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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Korean Society for Geospatial Information System
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Journal DOI :
The Korean Society for Geospatial Information System
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Volume & Issues
Volume 23, Issue 4 - Dec 2015
Volume 23, Issue 3 - Sep 2015
Volume 23, Issue 2 - Jun 2015
Volume 23, Issue 1 - Mar 2015
Selecting the target year
Accuracy Analysis of UAV Data Processing Using DPW
Choi, Yun Woong ; You, Ji Ho ; Cho, Gi Sung ;
Journal of Korean Society for Geospatial Information System, volume 23, issue 4, 2015, Pages 3~10
DOI : 10.7319/kogsis.2015.23.4.003
The various studies and applications for UAVS(Unmaned Aerial Vehicle System) have been recently increased as a new technology to create 3D spatial information rapidly and accurately. UAV(Unmanned Aerial Vehicle) is economical when comparing with conventional technique, such as satellite and aerial survey, and can quickly obtain high resolution data under 5cm. This paper examined the utilizing possibility to creating 3D spatial information and analysis the compatibility the UAV data obtained by non-metric digital camera with conventional numerical photogrammetric system. The DEM and normal orthophoto is created by exclusive S/W and DPW(Digital Photogrammetry Workstation) then analysis the accuracy of created data. As a result, the accuracy of the created DEM and normal orthophoto, which is obtained by UAV then processed by DPW, is not satisfied;so it is estimated that the compatibility the UAV data with conventional numerical photogrammetric system is low.
Development of Estimation Algorithm of Near-Surface Air Temperature for Warm and Cold Seasons in Korea
Kim, Do Yong ;
Journal of Korean Society for Geospatial Information System, volume 23, issue 4, 2015, Pages 11~16
DOI : 10.7319/kogsis.2015.23.4.011
Spatial and temporal information on near-surface air temperature is important for understanding global warming and climate change. In this study, the estimation algorithm of near-surface air temperature in Korea was developed by using spatial homogeneous surface information obtained from satellite remote sensing observations. Based on LST(Land Surface Temperature), NDWI(Normalized Difference Water Index) and NDVI(Normalized Difference Vegetation Index) as independent variables, the multiple regression model was proposed for the estimation of near-surface air temperature. The different regression constants and coefficients for warm and cold seasons were calculated for considering regional climate change in Korea. The near-surface air temperature values estimated from the multiple regression algorithm showed reasonable performance for both warm and cold seasons with respect to observed values (approximately
root mean-square error and nearly zero mean bias). Thus;the proposed algorithm using remotely sensed surface observations and the approach based on the classified warm and cold seasons may be useful for assessment of regional climate temperature in Korea.
An upgrade of Landslide Hazard Map with Analysis of Debris Flow using High-Quality Geospatial Information
Yang, In Tae ; Yu, Young Geol ; Park, Kheun ; Park, Jae Kook ;
Journal of Korean Society for Geospatial Information System, volume 23, issue 4, 2015, Pages 17~24
DOI : 10.7319/kogsis.2015.23.4.017
This study utilized high quality three-dimensional geospatial information produced by high-resolution Digital Aerial Photograph and Airborne LiDAR data in order to analyse landslides and debris flows induced by the heavy rainfall in Chuncheon area. Also, this study analysed correlation between the established landslide hazard map and the landslide factor effect and reviewed the analysis result of debris flows on the area where landslides with debris flows occurred frequently. Finally;the study proposed ways to renew the established landslide hazard map effectively and utilize the high quality three-dimensional Geospatial information on the landslide risk area.
A Study on Land Cover Map of UAV Imagery using an Object-based Classification Method
Shin, Ji Sun ; Lee, Tae Ho ; Jung, Pil Mo ; Kwon, Hyuk Soo ;
Journal of Korean Society for Geospatial Information System, volume 23, issue 4, 2015, Pages 25~33
DOI : 10.7319/kogsis.2015.23.4.025
The study of ecosystem assessment(ES) is based on land cover information, and primarily it is performed at the global scale. However, these results as data for decision making have a limitation at the aspects of range and scale to solve the regional issue. Although the Ministry of Environment provides available land cover data at the regional scale, it is also restricted in use due to the intrinsic limitation of on screen digitizing method and temporal and spatial difference. This study of objective is to generate UAV land cover map. In order to classify the imagery, we have performed resampling at 5m resolution using UAV imagery. The results of object-based image segmentation showed that scale 20 and merge 34 were the optimum weight values for UAV imagery. In the case of RapidEye imagery;we found that the weight values;scale 30 and merge 30 were the most appropriate at the level of land cover classes for sub-category. We generated land cover imagery using example-based classification method and analyzed the accuracy using stratified random sampling. The results show that the overall accuracies of RapidEye and UAV classification imagery are each 90% and 91%.
Method to Objectify Individual Factors of GIS-based Real Estate Appraisal
Kim, Tae Woo ; Kang, In Joon ; Park, Dong Hyun ; Hwang, Dae ;
Journal of Korean Society for Geospatial Information System, volume 23, issue 4, 2015, Pages 35~41
DOI : 10.7319/kogsis.2015.23.4.035
Real estate appraisal methods include profit-based, cost-based and comparison-based measures. The purpose of this study is to scientifically quantify the comparison-based method mostly utilized in valuating real estate property among the appraisal methods. The comparison method is to estimate the value of target property from other previously-traded property cases by comparing and adjusting their temporal gap, spatial gap and space-time gap. In appraisal practices, this comparison method is used generally for land property. If based on previous transactions; prices, time point of transaction, region and individual factors were analyzed to valuate. If based on official land values; official value, time point, region and individual factors are analyzed. Of these, the individual factors are an important process of comparing individual characteristics where real estate appraisers' subjective assessment could intervene. Though appraisers, as experts make generally precise assessment, still, it is a subjective judgment open to difference between appraisers themselves, causing disputes from time to time. In this recognition, the study seeks to quantify such a subjective assessment of appraisers by running GIS analysis on individual factor components including street condition, access condition;and plotting condition.
A Study on Pseudo-Range Correction Modeling in order to Improve DGNSS Accuracy
Sohn, Dong Hyo ; Park, Kwan Dong ;
Journal of Korean Society for Geospatial Information System, volume 23, issue 4, 2015, Pages 43~48
DOI : 10.7319/kogsis.2015.23.4.043
We studied on pseudo-range correction(PRC) modeling in order to improve differential GNSS(DGNSS) accuracy. The PRC is the range correction information that provides improved location accuracy using DGNSS technique. The digital correction signal is typically broadcast over ground-based transmitters. Sometimes the degradation of the positioning accuracy caused by the loss of PRC signals, radio interference, etc. To prevent the degradation, in this paper, we have designed a PRC model through polynomial curve fitting and evaluated this model. We compared two quantities, estimations of PRC using model parameters and observations from the reference station. In the case of GPS, the average is 0.1m and RMSE is 1.3m. Most of GPS satellites have a bias error of less than
and a RMSE within 3.0m. In the case of GLONASS, the average and the RMSE are 0.2m and 2.6m, respectively. Most of satellites have less than
for a bias error and less than 3.0m for RMSE. These results show that the estimated value calculated by the model can be used effectively to maintain the accuracy of the user's location. However;it is needed for further work relating to the big difference between the two values at low elevation.
Analysis of Integrated GPS/GLONASS/BDS Positioning Accuracy using Low Cost Receiver
Tae, Hyun U ; Park, Kwan Dong ; Kim, Mi So ;
Journal of Korean Society for Geospatial Information System, volume 23, issue 4, 2015, Pages 49~55
DOI : 10.7319/kogsis.2015.23.4.049
This paper explains major considerations for integrated GPS/GLONASS/BDS positioning, and then analyzes integrated GNSS positioning accuracies based on low-cost receivers in open-sky and poor reception environments. In an open-sky environment, horizontal RMSE of the integrated system positioning is about 1.2m. It shows improved result compared with single system positioning, the improvement ratio was 17-55%. In poor reception environments, we sometimes could not do positioning because the number of visible satellites gets below four. In an integrated positioning mode, the number of visible satellites was always higher than four, allowing us to find positions all the time. The horizontal RMSE of the integrated system positioning in poor reception environments is about 6.4m. Compared with single system positioning;the integrated system positioning shows better performance and the improvement ratio was 8-47% for the horizontal directions.
Estimating Spatio-Temporal Distribution of Climate Factors in Andong Dam Basin
Lim, Chul Hee ; Moon, Joo Yeon ; Lim, Yoon Jin ; Kim, Sea Jin ; Lee, Woo Kyun ;
Journal of Korean Society for Geospatial Information System, volume 23, issue 4, 2015, Pages 57~65
DOI : 10.7319/kogsis.2015.23.4.057
This study investigates characteristics of time series spatial distribution on climate factors in Andong Dam basin by estimating precise spatio-temporal distribution of hydro-meteorological information. A spatio-temporal distribution by estimating Semi-Variogram based on spatial autocorrelation was examined using the data from ASOS and 7 hydro-meteorological observatories in Andong Dam basin of upper Nakdonggang River, which were installed and observed by NIMR(National Institute of Meterological Research). Also, temperature and humidity as climate variables were analyzed and it was recognized that there is a variability in watershed area by time and months. Regardless of season, an equal spatial distribution of temperature at 14 o'clock and humidity at 10 o'clock was identified, and nonequal distribution was noticed for both variables at 18 o'clock. From monthly spatial analysis, the most unequal distribution of temperature was seen in January, and the most equal distribution was detected in September. The most unequal distribution of humidity was identified in May, and the most equal distribution was seen in January. Unlike in forest, seasonal spatial distribution characteristics were less apparent;but temperature and humidity had respective characteristics in hydro-meteorology.
Accuracy Analysis of GPS Ellipsoidal Height Determination in Accordance with the Surveying Conditions
Lee, Suk Bae ; Auh, Su Chang ;
Journal of Korean Society for Geospatial Information System, volume 23, issue 4, 2015, Pages 67~74
DOI : 10.7319/kogsis.2015.23.4.067
GNSS/Leveling technology makes it possible to get geoidal height geometrically using GNSS and Leveling technology. GNSS/Geoid technology refers to a technology for obtaining orthometric height by subtracting geoidal height achieved by Geoid technology from ellipsoidal height achieved by GNSS technology. The purpose of this study is to verify the accuracy of the ellipsoidal height determination in order to verify the accuracy of the orthometric height determination by the GNSS/Geoid technology. For the study, a test bed was selected in Kyungnam province and GNSS Static surveying was accomplished in the test bed and then the GNSS data was processed in accordance with various analysis conditions. So, it was verified the accuracy of the ellipsoidal heights determination in accordance with the surveying conditions under the GNSS Static surveying. According to the research results, to ensure the 3cm goal accuracy of the ellipsoidal height determination, it should be surveyed by four fixed points on the survey area periphery and more than two hours of the GNSS occupation time, And also, it was found that should be limited to a baseline distance of 20km under the GNSS Static surveying.