UAV Technology Research Articles

MAPPING GNSS RESTRICTED ENVIRONMENTS WITH A DRONE TANDEM AND INDIRECT POSITION CONTROL

Abstract. The problem of autonomously mapping highly cluttered environments, such as urban and natural canyons, is intractable with the current UAV technology. The reason lies in the absence or unreliability of GNSS signals due to partial sky occlusion or multi-path effects. High quality carrier-phase observations are also required in efficient mapping paradigms, such as Assisted Aerial Triangulation, to achieve high ground accuracy without the need of dense networks of ground control points. In this work we consider a drone tandem in which the first drone flies outside the canyon, where GNSS constellation is ideal, visually tracks the second drone and provides an indirect position control for it. This enables both autonomous guidance and accurate mapping of GNSS restricted environments without the need of ground control points. We address the technical feasibility of this concept considering preliminary real-world experiments in comparable conditions and we perform a mapping accuracy prediction based on a simulation scenario.

The use of uav technology in topographical research: some case studies from central and southern Italy

The paper highlights the large potential of the UAV (Unmanned Aerial Vehicle) remote-sensing technology applied to the Ancient Topography sector. There are several areas of application in which this new technology represents a useful tool, from the survey and monitoring of ancient monuments to the expeditious analysis of entire territorial sectors. Therefore occur some case studies conducted by the LabTAF of the University of Salento which have, as intervention centers, the Roman City of Aquinum (Southern Lazio), the Vicus Ad Pirum along Via Traiana and the territory between Lecce (Lupiae) and San Cataldo.

Low aerial imagery – an assessment of georeferencing errors and the potential for use in environmental inventory

Abstract Unmanned aerial vehicles are increasingly being used in close range photogrammetry. Real-time observation of the Earth’s surface and the photogrammetric images obtained are used as material for surveying and environmental inventory. The following study was conducted on a small area (approximately 1 ha). In such cases, the classical method of topographic mapping is not accurate enough. The geodetic method of topographic surveying, on the other hand, is an overly precise measurement technique for the purpose of inventorying the natural environment components. The author of the following study has proposed using the unmanned aerial vehicle technology and tying in the obtained images to the control point network established with the aid of GNSS technology. Georeferencing the acquired images and using them to create a photogrammetric model of the studied area enabled the researcher to perform calculations, which yielded a total root mean square error below 9 cm. The performed comparison of the real lengths of the vectors connecting the control points and their lengths calculated on the basis of the photogrammetric model made it possible to fully confirm the RMSE calculated and prove the usefulness of the UAV technology in observing terrain components for the purpose of environmental inventory. Such environmental components include, among others, elements of road infrastructure, green areas, but also changes in the location of moving pedestrians and vehicles, as well as other changes in the natural environment that are not registered on classical base maps or topographic maps.

Aerial and underwater sound of unmanned aerial vehicles (UAV, drones)

Unmanned aerial vehicles/systems (UAV/UAS, drones) are increasingly being used for terrestrial and marine ecological surveying and research. Studies on the potential disturbance of fauna by UAVs have been sparse, with most reports on the behavioral responses of birds. Responses of marine mammals have been reported in the case of pinnipeds on land, with very limited information on marine mammals at sea. Whether the stimulus was visual (the UAV or its shadow) or acoustic (noise) is unknown. While UAV technology is developing fast, guidelines for the responsible use of UAVs around fauna are lagging behind. We recorded aerial and underwater sound from four aerial drones in different environments. Sound spectra exhibited distinct tones <2 kHz. Median broadband source levels were 77–89 dB re 20 μPa rms at 1 m in air. Under water, median broadband received levels were <100 dB re 1 μPa rms varying with drone altitude, flight mode, and recorder depth. Drone power spectral density exceeded underwater ambient levels by up to 30 dB between 100 and 10 000 Hz. Drone levels were well below those commonly considered in underwater noise regulations. Simple sound propagation and transmission calculations predicted underwater levels within −3.2 to +6.2 dB of measured levels.

Comparison of UAV Technology vs No UAV Technology in Identification of Hazards at a MCI Scenario in Primary Care Paramedic Students

An abstract is not available for this content so a preview has been provided. As you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

When there was no GIS system: rediscovering archaeological researches of the 19th century through the use of the drone.: the case study of Mount Siri (Anzi, Basilicata)

Modern archaeologists often find it difficult to identify the exact position on the field (and on the maps) of the finds brought to light during archaeological excavations, particularly those conducted before the second half of the 20th century. In these cases, in fact, they are obliged to record data and information on their GIS as being unable to locate the correct place, or even the area, of those ancient archaeological investigations. This inability to be precise creates several problems from a topographical point of view and negatively influences the archaeological reconstruction of specific territories or sites. Therefore, how is it possible to correctly locate and, as a result, mark on the map what was discovered or excavated in the recent past? One possible solution is the 3D reconstruction of a modern landscape through the use of the UAV technology and some derived applications, such as digital techniques based on Structure from Motion and Imaged-Based methodologies. The 3D model can be analyzed using the GIS system, and through the analysis of the micro-relief and aerial photos it is possible to use an important tool to locate past archaeological investigations. In this paper, we present the case study of Mount Siri (Anzi, Basilicata), the location of several important archaeological discoveries which were made during the 19th century.

A new UAV PTZ Controlling System with Target Localization

In recent years, with the continuous exposure of unmanned aerial vehicles in the local battlefield, as well as the rapid development of UAV technology, UAV’s military application values, especially the advantages in the low-altitude reconnaissance have been the world’s attention. Unmanned reconnaissance aircraft is becoming very promising new equipment in technology battlefield and an important information combat front. However, most of the current UAV controlling systems only provide manually PTZ controlling functions, which is inconvenient for the user to control the sensor to monitor targets on demand. This paper propose a new UAV PTZ controlling system, which enables user to keep target in the view filed by simply selecting a position from the digital map. The proposed system is also able to do real-time target localization for any pixel of the video. Experimental results show that our system is easy for PTZ controlling and the localization error is small.

Development of an aerial counting system in oil palm plantations

This paper proposes the development of a counting aerial system capable of capturing, process and analyzing images of an oil palm plantation to register the number of cultivated palms. It begins with a study of the available UAV technologies to define the most appropriate model according to the project needs. As result, a DJI Phantom 2 Vision+ is used to capture pictures that are processed by a photogrammetry software to create orthomosaics from the areas of interest, which are handled by the developed software to calculate the number of palms contained in them. The implemented algorithm uses a sliding window technique in image pyramids to generate candidate windows, an LBP descriptor to model the texture of the picture, a logistic regression model to classify the windows and a non-maximum suppression algorithm to refine the decision. The system was tested in different images than the ones used for training and for establishing the set point. As result, the system showed a 95.34% detection rate with a 97.83% precision in mature palms and a 79.26% detection rate with a 97.53% precision in young palms giving an FI score of 0.97 for mature palms and 0.87 for the small ones. The results are satisfactory getting the census and high-quality images from which is possible to get more information from the area of interest. All this, achieved through a low-cost system capable of work even in cloudy conditions.

CLASSICAL PHOTOGRAMMETRY AND UAV – SELECTED ASCPECTS

Abstract. The UAV technology seems to be highly future-oriented due to its low costs as compared to traditional aerial images taken from classical photogrammetry aircrafts. The AGH University of Science and Technology in Cracow - Department of Geoinformation, Photogrammetry and Environmental Remote Sensing focuses mainly on geometry and radiometry of recorded images. Various scientific research centres all over the world have been conducting the relevant research for years. The paper presents selected aspects of processing digital images made with the UAV technology. It provides on a practical example a comparison between a digital image taken from an airborne (classical) height, and the one made from an UAV level. In his research the author of the paper is trying to find an answer to the question: to what extent does the UAV technology diverge today from classical photogrammetry, and what are the advantages and disadvantages of both methods? The flight plan was made over the Tokarnia Village Museum (more than 0.5 km2) for two separate flights: the first was made by an UAV - System FT-03A built by FlyTech Solution Ltd. The second was made with the use of a classical photogrammetric Cesna aircraft furnished with an airborne photogrammetric camera (Ultra Cam Eagle). Both sets of photographs were taken with pixel size of about 3 cm, in order to have reliable data allowing for both systems to be compared. The project has made aerotriangulation independently for the two flights. The DTM was generated automatically, and the last step was the generation of an orthophoto. The geometry of images was checked under the process of aerotriangulation. To compare the accuracy of these two flights, control and check points were used. RMSE were calculated. The radiometry was checked by a visual method and using the author's own algorithm for feature extraction (to define edges with subpixel accuracy). After initial pre-processing of data, the images were put together, and shown side by side. Buildings and strips on the road were selected from whole data for the comparison of edges and details. The details on UAV images were not worse than those on classical photogrammetric ones. One might suppose that geometrically they also were correct. The results of aerotriangulation prove these facts, too. Final results from aerotriangulation were on the level of RMS = 1 pixel (about 3 cm). In general it can be said that photographs from UAVs are not worse than classic ones. In the author's opinion, geometric and radiometric qualities are at a similar level for this kind of area (a small village). This is a very significant result as regards mapping. It means that UAV data can be used in mapping production.

CLASSICAL PHOTOGRAMMETRY AND UAV – SELECTED ASCPECTS

The UAV technology seems to be highly future-oriented due to its low costs as compared to traditional aerial images taken from classical photogrammetry aircrafts. The AGH University of Science and Technology in Cracow - Department of Geoinformation, Photogrammetry and Environmental Remote Sensing focuses mainly on geometry and radiometry of recorded images. Various scientific research centres all over the world have been conducting the relevant research for years. The paper presents selected aspects of processing digital images made with the UAV technology. It provides on a practical example a comparison between a digital image taken from an airborne (classical) height, and the one made from an UAV level. In his research the author of the paper is trying to find an answer to the question: to what extent does the UAV technology diverge today from classical photogrammetry, and what are the advantages and disadvantages of both methods? The flight plan was made over the Tokarnia Village Museum (more than 0.5 km&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;) for two separate flights: the first was made by an UAV - System FT-03A built by FlyTech Solution Ltd. The second was made with the use of a classical photogrammetric Cesna aircraft furnished with an airborne photogrammetric camera (Ultra Cam Eagle). Both sets of photographs were taken with pixel size of about 3 cm, in order to have reliable data allowing for both systems to be compared. The project has made aerotriangulation independently for the two flights. The DTM was generated automatically, and the last step was the generation of an orthophoto. The geometry of images was checked under the process of aerotriangulation. To compare the accuracy of these two flights, control and check points were used. RMSE were calculated. The radiometry was checked by a visual method and using the author's own algorithm for feature extraction (to define edges with subpixel accuracy). After initial pre-processing of data, the images were put together, and shown side by side. Buildings and strips on the road were selected from whole data for the comparison of edges and details. The details on UAV images were not worse than those on classical photogrammetric ones. One might suppose that geometrically they also were correct. The results of aerotriangulation prove these facts, too. Final results from aerotriangulation were on the level of RMS = 1 pixel (about 3 cm). In general it can be said that photographs from UAVs are not worse than classic ones. In the author's opinion, geometric and radiometric qualities are at a similar level for this kind of area (a small village). This is a very significant result as regards mapping. It means that UAV data can be used in mapping production.

QUALITY ANALYSIS ON 3D BUIDLING MODELS RECONSTRUCTED FROM UAV IMAGERY

Abstract. Recent developments in UAV technology and structure from motion techniques have effected that UAVs are becoming standard platforms for 3D data collection. Because of their flexibility and ability to reach inaccessible urban parts, drones appear as optimal solution for urban applications. Building reconstruction from the data collected with UAV has the important potential to reduce labour cost for fast update of already reconstructed 3D cities. However, especially for updating of existing scenes derived from different sensors (e.g. airborne laser scanning), a proper quality assessment is necessary. The objective of this paper is thus to evaluate the potential of UAV imagery as an information source for automatic 3D building modeling at LOD2. The investigation process is conducted threefold: (1) comparing generated SfM point cloud to ALS data; (2) computing internal consistency measures of the reconstruction process; (3) analysing the deviation of Check Points identified on building roofs and measured with a tacheometer. In order to gain deep insight in the modeling performance, various quality indicators are computed and analysed. The assessment performed according to the ground truth shows that the building models acquired with UAV-photogrammetry have the accuracy of less than 18 cm for the plannimetric position and about 15 cm for the height component.

QUALITY ANALYSIS ON 3D BUIDLING MODELS RECONSTRUCTED FROM UAV IMAGERY

Recent developments in UAV technology and structure from motion techniques have effected that UAVs are becoming standard platforms for 3D data collection. Because of their flexibility and ability to reach inaccessible urban parts, drones appear as optimal solution for urban applications. Building reconstruction from the data collected with UAV has the important potential to reduce labour cost for fast update of already reconstructed 3D cities. However, especially for updating of existing scenes derived from different sensors (e.g. airborne laser scanning), a proper quality assessment is necessary. The objective of this paper is thus to evaluate the potential of UAV imagery as an information source for automatic 3D building modeling at LOD2. The investigation process is conducted threefold: (1) comparing generated SfM point cloud to ALS data; (2) computing internal consistency measures of the reconstruction process; (3) analysing the deviation of Check Points identified on building roofs and measured with a tacheometer. In order to gain deep insight in the modeling performance, various quality indicators are computed and analysed. The assessment performed according to the ground truth shows that the building models acquired with UAV-photogrammetry have the accuracy of less than 18 cm for the plannimetric position and about 15 cm for the height component.

Flood-prone area delimitation using UAV technology, in the areas hard-to-reach for classic aircrafts: case study in the north-east of Apuseni Mountains, Transylvania

In the delimitation of flood-prone areas, particularly in areas that are difficult to access using traditional flight equipment, the most critical problem is the generation of a high-quality DEM of the major and minor riverbed, in order to obtain several hydraulic parameters (e.g., the surface of the drainage section, average water velocity) with equivalent accuracy. The chosen area for the case study represents one with the greatest history of hydrological risk factors in the Somesul Mic basin, given the extreme previous hydrological events that have taken place (e.g., in the year 1995) as well as the limited capacity of the river for upstream river flow, and to handle the volume of the flash floods. In this study, the use of UAV technology coupled with Leica MultiStation for validation made it possible to achieve this performance. Another advantage was the existence of the hydrometric station situated in the middle of the study area, the information from which was used for statistics, calibration of the measurements and validation of the results obtained (roughness of the riverbed, the debit with an overflow possibility). The hydraulic calculations performed on the 11 transverse profiles, conducted using the GIS terrain model, led to the high accuracy defining of the flood-prone areas corresponding to the flows in the major riverbed with probabilities of 1 and 5 %. Also highlighted on the 2D and 3D images were several civilian areas at risk in the case of extreme hydrological events, related to maximum flow.

Improving archaeological prospection using localized UAVs assisted photogrammetry: An example from the Roman Gold District of the Eria River Valley (NW Spain)

This paper reports the use of integrated geomatic applications based on LiDAR data and UAV assisted photogrammetry for the identification, description and interpretation of ancient Roman gold mining sites in Northwest Spain. The study compares Digital Elevation Models (DEMs) with different acquisition methods, resolution and accuracy for analysis of archaeological remains. DEMs have been analysed using different visualization tools, such as principal component analysis, local relief factor, multiple hillshading, sky-view-factor and openness in order to improve visualization of the models, aiming at the identification of archaeological features. Our study suggests that principal component analysis, openness and multiple hillshading were the most effective tools for identification of archaeological remains. The results indicate that 5m LiDAR provides insufficient resolution to perform detailed analysis and accurate description of the hydraulic systems, but the use of visualization tools improved the localization and description of remains. The 1m resolution LiDAR data highly improve the resolution and capabilities for recognition and interpretation of canals, water reservoirs and mining zones. In addition, the use of UAV technology for smaller detailed surveys has shown a powerful capacity to reduce costs and time-consuming processing calculations, gaining in data resolution. The implementation of .LAZ files allows classification and analysis of point clouds yielding similar results to LiDAR technology in vegetated areas. However, unlike airborne lasers, its application is mainly restricted to small survey areas. Our study has focused on two areas characterized by a diversity of roman gold mining elements preserved in the landscape, such as hydraulic systems (canals and water reservoirs, drained canals and other anthropic elements) and mining areas along the Eria River Valley Gold District. The work has been implemented with the creation of 3D virtual reconstructions of the selected features, which can help to visualize different elements of the archaeological record to the general public, providing a useful tool for preservation and display of cultural heritage.

Understanding public opinion of UAVs in Canada: A 2014 analysis of survey data and its policy implications

This study has two aims: first, assessing the knowledge of Canadians with regard to their awareness of the use of UAV technology for data collection; and second, testing the hypothesis that public opinion regarding the use of UAVs for data collection in Canada varies by application, by institution, by collection method, and by respondent demographics. The survey contains questions regarding awareness of UAV use in Canada, as well as (i) the degree of support found for use by specific groups, (ii) for law enforcement applications, (iii) for private or industry applications, (iv) for border or coastal surveillance, and (v) for visibility and data sharing practices. Polling data also enables the comparison of UAV support against traditionally piloted aircraft and automated UAVs. This study found a majority in support of the use of UAVs for safety or emergency-response purposes. However, this support falls away in cases where UAV are used to perform routinized acts of surveillance, or identification. These findings will be useful to legislators and regulators in developing policy on UAVs that takes into account public sentiment and opinion, and for private sector actors and governments in addressing public concerns about UAVs as the industry moves forward.

HOW MANY HIPPOS (HOMHIP): ALGORITHM FOR AUTOMATIC COUNTS OF ANIMALS WITH INFRA-RED THERMAL IMAGERY FROM UAV

Abstract. The common hippopotamus (Hippopotamus amphibius L.) is part of the animal species endangered because of multiple human pressures. Monitoring of species for conservation is then essential, and the development of census protocols has to be chased. UAV technology is considering as one of the new perspectives for wildlife survey. Indeed, this technique has many advantages but its main drawback is the generation of a huge amount of data to handle. This study aims at developing an algorithm for automatic count of hippos, by exploiting thermal infrared aerial images acquired from UAV. This attempt is the first known for automatic detection of this species. Images taken at several flight heights can be used as inputs of the algorithm, ranging from 38 to 155 meters above ground level. A Graphical User Interface has been created in order to facilitate the use of the application. Three categories of animals have been defined following their position in water. The mean error of automatic counts compared with manual delineations is +2.3% and shows that the estimation is unbiased. Those results show great perspectives for the use of the algorithm in populations monitoring after some technical improvements and the elaboration of statistically robust inventories protocols.

UAV Deployment Exercise for Mapping Purposes: Evaluation of Emergency Response Applications.

Exploiting the decrease of costs related to UAV technology, the humanitarian community started piloting the use of similar systems in humanitarian crises several years ago in different application fields, i.e., disaster mapping and information gathering, community capacity building, logistics and even transportation of goods. Part of the author’s group, composed of researchers in the field of applied geomatics, has been piloting the use of UAVs since 2006, with a specific focus on disaster management application. In the framework of such activities, a UAV deployment exercise was jointly organized with the Regional Civil Protection authority, mainly aimed at assessing the operational procedures to deploy UAVs for mapping purposes and the usability of the acquired data in an emergency response context. In the paper the technical features of the UAV platforms will be described, comparing the main advantages/disadvantages of fixed-wing versus rotor platforms. The main phases of the adopted operational procedure will be discussed and assessed especially in terms of time required to carry out each step, highlighting potential bottlenecks and in view of the national regulation framework, which is rapidly evolving. Different methodologies for the processing of the acquired data will be described and discussed, evaluating the fitness for emergency response applications.

Dynamic Analysis of a Deployable Oil Dispersant System for UAV Technology Applications

Dynamic Analysis of a Deployable Oil Dispersant System for UAV Technology Applications

Spatiotemporal evolution of a unique preserved meandering system in Central Europe — The Morava River near Litovel

Rivers are naturally dynamic over time and space and respond to the variability of water and sediment inputs and to anthropogenic pressures that cause changes to the river's behaviour and form. This study describes the evolution of part of the Morava River and the Kenický meander in the Litovelské Pomoraví protected area near the city of Olomouc. The research describes the historical development of the study area using aerial photos, UAV images and geodetic measurements. Long-term measurements and imaging using UAV technologies have allowed a large amount of information to be collected. This information was used to study the Kenický meander and the Morava River. Significant lateral channel changes in the banks have occurred in the past and generated the Kenický meander. A significant event occurred in the spring of 2012, when high water levels were caused a rupture of a meander-natural cutoff. The water level was monitored in the Kenický wood accumulation, which formed in the Kenický meander, before and after the rupture. Monitoring the movement of wood in the river basin is particularly important because the movement of ice in the winter can cause blockage of the channel and subsequent flooding of water over the banks and into the surrounding communities.

Drones and Privacy

Drones, also referred to as UAV's (Unmanned Aerial Vehicle), are an aircraft without a human pilot. Drones have been used by various military organisations for over a decade, but in recent years drones a have been emerging more and more in commercial and recreational capacity. The paper is aimed at drone and UAV technology capabilities and how they could and are currently effecting privacy laws globally in comparison to those currently in the Rep. of Ireland. Being investigated is the collection, retention and purpose of which civilian's information is being gathered. The authors also discuss the laws preventing the development and evolution of drone technology in the US in comparison to the Rep. of Ireland.