• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
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• pp.363-370
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• 1999

Remotely sensed data is regarded as a potentially effective data source for the measurement of water quality and for the environmental change of water bodies. In this study, we measured the spectral reflectance by using multi-spectral image of low resolution camera(LRC) which will be loaded in the OSMI multi-purpose satellite(KOMPSAT) scheduled to be launched on 1999 to use the data in analyzing water pollution. We also investigated the possibility of extraction of water quality factors in water bodies by using remotely sensed low resolution data such as NOAA/AVHRR. In this study, Shiwha-District and Sang-Sam Lake was set up as the subject areas for the study. In this part of the study, we measured the spectral reflectance of the water surface to analyze the radiance of the water bodies in low resolution spectral band and tried to analyze the water quality factors in water bodies by using radiance feature from another remotely sensed data such as NOAA/AVHRR. As the method of this study, first, we measured the spectral reflectance of the water surface by using SFOV( Single Field of View) to measure the reflectance of water quality analysis from every channel in LRC spectral band(0.4~O.9${\mu}{\textrm}{m}$). Second, we investigated the usefulness of ground truth data and the LRC data by measuring every spectral reflectance of water quality factors. Third, we analyzed water quality factors by using the radiance feature from another remotely sensed data such as NOAA/AVHRR. We carried out ratio process of what we selected Chlorophyll-a and suspended sediments as the first factors of the water quality. The results of the analysis are below. First, the amount of pollutants of Shiwha-Lake has been increasing every you since 1987 by factors of eutrophication. Second, as a result of the reflectance, Chlorophyll-a represented high spectral reflectance mainly around 0.52${\mu}{\textrm}{m}$ of green spectral band, and turbidity represented high spectral reflectance at 0.57${\mu}{\textrm}{m}$. But suspended sediments absorbed high at 0.8${\mu}{\textrm}{m}$. Third, Chlorophyll-a and suspended sediments could have a distribution chart as a result of the water quality analysis by using NOAA/AVHRR data.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.620-623
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• 2005

KARI has prepared Calibration and Validation activities for the KOMPSAT-2 (KOrea Multi-Purpose SATellite-2) MSC data that will be launched at the end of this year. Firstly, we divided the Cal/Val activities of it to four parts, Spatial, Spectral, Radiometric and Geometric, and defmed the detailed Cal/Val items from them. Secondly, Cal/Val targets have been defined and manufactured for the role of them. Thirdly, we have made the plan and the procedure for the Cal/Val items, developed the codes for them, studied more detailed method to do them, and trained the Cal/Val activities using the foreign satellite image data by ourselves. KARI has been now setting up the KOMPSAT-2 LEOP plan with the Cal/Val activities, and probably will finish the EOP Cal/Val activities for the KOMPSAT-2 MSC data by the next April or May.

• 대한원격탐사학회지
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• 제15권4호
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• pp.297-305
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• 1999

Ocean Scanning Multispectral Imager (OSMI) is a payload on the KOMPSAT satellite to perform global ocean color monitoring for the study of biological oceanography. The instrument images the ocean surface using a wisk-broom motion with a swath width of 800km and a ground sample distance (GSD) of < 1km over the entire field of view (FOV). The instrument is designed to have an on-orbit operation duty cycle of 20% over the mission lifetime of 3 years with the functions of programmable gain/offset and on-board image data compression/storage. The instrument also performs sun and dark calibration for on-board instrument calibration. The OSMI instrument is a multi-spectral imager covering the spectral range from 400nm to 900nm using CCD Focal Plane Array (FPA). The ocean colors are monitored using 6 spectral channels that can be selected via ground commands. KOMPSAT satellite with OSMI was integrated and the satellite level environment tests including instrument aliveness/functional test, such as launch environment, on-orbit environment (Thermal/Vacuum) and EMI/EMC test were performed at KARl. Test results met the requirements and the OSMI data were collected and analyzed during each test phase. The instrument is launched on the KOMPSAT satellite on December 21,1999 and is scheduled to start collecting ocean color data in the early 2000 upon completion of on-orbit instrument checkout.

• 한국정보통신학회논문지
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• 제12권2호
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• pp.321-327
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• 2008

광범위한 지역의 주기적인 정보 획득이 가능한 인공위성 영상은 환경탐사분야에서 새로운 대안으로 받아들여지고 있으며, 산림 분석에서도 활용될 수 있다. 이러한 인공위성 영상을 활용한 우리나라의 산림식생을 고려한 연구 이외에, 산림형태의 구분을 통한 지속적인 관리시스템에 관한 연구는 아직 미흡한 실정이다. 본 연구에서는 Landsat TM 위성영상을 이용하여 산림을 형태별로 분류한 후, 촬영시기가 3년 뒤인 다른 영상에서 나타난 산림형태의 변화를 분석하고 지속적인 모니터링을 위한 변화 추적시스템의 적용을 제시하고자 한다. 이를 위해 식생분류에 유리한 다중분광센서를 탑재한 Landsat TM 위성영상을 이용하여 산림형태의 변화를 분석하고, 이를 Web 상에서 주기적으로 모니터링 할 수 있게 하였다.

• 한국측량학회지
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• 제30권1호
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• pp.75-86
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• 2012

SAR는 기상상태와 태양고도 제약을 받지 않고 영상을 취득할 수 있는 장점을 갖지만 광학영상에 비해 시각적 가독성이 떨어지는 단점을 갖는다. 광학영상의 다중분광정보를 융합하여 SAR 영상의 가독성을 향상시키기 위한 다중센서 융합기술에 대한 관심이 증대되고 있다. 본 연구에서는 고속 퓨리에 변환을 통한 고주파 정보 추출 및 이상치 제거과정을 통해 SAR 영상의 공간적 세밀함과 다중분광영상의 분광정보를 유지할 수 있는 새로운 다중센서 융합기술을 제안하였다. 실험데이터로는 KOMPSAT-5호와 동일한 고해상도 X-band SAR 시스템을 장착한 TerraSAR-X 영상과 KOMPSAT-2호의 다중분광영상을 사용하였다. 제안기법의 효용성을 평가하기 위해 기존에 위성영상융합에 많이 사용된 융합기법과의 시각적/정량적 비교평가를 수행하였다. 실험 결과 기존 영상융합알고리즘에 비해 분광정보 보존측면에서 보다 향상된 결과를 보임을 확인할 수 있었다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.601-603
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• 2004

Multi-Spectral Camera(MSC) is a payload on the KOMPSAT -2 satellite to perform the earth remote sensing. The instrument images the earth using a push-broom motion with a swath width of 15 km and a ground sample distance (GSD) of 1 m over the entire field of view (FOV) at altitude 685 Km. The instrument is designed to have an on-orbit operation duty cycle of $20\%$ over the mission lifetime of 3 years with the functions of programmable gain! offset and onboard image data compression/storage. MSC instrument has one(1) channel for panchromatic Imaging and four(4) channel for multi-spectral Imaging covering the spectral range from 450nm to 900nm using TDI CCD Focal Plane Array (FPA). In this paper, the configuration, the interface of MSC hardware and the MSC operation concept are described. And the method of the MSC calibration are described and the design of MSC calibration operation to measure the change of MSC after Launch & Early Operation(LEOP) and normal mission operations are discussed and analyzed.

• 대한전자공학회논문지SP
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• 제44권5호
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• pp.28-34
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• 2007

위성 영상에서 도로를 효과적으로 추출하기 위한 히스토그램 기반 도로 경계선 추출자를 제안하였다. 제안한 추출자를 이용해 도로 경계선 양측의 도로와 비도로 영역 각 화소의 방향성 히스토그램 차를 계산하고, 그 에지 강도 맵을 구하여 도로의 경계선을 추출하였다. 그리고 원영상과 분할된 도로 군집 영상의 에지 강도 맵을 계층적으로 구하여 직선 도로와 곡선 도로를 추출한 다음, 도로의 연결성을 기반으로 하여 전체 도로망을 구성하였다. 제안한 추출자는 칼라 유사도를 계산하는 기존 방법과 달리 히스토그램 차를 기반으로 하기 때문에 잡영에 강건하게 도로를 추출할 수 있으며, 도로 경계선의 위치와 도로 폭도 함께 추출할 수 있을 뿐만 아니라 도로군집을 자동식별하기 때문에 다양한 분광특성의 도로들도 쉽게 추출할 수 있다. 제안한 추출자를 이용하여 1m의 공간 해상도를 갖는 IKONOS 위성 영상에 대해 실험하여 잡영에 강건하게 도로가 추출됨을 확인하였고, 직선 도로 뿐만 아니라 곡선도로 추출도 용이함을 확인하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
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• pp.376-381
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• 1998

In this study, we was measured the radiance reflectance by using multi-spectral image of low resolution camera(LRC) which will be loaded in the multi-purpose satellite(KOMPSAT) to use the data in analyzing water pollution. Also we investigated the possibility of extraction of water quality factors in rivers and water body by using high resolution remote sensing data such as Airborne MSS. Especially, we tried to extract the environmental factors related with eutrophication, and also tried to develop the process technique and the radiance feature of reflectance related with eutrophication. The results were summarized as follows: First, the spectrum of sun's rays which reaches the surface of the earth was consistent with visible rays bands of 0.4${\mu}{\textrm}{m}$~0.7${\mu}{\textrm}{m}$ and about 50% of total quantity of radiation were there. And at around 0.5${\mu}{\textrm}{m}$ of green spectral band in visible rays bands, the spectrum was highest. Second, as a result of the radiance reflectance Chlorophyll-a represented high spectral reflectance mainly around 0.52${\mu}{\textrm}{m}$ of green spectral band, and suspended sediments and turbidity represented high spectral reflectance at 0.8${\mu}{\textrm}{m}$ and at 0.57${\mu}{\textrm}{m}$ each. Third, as a result of the water quality analysis by using Airborne MSS, Chlorophyll-a could have a distribution chart when carried out ratio of B3 and BS to B7. And Band 7 was useful for making the distribution chart of suspended sediments. And when we carried out PCA, suspended sediments and turbidity had distributions at PC 1 , PC 4 each similarly to ground truth data. Above results can be changed according to the change of season and time. Therefore, in order to analyze more exactly the environmental factors of water quality by using LRC data, we need to investigate constantly the ground truth data and the radiance feature of reflectance of water body. Afterward in this study, we will constantly analyze the radiance feature of the surface of water in water body by measuring the on-the-spot radiance reflectance and using low resolution satellite image(SeaWiFs). Besides, we will gather the data of water quality analysis in water body and analyze the pattern of water pollution.

• 한국측량학회지
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• 제34권2호
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• pp.133-142
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• 2016

KOMPSAT-3A (KOrea Multi-Purpose SATellite-3A) was launched in March 25 2015 with specification of 0.5 meters resolution panchromatic and four 2.2 meters resolution multi spectral sensors in 12km swath width at nadir. To better understand KOMPSAT-3A positional accuracy, this paper reports a test result on the accuracy of recently released KOMPSAT-3A beta test images. A number of ground points were acquired from 1:1,000 digital topographic maps over the target area for the accuracy validation. First, the original RPCs (Rational Polynomial Coefficients) were validated without any GCPs (Ground Control Points). Then we continued the test by modeling the errors in the image space using shift-only, shift and drift, and the affine model. Ground restitution accuracy was also analyzed even though the across track image pairs do not have optimal convergence angle. The experimental results showed that the shift and drift-based RPCs correction was optimal showing comparable accuracy of less than 1.5 pixels with less GCPs compared to the affine model.

• 대한원격탐사학회지
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• 제31권2호
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• pp.161-170
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• 2015

본 논문은 아리랑 2호와 3호에 대한 고해상 다분광 영상 제작을 위한 효과적인 영상융합 기법을 제시한다. 제안된 기법은 널리 알려져 있는 CS 기반의 영상융합 기법을 기본으로 하고 있다. 제안된 기법의 융합 과정은 크게 두 가지 단계로 구분할 수 있다. 첫 번째는 가중 평균된 다분광 영상을 이용한 Intensity 영상의 제작 단계와 두 번째는 최적화된 융합 매개변수를 통한 고주파 영상의 생성 단계이다. 제안된 기법에서는 기존의 방법을 개선한 다른 새로운 형식의 융합 매개변수를 정의하였으며, 이는 고주파 영상, 전정색 영상과 다분광 영상 간 공분산/분산 비를 이용하여 도출된다. 본 알고리즘의 평가를 위해서 기존의 융합 방법들의 결과와 정량적, 시각적 비교분석을 수행하였다. 정량적 분석에는 Spatial ERGAS, Spectral ERGAS, SAM, Q4 평가 지표가 사용되었다. 분석결과, 제안된 기법은 기존의 CS 기반의 영상융합 기법에 비하여 공간적/분광적인 측면에서 모두 향상된 결과를 나타냈다.