COMPREHENSIVE ANALYSIS OF FLYING ALTITUDE FOR HIGH RESOLUTION SLOPE MAPPING USING UAV TECHNOLOGY

Abstract. Unmanned Aerial Vehicle (UAV) is one of the geoinformation data acquisition technologies that popularly used for slope mapping. UAV is capable to produce high resolution imageries in a short period. In order to obtained suitable results in slope mapping, specific UAV mapping factors have to be followed and the selection of the optimum Ground Control Point (GCP) and the UAV flying altitude become the most important factors. This paper presents the production of high resolution slope map using UAV technology. The research involved with the following steps, (i) preparation of field work (i.e. determination of the number of GCPs and flying altitude) and the flight mission; (ii) processing and evaluating of UAV images, and (iii) production of slope map. The research was successfully conducted at Kulim, Kedah, Malaysia as the condition of slope in that area is prone to the landslide incidences. A micro rotary wing UAV system known as DJI Phantom 4 was used for collecting the high resolution images with various flying altitudes. Due to the un-accessibility of the slope area, all the GCPs are measured from the point cloud data that was acquired from the Pheonix AL-32 LiDAR system. The analysis shows that the coordinates (X, Y and Z) accuracy is influenced by the flying altitude. As the flying altitude increases, the coordinate’s accuracy also increased. Furthermore, the results also show that the coverage slope area and number of tie point increases when the flying altitude increases. This practical study contributed to the slope work activities where the specific requirements for flying altitudes have been clearly stated.

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Updated Ganymede Mosaic from Voyager and Galileo observations

10.5194/epsc2021-314 ◽

2021 ◽

Author(s):

Elke Kersten ◽

Anatoly E. Zubarev ◽

Thomas Roatsch ◽

Klaus-Dieter Matz

Keyword(s):

High Resolution ◽

Planning Process ◽

Control Point ◽

Image Data ◽

Space Science ◽

Control Points ◽

Orientation Data ◽

Short Period ◽

High Resolution Images ◽

Observation Times

Abstract In preparation of the JUICE mission with the primary target Ganymede [1] we generated a new controlled version of the global Ganymede image mosaic using a combination of Voyager 1 and 2 and Galileo images. Baseline for this work was the new 3D control point network from Zubarev et al., 2016 [2], which uses the best available images from both missions and led to new position and pointing of the images. <ul> <li>Introduction</li> </ul> Voyager 1 and Voyager 2 encountered Jupiter in 1979. They took 490 Narrow Angle Camera (NAC) and Wide Angle Camera (WAC) images of Ganymede&#8217;s surface with pixel scales from 470 m/pxl down to 20 km/pxl. Galileo entered orbit around Jupiter in 1995 and flew by Ganymede 15 times to acquire 149 images (<20 km/pxl). The new control point network of Ganymede led to higher geodetic accuracy in the data and thus created the incentive to generate a new basemap with a resolution <1 km/pxl. <ul> <li>Image data</li> </ul> The Voyager and Galileo images were acquired under very differing illumination and viewing conditions and from different observation times, although they have been taken within a short period each. Together with the varying flyby altitudes it strongly influences the images&#8217; brightness, contrast, and resolution. Another fact is that images of Ganymede are limited, so there is barely an area covered twice with a proper resolution whereas the poles suffer from a lack of image data. To reach the highest possible coverage in the global mosaic, we selected 118 Voyager 1 and 2 images and 88 Galileo SSI images including high-resolution images (<500 m/pxl) from three close Ganymede encounters [3]. &#160; <ul> <li>Control</li> </ul> The 3D control point network was developed by the use of reconstructed spacecraft ephemerides [4] and consist of 3377 control points from 213 Voyager and Galileo images. The reprojection error is about 0.01-0.1 pixel and the coordinate accuracy of 78% of the control points is better than 5.0 km. <ul> <li>Mosaicking</li> </ul> The selected images were reprocessed with the new pointing and orientation data and then reprojected into the final cylindrical equidistant projection, where the small crater Anat defines the longitude system at 232&#176; East. After artefact correction, images with similar observation times and resolutions were set together to regional mosaics. The most work-intense part was the brightness and contrast correction of the regional mosaics and the remaining single images by tone-matching at the transition zones. The global Ganymede mosaic can be downloaded at https://janus.dlr.de/ and is archived at PSA: DOI &#8211; 10.5270/esa-mqhvfjf. <ul> <li>Outlook</li> </ul> The new Ganymede basemap with a global map scale of 359 m/pxl including some high-resolution images from Galileo increases the variety of available data products and should help during pre-JUICE arrival investigations of Ganymede and support the planning process. References [1] Grasset et al., 2013, Planetary and Space Science, 78, 1-21, DOI: 10.1016/S0032063312003777. [2] Zubarev et al., 2016, Solar System Research, 50, 5, 352-360, DOI: 10.1134/S0038094616050087. [3] Kersten et al., 2021, resubmitted to Planetary and Space Science. [4] Zubarev et al., 2015, Planetary and Space Science, 117, 246-249, DOI: 10.1016/S0032063315002007.

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THE USE OF HIGH RESOLUTION IMAGES TO EVALUATE THE EVENT OF FLOODS AND TO ANALYSIS THE RISK REDUCTION CASE STUDY: KAMPUNG PULO, JAKARTA

International Journal of Remote Sensing and Earth Sciences (IJReSES) ◽

10.30536/j.ijreses.2014.v11.a2610 ◽

2017 ◽

Vol 11 (2) ◽

pp. 127

Author(s):

M. Rokhis Khomarudin ◽

. Suwarsono ◽

Dini Oktavia Ambarwati ◽

Gunawan Prabowo

Keyword(s):

High Resolution ◽

Risk Reduction ◽

Aerial Photography ◽

Risk Level ◽

Vertical Evacuation ◽

Aerial Vehicle ◽

High Resolution Images ◽

Evacuation Plan

The flood hit Kampung Pulo region in almost every year. This disaster has caused the evacuation of some residents in weeks. Given the frequency of occurrence is quite high in the region it is necessary to do a study to support disaster risk reduction. This study aimed to evaluate the incidence of flooding that occurred in Kampung Pulo in terms of topography, river conditions, characteristics of the building, and socioeconomic conditions. Methods of study include geomorphology analysis, identification of areas of stagnant, the estimated number of people exposed, the estimation of socio-economic conditions of the population, as well as determining the location of an evacuation. The data used is high-resolution remote sensing imagery is QuickBird and SPOT-6. It also used the results of aerial photography using Unmanned Aerial Vehicle (UAV). Aerial photography was conducted on January 18, 2013, which is when the serious flooding that inundated almost the entire region of Kampung Pulo. Information risk level of buildings and population resulting from this study were obtained by using GIS. The results obtained from this study can be used to develop recommendations and strategies for flood mitigation in Kampung Pulo, Jakarta. One of them is the determination of the location for vertical evacuation plan in the affected areas.

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High-Resolution Image Simulation of a Tilted Crystal

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100179099 ◽

1990 ◽

Vol 48 (1) ◽

pp. 68-69

Author(s):

C. J. D. Hetherington

Keyword(s):

High Resolution ◽

Crystal Thickness ◽

Thin Specimen ◽

Atomic Structures ◽

Kikuchi Lines ◽

High Resolution Images ◽

Final Estimate ◽

Simulated Images ◽

Habit Planes

Most high resolution images are not directly interpretable but must be compared with simulations based on model atomic structures and appropriate imaging conditions. Typically, the only parameters that are adjusted, in addition to the structure models, are crystal thickness and microscope defocus. Small tilts of the crystal away from the exact zone axis have only rarely been considered. It is shown here that, in the analysis of an image of a silicon twin intersection, the crystal tilt could be accurately estimated and satisfactorily included in the simulations.The micrograph shown in figure 1 was taken as part of an HREM study of indentation-induced hexagonal silicon. In this instance, the intersection of two twins on different habit planes has driven the silicon into hexagonal stacking. However, in order to confirm this observation, and in order to investigate other defects in the region, it has been necessary to simulate the image taking into account the very apparent crystal tilt. The inability to orientate the specimen at the exact [110] zone was influenced by i) the buckling of the specimen caused by strains at twin intersections, ii) the absence of Kikuchi lines or a clearly visible Laue circle in the diffraction pattern of the thin specimen and iii) the avoidance of radiation damage (which had marked effects on images taken a few minutes later following attempts to realign the crystal.) The direction of the crystal tilt was estimated by observing which of the {111} planes remained close to edge-on to the beam and hence strongly imaged. Further refinement of the direction and magnitude of the tilt was done by comparing simulated images to experimental images in a through-focal series. The presence of three different orientations of the silicon lattice aided the unambiguous determination of the tilt. The final estimate of a 0.8° tilt in the 200Å thick specimen gives atomic columns a projected width of about 3Å.

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Combined Experimentaland Theoretical Determination of the Atomic Structure of the (310) Twin in NB

MRS Proceedings ◽

10.1557/proc-238-163 ◽

1991 ◽

Vol 238 ◽

Cited By ~ 3

Author(s):

Geoffrey H. Campbells ◽

Wayne E. King ◽

Stephen M. Foiles ◽

Peter Gumbsch ◽

Manfred Rühle

Keyword(s):

High Resolution ◽

Theoretical Models ◽

High Resolution Electron Microscopy ◽

Interatomic Potentials ◽

Image Simulation ◽

Theoretical Determination ◽

Atomic Structures ◽

Resolution Electron ◽

High Resolution Images

ABSTRACTA (310) twin boundary in Nb has been fabricated by diffusion bonding oriented single crystals and characterized using high resolution electron microscopy. Atomic structures for the boundary have been predicted using different interatomic potentials. Comparison of the theoretical models to the high resolution images has been performed through image simulation. On the basis of this comparison, one of the low energy structures predicted by theory can be ruled out.

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Towards Amazon Forest Restoration: Automatic Detection of Species from UAV Imagery

Remote Sensing ◽

10.3390/rs13132627 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2627

Author(s):

Marks Melo Moura ◽

Luiz Eduardo Soares de Oliveira ◽

Carlos Roberto Sanquetta ◽

Alexis Bastos ◽

Midhun Mohan ◽

...

Keyword(s):

Neural Networks ◽

Convolutional Neural Networks ◽

Forest Restoration ◽

Amazon Forest ◽

Forest Species ◽

Accuracy And Precision ◽

Identification Of Species ◽

Aerial Vehicle ◽

High Resolution Images ◽

Uav Images

Precise assessments of forest species’ composition help analyze biodiversity patterns, estimate wood stocks, and improve carbon stock estimates. Therefore, the objective of this work was to evaluate the use of high-resolution images obtained from Unmanned Aerial Vehicle (UAV) for the identification of forest species in areas of forest regeneration in the Amazon. For this purpose, convolutional neural networks (CNN) were trained using the Keras–Tensorflow package with the faster_rcnn_inception_v2_pets model. Samples of six forest species were used to train CNN. From these, attempts were made with the number of thresholds, which is the cutoff value of the function; any value below this output is considered 0, and values above are treated as an output 1; that is, values above the value stipulated in the Threshold are considered as identified species. The results showed that the reduction in the threshold decreases the accuracy of identification, as well as the overlap of the polygons of species identification. However, in comparison with the data collected in the field, it was observed that there exists a high correlation between the trees identified by the CNN and those observed in the plots. The statistical metrics used to validate the classification results showed that CNN are able to identify species with accuracy above 90%. Based on our results, which demonstrate good accuracy and precision in the identification of species, we conclude that convolutional neural networks are an effective tool in classifying objects from UAV images.

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UNMANNED AERIAL VEHICLE APPLICATIONS OF 3D MODELLING, VISUALIZATION AND PARAMETER CALCULATIONS

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-5-649-2018 ◽

2018 ◽

Vol XLII-5 ◽

pp. 649-652 ◽

Cited By ~ 1

Author(s):

V. Lambey ◽

A. D. Prasad

Keyword(s):

Point Cloud ◽

Low Cost ◽

3D Modelling ◽

Aerial Photogrammetry ◽

Average Accuracy ◽

Aerial Vehicle ◽

High Resolution Images ◽

Institute Of Technology ◽

Uav Images ◽

Economical Alternative

Abstract. Photogrammetric surveying with the use of Unmanned Aerial Vehicles (UAV) have gained vast popularity in short span. UAV have the potential to provide imagery at an extraordinary spatial and temporal resolution when coupled with remote sensing. Currently, UAV platforms are fastest and easiest source of data for mapping and 3D modelling. It is to be considered as a low-cost substitute to the traditional airborne photogrammetry. In the present study, UAV applications are explored in terms of 3D modelling, visualization and parameter calculations. National Institute of Technology Raipur, Raipur is chosen as study area and high resolution images are acquired from the UAV with 85% overlap. 3D model is processed through the point cloud generated for the UAV images. The results are compared with traditional methods for validation. The average accuracy obtained for elevation points and area is 97.99% and 97.75%. The study proves that UAV based surveying is an economical alternative in terms of money, time and resources, when compared to the classical aerial photogrammetry methods.

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Infrastructure Inspection Using an Unmanned Aerial System (UAS) With Metamodeling-Based Image Correction

Volume 2B: 42nd Design Automation Conference ◽

10.1115/detc2016-59193 ◽

2016 ◽

Cited By ~ 1

Author(s):

Chen-Ming Kuo ◽

Chung-Hsin Kuo ◽

Shu-Ping Lin ◽

Mark Christian E. Manuel ◽

Po Ting Lin ◽

...

Keyword(s):

High Resolution ◽

Ccd Camera ◽

Kriging Model ◽

Image Correction ◽

Railway Transport ◽

Truss Bridges ◽

Aerial Vehicle ◽

High Resolution Images ◽

Infrastructure Inspection ◽

Steel Truss Bridges

Public infrastructures such as bridges are common civil structures for road and railway transport. In Poland, many of the steel truss bridges were constructed in the 1950s or earlier. The aging managements and damage assessments are required to ensure safe operations of these old bridges. The first step of damage assessment is usually done via visual inspection. The said inspection procedure can be expensive, laborious and dangerous as it is often performed by trained personnel. As a solution to this, we have developed and used a custom-designed, modular aerial robot equipped with a CCD camera for the collection of high-resolution images. The images were merged into one single, high-resolution facade map that will be the basis for subsequent evaluation by bridge inspectors. It was observed that the collected images had encountered irregularities which decreases the reliability of the facade map. We have conducted experiments to estimate the correction of image perspective in terms of attitude and position of unmanned aerial vehicle (UAV). A Kriging model was utilized to parametrically model the aforementioned nonlinear relationship. The image reliability is then evaluated based on the variance of the parametric model. The generated information is further used for high fidelity automated image correction and stitching.

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Monitoring of a landslide through the use of UAV survey

10.5194/egusphere-egu2020-7696 ◽

2020 ◽

Author(s):

Simone Pillon ◽

Davide Martinucci ◽

Annelore Bezzi ◽

Giulia Casagrande ◽

Giorgio Fontolan ◽

...

Keyword(s):

High Resolution ◽

Control Point ◽

Ground Control ◽

Surface Model ◽

Ground Control Point ◽

North East ◽

Active Portion ◽

High Resolution Images ◽

Precise Assessment ◽

Friuli Venezia Giulia

The monitoring of landslides using UAVs is particularly convenient as these are dangerous areas that present access difficulties. This study aims to integrate monitoring carried out via traditional techniques (GNSS and total station surveys of benchmarks) with UAV photogrammetric survey, as the latter allows for a precise assessment of the volumes affected by movement. The Masarach landslide, located in Friuli Venezia Giulia (north east Italy), covers an area of approximately 200 ha. Two surveys were carried out two years apart in order to measure displacements of much greater magnitude than instrumental errors. In the first survey, restricted to the most active area, a six rotor UAV was used, with a maximum take-off mass of 4 kg, which carried a 20 Mpixel APS-C camera. 243 high resolution images were captured and 27 GCPs (Ground Control Point) were surveyed with a GNSS RTK reciever. In the second survey a DJI Phantom 4 Pro UAV was used, carrying a 20 Mpixel 1&#8220; sensor camera. 978 high resolution images were captured and 40 GCPs (Ground Control Point) were surveyed with a GNSS RTK reciever. Data were analyzed using Agisoft Metashape Professional to produce an orthophoto and a DSM (Digital Surface Model) with a ground resolution of 0.02 m and 0.04 m respectively. The DSMs were compared in ArcGIS to calculate the moving masses and highlight the areas of greatest instability. It emerged that approximately 10,000 cubic meters of landslide material were transported to the Arzino stream below, with verified displacements on the control point ranging from meters to centimeters. This work made it possible to accurately define the most active portion of the landslide.

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New Target for Accurate Terrestrial Laser Scanning and Unmanned Aerial Vehicle Point Cloud Registration

Sensors ◽

10.3390/s19143179 ◽

2019 ◽

Vol 19 (14) ◽

pp. 3179

Author(s):

Tilen Urbančič ◽

Žiga Roškar ◽

Mojca Kosmatin Fras ◽

Dejan Grigillo

Keyword(s):

Unmanned Aerial Vehicle ◽

Laser Scanning ◽

Point Clouds ◽

Precise Determination ◽

Reference Target ◽

Aerial Vehicle ◽

Uav Images ◽

Volume Targets

The main goal of our research was to design and implement an innovative target that would be suitable for accurately registering point clouds produced from unmanned aerial vehicle (UAV) images and terrestrial laser scans. Our new target is composed of three perpendicular planes that combine the properties of plane and volume targets. The new target enables the precise determination of reference target points in aerial and terrestrial point clouds. Different types of commonly used plane and volume targets as well as the new target were placed in an established test area in order to evaluate their performance. The targets were scanned from multiple scanner stations and surveyed with an unmanned aerial vehicle DJI Phantom 4 PRO at three different altitudes (20, 40, and 75 m). The reference data were measured with a Leica Nova MS50 MultiStation. Several registrations were performed, each time with a different target. The quality of these registrations was assessed on the check points. The results showed that the new target yielded the best results in all cases, which confirmed our initial expectations. The proposed new target is innovative and not difficult to create and use.

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