• 한국지구과학회지
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• 제31권1호
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• pp.1-7
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• 2010

그 동안 많은 연구에서 지형보정을 위한 프로그램들이 개발되어왔으며, 매우 효과적으로 지형보정을 수행하는 것으로 인정받아왔다. 특히, 한반도 뿐만이 아니라 세계적으로도 수치 지형자료가 보편적으로 보급되어 지형보정을 위한 기반 자료는 충분히 확보되고 있다. 이번 연구는 일반적인 광역탐사가 아닌 소규모 광체나 지질구조에 대한 정밀한 중력탐사에 대한 자동지형보정을 수행할 수 있도록 하는 프로그램을 개발하였다. 소규모 지하자원이나 지하공동 등의 소규모 지질현상에 대한 중력탐사에는 기존의 광역탐사에 적합한 지형보정프로그램보다 더욱 정밀한 지형보정프로그램이 필요하다. 따라서 본 연구를 통해서 개발된 자동정밀지형보정프로그램으로 정밀중력탐사를 보다 효율적으로 수행할 수 있게되었다. 본 연구에서 개발된 정밀지형보정프로그램에서는 multiquadric equation을 이용한 지형구현을 통해 보다 정밀한 지형 생성이 가능하게 설계하였으며, 연구자의 설정에 따라 중력측정점 주변에 자세한 지형값을 넣어 정밀한 지형보정이 가능하도록 하였다. 또한 기존의 광역중력탐사에서 무시되던 지형과 중력계 사이의 거리 차에 따른 옵션을 설정하여 정밀한 지형보정 수치를 산출하도록 하였다.

• 융복합기술연구소 논문집
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• 제12권1호
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• pp.1-5
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• 2022

This paper describes an algorithm for generating a terrain using a noise function and a height map as one of the procedural terrain generation methods. The polygon mesh data structure to represent the generated terrain concisely and render it is also described. The Perlin noise function is used as the noise technique for terrain mesh, and the height data of the terrain is generated by combining the four noise waves. In addition, the terrain height information can be also obtained from actual image data taken from the satellite. The algorithm presented in this paper generates the geometry part of the polygon topography from the height data obtained, and generated a material for texture mapping with two textures, that is, a diffuse texture and a normal texture. The validity of the terrain method proposed in this paper is verified through application examples, and its possibility can be confirmed through performance verification.

• 로봇학회논문지
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• 제7권3호
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• pp.171-181
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• 2012

Outdoor mobile robots are faced with various terrain types having different characteristics. To run safely and carry out the mission, mobile robot should recognize terrain types, physical and geometric characteristics and so on. It is essential to control appropriate motion for each terrain characteristics. One way to determine the terrain types is to use non-contact sensor data such as vision and laser sensor. Another way is to use contact sensor data such as slope of body, vibration and current of motor that are reaction data from the ground to the tire. In this paper, we presented experimental results on terrain classification using contact sensor data. We made a mobile robot for collecting contact sensor data and collected data from four terrains we chose for experimental terrains. Through analysis of the collecting data, we suggested a new method of terrain feature extraction considering physical characteristics and confirmed that the proposed method can classify the four terrains that we chose for experimental terrains. We can also be confirmed that terrain feature extraction method using Fast Fourier Transform (FFT) typically used in previous studies and the proposed method have similar classification performance through back propagation learning algorithm. However, both methods differ in the amount of data including terrain feature information. So we defined an index determined by the amount of terrain feature information and classification error rate. And the index can evaluate classification efficiency. We compared the results of each method through the index. The comparison showed that our method is more efficient than the existing method.

• Wind and Structures
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• 제28권4호
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• pp.239-253
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• 2019

Accurate numericalsimulation of wind field over complex terrain is an important prerequisite for wind resource assessment. In this study, numerical simulation of wind field over complex terrain was further carried out by taking the complex terrain around Siu Ho Wan station in Hong Kong as an example. By artificially expanding the original digital model data, Gambit and ICEM CFD software were used to create high-precision complex terrain model with high-quality meshing. The equilibrium atmospheric boundary layer simulation based on RANS turbulence model was carried out in a flat terrain domain, and the approximate inflow boundary conditions for the wind field simulation over complex terrain were established. Based on this, numerical simulations of wind field over complex terrain under different inflow wind directions were carried out. The numerical results were compared with the wind tunnel test and field measurement data for land and sea fetches. The results show that the numerical results are in good agreement with the wind tunnel data and the field measurement data which can verify the accuracy and reliability of the numerical simulation. The near ground wind field over complex terrain is complex and affected obviously by the terrain, and the wind field characteristics should be fully understood by numerical simulation when carrying out engineering application on it.

• 농촌계획
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• 제11권1호
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• pp.9-15
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• 2005

Preservation of geometrical context of terrains in a digitized format is useful in handling and making modification to the data. Digitization of three-dimensional terrain still proves a great challenge due to heavy load of context required to retain details of topological and geometrical information. Methods of simplification, restoration and multi-level terrain generation are often employed to transform the original data into a compressed digital format. However, reduction of the stored data size comes at an expense of loss of details in the original data set. This article reports on an alternative scheme for simplification and restoration of terrain data. The algorithm utilizes the fact that the terrain formation and patterns can be predicted and modeled through the fractal algorithm. This method was used to generate multi-level terrain model based on NGIS digital maps with preserving geometrical context of terrains.

• 항공우주시스템공학회지
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• 제16권6호
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• pp.1-7
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• 2022

지형 추종을 시뮬레이션하기 위해 레이다 모의 지형 스캔 정보 생성 기법이 제시되었다. 레이다 모의 지형 스캔 정보 생성 기법은 레이다가 원하는 방위각, 고각 방향에 순차적으로 다수의 빔을 방사하는 것을 모사한다. 방사되는 각 빔의 방위각은 모두 동일하고, 고각은 서로 다르다. 각 빔을 통해 획득한 지형 정보를 통합하여 레이다 모의 지형 스캔 정보가 생성된다. 레이다 모의 지형 스캔 정보는 레이다 탐지점들로 구성되어 있다. 레이다 탐지점은 레이다로부터 멀어질수록 빔 중심선으로부터 멀어지는 경향이 있다. 이는 빔 폭이 일정한 각도를 가지기 때문이며, 방사 위치로부터 멀어질수록 빔의 스캔 영역이 넓어지는 것과 관련이 있다. 본 논문에서는 빔을 모사하여 생성된 레이다 모의 지형 스캔 정보를 분석하기 위해 기하학 기반 지형 스캔 정보 생성 기법을 제시한다. 기하학 기반 지형 스캔 정보는 기하학 탐지점으로 구성되며, 모든 기하학 탐지점은 빔 중심선 위에 존재한다. 두 기법이 생성한 지형 스캔 정보의 위도, 경도를 분석하여 빔 폭의 영향이 반영된 레이다 모의 지형 스캔 정보가 생성되었는지 확인하였다.

• 한국시뮬레이션학회논문지
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• 제6권1호
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• pp.61-69
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• 1997

In 3D computer graphics, fractal techniques have been applied to terrain models. Even though fractal models are convenient way to get the data of terrain models, it is not easy to gain the final results by manipulating the data of terrain model. However, by using the object oriented programming techniques, we could reduce the effort of programming job to find the final result. In this paper, a set of classes made by object oriented programming technique is presented. To show the results, the data of a terrain model were made by a fractal technique, namely, the midpoint displacement methods with square lattices of points.

• 한국군사과학기술학회지
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• 제11권4호
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• pp.99-106
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• 2008

Digital Terrain Elevation Data is a set of numerical values that represent the heights of the terrain surface. Terrain has several properties. Among them, roughness is the most widely used one because it gives very useful information to land-based or land-reference platform. There are several ways to measure roughness of terrain. But each of them has own flaws. Moreover, it is not enough to represent the uniqueness of the terrain only by the roughness. We need another metric to measure the actual uniqueness. In this paper, we propose an improved method to measure essential characteristics, uniqueness, of terrain. It gives not only the roughness but also the unevenness. The combination of them makes up the uniqueness. And it can be applied even if there is no pre-planned path on the terrain.

• 항공우주시스템공학회지
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• 제18권1호
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• pp.88-98
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• 2024

본 논문에서는 디지털 지형 고도 데이터를 이용한 자동 지형 추종 시뮬레이터를 제안하였다. ATF Simulator는 Flight Simulator, Radar Simulator, TFC Simulator로 구성하였다. 지형 추종에 필요한 지형 정보로 디지털 지형 고도 데이터와 디지털 지형 고도 데이터를 이용하여 생성한 레이다 스캔 데이터를 활용하였다. ATF Simulator는 디지털 지형 고도 데이터를 이용하는 Passive mode, 레이다 스캔 데이터를 이용하는 Active mode, 두 가지 모두 이용하는 Hybrid mode로 세 가지 운용모드를 제공한다. LabVIEW 개발 환경과 MATLAB App Designer 개발 환경을 통해 지형 추종 시스템 개발에 소요되는 비용 및 시간을 줄일 수 있는 ATF Simulator를 개발하였으며 기능요구사항을 충족하는지 확인하여 검증하였다.

• 한국대기환경학회지
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• 제21권2호
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• pp.179-189
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• 2005

Recently air quality modeling studies for industrial complex and large cities located in the coastal regions have been carried out. Especially, the representation of atmospheric flow fields within a model domain is very important, because an adequate air quality simulation requires an accurate portrayal of the realistic three -dimensional wind fields. Therefore this study investigated effect of using high resolution terrain height data in numerical simulation. So the experiments were designed according to the detail terrain height with 3second resolution or not. Case 30s was the experiment using the terrain height data of USGS and Case 3s was the other using the detail terrain height data of Ministry of Environment. The results of experimental were more remarkable. In Case 3s, temperature indicated similar tendency comparing to observational data predicting maximum temperature during the daytime and wind speed made weakly for difference of terrain height.