• Title/Summary/Keyword: GCP matching

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AUTOMATIC PRECISION CORRECTION OF SATELLITE IMAGES

  • Im, Yong-Jo;Kim, Tae-Jung
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.40-44
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    • 2002
  • Precision correction is the process of geometrically aligning images to a reference coordinate system using GCPs(Ground Control Points). Many applications of remote sensing data, such as change detection, mapping and environmental monitoring, rely on the accuracy of precision correction. However it is a very time consuming and laborious process. It requires GCP collection, the identification of image points and their corresponding reference coordinates. At typical satellite ground stations, GCP collection requires most of man-powers in processing satellite images. A method of automatic registration of satellite images is demanding. In this paper, we propose a new algorithm for automatic precision correction by GCP chips and RANSAC(Random Sample Consensus). The algorithm is divided into two major steps. The first one is the automated generation of ground control points. An automated stereo matching based on normalized cross correlation will be used. We have improved the accuracy of stereo matching by determining the size and shape of match windows according to incidence angle and scene orientation from ancillary data. The second one is the robust estimation of mapping function from control points. We used the RANSAC algorithm for this step and effectively removed the outliers of matching results. We carried out experiments with SPOT images over three test sites which were taken at different time and look-angle with each other. Left image was used to select UP chipsets and right image to match against GCP chipsets and perform automatic registration. In result, we could show that our approach of automated matching and robust estimation worked well for automated registration.

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A Method to Improve Matching Success Rate between KOMPSAT-3A Imagery and Aerial Ortho-Images (KOMPSAT-3A 영상과 항공정사영상의 영상정합 성공률 향상 방법)

  • Shin, Jung-Il;Yoon, Wan-Sang;Park, Hyeong-Jun;Oh, Kwan-Young;Kim, Tae-Jung
    • Korean Journal of Remote Sensing
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    • v.34 no.6_1
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    • pp.893-903
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    • 2018
  • The necessity of automatic precise georeferencing is increasing with the increase applications of high-resolution satellite imagery. One of the methods for collecting ground control points (GCPs) for precise georeferencing is to use chip images obtained by extracting a subset of an image map such as an ortho-aerial image, and can be automated using an image matching technique. In this case, the importance of the image matching success rate is increased due to the limitation of the number of the chip images for the known reference points such as the unified control point. This study aims to propose a method to improve the success rate of image matching between KOMPSAT-3A images and GCP chip images from aerial ortho-images. We performed the image matching with 7 cases of band pair using KOMPSAT-3A panchromatic (PAN), multispectral (MS), pansharpened (PS) imagery and GCP chip images, then compared matching success rates. As a result, about 10-30% of success rate is increased to about 40-50% when using PS imagery by using PAN and MS imagery. Therefore, using PS imagery for image matching of KOMPSAT-3A images and aerial ortho-images would be helpful to improve the matching success rate.

Region Matching of Satellite Images based on Wavelet Transformation (웨이브렛 변환에 기반한 위성 영상의 영역 정합)

  • Park, Jeong-Ho;Cho, Seong-Ik
    • Journal of the Korean Association of Geographic Information Studies
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    • v.8 no.4
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    • pp.14-23
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    • 2005
  • This paper proposes a method for matching two different images, especially satellite images. In the general image matching fields, when an image is compared to other image, they may have different properties on the size, contents, brightness, etc. If there is no noise in each image, in other words, they have identical pixel level and unchanged edges, the image matching method will be simple comparison between two images with pixel by pixel. However, in many applications, most of images to be matched should have much different properties. This paper proposes an efficient method for matching satellite images. This method is to match a raw satellite image with GCP chips. From this we can make a geometrically corrected image. The proposed method is based on wavelet transformation, not required any pre-processing such as histogram equalization, analysis of raw image like the traditional methods.

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Accuracy Analysis According to the Number of GCP Matching (지상기준점 정합수에 따른 정확도 분석)

  • LEE, Seung-Ung;MUN, Du-Yeoul;SEONG, Woo-Kyung;KIM, Jae-Woo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.21 no.3
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    • pp.127-137
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    • 2018
  • Recently, UAVs and Drones have been used for various applications. In particular, in the field of surveying, there are studies on the technology for monitoring the terrain based on the high resolution image data obtained by using the UAV-equipped digital camera or various sensors, or for generating high resolution orthoimage, DSM, and DEM. In this study, we analyzed the accuracy of GCP(Ground control point) matching using UAV and VRS-GPS. First, we used VRS-GPS to pre-empt the ground reference point, and then imaged at a base altitude of 150m using UAV. To obtain DSM and orthographic images of 646 images, RMSE was analyzed using pix4d mapper version As a result, even if the number of GCP matches is more than five, the error range of the national basic map(scale : 1/5,000) production work regulations is observed, and it is judged that the digital map revision and gauging work can be utilized sufficiently.

Construction, Search of Ground Control Point Database and its Application for Satellite Image Correction (위성영상 보정을 위한 GCP 데이터베이스 구축, 검색 및 활용)

  • Lee, Young-Ran;Shin, Dongseok;Lee, Hae-Yeoun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.1 no.1
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    • pp.8-17
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    • 1998
  • This paper presents a method of construction and re-use of a GCP database for precision geometric correction of high resolution satellite images. Accurate geometric correction can be achieved by using accurate GCPs. The GCP information which is extracted from maps or other sources is saved in a database in conjunction with the corresponding image chips. The usage of the GCPs from the database gives reusability and efficiency in marking new GCPs. An image matching algorithm was developed to determine the corresponding positions between an image chip and a new image. The proposed technique can save time in the regular operation of satellite image preprocessing by propagating the pre-determined GCPs to the new image correction.

Development of Registration Image Chip Tool and Web Server for Building GCP DB (GCP DB 구축을 위한 영상칩 제작 툴 개발 및 Web서버 구축)

  • 손홍규;김기홍;김호성;백종하
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2004.04a
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    • pp.275-278
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    • 2004
  • The geo-referencing of satellite imagery is a key task in remote sensing. GCPs are points the position of which is known both in the image and in the supporting maps. Mapping function makes the determination of map coordinates of all image pixels possible. Generally manual operations are done to identify image points corresponding to the points on a digital topographic map. In order to accurately measure ground coordinates of GCPs, differential global positioning system (DGPS) surveying are used. To acquire the sufficient number of well distributed GCPs is one of the most time-consuming and cost-consuming tasks. This paper describes the procedure of automatically extracting GCOs using GCP database. GCP image chips and image matching technique are used for automatic extraction of GCPs. We developed image processing tool for making image chip GCPs and Web Server for management of GCPs.

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Accuracy Improvement of DEM Using Ground Coordinates Package (공공삼각점 위치자료를 이용한 DEM의 위치 정확도 향상)

  • Lee, Hyoseong;Oh, Jaehong
    • Korean Journal of Remote Sensing
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    • v.37 no.3
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    • pp.567-575
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    • 2021
  • In order to correct the provided RPC and DEM generated from the high-resolution satellite images, the acquisition of the ground control point (GCP) must be preceded. This task is a very complicate that requires field surveys, GPS surveying, and image coordinate reading corresponding to GCPs. In addition, since it is difficult to set up and measure a GCP in areas where access is difficult or impossible (tidal flats, polar regions, volcanic regions, etc.), an alternative method is needed. In this paper, we propose a 3D surface matching technique using only the established ground coordinate package, avoiding the ground-image-location survey of the GCP to correct the DEM produced from WorldView-2 satellite images and the provided RPCs. The location data of the public control points were obtained from the National Geographic Information Institute website, and the DEM was corrected by performing 3D surface matching with this package. The accuracy of 3-axis translation and rotation obtained by the matching was evaluated using pre-measured GPS checkpoints. As a result, it was possible to obtain results within 2 m in the plane location and 1 m in height.

Wavelet based Area Matching of Satellite Imagery

  • Park, J.H.;Park, J.H.;Kim, K.O.
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.423-425
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    • 2003
  • In this paper, we propose a new scheme for matching specified areas in a satellite image, which is a very efficient method because it can be effectively applied to images that have various features. These features may include different spatial resolution and brightness; sometimes they may different geometrical property. The proposed method can be applied to some application fields such as mosaicing of satellite imagery, GCP matching.

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Automatic Measuring of GCP's Image Coordinates using Control Point Patch and Auxiliary Points Matching (기준점 패치 및 보조점 정합에 의한 지상기준점의 영상좌표 자동관측)

  • Kang, Myung-Ho;Bang, Soo-Nam;Lee, Yong-Woong
    • Journal of Korean Society for Geospatial Information Science
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    • v.11 no.2 s.25
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    • pp.29-37
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    • 2003
  • An approach is described for automatic measuring of GCP's image coordinates from SPOT imagery and focused on the fulfillment an automatic orientation of satellite images. For the orientation of a stereopair of digital images, firstly, GCP(Ground Control Point) should be selected and then the work for measuring of image coordinates correspond to GCPs is required. In this study, we propose the method for extracting the GCP's image coordinates automatically using an image patch for control points and auxiliary points matching. For the evaluation of measurement accuracy, a comparison between points those are extracted manually and automatically by a proposed method have made. Finally, we shows the feasibility of automatic image coordinates measurment by applying in stereo modeling for SPOT images.

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The Study of the Geometric Structure Optimization for the Stereo X-ray Inspection System Using the Calibration (Calibration을 통한 스테레오 X-ray 검색장치의 기하구조 최적화 연구)

  • Hwang, Young-Gwan;Lee, Nam-Ho;Lee, Seung-Min;Park, Jong-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.9
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    • pp.3422-3427
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    • 2010
  • In this paper, we presents a sensor calibration technique using stereo X-ray images to provide efficient inspection of fast moving cargo objects. Stereo X-ray scanned images are acquired from a specially designed equipment which consists of a X-ray source, dual-linear array detector, and a conveyor system. Dual detector is installed so that rectified stereo X-ray images of objects are acquired. Using the stereo X-ray images, we carry out a sensor calibration to find the correspondences between the images and reconstruct 3-D shapes of real objects. Using the Image acquired from the stereo detectors with varying distances, we calculated the GCP(ground control point)of the image. And we figure out the error by comparing calculated GCP and GCP of the real object. The experimental results show the proposed technique can enhance the accuracy of stereo matching and give more efficient visualization for cargo inspection image.