• Title/Summary/Keyword: Satellite Stereo Imagery

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Analysis of Geometric and Spatial Image Quality of KOMPSAT-3A Imagery in Comparison with KOMPSAT-3 Imagery

  • Erdenebaatar, Nyamjargal;Kim, Jaein;Kim, Taejung
    • Korean Journal of Remote Sensing
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    • v.33 no.1
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    • pp.1-13
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    • 2017
  • This study investigates the geometric and spatial image quality analysis of KOMPSAT-3A stereo pair. KOMPSAT-3A is, the latest satellite of KOMPSAT family, a Korean earth observation satellite operating in optical bands. A KOMPSAT-3A stereo pair was taken on 23 November, 2015 with 0.55 m ground sampling distance over Terrassa area of Spain. The convergence angle of KOMPSAT-3A stereo pair was estimated as $58.68^{\circ}$. The investigation was assessed through the evaluation of the geopositioning analysis, image quality estimation and the accuracy of automatic Digital Surface Model (DSM) generation and compared with those of KOMPSAT-3 stereo pair with the convergence angle of $44.80^{\circ}$ over the same area. First, geopositioning accuracy was tested with initial rational polynomial coefficients (RPCs) and after compensating the biases of the initial RPCs by manually collected ground control points. Then, regarding image quality, relative edge response was estimated for manually selected points visible from two stereo pairs. Both of the initial and bias-compensated positioning accuracy and the quality assessment result expressed that KOMPSAT-3A images showed higher performance than those of KOMPSAT-3 images. Finally, the accuracy of DSMs generated from KOMPSAT-3A and KOMPSAT-3 stereo pairs were examined with respect to the reference LiDAR-derived DSM. The various DSMs were generated over the whole coverage of individual stereo pairs with different grid spacing and over three types of terrain; flat, mountainous and urban area. Root mean square errors of DSM from KOMPSAT-3A pair were larger than those for KOMPSAT-3. This seems due to larger convergence angle of the KOMPSAT-3A stereo pair.

A stereo matching method using minimum feature vector distance and disparity map (최소 특징 벡터 거리와 변이지도를 이용한 스테레오 정합 기법)

  • Ye, Chul-Soo
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.403-404
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    • 2006
  • In this paper, we proposed muli-dimensional feature vector matching method combined with disparity smoothness constraint. The smoothness constraint was calculated using the difference between disparity of center pixel and those of 4-neighbor pixels. By applying proposed algorithm to IKONOS satellite stereo imagery, we obtained robust stereo matching result in urban areas.

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Water Detection in an Open Environment: A Comprehensive Review

  • Muhammad Abdullah, Sandhu;Asjad, Amin;Muhammad Ali, Qureshi
    • International Journal of Computer Science & Network Security
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    • v.23 no.1
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    • pp.1-10
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    • 2023
  • Open surface water body extraction is gaining popularity in recent years due to its versatile applications. Multiple techniques are used for water detection based on applications. Different applications of Radar as LADAR, Ground-penetrating, synthetic aperture, and sounding radars are used to detect water. Shortwave infrared, thermal, optical, and multi-spectral sensors are widely used to detect water bodies. A stereo camera is another way to detect water and different methods are applied to the images of stereo cameras such as deep learning, machine learning, polarization, color variations, and descriptors are used to segment water and no water areas. The Satellite is also used at a high level to get water imagery and the captured imagery is processed using various methods such as features extraction, thresholding, entropy-based, and machine learning to find water on the surface. In this paper, we have summarized all the available methods to detect water areas. The main focus of this survey is on water detection especially in small patches or in small areas. The second aim of this survey is to detect water hazards for unmanned vehicles and off-sure navigation.

Evaluation of Geometric Modeling for KOMPSAT-1 EOC Imagery Using Ephemeris Data

  • Sohn, Hong-Gyoo;Yoo, Hwan-Hee;Kim, Seong-Sam
    • ETRI Journal
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    • v.26 no.3
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    • pp.218-228
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    • 2004
  • Using stereo images with ephemeris data from the Korea Multi-Purpose Satellite-1 electro-optical camera (KOMPSAT-1 EOC), we performed geometric modeling for three-dimensional (3-D) positioning and evaluated its accuracy. In the geometric modeling procedures, we used ephemeris data included in the image header file to calculate the orbital parameters, sensor attitudes, and satellite position. An inconsistency between the time information of the ephemeris data and that of the center of the image frame was found, which caused a significant offset in satellite position. This time inconsistency was successfully adjusted. We modeled the actual satellite positions of the left and right images using only two ground control points and then achieved 3-D positioning using the KOMPSAT-1 EOC stereo images. The results show that the positioning accuracy was about 12-17 m root mean square error (RMSE) when 6.6 m resolution EOC stereo images were used along with the ephemeris data and only two ground control points (GCPs). If more accurate ephemeris data are provided in the near future, then a more accurate 3-D positioning will also be realized using only the EOC stereo images with ephemeris data and without the need for any GCPs.

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Techniques for Measuring 3-D Positional Data of Terrain Features from Digital Satellite Imagery (위성영상을 이용한 지형지물 3차원 대지좌표 측정 기법)

  • 조봉환;박완용;고진우
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.14 no.2
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    • pp.189-197
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    • 1996
  • Digital Elevation Model, Ortho-image, and 3-D positional data of terrain features are indispensable elements for producing 3-D image information. In this research, digital pbotogrammetric studies were conducted to measure the 3-D positional data on high performance computer systems in order to replace analytical stereo-plotter-oriented tasks with those of digital workstations. Especially, technical approaches to measure these data on stereo workstation were developed and then the results were applied on SPOT satellite images. As the result of this study, the possibilities of the proposed technologies were tested and proved based on the ap-plication of the digital photogrammetric processes to extract 3-D ground coordinates of terrain features from digital satellite imagery.

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IKONOS Stereo Matching with Land Cover Map for DEM Generation

  • Lee, Hyo-Seong;Ahn, Ki-Weon;Park, Byung-Guk;Han, Dong-Yeob
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.580-583
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    • 2007
  • Various matching methods have been introduced by investigators to improve digital elevation model (DEM) accuracy of satellite imagery. This study proposed an area-based matching method according to land cover property using correlation coefficient of pixel brightness value between the two images for DEM generation from IKONOS stereo imagery. For this, matching line (where "matching line" implies straight line that is approximated to complex nonlinear epipolar geometry) is established by exterior orientation parameters to minimize search area. The matching is carried out based on this line. Land cover classes are divided off into water, urban land, forest and agricultural land. Matching size is selected using a correlation-coefficient image in the four areas. The selected sizes are $81{\times}81$ pixels window, $21{\times}21$ pixels window, $119{\times}119$ pixels window and $51{\times}51$ pixels window in the water area, urban land, forest land and agricultural land, respectively. And hence, DEM is generated from IKONOS stereo imagery using the selected matching sizes and land cover map on the four types.

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Development of A New Patch-Based Stereo Matching Algorithm for Extraction of Digiral Elevation Model from Satellite Imagery (위성영상으로부터 수치표고모형 추출을 위한 새로운 정합구역의 비선형 최소자승 영상정합 알고리즘 개발)

  • 김태정;이흥규
    • Korean Journal of Remote Sensing
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    • v.13 no.2
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    • pp.121-132
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    • 1997
  • This paper describes the development of a stereo matching algorithm for extracting Digital Elevation Model(DEM) from satellite images. This matching algorithm is based on a non-linear least squares correlation estimation but has improved matching speed. The algorithm consists of three steps: matching execution, matching control and matching optimization. Each is described. The performance of the presented algorithm is quantitatively analyzed with experiments on matching probability, matching speed and matching convergence radius.

Comparison of Single-Sensor Stereo Model and Dual-Sensor Stereo Model with High-Resolution Satellite Imagery (고해상도 위성영상에서의 동종센서 스테레오 모델과 이종센서 스테레오 모델의 비교)

  • Jeong, Jaehoon
    • Korean Journal of Remote Sensing
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    • v.31 no.5
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    • pp.421-432
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    • 2015
  • There are significant differences in geometric property and stereo model accuracy between single-sensor stereo that uses two images taken by stereo acquisition mechanism within identical sensor and dual-sensor stereo that randomly combines two images taken from two different sensors. This paper compares the two types of stereo pairs thoroughly. For experiment, two single-sensor stereo pairs and four dual-sensor stereo pairs were constituted using SPOT-5 stereo and KOMPSAT-2 stereo covering same area. While the two single-sensor stereos have stable geometry, the dual-sensor stereos produced two stable and two unstable geometries. In particular, the unstable geometry led to a decrease in stereo model accuracy of the dual-sensor stereos. The two types of stereo pairs were also compared under the stable geometry. Overall, single-sensor stereos performed better than dual-sensor stereos for vertical mapping, but dual-sensor stereos was more accurate for horizontal mapping. This paper has revealed the differences of two types of stereos with their geometric properties and positioning accuracies, suggesting important considerations for handling satellite stereo images, particularly for dual-satellite stereo images.

A Feasibility Study for Mapping Using The KOMPSAT-2 Stereo Imagery (아리랑위성 2호 입체영상을 이용한 지도제작 가능성 연구)

  • Lee, Kwang-Jae;Kim, Youn-Soo;Seo, Hyun-Duck
    • Journal of the Korean Association of Geographic Information Studies
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    • v.15 no.1
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    • pp.197-210
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    • 2012
  • The KOrea Multi-Purpose SATellite(KOMPSAT)-2 has a capability to provide a cross-track stereo imagery using two different orbits for generating various spatial information. However, in order to fully realize the potential of the KOMPSAT-2 stereo imagery in terms of mapping, various tests are necessary. The purpose of this study is to evaluate the possibility of mapping using the KOMPSAT-2 stereo imagery. For this, digital plotting was conducted based on the stereoscopic images. Also the Digital Elevation Model(DEM) and an ortho-image were generated using digital plotting results. An accuracy of digital plotting, DEM, and ortho-image were evaluated by comparing with the existing data. Consequently, we found that horizontal and vertical error of the modeling results based on the Rational Polynomial Coefficient(RPC) was less than 1.5 meters compared with the Global Positioning System(GPS) survey results. The maximum difference of vertical direction between the plotted results in this study and the existing digital map on the scale of 1/5,000 was more than 5 meters according as the topographical characteristics. Although there were some irregular parallax on the images, we realized that it was possible to interpret and plot at least seventy percent of the layer which was required the digital map on the scale of 1/5,000. Also an accuracy of DEM, which was generated based on the digital plotting, was compared with the existing LiDAR DEM. We found that the ortho-images, which were generated using the extracted DEM in this study, sufficiently satisfied with the requirement of the geometric accuracy for an ortho-image map on the scale of 1/5,000.

A METHOD FOR ADJUSTING ADAPTIVELY THE WEIGHT OF FEATURE IN MULTI-DIMENSIONAL FEATURE VECTOR MATCHING

  • Ye, Chul-Soo
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.772-775
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    • 2006
  • Muilti-dimensional feature vector matching algorithm uses multiple features such as intensity, gradient, variance, first or second derivative of a pixel to find correspondence pixels in stereo images. In this paper, we proposed a new method for adjusting automatically the weight of feature in multi-dimensional feature vector matching considering sharpeness of a pixel in feature vector distance curve. The sharpeness consists of minimum and maximum vector distances of a small window mask. In the experiment we used IKONOS satellite stereo imagery and obtained accurate matching results comparable to the manual weight-adjusting method.

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