• Korean Journal of Geomatics
• /
• v.1 no.1
• /
• pp.1-5
• /
• 2001

This paper presents an investigation into the operational comparison of SPOT triangulation to build GCP library by analytical plotter and DPW (digital photogrammetric workstation). GCP database derived from current SPOT images can be used to other image sensors of satellite, if any reasons, such as lack of topographic maps or GCPs. But, general formulation of a photogrammetric process for GCP measurement has to take care of the scene interpretation problem. There are two classical methods depending on whether an analytical plotter or DPW is being used. Regardless of the method used, the measurement of GCPs is the weakest point in the automation of photogrammetric orientation procedures. To make an operational comparison, five models of SPOT panchromatic images (level 1A) and negative films (level 1AP) were used. Ten images and film products were used for the five GRS areas. Photogrammetric measurements were carried out in a manual mode on P2 analytical plotter and LH Systems DPW770. We presented an approach for exterior orientation of SPOT images, which was based on the use of approximately eighty national geodetic control points as GCPs which located on the summit of the mountain. Using sixteen well-spaced geodetic control points per model, all segments consistently showed RMS error just below the pixel at the check points in analytical instrument. In the case of DPW, half of the ground controls could not found or distinguished exactly when we displayed the image on the computer monitor. Experiment results showed that the RMS errors with DPW test was fluctuated case by case. And the magnitudes of the errors were reached more than three pixels due to the lack of image interpretation capability. It showed that the geodetic control points is not suitable as the ground control points in DPW for modeling the SPOT image.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.6 no.2
• /
• pp.34-41
• /
• 1988

Nowadays the considerable improvements, not only in photogrammetric equipment but also in adjustment methods have led to a high accuracy of Aerial Triangulation and reach the step to obtain A.T. technique that uses Global Position System without ground control survery. The enterance of analytical plotter have made considerable development both in accuracy and in efficiency and improved working environment of A.T. by the combination of On-Line Analytical Plotting System. In this paper, in A.T., with using of analytical polotter, aims to improve the acccuracy in coordinates determination of low level control point. The result shows that in case of A.T. with analytical plotter AVIOLYT BC2, the accuracy of control points improves to 7% in planimetry and to 40% in height compared to A.T. with precision plotter Autograph A-8.

• Journal of Korean Society for Geospatial Information Science
• /
• v.15 no.2 s.40
• /
• pp.15-23
• /
• 2007

This paper presents a shoreline change analysis on a reclaimed land, using a pair of aerial photographs taken before and after the reclamation. Shorelines that are defined by a tide datum, i.e. Approximately Highest High Water Level, were mapped by both analytical and digital photogrammetric methods. The past shorelines were overlapped with digital cadastral map from which areas of retracted and protruded lands were computed. Magnitude of shoreline changes was estimated by calculating areas between the past and present shorelines. Comparisons in terms of areas showed a fairly good agreement between the two methods. However, particularly in the estuary of complex morphology, shoreline mapping by digital photogrammetric method requires images to be scanned at a resolution higher than 1200 dpi.

• Korean Journal of Geomatics
• /
• v.3 no.2
• /
• pp.107-114
• /
• 2004

The National Geographic Information Institute (NGII) in korea, through the National Geographic Information System (NGIS) Program, has prepared to generate and disseminate digital elevation data for Korea. This is a pilot research to propose a policy for production, maintenance, and supply of Korea Digital Elevation Data(KDED). Customer demands for accuracy and resolution of DEM was surveyed through a questionnaire. In order to investigate the quality, the technical efficiency and the production cost, a tentative DEM in a small test site was generated based on digital topographic maps (original paper map scale 1:5,000), analytical plotter, and LIDAR. The Accuracy standard for KDED was derived based on source data generation methods. As a result of this research, a uniformly spaced grid model was recommended for KDED. Its preferable grid space is 5m in urban areas and its vicinity, and 10m in field and mountainous area. LIDAR has been valuated as a proper KDED generation method fulfilling customers' demands for the accuracy.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.5 no.2
• /
• pp.47-55
• /
• 1987

In this paper, the direct linear transformation is described in which a inner and exterior orientation parameters are treated as unknown for non-iterative direct space resection, and the computer program was developed to obtain object space coordinates. Image coordinates measurements are conducted with analogue stereo-plotter and digitizer. To prove the appropriateness of the two image coordinate measurement devices and the DLT method, the standard errors of object space coordinates are compared with semi-analytical method.

• Journal of Korean Society for Geospatial Information Science
• /
• v.1 no.2 s.2
• /
• pp.177-184
• /
• 1993

To obtain large scale precise geographical information in local area we determined external orientation parameters of camn exactly and conducted aerial photography using remote control airship loaded 35mm non-metric camera that produced systematic error coefficients. Ground control Points were determined by differential GPS. Therefore we can try to improve accuracy and economical efficiency. Also, it is suggested that remote control airship photogrammetry can be applied to make large scale topographic map using analytical plotter as calibrated accuracy.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2004.02a
• /
• pp.73-81
• /
• 2004

National Geographic Information Institute (NGII) in Korea, through National Geographic Information System (NGIS) Program, has prepared to generate and disseminate digital elevation data for Korea. This is a pilot research to propose a policy for generation, maintenance, and supply of Korea Digital Elevation Data (KDED). Customer demands for accuracy and resolution of DEM was surveyed through questionnaire. In order to investigate the quality, the technical efficiency and the production cost, a tentative DEM in a small test site was generated based on digital topographic maps (original paper map scale 1 :5,000), analytical plotter, and LIDAR. Accuracy standard for KDED was derived based on source data and generation methods. As results of this research, we recommend uniformly spaced grid model for KDED. Its preferable grid space is 5m in urban and its vicinity; and 10m in field and mountainous area. LIDAR has been valuated as a proper KDED generation method fulfilling customers demand for the accuracy.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.14 no.2
• /
• pp.189-197
• /
• 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.

• Journal of Korean Society for Geospatial Information Science
• /
• v.6 no.2 s.12
• /
• pp.45-58
• /
• 1998

Digital photogrammetry is growing today using inexpensive personal confuter and digital image Processing technique instead of expensive analytical plotter in data acquisition from aerial photograph. Ortho photo in replacement of paper map is indispensable in the application of Geo-Spatial Information System and research activities about it are active in the domestic domain. Also the availability of ortho photo is greatly various in existing related fields using topographic map and expected to be used for new technology in near future. For this purpose, design of each module for ortho photo has been carried out with digital map and image. It was shown that the batch program for ortho photo generation developed in this study, could be used effectively as an effective data acquisition method for GSIS.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.17 no.4
• /
• pp.359-372
• /
• 1999

Recently, the digital map of national basemap has been made through NGIS(National Geographic Information System) project in Korea. The digital map should have to be corrected or updated to cope with the changes in topography in future. For that, the efficient method correspond with digital map should be presented. Digital photogrammetric system has been considered as an efficient method for digital mapping because it provides the results in digital form, but the system if not fully tested because the commercial system is in early stage. This study aims to present the way to correct or update digital map using the digital photogrammetric system. Digital mapping in the environment of digitalphotogrammetric system was executed and the results were analyzed and compared with those from analytical plotter.