• Journal of Korean Society for Geospatial Information Science
• /
• v.21 no.4
• /
• pp.29-35
• /
• 2013

Generally, Calculation of carbon dioxide absorption in the forest area is calculated using the information of the forest, such as tree height and DBH(Diameter of Breast Height). Tree height and DBH of these are obtained using the remote sensing data such as imagery and information of local forest survey. However, Mixed forest with a high proportion of field survey to lower the accuracy of forest information. In this study, vertical structure of the tree were identified by applying region growing method based on the slope using LiDAR data and height and number of the tree were identified by applying extracting top of the tree algorithm. Through the vertex tree extraction algorithm to identify height of tree and the number of individuals, substitute this for the DBH relation formula which is drawn from data through field surveys. In this, a quantitative calculation of carbon dioxide absorption were able to calculate the basic data. Also, carbon dioxide absorption of three type trees were calculated and average per unit area of carbon dioxide absorption were able to estimate.

• Journal of Digital Contents Society
• /
• v.7 no.1
• /
• pp.9-14
• /
• 2006

In this paper, we propose the algorithm that automatically measures the height of the object to move on the base plane by using the geometric information. To extract a moving object from images, we use the difference image and morphology operation. The top and bottom point of an object are extracted by the histogram vertical projection in the extracted region. The two points, top and bottom, are used for measuring the height. Given the vanishing line of the ground plane, the vertical vanishing point, and at least one reference height in the scene; then the height of any point from the ground may be computed by specifying the image of the point and the image of the vertical intersection with the ground plane at that point. Through a confidence valuation of the height to be measured, we confirmed similar actual height and result in the simulation experiment.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
• /
• 2006.05a
• /
• pp.138-145
• /
• 2006

Recently the extraction of building height information has been investigated using remotely sensed image and digital maps. In this study, based on the digital photogrammetry principle and mono imagery method the building height information can be extracted by using relationship between ground coordinates and image coordinates, To evaluate the result the comparison was done with building height from 1:5000 aerial photo. The experiment shows that extraction of building height could be performed using IKONOS single imagery and digital map and it is proved that the building height could be reconstructed within some extent.

• Journal of the Korea Society of Computer and Information
• /
• v.28 no.2
• /
• pp.99-110
• /
• 2023

In this paper, we propose a system termed ForestLi that can accurately estimate the diameter at breast height (DBH) and tree height using LiDAR point cloud data. The ForestLi system processes LiDAR point cloud data through the following steps: downsampling, outlier removal, ground segmentation, ground height normalization, stem extraction, individual tree segmentation, and DBH and tree height measurement. A commercial system, such as LiDAR360, for processing LiDAR point cloud data requires the user to directly correct errors in lower vegetation and individual tree segmentation. In contrast, the ForestLi system can automatically remove LiDAR point cloud data that correspond to lower vegetation in order to improve the accuracy of estimating DBH and tree height. This enables the ForestLi system to reduce the total processing time as well as enhance the accuracy of accuracy of measuring DBH and tree height compared to the LiDAR360 system. We performed an empirical study to confirm that the ForestLi system outperforms the LiDAR360 system in terms of the total processing time and accuracy of measuring DBH and tree height.

• Journal of Korea Society of Industrial Information Systems
• /
• v.22 no.2
• /
• pp.53-60
• /
• 2017

In This Paper, We Propose a Method to Estimate the Human Height from the Depth Image Obtained using a Depth Camera. Using the depth Image, Accurate Measurement for Human Height is Possible Compared with Color Image. This Paper Presents a Method to Detect the Center of a Person in the Vertical Direction and to Accumulate the Measured Height Values ​at the Center Position. Simulation Results Show that the Proposed Method has Better Performance than the Conventional Methods.

• Spatial Information Research
• /
• v.15 no.2
• /
• pp.181-187
• /
• 2007

To make digital terrain data, automatic correlation matching by stereo airborne/satellite images has been researched. The result of automatic correlation matching has a limit on extracting exact ground height because of angle of sensor, tree of height. Therefore, the amount of editing works depend on the distribution of spatial feature in images as well as image quality. This paper shows that the automatic correlation matching result was affected by density and height of tree.

• Journal of Korean Society for Geospatial Information Science
• /
• v.2 no.2 s.4
• /
• pp.143-151
• /
• 1994

3-D coordinates that result form GPS survey are not applied directly in korea because they are based on WGS 84 ellipsoid. Thus they must be transformed into longitude, latitude on the Bessel ellipsoid and orthometric height. Transformation parameters must be determined in order to perform the coordinate transformation. Also, coordinate transformation be preformed on longitude, latitude and ellipsoidal height. First estimation of Bessel geoidal height must be accomplished to acquire Bessel ellipsoidal height This paper suggests accuracy of coordinate transformation according to the estimation method of Bessel geoidal height. Also, This paper suggests that Bessel geoidal height have influence on the coordinates transformation.

• Spatial Information Research
• /
• v.9 no.1
• /
• pp.1-13
• /
• 2001

Nowadays, SAR Interferometry is actively being studied as a new technique in topographic mapping using satellite imagery. It extracts height values using phase information derived by two SAR imageries covering same areas. Unlike when using SPOT imagery, it is not affected by atmospheric conditions and time. So to speak, we can say that SAR Interferometry is flexible in imagery acquisitions and can get height data economically over wide area. So, it is expected that SAR Interferometry will be widely using in GIS applications. But, in some area occurring geometric distortion, height data are misjudged or not extracted depending on phase unwrapping algorithms. IN the case of ERS tandem data, the accuracy of height data was worst in mountain area. It is the because of the short incidence angle resulted in layover effect. Of the phase unwrapping algorithms, path-following was better in height accuracy but could not get data in layover area. In this area, we could get height data using Height Sensitivity. In concludion, we could get DEM that maintained the accuracy of path-following method and have overall data across imagery.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.24 no.2
• /
• pp.78-90
• /
• 2021

In order to construct a precision geoid, it has been diversified into land, sea, aviation, and satellite gravity measurement methods, and measurement technology has developed, making it possible to secure high-resolution, high-precision gravity data. The construction of precision geoids can be fast and conveniently decided through GNSS surveys without separate leveling, and since 2014, the National Geographic Information Institute has been developing a hybrid geoid model to improve the accuracy of height surveying based on GNSS. In this study, the results of the GNSS height measurement were compared and analyzed choosing existing public reference points to verify the GNSS height measurement of public surveys. Experiments are conducted with GNSS height measurements and analyzed precision for public reference points on coastal, border, and mountainous terrain presented as low-precision areas or expected-to-be low-precision in research reports. To verify the GNSS height measurement, the GNSS ellipsoid height of the surrounding integrated datum to be used as a base point for the GNSS height measurement at the public datum. Based on the checked integrated datum, the GNSS ellipsoid of the public datum was calculated, and the elevation was calculated using the KNGeoid18 model and compared with the results of the direct level measurement elevation. The analysis showed that the results of GNSS height measurement at public reference points in the coastal, border, and mountainous areas were satisfied with the accuracy of public level measurement in grades 3 and 4. Through this study, GNSS level measurement can be used more efficiently than existing direct level measurements depending on the height accuracy required by users, and KNGeoids 18 can also be used in various fields such as autonomous vehicles and unmanned aerial vehicles.

• Journal of the Korea Society of Computer and Information
• /
• v.21 no.2
• /
• pp.79-88
• /
• 2016

In this paper, we propose an efficient automatic observation system for cloud amount and height observations. Observation system consists of clouds observations machinery, operational programs, cloud amount extraction program, cloud height extraction program, expert support programs. The experiment was conducted at the Daegwallyeong and Busan, through experimental observation confirmed the usefulness of the proposed system.