• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.383-392
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• 1993

Identification of rice paddy fields and estimation of their areas from the images taken by LANDSAT-5/TM were attempted. The results were verified by aerial photographs and also by ground observations. Changes of the spectral characteristics of rice plants were measured with a portable spectroradiometer during the growth period. Analyzing these characteristics, an index was developed for evaluating the growth and the yield of rice . Applying the index to the data observed by LANDSAT-5.TM on Sep. 26, 1986, Oct .20, 1989 and Sep, 21, 1990, it was confirmed that the estimated derived from the index agreed with actual values. The results well demonstrated its feasibility for evaluating the yield of rice by a satellite like LANDSAT-5/TM.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.410-414
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• 2004

The MODIS Land Rapid Response System (RRS) has been developed to provide rapid access to MODIS data globally, with initial emphasis on 250 m color composite imagery and active fire data. Fire detection is based on a contextual algorithm that exploits the strong emission of mid-infrared radiation from fires. This algorithm examines each pixel of the MODIS swath, and ultimately assigns to each one of the following classes: missing data, cloud, water, non-fire, fire, or unknown. In this paper, we introduce the MODIS Rapid Response System established at the Korea Aerospace Research Institute (KARI) and present some application results for Korea using the direct broadcast data acquired at KARI ground station.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.498-500
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• 2004

QPSK (Quaternary Phase Shift Keying) will be adopted as the modulation of HRIT (High Rate Information Transmission) which is transmitted to COMS (Communication, Ocean and Meteorological Satellite) through HPA (High Power Amplifier) in ground segment. Due to the nonlinearity of HPA, IMD (Inter-Modulation Distortion) of multi-carrier signals and PAPR (Peak-to-Average Power Ratio) of modulated HRIT must be considered to estimate the output power of HPA. In this paper, we measured the PAPR to various the roll-off factor of RRC (Root Raised Cosine filter) which is filtering the modulated HRIT signal for reducing ISI (Inter-Symbol Interference) and bandwidth. It was found that the minimum PAPR is 2.78dB at 0.5 of roll-off factor for scrambled data. It's 2.78dB of P APR will be in output power selecting in COMS earth station.

• Proceedings of the KSRS Conference
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• v.1
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• pp.336-339
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• 2006

In this paper, the preliminary transfer orbit analysis results for the COMS mission were presented. As the first step of transfer orbit analysis, the preliminary analyses of LAE burn strategy, geometrical visibility, and launch window were performed. For the analysis process, all launcher nominates were divided into three groups according to the declination of LAE thrust angle. So, the three launch cases were assigned as the representative launcher of each group, respectively. They are Ariane-5, Atlas summer and winter launch cases. And all analyses were performed at the representative launcher of each group. One nominal and three back-up plans were considered for the establishment of LAE burn strategy. And for geometrical visibility analysis, four TT&C ground stations were considered. Finally, the preliminary launch window analysis was performed about the duration of one year from the first day of September 2008. The analysis results show that the all launch cases comply with the transfer orbit operation requirements.

• Proceedings of the KSRS Conference
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• v.2
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• pp.780-783
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• 2006

The KOrea Multi-Purpose Satellite-2 (KOMPSAT-2) was launched in July 2006 and the main mission of the KOMPSAT-2 is a high resolution imaging for the cartography of Korea peninsula by utilizing Multi Spectral Camera (MSC) images. The camera resolutions are 1 m in panchromatic scene and 4 m in multi-spectral imaging. This paper provides an initial geometric accuracy assessment of the KOMPSAT-2 high resolution image without ground control points and briefly introduces the sensor model of KOMPSAT-2. Also investigated and evaluated the obtained 3-dimensional terrain information using the MSC pass image and scene images acquired from the KOMPSAT-2 satellite.

• Proceedings of the KSRS Conference
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• v.2
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• pp.899-902
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• 2006

For a quick and accurate 3D modelling of a building, laser scanning data, digital maps, aerial photographs and satellite images should be fusioned. Moreover, library establishment according to a standard structure of a building and effective texturing method are required in order to determine the structure of a building. In this study, we made a standard library by categorizing Korean village forms and presented a model that can predict a structure of a building from a shape of the roof on an aerial photo image. We made an ortho image using the high-definition digital image and considerable amount of ground scanning point cloud and mapped this image. These methods enabled a more quick and accurate building modelling.

• Proceedings of the KSRS Conference
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• v.1
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• pp.67-70
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• 2006

KARI is developing Image Data Acquisition and Control System (IDACS) for pre-processing meteorological and ocean data acquired on geostationary orbit. This paper describes the functions and architecture of IDACS and gives its operation policy including backup operation to overcome limitation of single-configured antenna system. The COMS IDACS provides the capability to receive the raw sensor data and disseminate processed MI data to users via a satellite. From the processed image data, users can produce a set of meteorological and ocean products for a wide range of applications. Most of IDACS subsystems are being developed by Korean technologies and experience acquired from previous projects. In case of COMS geometric correction software module, as it is closely dependent on the characteristics of imagers and spacecraft bus system, it is being co-developed with overseas prime contractor who develops spacecraft bus system.

• Proceedings of the KSRS Conference
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• v.2
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• pp.578-581
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• 2006

Usually to achieve precise geolocation of satellite images, we need to get GCPs (Ground control points) from individual scenes. This requirement greatly increases the cost and processing time for satellite mapping. In this article, we focus on finding appropriate sensor models for entire image strips composing of several adjacent scenes. We tested the feasibility of modelling whole satellite image strips by establishing sensor models of one scene with GCPs and by applying the models to neighboring scenes without GCPs. For this, we developed two types of sensor models: collinearity-based type and orbit-based type and tested them using different sets of unknowns. Results indicated that although the performance of two types was very similar, for modelling individual scenes, it was not for modelling the whole strips. Moreover, the performance of sensor models was remarkably sensitive to different sets of unknowns. It was found that the orbit-based model using attitude biases as unknowns can be used to model SPOT image strips of 420 Km in length.

• Proceedings of the KSRS Conference
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• v.2
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• pp.860-863
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• 2006

Epipolar images have to be generated to stereo display aerial images or satellite images. Pushbroom sensor is used to acquire high resolution satellite images. These satellite images have curvilinear epipolar lines unlike the epipolar lines of frame images, which are straight lines. The aforementioned fact makes it difficult to generate epipolar images for pushbroom satellite images. If we assume a linear transition of the sensor having constant speed and attitude during image acquisition, we can generate epipolar images based on parallel projection model (2D Affine model). Recent high resolution images are provided with RPC values so that we can exploit these values to generate epipolar images without using ground control points and tie point. This paper provides a procedure based on the parallel projection model for generating epipolar images directly from a stereo IKONOS images, and experimental results.

• Proceedings of the KSRS Conference
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• 2007.03a
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• pp.134-137
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• 2007

GB-SAR (Ground-Based Synthetic Aperture Radar) 시스템은 지상에서 안테나의 정밀한 일축 제어를 통해 합성 구경(synthetic aperture) 효과를 얻어 높은 해상도의 영상을 얻는 레이더 스캐너(Radar Scanner) 의 일종이다. GB-SAR는 장기간에 걸쳐 안정 적으로 마이크로파 영상 및 위상을 얻을 수 있기 때문에，SAR간섭기법(interferometry)을 통하여 비교적 안정된 산란체의 시간에 따른 변위를 cm 혹은 mm 정밀도로 정량적으로 얻을 수 있으며, 또한 긴밀도(coherence)를 통해 산란체의 안정성을 정성적으로 추출해 낼 수 있다. 이 논문에서는 GB-SAR 시스템의 개발을 소개하고 여러 가지 영상 획득 모드를 통하여 얻어진 SAR 영상， DInSAR, Cross-Track InSAR, ${\triangle}k-InSAR$, PSInSAR, 및 SAR Polarimetry 등 GB-SAR 시스템의 다양한 응용 가능성을 간략하게 보였다.