• 제목/요약/키워드: Simulated Satellite Image

검색결과 62건 처리시간 0.024초

Laboratory geometric calibration simulation analysis of push-broom satellite imaging sensor

  • Reza Sh., Hafshejani;Javad, Haghshenas
    • Advances in aircraft and spacecraft science
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    • 제10권1호
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    • pp.67-82
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    • 2023
  • Linear array imaging sensors are widely used in remote sensing satellites. The final products of an imaging sensor can only be used when they are geometrically, radiometrically, and spectrally calibrated. Therefore, at the first stages of sensor design, a detailed calibration procedure must be carefully planned based on the accuracy requirements. In this paper, focusing on inherent optical distortion, a step-by-step procedure for laboratory geometric calibration of a typical push-broom satellite imaging sensor is simulated. The basis of this work is the simulation of a laboratory procedure in which a linear imager mounted on a rotary table captures images of a pin-hole pattern at different angles. By these images and their corresponding pinhole approximation, the correction function is extracted and applied to the raw images to give the corrected ones. The simulation results illustrate that using this approach, the nonlinear effects of distortion can be minimized and therefore the accuracy of the geometric position of this method on the image screen can be improved to better than the order of sub-pixel. On the other hand, the analyses can be used to proper laboratory facility selection based on the imaging sensor specifications and the accuracy.

MONITORING OF MOUNTAINOUS AREAS USING SIMULATED IMAGES TO KOMPSAT-II

  • Chang Eun-Mi;Shin Soo-Hyun
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.653-655
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    • 2005
  • More than 70 percent of terrestrial territory of Korea is mountainous areas where degradation becomes serious year by year due to illegal tombs, expanding golf courses and stone mine development. We elaborate the potential usage of high resolution image for the monitoring of the phenomena. We made the classification of tombs and the statistical radiometric characteristics of graves were identified from this project. The graves could be classified to 4 groups from the field survey. As compared with grouping data after clustering and discriminant analysis, the two results coincided with each other. Object-oriented classification algorithm for feature extraction was theoretically researched in this project. And we did a pilot project, which was performed with mixed methods. That is, the conventional methods such as unsupervised and supervised classification were mixed up with the new method for feature extraction, object-oriented classification method. This methodology showed about $60\%$ classification accuracy for extracting tombs from satellite imagery. The extraction of tombs' geographical coordinates and graves themselves from satellite image was performed in this project. The stone mines and golf courses are extracted by NDVI and GVI. The accuracy of classification was around 89 percent. The location accuracy showed extraction of tombs from one-meter resolution image is cheaper and quicker way than GPS method. Finally we interviewed local government officers and made analyses on the current situation of mountainous area management and potential usage of KOMPSAT-II images. Based on the requirement analysis, we developed software, which is to management and monitoring system for mountainous area for local government.

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농림업 중형위성 탑재체 개발을 위한 기술 사양 및 활용 분석 (Analysis on Technical Specification and Application for the Medium-Satellite Payload in Agriculture and Forestry)

  • 김범승;김현철;송경민;홍석영;이우경
    • 한국위성정보통신학회논문지
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    • 제10권4호
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    • pp.117-127
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    • 2015
  • 최근 국내외에서 폭넓게 개발되어 활용되고 있는 지구관측용 위성 탑재체에 대한 개발과 연구는 영상 활용분야에서 활발하게 진행되고 있다. 또한 위성에 광학센서 및 영상 레이더 등을 장착하여 다양한 지역의 영상을 수집하고 분석함과 동시에 기반 기술들의 비약적인 발전이 이루어졌다. 국내에서 추진 중인 차세대 중형위성 개발 사업은 국내 독자기술로 탑재체를 개발할 목표에 있고 농촌진흥청, 기상청, 환경부, 국토교통부 등에서 공동으로 활용할 계획에 있다. 본 논문에서는 국내 농림업 환경에 적합한 위성 탑재체 기술사양을 제안하기 위해 위성 영상을 활용한 농림업 연구사례를 조사하여 농림업 세부 활용 분야에 따른 위성 탑재체 기술 사양을 분석하였다. 국내 위성영상 활용 전문가를 대상으로 실시한 설문 및 자문조사 결과를 바탕으로 국내외 지구관측 농림업 활용 위성의 탑재체 개발 현황, 계획 그리고 활용 등을 분석하여 독자적인 농림업 중형위성 탑재체 개발을 위한 기술사양을 제안하였다. 또한 한반도 농경지를 대상으로 위성 모의 운용실험 수행을 통해 위성 탑재체의 관측 성능을 검증하였다. 본 논문에서 제안한 결과는 향후 농림업 중형위성 탑재체 개발에 있어 적합한 사양을 제공하고 사용자들이 위성영상을 효율적으로 사용할 수 있는 방향으로서 기술적 기초 정보로 활용될 것으로 기대된다.

Characteristics of Multi-Spatial Resolution Satellite Images for the Extraction of Urban Environmental Information

  • Seo, Dong-Jo;Park, Chong-Hwa;Tateishi, Ryutaro
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
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    • pp.218-224
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    • 1998
  • The coefficients of variation obtained from three typical vegetation indices of eight levels of multi-spatial resolution images in urban areas were employed to identify the optimum spatial resolution in terms of maintaining information quality. These multi-spatial resolution images were prepared by degrading 1 meter simulated, 16 meter ADEOS/AVNIR, and 30 meter Landsat-TM images. Normalized Difference Vegetation Index (NDVI), Perpendicular Vegetation Index (PVI) and Soil Adjusted Ratio Vegetation Index (SARVI) were applied to reduce data redundancy and compare the characteristics of multi-spatial resolution image of vegetation indices. The threshold point on the curve of the coefficient of variation was defined as the optimum resolution level for the analysis with multi-spatial resolution image sets. Also, the results from the image segmentation approach of region growing to extract man-made features were compared with these multi-spatial resolution image sets.

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The Evaluations of Sensor Models for Push-broom Satellite Sensor

  • Lee, Suk-Kun;Chang, Hoon
    • Korean Journal of Geomatics
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    • 제4권1호
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    • pp.31-37
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    • 2004
  • The aim of this research is comparing the existing approximation models (e.g. Affine Transformation and Direct Linear Transformation) with Rational Function Model as a substitute of rigorous sensor model of linear array scanner, especially push-broom sensor. To do so, this research investigates the mathematical model of each approximation method. This is followed by the assessments of accuracy of transformation from object space to image space by using simulated data generated by collinearity equations which incorporate or depict the physical aspects of linear array sensor.

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Examining a Vicarious Calibration Method for the TOA Radiance Initialization of KOMPSAT OSMI

  • Sohn, Byung-Ju;Yoo, Sin-Jae;Kim, Yong-Seung;Kim, Do-hyeong
    • 대한원격탐사학회지
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    • 제16권4호
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    • pp.305-313
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    • 2000
  • A vicarious calibration method was developed for the OSMI sensor calibration. Employing measured aerosol optical thickness by a sunphotometer and a sky radiometer and water leaving radiance by ship measurements as inputs, TOA (top of the atmosphere) radiance at each OSMI band was simulated in conjunction with a radiative transfer model (Rstar5b) by Nakajima and Tanaka (1988). As a case of examining the accuracy of this method, we simulated TOA radiance based on water leaving radiance measured at NASA/MOBY site and aerosol optical thickness estimated nearby at Lanai, and compared simulated results with SeaWiFS-estimated TOA radiances. The difference falls within about $\pm$5%, suggesting that OMSI sensor can be calibrated with the suggested accuracy. In order to apply this method for the OSMI sensor calibration, ground-based sun photometry and ship measurements were carried out off the east coast of Korean peninsula on May 31, 2000. Simulations of TOA radiance by using these measured data as input to the radiative transfer model show that there are substantial differences between simulated and OSMI-estimated radiances. Such a discrepancy appears to be mainly due to the cloud contamination because satellite image indicates optically thin clouds over the experimental area. Nevertheless results suggest that sensor calibration can be achieved within 5% uncertainty range if there are ground-based measurements of aerosol optical thickness, and water leaving radiances under clear-sky and optically thin atmospheric conditions.

Optical Performance Measurement of the MATS Satellite

  • Park, Woojin;Hammar, Arvid;Lee, Sunwoo;Chang, Seunghyuk;Pak, Soojong
    • 천문학회보
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    • 제43권1호
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    • pp.49.1-49.1
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    • 2018
  • The MATS (Mesosphere Airglow/Aerosol Tomography Spectroscopy) satellite is the next Swedish science microsatellite. We report optical performance test results of the limb telescope, which is the major payload. This telescope is designed with "linear astigmatism-free" (LAF) off-axis optical system in order to have high optical performance across the wide field of view. We measured Modulation Transfer Function (MTF) and Encircled Energy Diameter (EED) of the limb telescope. Full field imaging tests show expected results without linear astigmatism across the full field of view ($5.67^{\circ}{\times}0.91^{\circ}$). Since the amount of stray light is from the earth and the sun, we also simulated and measured the stray light in the field image.

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고해상도 다중분광영상 제작을 위한 합성방법의 비교 (Comparison of Image Merging Methods for Producing High-Spatial Resolution Multispectral Images)

  • 김윤형;이규성
    • 대한원격탐사학회지
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    • 제16권1호
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    • pp.87-98
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    • 2000
  • 상업위성에서 공급되는 고해상도영상의 활용을 증대하기 위한 영상합성에 대한 관심이 증가하고 있다. 합성에 사용된 고해상도 흑백영상과 저해상도 다중분광영상은 항공기탑재 다중분광 주사기에 의해 촬영된 네 밴드의 영상을 이용하여 모의 제작하였다. 모의 합성된 2rl 해상도의 흑백 영상과 Bnl 해상도의 네 밴드 영상에 대하여 다섯 가지 합성방법(MWD, ItIS, PCA, HPF, CN, PCA) 을 적용하였다. 합성된 영상에 대해서 원래 영상들이 가지고 있던 공간해상도와 분광정보 측면의 특성을 분석하고자, 육안판독, 통계치비교, semivariogram, 분광반사특성 등을 비교하였다. MWD 변환방법에 의하여 합성된 영상이 공간해상도 및 분광정보 측면에서 모두 합성에 사용된 원래 영상과 근접한 결과를 보였다.

위성영상을 이용한 2024년 압록강 홍수량 및 침수범위 추정 (Estimation of Flood Flow and Inundation Range of the Aprokgang(Riv.) in 2024 using Satellite Images)

  • 김주훈;최윤석;김동필
    • 대한토목학회논문집
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    • 제44권5호
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    • pp.673-681
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    • 2024
  • 본 연구는 위성영상을 이용하여 2024년 발생한 압록강 하류 지역의 홍수량 및 홍수범위를 추정하는 것을 목적으로 하였다. 본 연구의 대상지역은 북한에서 가장 긴 강인 압록강 유역을 대상으로 하였다. 홍수 전·후의 침수범위 분석을 위해 위성영상 Sentinel-1A(SAR-C) 자료를 이용하였다. 위성영상을 이용한 침수범위 분석결과 홍수 전·후의 수체면의 변화가 있음을 확인할 수 있었다. 그러나 홍수 후의 영상은 홍수의 첨두유출이 발생한 시점보다 6일이 경과한 후의 영상으로 정확한 침수범위를 추출하는데는 한계가 있다. 위성강수와 지상계측 강우를 이용하여 분석한 결과 강우량은 500년 빈도를 상회하는 것으로 분석되었으며, 발생한 첨두홍수량은 85,102 m3/s로 분석되었다. AW3D30의 등고선을 이용하여 침수범위를 분석한 결과 등고선 15 m 내외에서 침수범람 범위가 발생한 것으로 판단하였다. 향후 침수해석 모형의 활용을 통해 보다 과학적인 침수범람 범위를 추출할 수 있는 연구가 필요하다.

Creation of 3D Maps for Satellite Communications to Support Ambulatory Rescue Operations

  • Nakajima, Isao;Nawaz, Muhammad Naeem;Juzoji, Hiroshi;Ta, Masuhisa
    • Journal of Multimedia Information System
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    • 제6권1호
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    • pp.23-30
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    • 2019
  • A communications profile is a system that acquires information from communication links to an ambulance or other vehicle moving on a road and compiles a database based on this information. The equipment (six sets of HDTVs, fish-eye camera, satellite antenna with tracking system, and receiving power from the satellite beacon of the N-star) mounted on the roof of the vehicle, image data were obtained at Yokohama Japan. From these data, the polygon of the building was actually produced and has arranged on the map of the Geographical Survey Institute of a 50 m-mesh. The optical study (relationship between visibility rate and elevation angle) were performed on actual data taken by fish-eye lens, and simulated data by 3D-Map with polygons. There was no big difference. This 3D map system then predicts the communication links that will be available at a given location. For line-of-sight communication, optical analysis allows approximation if the frequency is sufficiently high. For non-line-of-sight communication, previously obtained electric power data can be used as reference information for approximation in certain cases when combined with predicted values calculated based on a 3D map. 3D maps are more effective than 2D maps for landing emergency medical helicopters on public roadways in the event of a disaster. Using advanced imaging technologies, we have produced a semi-automatic creation of a high-precision 3D map at Yokohama Yamashita Park and vicinity and assessed its effectiveness on telecommunications and ambulatory merits.