Youn-Soo Kim

Improved Additive-Wavelet Image Fusion

Effective image-fusion methods inject the necessary geometric information and preserve the radiometric information. To preserve the radiometric information, the injected high frequency of a panchromatic (pan) image must follow the frequency of the multispectral (MS) image. In this letter, an improved additive-wavelet (AW) fusion method is presented using the à trous algorithm. The proposed method does not decompose the MS image; thus, it preserves the radiometric information of the MS image and can inject high frequency following the frequency of the MS image using a low-resolution pan image. Experimental results obtained using IKONOS data indicate that the proposed method produces superior-quality images compared with the AW luminance proportional method in a quantitative analysis.

Application of TerraSAR-X Data for Emergent Oil-Spill Monitoring

Synthetic aperture radar (SAR) signals can propagate through hazardous weather and atmospheric conditions with heavy cloud cover, volcanic dust, snow, or rain. The all-weather capabilities of SARs have attracted significant interest in remote sensing communities, since serious environmental disasters such as oil spills have been highly ¿elusive¿ to optical sensors, making visible spectrum data vulnerable to rapidly changing atmospheric conditions. In this paper, we discuss the technical functionalities of TerraSAR-X from the emergency response perspective, describing its technical abilities in terms of a damping ratio, radiometric accuracy, and noise level with reference to the actual Hebei Spirit oil-spill incident that occurred on the west coast of the Korean peninsula in December 2007. The damping ratios estimated from the TerraSAR-X data as a function of Bragg wavenumber for various wind speeds indicate that TerraSAR-X data can be effectively used to identify oil-spill areas with acceptable accuracy. We also received ERS-2, ENVISAT, RADARSAT-1, and ALOS PALSAR data for this oil-spill event, not simultaneously but with varying time delays. The processing results for the multitemporal data sets obtained from the X- and C-band SAR systems are useful since they can be used to determine the near-real-time migration of spilt oil. The results of the current study indicate that there are distinct advantages of using X-band TerraSAR-X data for oil-spill detection compared to the data obtained at other available frequencies.

Object-oriented land cover classification of panchromatic KOMPSAT-1 and SPOT-5 data

In this paper the use of an object-oriented classification approach for the identification of basic land cover types from panchromatic images is examined. Based on data recorded by KOMPSAT-1 and SPOT-5 the same classification procedure will be applied to both data sets and the results compared to a visual classification. Results show that a classifier which not only relies on the spectral values of individual pixels but rather on a number of features, calculated for previously identified image segments can be readily used for the semi-automatic classification of basic land cover types from panchromatic data. It is also robust enough to be able to analyze new data with minimal input by the user.

Enhanced semi-automatic image classification of high-resolution data

With the launch of KOMPSAT-2 at the end of 2005 the availability of high resolution data should be greatly improved. The use of download facilities in Europe will allow increased coverage without interfering with the original mission of KOMPSAT-2. With platforms currently under development by the European Space Agency such as the service support environment (SSE) and eoPortal larger audiences can be reached with different technical know-how. As these platforms go beyond mere data distribution but allow the implementation of applications this opens new possibilities but also poses new demands on application development. In this paper an object oriented classifier is used to derive basic land cover classes from high-resolution satellite image. The result is then integrated with vector data to identify different land user categories.

Agricultural land cover classification using rapideye satellite imagery in South Korea - first result -

Global climate changes as well as abnormal climate phenomena have affected the agricultural environment on a great scale. Thus, there is a strong need for countermeasures by making full use of agriculture related information. As agricultural lands in South Korea are mostly operated by private farmers on a small parcel level, it is difficult to gather information for an overview on changing crop condition and to construct database necessary for disease management, production estimation and compensation measures on a regional or governmental level. The objective of this study is to evaluate the multispectral reflectance characteristics of RapidEye image data to classify agricultural land cover as well as crop condition in South Korea. As the RapidEye sensor offers the spectral information in red edge range as a first multispectral satellite system, we focus on the usefulness of red edge reflectance for identifying crop species and for interpreting crop growth or stress condition.

Observation of Crude Oil Spill Off the West Coast of Korea using TerraSAR-X, ENVISAT ASAR and ALOS PALSAR

On December 7th, 2007, more than 10,000 tons of crude oil from a tanker leaked into the Yellow Sea off the west coast of Korean Peninsula. Several SAR images including TerraSAR-X, ENVISAT ASAR, RADARSAT-1, ERS-2 SAR and ALOS PALSAR were acquired over the contaminated area from oil spill. Observed dark patches in SAR images, due to the presence of oil slicks, were extracted using adaptive thresholding methods, and then classified based on field information. The damping ratio, which is a ratio between slick-free and slick-covered sea surface, was analyzed by the SAR radar frequencies and wind condition. With the acquired SAR images in temporal resolutions, the movement of oil slicks was monitored and traced.

KOMPSAT European cooperation

The KOMPSAT European Cooperation aims at enhancing existing and establishing new collaborations between KARI and various European institutions. The objective is to create mutual data and information exchange possibilities and to develop new data applications of available and future space based Earth Observation sensors. In this paper, the concepts of a KOMPSAT European Regional Application Archive (KERAA), a joint development between KARI, ARCS and other European partners is presented. This includes the establishment of an additional KOMPSAT-2 downlink in Europe, and the developments of a state-of-the-art user service system for urban and environmental security monitoring. The technologies chosen for searching the catalog, presenting and selecting the results and to access the available data at the regional application center include a WebMapServer (WMS), a WebFeatureServer (WFS), and a WebCoverageServer (WCS) together with the spatial enabled PostGIS/PostgreSQL database. In addition, the KERAA system is interconnected with the Service Support Environment (SSE) run by the European Space Agency (ESA), fully supporting the integration into WebServices.

Current state and future prospect of technology development in satellite application

Korea developed several satellites through government-led satellite development projects, and now operates earth observation satellites of various sensors, science and technology satellites, and communication satellites. Satellites can be utilized in many fields, and Satellite Information, Global Navigation Satellite System, Satellite Communications and Broadcasting, Space Solar Power System are typical application fields. Now that we have developed and operated several satellites, we have to concentrate more efforts on satellite application. In this paper, we reviewed the current states of the technologies of four satellite application fields mentioned above and analyzed the future prospects of them.

Automatic building information extraction by modified volumetric shadow analysis from high resolution multispectral data

This paper presents a new approach to stable automatic extraction of building information from a high resolution satellite image set, panchromatic (PAN) image and multispectral (MS) images shot in a same date. The proposed approach is based on semi-automatic volumetric shadow analysis (SVSA). The proposed approach extracts a height and some information of a same building by SVSA from PAN image and MS images, respectively. The height and some information are used to calculate a maximum cost value by cost functions. A height with maximum cost value is determined as a true height. The true height is used to find a footprint position of the building. This paper also presents an automatic building extraction result by the proposed approach and roof extraction. For test, a Kompsat-2 image set was used. The results showed that the proposed approach can extract building information stably from a high resolution satellite image set.

Integration of Digital Earth and physics engine for spatial simulation

The spatial simulation such as one of the landslide may play an important part for research, decision-making or forecast of spatial variation. Digital Earth (DE) can be become a very useful platform for the spatial simulation. Google Earth, very successful use case for DE, is very useful platform for visualizing geo-referenced data, but limited for the spatial simulation. In the paper, a method for integration of DE and a physics engine was proposed. The proposed method simulates a spatial change by the local physics engine and combines the simulation result with images of DE on online. The paper presents simple landslide simulation by the simple integration software, implemented by the proposed method.