scholarly journals A Framework for Multiple Ground Target Finding and Inspection Using a Multirotor UAS

Sensors ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 272 ◽  
Author(s):  
Ajmal Hinas ◽  
Roshan Ragel ◽  
Jonathan Roberts ◽  
Felipe Gonzalez
Keyword(s):  
Target Detection ◽  
Low Cost ◽  
Target Position ◽  
Position Estimation ◽  
Quality Data ◽  
Unmanned Aerial Systems ◽  
Modular Software ◽  
Ground Target ◽  
High Level ◽  
Aerial Systems

Small unmanned aerial systems (UASs) now have advanced waypoint-based navigation capabilities, which enable them to collect surveillance, wildlife ecology and air quality data in new ways. The ability to remotely sense and find a set of targets and descend and hover close to each target for an action is desirable in many applications, including inspection, search and rescue and spot spraying in agriculture. This paper proposes a robust framework for vision-based ground target finding and action using the high-level decision-making approach of Observe, Orient, Decide and Act (OODA). The proposed framework was implemented as a modular software system using the robotic operating system (ROS). The framework can be effectively deployed in different applications where single or multiple target detection and action is needed. The accuracy and precision of camera-based target position estimation from a low-cost UAS is not adequate for the task due to errors and uncertainties in low-cost sensors, sensor drift and target detection errors. External disturbances such as wind also pose further challenges. The implemented framework was tested using two different test cases. Overall, the results show that the proposed framework is robust to localization and target detection errors and able to perform the task.

scholarly journals Accuracy of 3D Landscape Reconstruction without Ground Control Points Using Different UAS Platforms

Drones ◽  
2020 ◽  
Vol 4 (2) ◽  
pp. 13 ◽  
Author(s):  
Margaret Kalacska ◽  
Oliver Lucanus ◽  
J. Pablo Arroyo-Mora ◽  
Étienne Laliberté ◽  
Kathryn Elmer ◽  
...  
Keyword(s):  
Low Cost ◽  
Ground Control ◽  
Unmanned Aerial Systems ◽  
Control Points ◽  
Model Errors ◽  
Positional Accuracy ◽  
Ground Control Points ◽  
Digital Elevation ◽  
High Level ◽  
Aerial Systems

The rapid increase of low-cost consumer-grade to enterprise-level unmanned aerial systems (UASs) has resulted in the exponential use of these systems in many applications. Structure from motion with multiview stereo (SfM-MVS) photogrammetry is now the baseline for the development of orthoimages and 3D surfaces (e.g., digital elevation models). The horizontal and vertical positional accuracies (x, y and z) of these products in general, rely heavily on the use of ground control points (GCPs). However, for many applications, the use of GCPs is not possible. Here we tested 14 UASs to assess the positional and within-model accuracy of SfM-MVS reconstructions of low-relief landscapes without GCPs ranging from consumer to enterprise-grade vertical takeoff and landing (VTOL) platforms. We found that high positional accuracy is not necessarily related to the platform cost or grade, rather the most important aspect is the use of post-processing kinetic (PPK) or real-time kinetic (RTK) solutions for geotagging the photographs. SfM-MVS products generated from UAS with onboard geotagging, regardless of grade, results in greater positional accuracies and lower within-model errors. We conclude that where repeatability and adherence to a high level of accuracy are needed, only RTK and PPK systems should be used without GCPs.

scholarly journals “Open” Category Unmanned Aerial Systems Harmonized Standards and Requirements Complex

2019 ◽  
Vol 25 (3) ◽  
pp. 74-80
Author(s):  
Andon Andonov
Keyword(s):  
Aviation Safety ◽  
Global Scale ◽  
Civil Aviation ◽  
Critical Conditions ◽  
Unmanned Aerial Systems ◽  
Unmanned Systems ◽  
The Common ◽  
High Level ◽  
The Military ◽  
Aerial Systems

Abstract The steadily increasing use of unmanned aerial systems (UAS) is an important factor for the military and civil aviation safety on a global scale. One of the critical conditions for the efficient functioning of the European aviation safety system is the establishment and implementation in practice of a comprehensive regulatory framework for the use of unmanned systems in the Common European Airspace. The aviation authorities and industry strive to introduce a set of rules and requirements that adequately and flexibly guarantee a high level of safety without limiting the development of the UAS market. This article proposes a set of standards that should be met by “Open” category UAS with the intention to execute operations in the European airspace.

scholarly journals Assessing the Accuracy of Digital Surface Models Derived from Optical Imagery Acquired with Unmanned Aerial Systems

Drones ◽  
2019 ◽  
Vol 3 (1) ◽  
pp. 15 ◽  
Author(s):  
Salvatore Manfreda ◽  
Petr Dvorak ◽  
Jana Mullerova ◽  
Sorin Herban ◽  
Pietro Vuono ◽  
...  
Keyword(s):  
3D Model ◽  
Low Cost ◽  
Three Dimensional ◽  
Careful Consideration ◽  
Ground Control ◽  
Unmanned Aerial Systems ◽  
Control Points ◽  
Earthen Dam ◽  
Ground Control Points ◽  
Aerial Systems

Small unmanned aerial systems (UASs) equipped with an optical camera are a cost-effective strategy for topographic surveys. These low-cost UASs can provide useful information for three-dimensional (3D) reconstruction even if they are equipped with a low-quality navigation system. To ensure the production of high-quality topographic models, careful consideration of the flight mode and proper distribution of ground control points are required. To this end, a commercial UAS was adopted to monitor a small earthen dam using different combinations of flight configurations and by adopting a variable number of ground control points (GCPs). The results highlight that optimization of both the choice and combination of flight plans can reduce the relative error of the 3D model to within two meters without the need to include GCPs. However, the use of GCPs greatly improved the quality of the topographic survey, reducing error to the order of a few centimeters. The combined use of images extracted from two flights, one with a camera mounted at nadir and the second with a 20° angle, was found to be beneficial for increasing the overall accuracy of the 3D model and especially the vertical precision.

Detection of Conflicts Between ADS-B-Equipped Aircraft and Unmanned Aerial Systems

2020 ◽  
Vol 2674 (1) ◽  
pp. 197-204
Author(s):  
John H. Mott ◽  
Zachary A. Marshall ◽  
Mark A. Vandehey ◽  
Mike May ◽  
Darcy M. Bullock
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Federal Aviation Administration ◽  
Unmanned Aircraft ◽  
Sensor Technology ◽  
Unmanned Aerial Systems ◽  
Aircraft Flight ◽  
Flight Operations ◽  
Aerial Systems ◽  
Operational Simplicity

Versatile unmanned aerial system (UAS) platforms have grown significantly in popularity by virtue of their low cost relative to manned aircraft, high performance, and operational simplicity. While the Federal Aviation Administration (FAA) currently regulates the operating altitudes, speeds, weights, pilot qualifications, and locations of drones, a lack of capacity and technology prohibits sufficient enforcement of these restrictions. To assess the frequency and severity of manned and unmanned aircraft separation incidents, and to examine the emerging sensor technology available to facilitate such assessment, flight operations in controlled airspace around Orlando Melbourne International Airport (KMLB) were monitored. One sensor system deployed at KMLB reported UAS locations, altitudes, and flight durations, while a second system reported manned aircraft positions, altitudes, and timestamps using ADS-B signals. Evaluation of flight operations data in the vicinity of KMLB revealed eight potential drone incursions over a 2-week period. Aircraft flight paths were retroactively tracked to map these unmanned and manned aerial conflicts; aircraft identification information was also researched to contextualize the incidents. The frequency and magnitude of identified events suggest the need for additional research to further explore the problem scope and potential solutions.

scholarly journals FESSTVaL: Field Experiment on sub-mesoscale spatio-temporal variability in Lindenberg – the campaign 2021 an its predecessors

2021 ◽  
Author(s):  
Cathy Hohenegger ◽  
Felix Ament ◽  
Frank Beyrich ◽  
Ivan Bastak Duran ◽  
Ulrich Löhnert ◽  
...  
Keyword(s):  
Field Experiment ◽  
Temporal Variability ◽  
Low Cost ◽  
Unmanned Aerial Systems ◽  
Near Surface ◽  
Cold Pools ◽  
Measurement Strategy ◽  
Meteorological Observatory ◽  
Spatio Temporal ◽  
Aerial Systems

<p>Measuring submesoscale variability is the core task of the field campaign FESSTVaL (Field Experiment on Sub-Mesoscale Spatio-Temporal Variability in Lindenberg).  FESSTVaL focuses on three sources of submesoscale variability: cold pools, wind gusts and boundary layer pattern. It took place in the summer months of 2021 at the Meteorological Observatory Lindenberg – Richard-Aßmann-Observatory (MOL-RAO) of the German Weather Service (DWD) near Berlin and was initiated by the Hans-Ertel-Center for Weather Research (HErZ).</p><p>In order to capture phenomena at the submesoscale (500 m – 5 km), generally not captured by conventional measurement network, a hierarchical measurement strategy is adopted. This includes wind profiling stations with a coordinated scanning strategy of several Doppler Lidars, two mobile profilers to measure thermodynamic properties and precipitation, more than 100 stations with near-surface measurements of air temperature, pressure and soil moisture, more than 20 automatic weather stations, an X-Band radar, and a number of energy balance stations. This equipment is augmented by the extensive ground-based remote sensing array at the MOL-RAO, operated by DWD and by flights operated by Unmanned Aerial Systems. Complementing to this, the benefit of a citizen-science measurement network is investigated during the campaign with “Internet-of-things” based technology and low-cost sensors built and maintained by citizens. The measurements are supplemented by high-resolution large-eddy simulations (ICON-LES).</p><p>Originally planned for the summer 2020, FESSTVaL had to be postponed to 2021 and replaced by three local individual campaigns, conducted in Bayern, Lindenberg and Hamburg in 2020. Those three test campaigns demonstrated the ability of the envisionned measurement strategy and planned instruments to capture submesoscale variability and submesoscale weather phenomean. This talk will give a brief overview on the results of these three campaigns, as a foretaste to FESSTVaL, together with some of the very first measurements taken during FESSTVaL. </p>

scholarly journals Hybrid TOA/RSS Range-Based Localization with Self-Calibration in Asynchronous Wireless Networks

2019 ◽  
Vol 8 (2) ◽  
pp. 31 ◽  
Author(s):  
Angelo Coluccia ◽  
Alessio Fascista
Keyword(s):  
Low Cost ◽  
Computational Cost ◽  
Closed Form Solution ◽  
Target Position ◽  
Form Solution ◽  
Position Estimation ◽  
Model Parameters ◽  
Time Of Arrival ◽  
Synchronization Errors ◽  
Step Algorithm

The paper addresses the problem of localization based on hybrid received signal strength (RSS) and time of arrival (TOA) measurements, in the presence of synchronization errors among all the nodes in a wireless network, and assuming all parameters are unknown. In most existing schemes, in fact, knowledge of the model parameters is postulated to reduce the high dimensionality of the cost functions involved in the position estimation process. However, such parameters depend on the operational wireless context, and change over time due to the presence of dynamic obstacles and other modification of the environment. Therefore, they should be adaptively estimated “on the field”, with a procedure that must be as simple as possible in order to suit multiple real-time re-calibrations, even in low-cost applications, without requiring human intervention. Unfortunately, the joint maximum likelihood (ML) position estimator for this problem does not admit a closed-form solution, and numerical optimization is practically unfeasible due to the large number of nuisance parameters. To circumvent such issues, a novel two-step algorithm with reduced complexity is proposed: A first calibration phase exploits nodes in known positions to estimate the unknown RSS and TOA model parameters; then, in a second localization step, an hybrid TOA/RSS range estimator is combined with an iterative least-squares procedure to finally estimate the unknown target position. The results show that the proposed hybrid TOA/RSS localization approach outperformed state-of-the-art competitors and, remarkably, achieved almost the same accuracy of the joint ML benchmark but with a significantly lower computational cost.

scholarly journals Advanced Software Ground Station and UAV Development for NLoS Control Using Mobile Communications

2015 ◽  
Vol 2015 ◽  
pp. 1-20 ◽  
Author(s):  
Amr AbdElHamid ◽  
Peng Zong ◽  
Bassant Abdelhamid
Keyword(s):  
Mobile Communications ◽  
Low Cost ◽  
Weather Forecast ◽  
Small Scale ◽  
Unmanned Aerial Systems ◽  
Long Distance ◽  
Ground Station ◽  
Commercial Off The Shelf ◽  
End Node ◽  
Aerial Systems

Over the last decades, Unmanned Aerial Systems (UASs) have gained much attention due to their various applications in different sections. However, their communication range is limited to utilized communication equipment. Therefore, utilization of GSM channels opens a new prospect towards long distance UAV missions and mobile command and control centers. This paper demonstrates new design and development of a small-scale UAV and a Ground Control Station (GCS) using GSM bidirectional communications for Non-Line of Sight (NLoS) long range control. GCSs are considered the front end node in UAV guidance process. Therefore, the proposed GCS employs a two-layer framework to consider all ground pilot requirements. Moreover, a new exploitation of global weather forecast data is added to the GCS. On the other hand, the proposed airborne system utilizes a new integration of different Commercial off-the-Shelf (COTS) components and excludes short range receivers. The ground and flight tests show that stable bidirectional GSM communication is established, reliable hardware integration is accomplished, real time performance is achieved, GCS functional fidelity is obtained, and low cost is maintained. Finally, some qualitative aspects of the proposed platform are presented to address the detailed features.

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