• Title/Summary/Keyword: Urban Image

Search Result 979, Processing Time 0.027 seconds

Analysis of Land Cover Characteristics with Object-Based Classification Method - Focusing on the DMZ in Inje-gun, Gangwon-do - (객체기반 분류기법을 이용한 토지피복 특성분석 - 강원도 인제군의 DMZ지역 일원을 대상으로 -)

  • Na, Hyun-Sup;Lee, Jung-Soo
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.17 no.2
    • /
    • pp.121-135
    • /
    • 2014
  • Object-based classification methods provide a valid alternative to traditional pixel-based methods. This study reports the results of an object-based classification to examine land cover in the demilitarized zones(DMZs) of Inje-gun. We used land cover classes(7 classes for main category and 13 classes for sub-category) selected from the criteria by Korea Ministry of Environment. The average and standard deviation of the spectrum values, and homogeneity of GLCM were chosen to map land cover types in an hierarchical approach using the nearest neighborhood method. We then identified the distributional characteristics of land cover by considering 3 topographic characteristics (altitude, slope gradient, distance from the Southern Limited Line(SLL)) within the DMZs. The results showed that scale 72, shape 0.2, color 0.8, compactness 0.5 and smoothness 0.5 were the optimum weight values while scale, shape and color were most influenced parameters in image segmentation. The forests (92%) were main land cover type in the DMZs; the grassland(5%), the urban area (2%) and the forests (broadleaf forest: 44%, mixed forest: 42%, coniferous forest: 6%) also occupied mostly in land cover classes for sub-category. The results also showed that facilities and roads had higher density within 2 km from the SLL, while paddy, field and bare land were distributed largely outside 6 km from the SLL. In addition, there was apparent distinction in land cover by topographic characteristics. The forest had higher density at above altitude 600m and above slope gradient $30^{\circ}$ while agriculture, bare land and grass land were distributed mainly at below altitude 600m and below slope gradient $30^{\circ}$.

A Study on the Improvement of Image-Based Water Level Detection Algorithm Using the Region growing (Region growing 기법을 적용한 영상기반 수위감지 알고리즘 개선에 대한 연구)

  • Kim, Okju;Lee, Junwoo;Park, Jinyi;Cho, Myeongheum
    • Korean Journal of Remote Sensing
    • /
    • v.36 no.5_4
    • /
    • pp.1245-1254
    • /
    • 2020
  • In this study, the limitations of the existing water level detection algorithm using CCTV images were recognized and the water level detection algorithm was improved by applying the Region growing technique. It applied three techniques (Horizontal projection profile, Texture analysis, and Optical flow) to estimate the water area, and the results were analyzed in a comprehensive analysis to select the initial water area. The water level was then continuously detected by the Region growing technique, referring to the initial water area. As a result, it was possible to confirm that the exact level of water was detected without being affected by environmental factors compared to the existing level detection algorithm, which had frequent mis-detection phenomena depending on the surrounding environmental factors. In addition, the water level was detected in the video showing flooded roads in urban areas, not in the video of the river. These results are believed to be able to supplement the difficulty of monitoring at all times with limited manpower by automatically detecting the level of water through numerous CCTV footage installed throughout the country, and to contribute to laying the foundation for preventing disasters caused by torrential rains and typhoons in advance.

A Study on the Applicability of Deep Learning Algorithm for Detection and Resolving of Occlusion Area (영상 폐색영역 검출 및 해결을 위한 딥러닝 알고리즘 적용 가능성 연구)

  • Bae, Kyoung-Ho;Park, Hong-Gi
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.20 no.11
    • /
    • pp.305-313
    • /
    • 2019
  • Recently, spatial information is being constructed actively based on the images obtained by drones. Because occlusion areas occur due to buildings as well as many obstacles, such as trees, pedestrians, and banners in the urban areas, an efficient way to resolve the problem is necessary. Instead of the traditional way, which replaces the occlusion area with other images obtained at different positions, various models based on deep learning were examined and compared. A comparison of a type of feature descriptor, HOG, to the machine learning-based SVM, deep learning-based DNN, CNN, and RNN showed that the CNN is used broadly to detect and classify objects. Until now, many studies have focused on the development and application of models so that it is impossible to select an optimal model. On the other hand, the upgrade of a deep learning-based detection and classification technique is expected because many researchers have attempted to upgrade the accuracy of the model as well as reduce the computation time. In that case, the procedures for generating spatial information will be changed to detect the occlusion area and replace it with simulated images automatically, and the efficiency of time, cost, and workforce will also be improved.

Comparison of Observation Performance of Urban Displacement Using ALOS-1 L-band PALSAR and COSMO-SkyMed X-band SAR Time Series Images (ALOS-1 L-band PALSAR와 COSMO-SkyMed X-band SAR 시계열 영상을 이용한 도심지 변위관측 성능 비교 분석)

  • Choi, Jung-Hyun;Kim, Sang-Wan
    • Korean Journal of Remote Sensing
    • /
    • v.34 no.2_1
    • /
    • pp.283-293
    • /
    • 2018
  • We applied PSInSAR to two SAR satellite (ALOS-1 and COSMO-SkyMed) images and analyzed the difference in displacement observation performance according to sensor characteristics. The building layer was extracted from the digital topographic map, and the PS extracted from the SAR image was classified into two groups(building structure and ground surface) for density analysis. The density of PS extracted from the research area was $0.023point/m^2$ for ALOS-1 PALSAR and $0.1point/m^2$ for COSMO-SkyMed, more than 4 times PS was extracted compared to ALOS-1. In addition, not only the PS density in the building, but also the density in the ground were greatly increased. The average displacement velocity of ALOS-1 PALSAR is within ${\pm}1cm/yr$, while for COSMO-SkyMed it is within ${\pm}0.3cm/yr$. Although it is difficult to make quantitative comparisons because it does not use the data for the same period, it can be said that the accuracy of X-band SAR system is very high compared to the L-band. In consideration of PS observation density and observation accuracy of displacement, X-band SAR data is very effective in research where it is important to acquire useful signals from the ground surface, such as ground subsidence and sinkhole.

Downscaling GPM Precipitation Using Finer-scale MODIS Based Optical Image in Korean Peninsula (MODIS 광학 영상 자료를 통한 한반도 GPM 강우 자료의 상세화 기법)

  • Oh, Seungcheol;Jeong, Jaehwan;Lee, Seulchan;Choi, Minha
    • Korean Journal of Remote Sensing
    • /
    • v.36 no.5_1
    • /
    • pp.749-762
    • /
    • 2020
  • Precipitation is closely related to various hydrometeorological phenomena, such as runoff and evapotranspiration. In Korean Peninsula, observing rainfall intensity using weather radar and rain gauge network is dominating due to their accurate, intuitive and precise detecting power. However,since these methods are not suitable at ungauged regions, rainfall detection using satellite is required. Satellite-based rainfall data has coarse spatial resolution (10 km, 25 km), and has a limited range of usage due to its reliability of data. The aim of this study is to obtain finer scale precipitation. Especially, to make the applicability of satellite higher at ungauged regions, 10 km satellite-based rainfall data was downscaled to 1 km data using MODerate Resolution Imaging Spectroradiometer (MODIS) based cloud property. Downscaled precipitation was verified in urban region, which has complex topographical and environmental characteristics. Correlation coefficient was similar in summer (+0), decreased in spring (-0.08) and autumn (-0.01), and increased in winter (+0.04) season compared to Global Precipitation Measurement (GPM) based precipitation. Downscaling without calibration using in situ data could be useful in areas where rain gauge system is not sufficient or ground observations are rarely available.

A Base Study of Intergrated Map for Integrated Coastal Zone Management (연안통합관리를 위한 통합수치도 개발에 관한 연구)

  • Yi, Gi-Chul;Suh, Sang-Hyun;Jeong, Hui-Gyun;Park, Chang-Ho;Yeo, Ki-Tae
    • Journal of the Korean association of regional geographers
    • /
    • v.9 no.4
    • /
    • pp.425-436
    • /
    • 2003
  • Integrated approach is presented by developing the technology and the ways of the practical use of the integrated digital map of and Electronical Navigational Chart (ENC) and Digital Terrain Map (DTM) for the effective and scientific based conservation, development and management of coastal area in this study. At first as preliminary studies to make eventual integrated maps, the necessity of the integrated map is described with the concept of coastal areas. Then, the characteristics of digital maps developed by Korean Geography Institute and National Marine Investigation Institute are carefully analyzed and integrated to a digital map as a test for edge matching in coastal line. Developed test coastal map was overlayed with a high-resolution satellite image (KVR-1000). The ground survey using Global Positioning System was conducted for the analysis of edge matching along the coastal line. Results from the edge matching analysis of coastal lines showed about 14 meters mean difference in artificial terrain and 4 meters mean difference in natural terrain. The problems, causes and solutions for the edge-matched differences are described. Furthermore, the value of utilization, the future use and various fields of application produced by the integrated digital map database are suggested as a basis for ICZM implementation in South Korea.

  • PDF

The Meaning for Marriage Migrant Women to have College Experience (결혼이주여성의 전문대학 학습경험 의미)

  • Baek, Eun-Sook;Han, Sang-Kil
    • The Journal of the Korea Contents Association
    • /
    • v.17 no.4
    • /
    • pp.179-199
    • /
    • 2017
  • This research was conducted in a phenomenological method to explore what the meaning for marriage migrant women to have college experience is. In other words, It is to find out what the motivation for them to enroll the college is and what the experience of studying in college implies. Also, figuring out how the expectation for life after the college experience is built up structurally is the purpose of the research. To ensure the qualitative warranty of the research, the participants are selected by "Sampling and Data Collection Strategy" suggested by Miles & Huberman (1994); and those selected participants are six marriage migrant women in urban-rural area with 10~18 years of residence period. The information for this research had been collected by in-depth and additional interviews along with observation towards these six participants. The result is the following. First, the motivation for them to enroll the college is; to realize of one's dream, to have confident parental model, to pursuit stabilized domestic economy, to have a professional occupation, and to make it as a mean of searching one's career path. Second, the experience of studying in college implies; enhancing communication ability, establishing self-image in the family and its relationship, having confident in raising children, enhancing healthy living of family, enhancing human relations, and lifelong learning person through set of learning. Third, the structure of how it build the future life is; having independent life pursuing stable living economically, living as a confident Korean by pursuing the value of learning and having a life of human being.

Evaluation on Tie Point Extraction Methods of WorldView-2 Stereo Images to Analyze Height Information of Buildings (건물의 높이 정보 분석을 위한 WorldView-2 스테레오 영상의 정합점 추출방법 평가)

  • Yeji, Kim;Yongil, Kim
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.33 no.5
    • /
    • pp.407-414
    • /
    • 2015
  • Interest points are generally located at the pixels where height changes occur. So, interest points can be the significant pixels for DSM generation, and these have the important role to generate accurate and reliable matching results. Manual operation is widely used to extract the interest points and to match stereo satellite images using these for generating height information, but it causes economic and time consuming problems. Thus, a tie point extraction method using Harris-affine technique and SIFT(Scale Invariant Feature Transform) descriptors was suggested to analyze height information of buildings in this study. Interest points on buildings were extracted by Harris-affine technique, and tie points were collected efficiently by SIFT descriptors, which is invariant for scale. Searching window for each interest points was used, and direction of tie points pairs were considered for more efficient tie point extraction method. Tie point pairs estimated by proposed method was used to analyze height information of buildings. The result had RMSE values less than 2m comparing to the height information estimated by manual method.

Agricultural drought monitoring using the satellite-based vegetation index (위성기반의 식생지수를 활용한 농업적 가뭄감시)

  • Baek, Seul-Gi;Jang, Ho-Won;Kim, Jong-Suk;Lee, Joo-Heon
    • Journal of Korea Water Resources Association
    • /
    • v.49 no.4
    • /
    • pp.305-314
    • /
    • 2016
  • In this study, a quantitative assessment was carried out in order to identify the agricultural drought in time and space using the Terra MODIS remote sensing data for the agricultural drought. The Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) were selected by MOD13A3 image which shows the changes in vegetation conditions. The land cover classification was made to show only vegetation excluding water and urbanized areas in order to collect the land information efficiently by Type1 of MCD12Q1 images. NDVI and EVI index calculated using land cover classification indicates the strong seasonal tendency. Therefore, standardized Vegetation Stress Index Anomaly (VSIA) of EVI were used to estimated the medium-scale regions in Korea during the extreme drought year 2001. In addition, the agricultural drought damages were investigated in the country's past, and it was calculated based on the Standardized Precipitation Index (SPI) using the data of the ground stations. The VSIA were compared with SPI based on historical drought in Korea and application for drought assessment was made by temporal and spatial correlation analysis to diagnose the properties of agricultural droughts in Korea.

Culture and Ecology-Oriented City Marketing: A Case Study of Gangneung City (문화.생태를 이용한 도시마케팅 사례 연구)

  • Heo, Chung-Uk
    • Korean Business Review
    • /
    • v.22 no.2
    • /
    • pp.157-179
    • /
    • 2009
  • This papers aims to focus on the city marketing as the green growth policy strategies using a case study of Gangneung City, Republic of Korea. In the case study it was verified the fields of urban growth including ecology, culture, alternative and recycled energy, green transportation system. The implications of the study were as follows: First, the city government had regenerated the coastal pine forest through removing unlicensed buildings which were squatted down in decades. Secondly, the city government has recognized the value of culture that possessed various types of cultural asserts. Thirdly, it is possible to use and produce the ocean energy with the tidal power plant, wind power plant and green deep water because Gangneung City has the ocean-oriented image and is located the coastal region. Lastly, the city government has been utilizing the LED traffic light using solar heat and is going to apply the green car like an electric car. This paper indicates the importance of the alternatives of the green growth-oriented policy through city marketing using the concept of culture and ecology. The city government will strive after an advanced triple bottom line with the ecological sustainability, cultural diversity and economic effectiveness in the near future.

  • PDF