• Proceedings of the KSRS Conference
• /
• 2003.11a
• /
• pp.1140-1142
• /
• 2003

Imagery and gridded data can be used as the sources of extracting important information and data layers in utilizing GIS. The existing metadata standard to distribute and to utilize the geographic information are mainly concentrated at the vector data and do not provide metadata components for imagery and gridded data. In this study, metadata components for imagery and gridded data have been investigated. Firstly, existing international metadata standards such as ISO and domestic standards of TTA have been analyzed. Based on th results, the draft metadata for imagery and gridded data have been proposed as the extensions of domestic metadata standard distribution. The draft metadata could contribute to build the basic standards to access and utilize proper imagery and gridded data fit to various application field, and this will be fundamental bases for activating GIS in public and private sectors.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.20 no.1
• /
• pp.110-120
• /
• 2008

Gridded bathymetric data of 30 seconds apart in Korea marginal seas $(30^{\circ}N{\sim}44^{\circ}N,\;117^{\circ}E{\sim}143^{\circ}E)$ are produced. In order to make the data, both updated gridded data of 1 minute apart on internet sites and all the digital nautical charts issued by National Oceanographic Research Institute (NORI) in Oct. 2007 are used. The reference level of the gridded data is approximate level of lowest low water and the horizontal coordinates are based on the WGS84 ellipsoid. Especially a developed computer program can collect all the sounding data including depth contour directly from the digital charts and UTM coordinates of the data are converted to the WGS84 coordinates from which accuracy of data is significantly improved. An interpolation method is adopted to produce the gridded data which are compared and analyzed against the existing gridded data. In this gridded data we can see significantly detailed topographic features which could not be found in the previous data.

• 한국공간정보시스템학회:학술대회논문집
• /
• 2004.12a
• /
• pp.153-158
• /
• 2004

Nowadays, the demand of the output analyzed from the gridded data has been sharply increased as the remote sensing technologies and GIS related industry have been developed. Therefore, a metadata access system which fits the requirements of the users should be developed for better managing and utilizing gridded data. In this background, this study defined a common application schema through the analysis of the metadata built by numerous institutes based on the draft metadata standards proposed from the study which maily concentrated on establishing the standards of distributing metadata for the gridded data supported by ETRI at 2003. Also, XML based integrated system was developed to access metadata maintained by SaTReC as well as SIMC to facilitate more convenient data access for the grid data users. The results of the pilot system developed from this study can be expected to contribute to build an more efficient and enlarged integrated access system of the metadata for the gridded data.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2004.11a
• /
• pp.197-202
• /
• 2004

Nowadays, the demand of the output analyzed from the gridded data has been sharply increased as the remote sensing technologies and GIS related industry have been developed. Therefore, a metadata access system which fits the requirements of the users should be developed for better managing and utilizing gridded data. In this background, this study defined a common application schema through the analysis of the metadata built by numerous institutes based on the draft metadata standards proposed from the study which maily concentrated on establishing the standards of distributing metadata for the gridded data supported by ETRI at 2003. Also, XML based integrated system was developed to access metadata maintained by SaTReC as well as SIMC to facilitate more convenient data access for the grid data users. The results of the pilot system developed from this study can be expected to contribute to build an more efficient and enlarged integrated access system of the metadata for the gridded data.

• Atmosphere
• /
• v.17 no.3
• /
• pp.255-268
• /
• 2007

This study generated and evaluated the high resolution (5 km) gridded data of monthly mean, maximum and minimum temperature from 2002 to 2005 over South Korea using a modified PRISM(Parameter-elevation Regressions on Independent Slopes Model: K-PRISM) developed by Daly et al. (2003). The performance of K-PRISM was evaluated by qualitative and quantitative ways using the observations and gridded data derived by inverse distance weighting (IDW) and hypsometric methods (HYPS). For the generation of high resolution gridded data, geographic informations over South Korea, such as the digital elevation, topographic facet and coastal proximity, are derived from the 1 km digital elevation data. The spatial patterns of temperature derived by K-PRISM were more closely linked to topography and coastal proximity than those by IDW. The K-PRISM performed much better than IDW for all months and temperatures, but it was equal to or slightly better than the HYPS. And the performances of K-PRISM were better in the minimum and mean temperature (winter) than the in maximum temperature (summer).

• Journal of Korean Society for Geospatial Information Science
• /
• v.18 no.2
• /
• pp.55-61
• /
• 2010

Using 3D point data implemented from terrestrial LiDAR, this research has modelled geospatial data in 2 categories(gridded & un-gridded) and conducted LOS analysis experiment using outcome from the modeling exercise. To compare LOS analysis results from each of the 2 models in the above, maximum LOS (line of sight) range in the experimental area was specified as 30m in Area A, 40m in Area B and 50m in Area C and the time taken by LOS analysis and the number of visible points were measured. As for the LOS analysis experiment results, in comparison with the gridded model, the un-gridded model took about 3.9 times more time in Area A, 5.4 times in Area B and 6.5 times in Area C. In addition, about 0.97 times fewer points were measured in Area A, 0.93 times in Area B and 0.94 times in Area C. The difference between gridded model and un-gridded model in terms of the time taken by LOS analysis increased, as the maximum LOS range extended. On the other hand, the number visible points did not vary significantly in reference to the size of visible range.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.19 no.4
• /
• pp.270-279
• /
• 2017

Regional assessment of crop productivity using a gridded simulation approach could aid policy making and crop management. Still, little effort has been made to develop the systems that allows gridded simulations of crop growth using ORYZA 2000 model, which has been used for predicting rice yield in Korea. The objectives of this study were to develop a series of data processing modules for creating input data files, running the crop model, and aggregating output files in a region of interest using gridded data files. These modules were implemented using C++ and R to make the best use of the features provided by these programming languages. In a case study, 13000 input files in a plain text format were prepared using daily gridded weather data that had spatial resolution of 1km and 12.5 km for the period of 2001-2010. Using the text files as inputs to ORYZA2000 model, crop yield simulations were performed for each grid cell using a scenario of crop management practices. After output files were created for grid cells that represent a paddy rice field in South Korea, each output file was aggregated into an output file in the netCDF format. It was found that the spatial pattern of crop yield was relatively similar to actual distribution of yields in Korea, although there were biases of crop yield depending on regions. It seemed that those differences resulted from uncertainties incurred in input data, e.g., transplanting date, cultivar in an area, as well as weather data. Our results indicated that a set of tools developed in this study would be useful for gridded simulation of different crop models. In the further study, it would be worthwhile to take into account compatibility to a modeling interface library for integrated simulation of an agricultural ecosystem.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.6 no.4
• /
• pp.272-289
• /
• 2004

The spatial resolution of local weather and climate information for agronomic practices exceeds the current weather service scale. To supplement the insufficient spatial resolution of official forecasts and observations, gridded climate data are frequently generated. Most ecological models can be run using gridded climate data to produce ecosystem responses at landscape scales. In this lecture, state of the art techniques derived from geospatial climatology, which can generate gridded climate data by spatially interpolating point observations at synoptic weather stations, will be introduced. Removal of the urban effects embedded in the interpolated surfaces of daily minimum temperature, incorporation of local geographic potential for cold air accumulation into the minimum temperature interpolation scheme, and solar irradiance correction for daytime hourly temperature estimation are presented. Some experiences obtained from their application to real landscapes will be described.

• Journal of the Korean Data and Information Science Society
• /
• v.28 no.5
• /
• pp.1133-1144
• /
• 2017

Cluster analysis with meteorological data allows to segment meteorological region based on meteorological characteristics. By the way, meteorological observed data are not adequate for cluster analysis because meteorological stations which observe the data are located not uniformly. Therefore the clustering of meteorological observed data cannot reflect the climate characteristic of South Korea properly. The clustering of $5km{\times}5km$ gridded data derived from a numerical model, on the other hand, reflect it evenly. In this study, we analyzed long-term grid data for temperatures and precipitation using cluster analysis. Due to the monthly difference of climate characteristics, clustering was performed by month. As the result of K-Means cluster analysis is so sensitive to initial values, we used initial values with Ward method which is hierarchical cluster analysis method. Based on clustering of gridded data, cluster of meteorological stations were determined. As a result, clustering of meteorological stations in South Korea has been made spatio-temporal segmentation.

• Proceedings of the KSRS Conference
• /
• 2007.10a
• /
• pp.33-36
• /
• 2007

We have persistently constructed gridded products of surface wind/wind stress over the world ocean using satellite scatterometer (ERS and Qscat). They are available for users as the Japanese Ocean Flux data sets with Use of Remote sensing Observation (J-OFURO) data together with heat flux components. Recently, a new version data of the Qscat/SeaWinds based on improved algorithm for rain flag and high wind-speed range have been delivered, and allowed us to reconstruct gridded product with higher spatial resolution. These products are validated by comparisons with in-situ measurement data by mooring buoys such as TAO/TRITON, NDBC and the Kuroshio Extension Observation (KEO) buoys, together with numerical weather prediction model products such as the NCEP-1 and 2. Results reveal that the new product has almost the same magnitude in mean difference as the previous version of Qscat product and much smaller than the NCEP-1 and 2. On the other hand, it is slightly larger root-mean-square (RMS) difference than the previous one and NCEPs for the comparison using the KEO buoy data. This may be due to the deficit of high wind speed data in the buoy measurement. The high resolution product, together with sea surface temperature (SST) one, is used to examine a new type of relationship between the lower atmosphere and upper ocean in the Kuroshio Extension region.