM images. For example, the portion indicated by the dotted line may be a c-axis coordinate outside the range of the DSM image. If the calculated c _j deviates from the DSM image, the electronic device excludes the corresponding interval from the analysis target pixel.

의 좌표가 결정되고, 도 4와 같이 직선이 결정되면, 전자장치는 특정 검사점부터 검사대상 픽셀들 간의 직선 거리를 [수학식 3]을 이용하여 각각 산출한다(S640). Equation 2 calculates the c-axis coordinates (c _j ) of all the inspection target pixels to determine the inspection target pixels

When the coordinates of, are determined and a straight line is determined as shown in FIG. 4, the electronic device calculates the straight line distances between the pixels to be inspected from the specific inspection point by using Equation 3 (S640).

Referring to [Equation 3], s is a scale factor according to the resolution of the DSM and is used to convert the unit value of the pixel coordinate system into the actual distance. For example, if 5 cm / pixel is applied to the spatial resolution of the DSM, s may be 0.05 since it must be converted into meters (m). If the DSM is applied to a spatial resolution of 10cm / pixel, s may be 0.1. Since the electronic device calculates the distance between the specific inspection point and the inspection target pixels, the D is calculated by the number of inspection target pixels in operation S640.

When both the distance between the specific inspection point and the inspection target pixels are calculated, the electronic device calculates an altitude difference between the specific inspection point i and the inspection target pixel j using Equation 4 (S650).

In Equation 4, h _j is the altitude of the inspection target pixel, h _i is the altitude of a specific inspection point, and each altitude can be known from the target area DSM. In operation S650, the electronic device calculates an altitude difference between each of the pixels to be inspected and the specific inspection point.

를 이용하여 검사대상 픽셀들 각각에 대한 고도각을 [수학식 5]를 이용하여 산출한다(S660). The electronic device is a distance D and an altitude difference calculated by Equations 3 and 4

An altitude angle for each of the pixels to be inspected is calculated using Equation 5 (S660).

는 각각 [수학식 3]과 [수학식 4]에 의해 산출된 두 지점 간의 거리와 고도차이다. S660단계에서, 전자장치가 특정 검사점과 모든 검사대상 픽셀들 간의 고도각을 산출함으로써, 현재 방위각에서 특정 검사점을 기준으로 모든 검사대상 픽셀들과의 고도각 산출이 완료된다.Referring to Equation 5, EL is the altitude difference between a specific checkpoint i and the inspected pixel j, and D and

Are the distance and altitude difference between the two points calculated by Equations 3 and 4, respectively. In operation S660, the electronic device calculates an elevation angle between the specific inspection point and all the inspection target pixels, thereby completing the calculation of the elevation angle with all the inspection target pixels based on the specific inspection point at the current azimuth.

The electronic device outputs the coordinates, the maximum altitude angle, and the azimuth angle (AZ) information of the inspection target pixel in which the maximum altitude is calculated among all the altitude angles calculated in operation S660 (S670). In operation S670, the coordinates of the inspection target pixel whose maximum elevation angle is calculated may be determined as an area EMP where the signal is shielded when the current elevation direction is directed toward the azimuth angle AZ. Operation S670 corresponds to operation S540 of FIG. 5.

If the rotation angle used for calculating the maximum elevation angle is less than 360 °, the electronic device increases the rotation angle n ° (S550), and if the increased rotation angle exceeds 360 ° (S560-Yes), It is determined that the altitude angle calculation for the bearing has been completed.

On the other hand, if the increased rotation angle in step S550 is less than 360 ° (S560-No), the electronic device enters step S520.

On the other hand, if the current rotation angle is 0 degrees in step S600 (S600-Yes), the electronic device sets r _j = {r _i , r _i , r _i , r,? R _i } as the inspection range for the r axis ( S680).

The electronic device sets the c-axis coordinate to c _j = {c _i , c _{i + 1} , c _{i + 2} , ..., c _max } with reference to the r-axis inspection range set in step S680 (S690). That is, when the rotation angle is 0 degrees, r _j may equally use r _i , and c _j may be a pixel from all c _i to the right end region of the image having a r _i value.

When the r-axis inspection range, that is, the r-axis coordinates and the c-axis coordinates of the inspection target pixels are set, the electronic device may calculate the maximum elevation angle when the rotation angle is 0 degrees by performing steps S640 to S670.

7 is a view for explaining the EMP determination process by comparing the elevation angle.

In FIG. 7, the left image is a target area DSM, where blue is a building area, red is a road area, and a green straight line is a straight line generated by an arbitrary azimuth from a specific inspection point. In addition, the right image shows an elevation angle between each of the a, b, and c positions and a specific inspection point based on the 2D distance when the positions of the inspection target pixels located on the green straight line are a, b, and c. The solid blue line in the right image means the length where the obstacle located in a overlaps with the green straight line, and the solid red line means the length where the green straight line overlaps the road area.

In the case of FIG. 7, when comparing three points a, b, and c which are positions of the inspection target pixels, an altitude angle at position a is determined as the maximum altitude angle. The electronic device may determine the EMP at each azimuth angle by outputting information (coordinates, azimuth information, etc.) of the maximum altitude angle as a result value while calculating the altitude angle for each inspection target pixel. .

8 is a block diagram illustrating an apparatus 800 for simulating a viewing environment of a DSM-based navigation satellite according to an embodiment of the present invention.

Referring to FIG. 8, the DSM-based navigation satellite observation environment simulation apparatus 800 may include a storage unit 810, a road network DSM acquisition unit 820, a shielding area determination unit 830, and a DB (Database, 840). have.

The storage unit 810 stores the target area DSM and the road network DSM in the target area acquired by the road network DSM obtaining unit 820 for simulating the observation environment of the navigation satellite.

The road network DSM acquiring unit 820 overlaps the layer of the numerical map representing the target area DSM and the road network for the target area, and obtains the first method of obtaining the road network DSM, and orthogonal images of the target area DSM and the target area. The road network DSM is obtained by one of the second methods of obtaining the road network DSM by overlapping the digitized vector-based layer.

The shielding area determining unit 830 uses the altitude values provided by the target area DSM and the road area provided by the road network DSM to prevent obstacles located in the target area at a specific inspection point located in the road area of the road network DSM. Determine the area (EMP) where the signal from the navigation satellite is shielded.

To this end, the shielding area determining unit 830 includes a global azimuth elevation calculating unit 832 and a shielding area determining unit 834.

The total azimuth altitude calculation unit 832 calculates altitude angles for all azimuths at an interval of n ° from a specific inspection point located in a road area to a total azimuth angle from 0 ° to 360 °, between a specific inspection point and each bearing. Elevation angles are calculated for a plurality of pixels to be positioned. That is, the total azimuth elevation calculator 832 calculates an elevation angle between a specific inspection point and a plurality of pixels to be inspected for each azimuth angle at an n ° interval. n is a constant greater than 0, and varies, for example, 0.1, 0.2, 5, 10, and the like. When the user wants to obtain a high resolution EMP, n may be set small by using a user interface (not shown), and the azimuth altitude calculation unit 832 may calculate the altitude angle at intervals of n set by the user interface. Can be.

In detail, when the specific inspection point located in the road area is selected in the road network DSM, the total azimuth elevation calculation unit 832 sets the pixel coordinates and the rotation angle of the selected specific inspection point. When the rotation angle is not 0 degrees, the full azimuth elevation calculation unit 832 calculates a normal normal to a straight line passing through a specific inspection point while having a set rotation angle with reference to [Equation 1], and calculates a specific inspection point. The inspection range for the r-axis of inspection pixels is determined by considering the pixel coordinates and the slope of the straight line.

Then, the azimuth elevation angle calculation unit 832 calculates the c-axis coordinates of the inspection target pixels using the rotation angle, the normal calculated for the rotation angle, and the r-axis coordinates of the inspection target pixels included in the inspection range. 2]. When the coordinates of the inspection target pixels are determined by the calculated c-axis coordinates, the total azimuth elevation angle calculation unit 832 calculates the linear distance between the inspection target pixels from the specific inspection point with reference to [Equation 3], An altitude difference between a specific test point and a test target pixel is calculated with reference to [Equation 4].

When both the altitude difference between the specific inspection point and the inspection target pixels are calculated, the omnidirectional elevation angle calculation unit 832 applies the linear distance and the altitude difference calculated above to Equation 5 based on the inspection point pixel. Calculate the elevation angle for each of these.

The shielding area determining unit 834 determines the position of the inspection target pixel at which the maximum altitude angle is calculated among the plurality of altitude angles calculated for each azimuth based on a specific inspection point by the azimuth altitude calculation unit 832 at each azimuth angle. It is determined that the signal is shielded area.

The shielding area determination unit 834 maps and stores the coordinates, the altitude elevation angle, and the azimuth information of the inspection target pixel whose maximum altitude is calculated for each azimuth based on a specific inspection point in the DB 840.

FIG. 9 is a diagram illustrating a skyplot of the EMP generation result at the first specific checkpoint, and FIG. 10 is a diagram representing a skyplot at the second specific checkpoint. Both examples show examples when n is set to 1 °.

Referring to FIG. 9, the target area is an AAA researcher, and the first specific inspection point is the entrance to the parking lot of the construction experiment building (the area indicated by the white square in the lower red portion of the right image). In the case of the first specific inspection point (entrance to the parking lot of the construction experiment building), it can be seen that the signal is shielded by the buildings in the north-east side while there is no obstacle in the south-west direction.

Referring to FIG. 10, the target area is an AAA researcher, and the second specific inspection point is an MS center parking lot entrance (a portion of a white square near the gown of the right image). In the case of the second specific inspection point, there is a shielding phenomenon as a whole by surrounding buildings, but since the road is located in the southeast direction, the time is smooth. As shown in FIG. 9 and FIG. 10, it is understood that the signal shielding phenomenon due to spatial characteristics is well reflected in the EMP calculation result by detecting an area where signals are shielded using the target area DSM and the road network DSM according to the present invention. Can be.

On the other hand, the observation environment simulation method of the DSM-based navigation satellite of the electronic device according to the present invention is typically provided by being included in a recording medium that can be read through a computer by a program of instructions for implementing the same type. Can be easily understood by the technician.

Accordingly, the present invention provides a program stored in a computer-readable recording medium executed on a computer in order to implement a method for simulating the observation environment of a DSM-based navigation satellite of an electronic device.

On the other hand, while described and illustrated in connection with a preferred embodiment for illustrating the technical idea of the present invention, the present invention is not limited to the configuration and operation as shown and described as described above, and depart from the scope of the technical idea It will be apparent to those skilled in the art that many modifications and variations can be made to the present invention without departing from the scope of the invention. Accordingly, all such suitable changes and modifications and equivalents should be considered to be within the scope of the present invention. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

800: DSM-based navigation satellite observation environment simulation device
810: storage unit
820: road network DSM acquisition unit
830: shielding area determining unit

Claims (7)

In the method for simulating the observation environment of the navigation satellite based on the digital surface model (DSM) of the electronic device,
(A) The electronic device obtains a grid-based DSM for a target area (hereinafter referred to as a 'target area DSM') and a grid-based DSM for a road area within the target area (hereinafter referred to as a 'road network DSM'). Doing; And
(B) The electronic device is located within the target area at a specific inspection point located in the road area of the road network DSM by using the altitude values provided by the target area DSM and the road area provided by the road network DSM. And determining an area in which a signal from the navigation satellite is shielded by obstacles. The method of claim 1,
Step (A) is
A first method of obtaining the road network DSM by overlapping layers of the numerical map representing the target area DSM and the road network for the target area, and a vector based generated by digitizing the orthoimage of the target area DSM and the target area And obtaining the road network DSM by one of the second methods of obtaining the road network DSM by overlapping layers. The method of claim 1,
Step (B) is,
(B1) Compute altitude angles for all azimuths in n ° intervals (where n is a constant) from a specific inspection point located in the road area from 0 ° to 360 ° in the all directions, wherein n is a specific inspection point and each bearing. Calculating elevation angles for a plurality of pixels to be inspected positioned in between; And
(B2) determining the position of the inspection target pixel whose maximum altitude angle is calculated among the plurality of altitude angles calculated for each azimuth based on the specific inspection point in step (B1) as an area where the signal is shielded at each azimuth angle; Observation environment simulation method of the DSM-based navigation satellite, characterized in that it comprises a. The method of claim 3,
In the step (B1), for each azimuth angle of n ° intervals from the entire azimuth 0 ° to 360 °,
(B11) setting a pixel coordinate and a rotation angle of the selected specific inspection point when a specific inspection point located in a road area is selected in the road network DSM;
(B12) calculating a normal orthogonal to a straight line passing through the specific inspection point while having the rotation angle;
(B13) determining an inspection range with respect to the r (row) axis of the pixels to be examined by considering the pixel coordinates of the specific inspection point and the slope of the straight line;
(B14) calculating c (column) column coordinates of the inspection target pixels using the rotation angle, a normal line calculated for the rotation angle, and r-axis coordinates of inspection target pixels included in the inspection range. ;
(B15) if the coordinates of the inspection target pixels are determined by the c-axis coordinates calculated in the operation (B14), calculating a straight line distance between the inspection target pixels from the specific inspection point;
(B16) calculating an altitude difference between the specific inspection point and the inspection pixel with reference to the target area DSM; And
(B17) calculating an altitude angle for each of the pixels to be inspected using the straight line distance calculated in the step (B15) and the altitude difference calculated in the step (B16). Method of simulation of observation environment of navigational satellite. In the device for simulating the observation environment of the navigation satellite based on DSM (Digital Surface Model),
Grid-based DSM of the target area (hereinafter referred to as 'target area DSM') and grid-based DSM of road area within the target area (hereinafter referred to as 'road network DSM') for simulating the observation environment of the navigation satellite. A storage unit for storing; And
By using the altitude values provided by the target area DSM and the road area provided by the road network DSM, obstacles located in the target area at a specific inspection point located in the road area of the road network DSM may be used. Apparatus for simulating the observation environment of the DSM-based navigation satellite comprising a; The method of claim 5,
A first method of obtaining the road network DSM by overlapping layers of the numerical map representing the target area DSM and the road network for the target area, and a vector based generated by digitizing the orthoimage of the target area DSM and the target area And a road network DSM acquiring unit for acquiring the road network DSM by one of a second method of acquiring the road network DSM by overlapping layers. The method of claim 5,
The shielding area determiner,
Compute altitude angles for all azimuths at n ° intervals from a specific inspection point located in the road area to all directions 0 ° to 360 °, wherein a plurality of pixels to be inspected are located between the specific inspection point and each bearing. A total azimuth altitude calculation unit for calculating altitude angles with respect to; And
A shielding which determines the position of the inspection target pixel whose maximum altitude is calculated from among a plurality of altitudes calculated for each azimuth based on the specific inspection point in the all azimuth altitude calculation unit as an area where a signal is shielded at each azimuth Observation environment simulation apparatus of the DSM-based navigation satellite, characterized in that it comprises a region determination unit.

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