The Estimation of Precisions in the Planning of Uas Photogrammetric Surveys (original) (raw)

Accuracy assessment of 3D photogrammetric models from an Unmanned Aerial Vehicle

Drones, 2019

The unmanned aerial vehicle (UAV) photogrammetric survey of an archaeological site has proved itself to be particularly efficient. In order to obtain highly accurate and reliable results, it is necessary to design carefully the flight plan and the geo-referencing, while also evaluating the indicators of the accuracy rate. Using as a test case a UAV photogrammetric survey conducted on the archaeological site of the Roman Amphitheatre of Avella (Italy), in this paper, we propose a pipeline to assess the accuracy of the results according to some quality indicators. The flight configuration and the georeferencing chosen is then be checked via the residuals on the ground control points (GCPs), evenly distributed on the edges and over the entire area. With the aim of appraising the accuracy of the final model, we will suggest a method for the outlier detection, taking into account the statistical distribution (both global and of portion of the study object) of the reprojection errors. A filter to reduce the noise within the model will then be implemented through the detection of the angle formed by homologous rays, in order to reach a compromise between the number of the usable points and the reduction of the noise linked to the definition of the 3D model.

Comparative Analysis of 3D Photogrammetry Modeling Software Packages for Drones Survey

The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2019

Drones are becoming popular in spatial mapping or survey. The use of drones survey can be seen from it low flying heights (capable to create a clear images), accessible on difficult or non-friendly vehicle access areas, faster data acquisition and higher data resolution henceforth improve the quality of the survey. However, this paper focuses on the post-processing of drone images for 3D surface modeling. With the motivation of producing better 3D models, four software packages are used for comparison. Those software packages are eyesMap3D, Drone Deploy, Agisoft PhotoScan and Pix4Dmapper. The equipment used to ensure a high level of quality model is the Leica GPS1200+ stationary GPS module and the DJI Phantom 4 PRO drone. The Leica GPS1200+ stationary GPS module were used to track the exact position of tie points on the ground. Meanwhile the DJI Phantom 4 PRO drone is used as data inputs (images) for the software packages stated. In addition, the drone is used to fly over a golf course, with a challenge of homogenous surface for 3D surface modeling. Based on the output, it shows that each software packages produces slightly different outputs. This paper summarizes the outputs and discusses the key elements in each software packages. This variation might be useful for future references in 3D surface modeling that can conform in different applications requirements.

Digital Terrain Models Generated with Low-Cost UAV Photogrammetry: Methodology and Accuracy

ISPRS International Journal of Geo-Information

Digital terrain model (DTM) generation is essential to recreating terrain morphology once the external elements are removed. Traditional survey methods are still used to collect accurate geographic data on the land surface. Given the emergence of unmanned aerial vehicles (UAVs) equipped with low-cost digital cameras and better photogrammetric methods for digital mapping, efficient approaches are necessary to allow rapid land surveys with high accuracy. This paper provides a review, complemented with the authors’ experience, regarding the UAV photogrammetric process and field survey parameters for DTM generation using popular commercial photogrammetric software to process images obtained with fixed-wing or multicopter UAVs. We analyzed the quality and accuracy of the DTMs based on four categories: (i) the UAV system (UAV platforms and camera); (ii) flight planning and image acquisition (flight altitude, image overlap, UAV speed, orientation of the flight line, camera configuration, a...

Evaluation of UAV Photogrammetric Accuracy for Mapping and Earthworks Computations

GEOMATICA, 2014

This study quantifies the accuracies achieved and tests the validity of an in-house developed Unmanned Aerial Vehicle (UAV) system employed in a stockpile volumetric survey. UAV photogrammetric results are compared with conventional GNSS survey results. To test the repeatability of the UAV system, multiple flights were flown over the same stockpile using different GNSS ground control, at different times and weather conditions. Positional accuracies of UAV photogrammetric results were found to be very similar to those from GNSS RTK survey, at the scale of photography flown. UAV stockpile volume results agreed with those from GNSS within 3 755 m3 (0.7%) on a 530 255 m3 pile. Stockpile volume comparisons between subsequent UAV surface models agreed within 877 m3 (0.2%) on the same pile. Geometric analysis of independent UAV photogrammetric models over the same area indicated that they could be considered the same at a 95% confidence level. We conclude that the UAV photogrammetric appro...

Development and Evaluation of a UAV-Photogrammetry System for Precise 3D Environmental Modeling

Sensors (Basel, Switzerland), 2015

The specific requirements of UAV-photogrammetry necessitate particular solutions for system development, which have mostly been ignored or not assessed adequately in recent studies. Accordingly, this paper presents the methodological and experimental aspects of correctly implementing a UAV-photogrammetry system. The hardware of the system consists of an electric-powered helicopter, a high-resolution digital camera and an inertial navigation system. The software of the system includes the in-house programs specifically designed for camera calibration, platform calibration, system integration, on-board data acquisition, flight planning and on-the-job self-calibration. The detailed features of the system are discussed, and solutions are proposed in order to enhance the system and its photogrammetric outputs. The developed system is extensively tested for precise modeling of the challenging environment of an open-pit gravel mine. The accuracy of the results is evaluated under various ma...

3D Modeling with Photogrammetry by Uavs and Model Quality Verification

ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences, 2017

This paper deals with a test lead by Geomatics laboratory (DICEAM, Mediterranea University of Reggio Calabria), concerning the application of UAV photogrammetry for survey, monitoring and checking. The study case relies with the surroundings of the Department of Agriculture Sciences. In the last years, such area was interested by landslides and survey activities carried out to take the phenomenon under control. For this purpose, a set of digital images were acquired through a UAV equipped with a digital camera and GPS. Successively, the processing for the production of a 3D georeferenced model was performed by using the commercial software Agisoft PhotoScan. Similarly, the use of a terrestrial laser scanning technique allowed to product dense cloud and 3D models of the same area. To assess the accuracy of the UAV-derived 3D models, a comparison between image and range-based methods was performed.

UAV photogrammetry for mapping and 3D modeling–current status and future perspectives–

Proceedings of the …, 2011

a 3D Optical Metrology (3DOM) unit, FBK Trento, Italy -@fbk.eu -http://3dom.fbk.eu -http://www.zenit-sa.com/ Commission I, ICWG I/V ABSTRACT: UAV platforms are nowadays a valuable source of data for inspection, surveillance, mapping and 3D modeling issues. New applications in the short-and close-range domain are introduced, being the UAVs a low-cost alternatives to the classical manned aerial photogrammetry. Rotary or fixed wing UAVs, capable of performing the photogrammetric data acquisition with amateur or SLR digital cameras, can fly in manual, semi-automated and autonomous modes. With a typical photogrammetric pipeline, 3D results like DSM/DTM, contour lines, textured 3D models, vector data, etc. can be produced, in a reasonable automated way. The paper reports the latest developments of UAV image processing methods for photogrammetric applications, mapping and 3D modeling issues. Automation is nowadays necessary and feasible at the image orientation, DSM generation and orthophoto production stages, while accurate feature extraction is still an interactive procedure. New perspectives are also addressed. Figure 1: Example of scenes surveyed with a UAV system (Microdrone MD4-200) and photogrammetric results achieved from the acquired images: digital surface model, orthoimages and overlaid contours (archaeological area in Montalcino, Italy).

U.PH.O and Mago: Two Useful Instruments in Support of Photogrammetric Uav Survey

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

In emergency and critical scenarios, the UAV could play a key role in accessing unreachable sites in a safe and rapid way, guaranteeing at the same time the necessary accuracy and precision of the survey. In this context, UAV survey campaigns have been performed by the authors in Norcia (Italy), hit by tragic seismic events in August and October 2016. The surveys were motivated by the artistic and historical value of monuments, the need to plan and design the restoring and retrofitting of buildings, and also to quantify and manage the ruins. Goal of such surveys was the description of the structures geometry with a centimetric precision and a high level of reliability. Recently, the authors have conceived two tools, U.Ph.O (Unmanned Photogrammetric Office) and MAGO (Adaptive Mesh for Orthophoto Generation), dedicated to the planning and restitution phases of the survey, respectively. U.Ph.O. and MAGO are here applied to two different buildings in Norcia, i.e. the Civic Tower of Norcia and San Salvatore Church of Campi di Norcia. The former is a standing-out structure, surrounded by the complex of the historical centre, while the latter is located in an isolated site in the countryside. These features make the survey planning and the orthophoto reconstruction completely different, mainly due to the different optimal shooting geometry and the presence or absence of obstructions.

A generic approach for photogrammetric survey using a six-rotor unmanned aerial vehicle

IOP Conference Series: Earth and Environmental Science, 2014

This paper discusses a rapid production of slope mapping using multi-rotor unmanned aerial vehicle (UAV). The objective of this study is to determine the accuracy of the photogrammetric results based on novel method of multi-rotor UAV images as well as to analyze the slope error distribution that are obtained from the UAV images. This study only concentrates on multi-rotor UAV which also known as Hexacopter. An operator can control the speed of multi-rotor UAV during flight mission. Several ground control points and checkpoints were established using Real Time Kinematic Global Positioning System (RTK-GPS) at the slope area. Ground control points were used in exterior orientation during image processing in sequence to transform image coordinates into local coordinate system. Checkpoints were established at the slope area for accuracy assessment. A digital camera, Sony NEX-5N was used for image acquisition of slope area from UAV platforms. The digital camera was mounted vertically at the bottom of UAV and captured the images at an altitude. All acquired images went through photogrammetric processing including interior orientation, exterior orientation and bundle adjustment using photogrammetric software. Photogrammetric results such as digital elevation model, and digital orthophoto including slope map were assessed. UAV is able to acquire data within short period of time with low budget compared to the previous methods such as satellite images and airborne laser scanner. Analysis on slope analysis and error distribution analysis are discussed in this paper to determine the quality of slope map in the area of interest. In summary, multi-rotor UAV is suited in slope mapping studies.