scholarly journals Optimization of prism-based stereoscopic imaging systems at the optical design stage with respect to required 3D measurement accuracy

2020 ◽  
Vol 28 (17) ◽  
pp. 24418
Author(s):  
Alexey V. Gorevoy ◽  
Alexander S. Machikhin ◽  
Demid D. Khokhlov ◽  
Vladislav I. Batshev
Keyword(s):  
Measurement Accuracy ◽  
Optical Design ◽  
Imaging Systems ◽  
Design Stage ◽  
3D Measurement ◽  
Stereoscopic Imaging

scholarly journals Experimental Study on 3D Measurement Accuracy Detection of Low Altitude UAV for Repeated Observation of an Invariant Surface

Processes ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 4
Author(s):  
Sha Gao ◽  
Shu Gan ◽  
Xiping Yuan ◽  
Rui Bi ◽  
Raobo Li ◽  
...  
Keyword(s):  
Experimental Study ◽  
Unmanned Aerial Vehicle ◽  
Structure From Motion ◽  
Measurement Accuracy ◽  
Test Plot ◽  
3D Measurement ◽  
Difference Model ◽  
Repeated Observations ◽  
Aerial Vehicle ◽  
Low Altitude

Low-altitude unmanned aerial vehicle (UAV) photogrammetry combined with structure-from-motion (SFM) algorithms is the latest technological approach to imaging 3D stereo constructions. At present, derivative products have been widely used in landslide monitoring, landscape evolution, glacier movement, volume measurement, and landscape change detection. However, there is still a lack of research into the accuracy of 3D data positioning based on the structure-from-motion of unmanned aerial vehicle (UAV-SFM) technology, itself, which can affect the measurable effectiveness of the results in further applications of this technological approach. In this paper, validation work was carried out for the DJI Phantom 4 RTK UAV, for earth observation data related to 3D positioning accuracy. First, a test plot with a relatively stable surface was selected for repeated flight imaging observations. Specifically, three repeated flights were performed on the test plot to obtain three sorties of images; the structure from motion and multi-view stereo (SFM-MVS) key technology was used to process and construct a 3D scene model, and based on this model the digital surface model (DSM) and digital orthophoto map (DOM) data of the same plot with repeated observations were obtained. In order to check the level of 3D measurement accuracy of the UAV technology itself, a window selection-based method was used to sample the point cloud set data from the three-sortie repeat observation 3D model. The DSM and DOM data obtained from three repeated flights over the surface invariant test plots were used to calculate the repeat observation 3D point errors, taking into account the general methodology of redundant observation error analysis for topographic surveys. At the same time, to further analyze the limits of the UAV measurement technique, possible under equivalent observation conditions with the same processing environment, a difference model (DOD) was constructed for the DSM data from three sorties, to deepen the overall characterization of the differences between the DSMs obtained from repeated observations. The results of the experimental study concluded that both the analysis of the 3D point set measurements based on window sampling and the accuracy evaluation using the difference model were generally able to achieve a centimeter level of planimetric accuracy and vertical accuracy. In addition, the accuracy of the surface-stabilized hardened ground was better, overall, than the accuracy of the non-hardened ground. The results of this paper not only probe the measurement limits of this type of UAV, but also provide a quantitative reference for the accurate control and setting of an acquisition scheme of the UAV-based SfM-MVS method for geomorphological data acquisition and 3D reconstruction.

System concept and optical design of miniaturized projection and imaging systems with OLED microdisplays

2005 ◽  
Author(s):  
Stefan Riehemann ◽  
Martin Palme ◽  
Uwe Lippmann ◽  
Nancy Wolf ◽  
Gunther Notni
Keyword(s):  
Optical Design ◽  
Imaging Systems ◽  
System Concept

scholarly journals Studies on Three-Dimensional (3D) Accuracy Optimization and Repeatability of UAV in Complex Pit-Rim Landforms As Assisted by Oblique Imaging and RTK Positioning

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 8109
Author(s):  
Rui Bi ◽  
Shu Gan ◽  
Xiping Yuan ◽  
Raobo Li ◽  
Sha Gao ◽  
...  
Keyword(s):  
Measurement Accuracy ◽  
Three Dimensional ◽  
Surface Model ◽  
Observation Data ◽  
3D Measurement ◽  
Oblique View ◽  
Mountain Environments ◽  
Repeated Observation ◽  
Order Of Magnitude ◽  
Oblique Images

Unmanned Aerial Vehicles (UAVs) are a novel technology for landform investigations, monitoring, as well as evolution analyses of long−term repeated observation. However, impacted by the sophisticated topographic environment, fluctuating terrain and incomplete field observations, significant differences have been found between 3D measurement accuracy and the Digital Surface Model (DSM). In this study, the DJI Phantom 4 RTK UAV was adopted to capture images of complex pit-rim landforms with significant elevation undulations. A repeated observation data acquisition scheme was proposed for a small amount of oblique-view imaging, while an ortho-view observation was conducted. Subsequently, the 3D scenes and DSMs were formed by employing Structure from Motion (SfM) and Multi-View Stereo (MVS) algorithms. Moreover, a comparison and 3D measurement accuracy analysis were conducted based on the internal and external precision by exploiting checkpoint and DSM of Difference (DoD) error analysis methods. As indicated by the results, the 3D scene plane for two imaging types could reach an accuracy of centimeters, whereas the elevation accuracy of the orthophoto dataset alone could only reach the decimeters (0.3049 m). However, only 6.30% of the total image number of oblique images was required to improve the elevation accuracy by one order of magnitude (0.0942 m). (2) An insignificant variation in internal accuracy was reported in oblique imaging-assisted datasets. In particular, SfM-MVS technology exhibited high reproducibility for repeated observations. By changing the number and position of oblique images, the external precision was able to increase effectively, the elevation error distribution was improved to become more concentrated and stable. Accordingly, a repeated observation method only including a few oblique images has been proposed and demonstrated in this study, which could optimize the elevation and improve the accuracy. The research results could provide practical and effective technology reference strategies for geomorphological surveys and repeated observation analyses in sophisticated mountain environments.

Design of Refractive Index Test Equipment of High Refractive Index Glass Beads by Secondary Rainbow Method

2011 ◽  
Vol 66-68 ◽  
pp. 1320-1324 ◽  
Author(s):  
Dong Hua Guo ◽  
Jun Ma ◽  
Xue Feng Ma ◽  
Lei Peng
Keyword(s):  
Refractive Index ◽  
Measurement Accuracy ◽  
Optical Design ◽  
High Refractive Index ◽  
Glass Beads ◽  
Test Method ◽  
Test Equipment ◽  
Index Test ◽  
Statistical Measurement ◽  
Cause Of Error

This paper explains the theory of the secondary rainbow and provides a test method of refractive index of the high refractive index glass beads. We carry out the optical design relate to the method, and design a refractive index test equipment. Additionally, we analyze the calibration requirements of the equipment and discuss the cause of error and measurement accuracy. The designed equipment can achieve a continuous, accurate, statistical measurement.

Measurement of Three-Dimensional Environment with a Fish-Eye Camera Based on Structure from Motion - Error Analysis

2009 ◽  
Vol 21 (6) ◽  
pp. 680-688 ◽  
Author(s):  
Kenji Terabayashi ◽  
◽  
Hisanori Mitsumoto ◽  
Toru Morita ◽  
Yohei Aragaki ◽  
...  
Keyword(s):  
Structure From Motion ◽  
Measurement Accuracy ◽  
Three Dimensional ◽  
Simultaneous Estimation ◽  
3D Measurement ◽  
Motion Error ◽  
3 Dimensional ◽  
Wide Range ◽  
Large Distortion ◽  
Fish Eye

This paper proposes a method for measuring 3-dimensional (3D) environment and estimating camera movement with two fish-eye images. This method deals with large distortion of images from a fish-eye camera to calibrate internal and external camera parameters precisely by simultaneous estimation. In this paper, we analyze 3D measurement accuracy based on a theoretical model and evaluate it in practical analysis in experimental and real environments. These analyses show that the theoretical measurement error model works over a wide range of fish-eye views.

Optical design and performance of the Stereoscopic Imaging Channel for the ESA BepiColombo mission

2017 ◽  
Author(s):  
Vania Da Deppo ◽  
Emanuele Simioni ◽  
Donato Borrelli ◽  
Michele Dami ◽  
Riccardo Paolinetti ◽  
...  
Keyword(s):  
Optical Design ◽  
Stereoscopic Imaging ◽  
And Performance
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