• Korea Multimedia Society
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• v.19 no.4
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• pp.11-17
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• 2015

• Korean Journal of Remote Sensing
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• v.27 no.5
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• pp.587-599
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• 2011

As one measure of image interpretability, NIIRS(National Imagery Interpretability Rating Scale) has been used. Unlike MTF(Modulation Transfer Function), SNR(Signal to Noise Ratio), and GSD(Ground Sampling Distance), NIIRS can describe the quality of overall image at user's perspective. NIIRS is observed with human observation directly or estimated by edge analysis. For edge analysis specially manufactured artificial target is used commonly. This target, formed with a tarp of black and white patterns, is deployed on the ground and imaged by the satellite. Due to this, the artificial target-based method needs a big expense and can not be performed often. In this paper, we propose a new edge analysis method that enables to estimate NIIRS accurately. In this method, natural targets available in the image are used and characteristics of the target are considered. For assessment of the algorithm, various experiments were carried out. The results showed that our algorithm can be used as an alternative to the artificial target-based method.

• Proceedings of KOSOMES biannual meeting
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• 2006.05a
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• pp.47-52
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• 2006

The cultural grounds of laver has been surveyed using SPOT-5 satellite images to calculate the facilities of laver cultivation area in the coastal waters of Korea 10m resolution multispectral images of SPOT-5 are adopted for the south area of Daebu Island, Hwaseong city to develop an automatic detection approach of laver nets that consists of the following: band difference technique, canny edge detector and morphological analysis. The satellite-based facilities number was relatively high as compared with the licensed number in 2005, 676,749 chaek and 572,745 chaek(柵, unit of measure for laver farm), respectively. The data could be applied to achieve a good harvest for laver seaweed growers and to control its national production keeping a stable market price for the government body.

• Korean Journal of Remote Sensing
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• v.13 no.2
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• pp.85-98
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• 1997

A geometric model of pushbroom-type linear CCD camera images is proposed in this paper. At present, this type of cameras are used for obtaining almost all kinds of high-resolution optical images from satellites. The proposed geometric model includes not only a forward transformation which is much more efficient. An inverse transformation function cannot be derived analytically in a closed form because the focal point of an image varies with time. In this paper, therefore, an iterative algorithm in which a focal point os converged to a given pixel position is proposed. Although the proposed model can be applied to any pushbroom-type linear CCD camera images, the geometric model of the high-resolution multi-spectral camera on-board KITSAT-3 is used in this paper as an example. The flight model of KITSAT-3 is in development currently and it is due to be launched late 1998.

• Proceedings of the Korea Contents Association Conference
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• 2004.05a
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• pp.161-168
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• 2004

우리가 살아가는 3차원 이상의 지형공간을 영상으로 구형하기 위하여 필수적으로 요구되는 DEM을 비교적 손쉽게 확보할 수 있는 SPOT 영상을 이용하여 자동으로 생성할 수 있는 방법을 제시하고 에피폴라 투영법에 의한 결과영상의 평가를 통하여 몇 가지 좋은 방법을 제안하고자 한다 현재 보유하고 우리나라 춘천시의 SPOT 위성 팬크로 영상과 수치지도의 DEM영상과의 생성결과를 비교 평가하였다. SPOT2-3호(10m)에서 수집한 중복영상에서 자동으로 수치표고모델을 작성함으로서 다양한 영상정보의 활용이 가능해 따라 입체영상지도제작 및 분석이 가능해지고 있다. 본 연구에서는 SPOT 60km의 춘천지역을 대상으로 한눈에 영상과 영상을 재현할 수 있도록 고해상도의 인공위성 영상자료를 처리하여 영상지도를 제작하기 위한 수치표고모형을 자동으로 추출할 수 있도록 하였다.

• Proceedings of the KSRS Conference
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• 2006.03a
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• pp.193-197
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• 2006

지상측정 및 위성영상탑재 광학센서를 이용하여 벼 주요 생육시기에 대한 군락의 엽질소 함량을 추정하였다. 6월부터 10월에 걸쳐 주요 생육시기 $5{\sim}6$회에 걸쳐 Orbview 및 QuickBird와 같이 4m 이하의 고해상도 다중영상을 취득하였다. 위성영상 취득일에 가능한한 맞추어 인공광원을 사용하는 2종의 능동형 광학 (G)NDVI 센서를 이용한 벼 군락의 반사특성을 측정하였으며 동시에 식물체 샘플링을 통한 생육량, 엽면적지수, 엽질소 함량 등을 분석하였다. 시기별 영상의 분광반사특성 및 (G)NDVI와 벼 생육량 및 엽질소 함량과의 관계를 알아보기 위해 상관분석 및 회귀분석을 수행하였다. 지상센서 및 위성영상 유래 (G)NDVI의 값을 서로 비교해 보면 전체적으로 지상센서를 이용하여 측정한 (G)NDVI값이 위성영상 유래 (G)NDVI값보다 크게 나타났다. 하지만 두 센서 모두 엽면적지수 변화에 따른 (G)NDVI의 변화를 살펴보면 엽면적지수가 2 정도가 될 때까지는 함께 증가하다가 2보다 커지면서는 변화가 없이 머무르는 경향은 같게 나타났다. 엽면적지수의 변화는 군락의 엽질소함량 변화와 선형적인 관계($R^2=0.80$)로 나타났다. 분얼기부터 성숙초기까지의 자료를 이용하여 지상센서 및 위성영상 유래 (G)NDVI를 이용한 벼 군락의 엽질소 함량과의 관계를 살펴보니 지수함수적 관계($R^2=0.90$)로 나타났다. 위성영상 유래 (G)NDVI를 이용한 벼 군락의 엽질소 함량 추정식을 이용하여 신평면 최고쌀 생산단지에 대한 엽질소 함량 지도를 작성하였다.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.183.2-183.2
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• 2012

최근 인공위성의 대형화 및 중량화 추세는 종종 기존 설비 내에서의 위성체 조립 및 시험업무의 작업성과 능률성을 심각하게 저해하는 요소로 작용한다. 이에 상기 업무의 원활한 수행을 위해서는 최적화된 설계의 기계지상지원장비(Mechanical Ground Support Equipment, MGSE)의 개발 및 활용이 요구되어지며, 이는 전체 위성개발기간 동안 요구되는 모든 시험 구성, 외부 설비 및 장비와의 인터페이스, 작업자의 동선 및 접근성 등을 종합적으로 고려해야 하는 작업이다. 특히 고해상도 영상안테나와 같이 높은 수준의 정렬 조건이 부과되는 탑재체의 경우 이의 장착, 정렬 및 지상전개시험 등을 위해서는 탑재체 및 위성체의 특성을 고려한 전용 장비의 개발도 필수적이다. 본 논문에서는 한국항공우주연구원이 최근 개발한 중대형급 지상관측 영상레이더 위성 개발 과제에 활용된 기계지상지원장비의 설계, 제작 및 운용 방법을 종합적으로 기술하였다.

• Korean Journal of Remote Sensing
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• v.15 no.3
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• pp.209-216
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• 1999

KITSAT-3, the third satellite of KITSAT series which has been developed for the last four and half years with purely Korean design and implementation technology, was launched successfully at last. All subsystems were tested and validated during the initial operation of the satellite. During the initaial operation phase, the Earth imaging camera on board KITSAT-3 acquisited several tens of scenes all over the world and transmitted the image data to ground station. The quality of images and the reliability of data transmission-reception system were tested qualititively and quantititively, respectively. In this paper, we summarize the camera, data handling, on-board memory, and image data transmission system of KITSAT-3 as well as the image receiving and archiving system in ground station. The error rate of image data transmission and reception was tested during the initial operation phase. The average data transmission error rate satisfied the initial requirement of less than 1%. The error rate will be reduced through the continuous work of test and stabilization of the ground system hardware.

• Korean Journal of Remote Sensing
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• v.12 no.1
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• pp.26-42
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• 1996

The CCD Earth Images Experiment(CEIE) is one of the main payload of the KITSAT-1. Since it was launched on Oct. 10, 1992, the CEIE has taken more than 500 images on the Earth surface world-wide so far. An image from the space is very different from a feature on the real Earth surface due to various radiometric and geometric distortions. Preprocessing to remove those distortions has to take place before the images data are processed and analyzed further for various applications. This paper describes the procedure to perform preprocessing including radiometric and geometric correction.e-processing system. The GCP marking using this technique showed a sufficient accuracy for KITSAT1,2 narrow camera images.

• Journal of the Society of Disaster Information
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• v.16 no.1
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• pp.79-86
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• 2020

Purpose: In this study, a model was developed to estimate the storage in Cheonan reservoir using images taken by Sentinel-1 satellite. Method: A total of three reservoirs were studied. All three reservoirs are small reservoirs whose water level is being measured. The preprocessing of Sentinel-1 images was done using SNAP distributed by the European Space Agency(ESA), and the storage was estimated by classifying water surface by the threshold classification method. The estimated reservoir area was compared with satellite and drones images taken on the same day. The correlation was derived by comparing the estimated reservoir area with the actual measurement. Results and Conclusions: The storage values estimated by satellite image analysis showed similar values to the actual measurement data. However, because of the underestimation of the reservoir area due to green algae and Epilithic diatom of summer reservoirs and the low resolution of satellite images, it is dificult to detect reservoir area by satellite images less than 10,000㎡.