• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.37 no.6
• /
• pp.525-533
• /
• 2019

There are two feature collection methods in digital mapping using the UAV (Unmanned Aerial Vehicle) Photogrammetry: vectorization and stereo plotting. In vectorization, planar information is extracted from orthomosaics and elevation value obtained from a DSM (Digital Surface Model) or a DEM (Digital Elevation Model). However, the exact determination of the positional accuracy of 3D features such as ground facilities and buildings is very ambiguous, because the accuracy of vectorizing results has been mainly analyzed using only check points placed on the ground. Thus, this study aims to review the possibility of 3D spatial information acquisition and digital map production of vectorization by analyzing the corner point coordinates of different layers as well as check points. To this end, images were taken by a Phantom 4 (DJI) with 3.6 cm of GSD (Ground Sample Distance) at altitude of 90 m. The outcomes indicate that the horizontal RMSE (Root Mean Square Error) of vectorization method is 0.045 cm, which was calculated from residuals at check point compared with those of the field survey results. It is therefore possible to produce a digital topographic (plane) map of 1:1,000 scale using ortho images. On the other hand, the three-dimensional accuracy of vectorization was 0.068~0.162 m in horizontal and 0.090~1.840 m in vertical RMSE. It is thus difficult to obtain 3D spatial information and 1:1,000 digital map production by using vectorization due to a large error in elevation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.35 no.3
• /
• pp.145-154
• /
• 2017

In recent years, demand for 1 / 1,000 digital map production has increased in various fields such as construction and urban planning. As a result, the use of low-cost non-metric cameras that replace expensive aerial photogrammetry equipment is required. In Korea, researches are being continuously carried out to produce a large scale digital map by photographing a small target area with a non-metric camera. However, due to the limitation of the accuracy of the non-metric camera, it is difficult to do digital mapping with stereoscopic photographs. In this study, we tried to verify the possibility of large-scale digital mapping to utilize non-metric camera for public survey. For this purpose, the accuracy of the digital mapping results of the non-metric camera and the results of the DMC camera were compared and analyzed. After performing in-situ self-calibration including 8 standard additional parameters, we plotted to a scale of 1/1,000 and confirmed that the RMSE is suitable for public survey accuracy of ${\pm}0.145m$ in horizontal and ${\pm}0.153$ m in vertical.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.20 no.1
• /
• pp.13-19
• /
• 2002

In a different way of satellite image or aerial photo, the image acquired by terrestrial photogrammetry has to go through complicated management according to the desired precision and analysis range. In this study, digital surface model and ortho image for cultural asset, terrestrial structures, were made by reflectorless total station in order to increase the application of single photo, and that was analyzed and compared with the method using stereo image. Single photo is expected to be utilized as the measuring method for drawing cultural assets or examining the stability of slope in which high precision doesn't need by performing the various geometric and visual analysis using ortho image made by excluding the difficulties of acquisition and plotting of stereo image.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.19 no.1
• /
• pp.80-93
• /
• 2016

Parcel boundary demarcation in agricultural area is commonly performed by terrestrial surveying methods, which have been pointed out as drawbacks to require consuming too much time and heavy expenditure. With the developments of high performance digital aerial cameras, however, studies on cadastral boundary demarcation with an aerial photogrammetric method attract a great attention in recent years. In this paper, an approach is presented to rapidly demarcate parcel boundaries coinciding with real ground ones in agricultural areas by extracting boundaries from the high resolution aerial orthoimages based on aerial targets. In order to investigate the feasibility of the proposed method, the accuracy of coordinates and area of parcel boundaries extracted from the aerial targets appeared in orthoimages compared with that of terrestrial boundary surveying results over the selected two test agricultural areas. Aerial image data were processed taken by a ADS80 digital camera with a GSD of 8cm in Changwon region, and by a DMCII camera with a GSD of 5cm in Suwon respectively. The result shows that the accuracy of parcel demarcation using aerial images is within the tolerance limits of coordinates and areas compared with that of terrestrial surveying. The proposed method using aerial target-based high resolution aerial images is therefore expected to be usefully applied in the agricultural parcel demarcation.