Artykuły w czasopismach: „Aerial tethers”

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Sandino, Luis A., Manuel Bejar, Konstantin Kondak i Anibal Ollero. "Multi-Sensor Data Fusion for a Tethered Unmanned Helicopter Using a Square-Root Unscented Kalman Filter". Unmanned Systems 04, nr 04 (październik 2016): 273–87. http://dx.doi.org/10.1142/s2301385016500114.

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The use of tethered Unmanned Aircraft Systems (UAS) in aerial robotic applications is a relatively unexplored research field. This work addresses the attitude and position estimation of a small-size unmanned helicopter tethered to a moving platform using a multi-sensor data fusion algorithm based on a numerically efficient sigma-point Kalman filter implementation. For that purpose, the state prediction is performed using a kinematic process model driven by measurements of the inertial sensors (accelerometer and gyroscope) onboard the helicopter and the subsequent correction is done using information from additional sensors like magnetometer, barometric altimeter, LIDAR altimeter and magnetic encoders measuring the tether orientation relative to the helicopter. Assuming the tether is kept taut by an actuated device on the platform during the system operation, the helicopter position is estimated relative to the anchor point. Although this configuration avoids the need of a GPS, a standard operation mode for estimation of the absolute position (the position relative to the inertial reference frame) incorporating corrections with the GPS position and velocity measurements, is also implemented in order to highlight the benefits of the proposed tethered setup. The filter performance is evaluated in simulations.

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Glazner, R., J. Ballard i AR Armitage. "Predation refuge values of marsh and mangrove vegetation for the marsh periwinkle Littoraria irrorata". Marine Ecology Progress Series 672 (19.08.2021): 153–62. http://dx.doi.org/10.3354/meps13785.

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Black mangroves Avicennia germinans are becoming increasingly common in coastal wetlands in the Gulf of Mexico (USA). As mangroves displace salt marsh vegetation, there may be consequences for associated wetland fauna. In a series of field studies, we compared prey refuge values between marsh and mangrove vegetation for a vertically migrating gastropod, the marsh periwinkle Littoraria irrorata. Littoraria were tethered to marsh grasses (Spartina alterniflora) or the aerial roots (pneumatophores) of Avicennia in arrays that fully crossed vegetation type (Spartina vs. Avicennia), tether height (base vs. canopy), and wetland location (edge vs. interior marsh platform). After 1 d, acute predation rates were twice as high on Littoraria tethered to the base of Spartina stems than on those tethered to pneumatophores, suggesting that mangroves provided superior refuge from benthic predators like blue crabs. In the canopy, Spartina reduced acute predation rates by 75%, indicating that marsh grasses may provide superior refuge from aerial predators (possibly wetland birds). After 7 d, the effect of vegetation type diminished, but Littoraria mortality was 2 times higher on the benthos than in the canopy. Links between vegetation type and predation intensity on this important basal consumer may have broader consequences for trophic dynamics in coastal wetlands that are experiencing mangrove encroachment.

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Kanoria, Akshay A., i Rajkumar S. Pant. "Winged Aerostat Systems for Better Station Keeping for Aerial Surveillance". Advanced Materials Research 433-440 (styczeń 2012): 6871–79. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.6871.

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An aerostat is a tethered balloon with an aerodynamically shaped envelope containing a lighter-than-air gas that generates bulk of the lifting force. Aerostats are used extensively as an aerial platform for many scientific and commercial applications. Conventional aerostats envelopes have an ellipsoidal shape, due to which they suffer from a large amount of horizontal displacement (called blowby) due to the ambient winds. If the drag force acting on aerostat is high, the resulting blowbyis higher and a longer tether is required to maintain the specified operating altitude; this results in lower payload capacity. Recent studies have shown that winged aerostats (which have an envelope with airfoil cross-section) can reduce blowbydue to a much higher lift/drag ratio. This paper presents a comparative analysis of the operational effectiveness of a winged and conventional aerostat for scientific data gathering in lower Himalayas at various ambient wind speeds. The winged aerostat is seen to be much smaller in size, and has a much lower reduction in operating altitude due to blowby. The paper also describes the design of a prototype winged aerostat currently under development.

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Li, J. M., C. R. Li, G. Z. Su, W. Li, L. L. Ma i Y. K. Liu. "MAPPING SYSTEM AND PHOTOGRAMMETRIC PROCESSING METHOD FOR TETHERED BALLOON PLATFORM". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W16 (17.09.2019): 157–61. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w16-157-2019.

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Abstract. As a platform with the advantages of safety, wide altitude range and long flight time, tethered balloon has been used in archaeology, coastal, island mapping and other related fields. Tethered balloon is tied to the mooring system by tether rope, and often moves in a small range with the airflow, resulting in a very close distance between the camera stations. Due to the small base-to-height ratio, failure of relative orientation or poor quality of point cloud tend to appear frequently. In this paper, a mapping system for tethered balloon is introduced which consists of a wide-angle camera, two auxiliary orientation cameras, and a dual GNSS/IMU system. The wide-angle camera combined by five cameras provides a larger observation range. Two auxiliary orientation cameras installed at the end of extension rods are designed to increase the baseline. The system should be operated during the taking-off, hovering and landing stages of the tethered balloon, so as to take images of different altitudes. The system has been adopted in the first experimental flight in 2018 to perform island topographic survey. Data processing method was applied to test the effect of the system. The method that choosing wide-angle images of different heights, and auxiliary images at low-altitude can be used for aerial triangulation successfully, and obtain point cloud with good quality. The results showed that by adding auxiliary cameras and taking images of different heights for data processing, the problem of small intersection angle could be overcome to some extent.

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Poltavsky, A. V. "Telecommunication of communication and control systems on unmanned aerial vehicles platforms". Civil Aviation High Technologies 24, nr 2 (25.04.2021): 58–69. http://dx.doi.org/10.26467/2079-0619-2021-24-2-58-69.

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The review article discusses the possibility of using tethered high-altitude telecommunication platforms (VTPS) based on unmanned aerial vehicles (as tethered UAVs), which are also called – "tethered drones" Flying COWs (Cell on Wings). Their essence lies in the fact that sufficiently high electrical voltage is applied to a flexible metal cable from a ground-based mobile control point in order to solve the multidisciplinary VTP tasks for the local cellular coverage on a vast territory. These unmanned aerial systems with VTP and tethered UAVs, which retransmit signals in relation to a specific area as a part of the objects of modern geo information systems (GIS) covering particular regions, territories and hard-to-reach areas with a radio signal can find its fairly wide application in the near future, besides radio or optical communication of VTP can be used as a network of telecommunication channels for receiving/transmitting information.

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Marks, A. R. "AERIAL PHOTOGRAPHY FROM A TETHERED HELIUM FILLED BALLOON". Photogrammetric Record 13, nr 74 (26.08.2006): 257–61. http://dx.doi.org/10.1111/j.1477-9730.1989.tb00677.x.

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Nirmalasari, Nining, i Junaiti Sahar. "Manajemen Mitigasi Bencana Menggunakan Teknologi Balloon Tethered". Jurnal Penelitian Kesehatan "SUARA FORIKES" (Journal of Health Research "Forikes Voice") 11, nr 4 (4.06.2020): 414. http://dx.doi.org/10.33846/sf11419.

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Introduction: The occurrence of natural disasters in Indonesia from year to year continues to occur, with the progress of communication technology that is increasingly expected to be able to facilitate communication when a disaster occurs. Such as the use of balloon tethered technology that can function for disaster mitigation, with the use of balloon tethered that is tethered in areas that are at risk of disaster prone. Methods: The method used by the author was literature review. The database used by the author were Google Scholar, IEEE Xplore, GEOECO, EBSCOhost, Researchgate and the keywords were disaster mitigation, Tethered Balloon technology, Aerial Platform. Results: This tethered balloon technology consists of a combination of flying balloons, tethered, and payload, for the use of disaster mitigation and supports faster broadband communication networks to users before or during and after a disaster. The rescue team can work more effectively and efficiently with the help of this tethered balloon technology. Conclusion: Cross-sectoral collaboration involving various disciplines is needed for disaster mitigation management. The role of the government is very large for the availability of communication technology such as tethered balloons. Keywords: disaster mitigation; tethered balloon; platform ABSTRAK Pendahuluan: Kejadian bencana alam di Indonesia dari tahun ke tahun terus terjadi, dengan adanya kemajuan teknologi komunikasi yang semakin berkembang diharapkan dapat memudahkan komunikasi saat terjadi bencana. Seperti pada penggunaan teknologi balon tethered yang dapat berfungsi untuk mitigasi bencana, dengan penggunaan balon tethered yang ditambatkan di daerah yang beresiko rawan bencana. Metode: Metode yang digunakan penulis adalah literature review. Database yang digunakan penulis adalah Google Scholar, IEEE Xplore, GEOECO, EBSCOhost, Researchgate dengan mitigasi bencana, tehnologi Tethered Balloon, Aerial Platform. Hasil: Teknologi balon tethered terdiri atas gabungan balon terbang, tethered, dan payload, untuk penggunaan mitigasi bencana dan mendukung jaringan komunikasi broadband yang lebih cepat kepada pengguna sebelum atau selama dan sesudah bencana. Tim penyelamat dapat bekerja lebih efektif dan efisien dengan bantuan teknologi balon tethered ini. Kesimpulan: kerjasama lintas sektoral yang melibatkan berbagai disiplin ilmu dibutuhkan untuk manajemen mitigasi bencana. Peranan pemerintah sangat besar untuk ketersediaan teknologi komunikasi seperti balon tethered ini. Kata kunci: mitigasi bencana; tethered balloon; platform

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Molina, P., M. Blázquez, J. Sastre i I. Colomina. "A METHOD FOR SIMULTANEOUS AERIAL AND TERRESTRIAL GEODATA ACQUISITION FOR CORRIDOR MAPPING". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-1/W4 (26.08.2015): 227–32. http://dx.doi.org/10.5194/isprsarchives-xl-1-w4-227-2015.

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In this paper, we present mapKITE, a new mobile, simultaneous terrestrial and aerial, geodata collection and post-processing method. On one side, the method combines a terrestrial mobile mapping system (TMMS) with an unmanned aerial mapping one, both equipped with remote sensing payloads (at least, a nadir-looking visible-band camera in the UA) by means of which aerial and terrestrial geodata are acquired simultaneously. This tandem geodata acquisition system is based on a terrestrial vehicle (TV) and on an unmanned aircraft (UA) linked by a 'virtual tether', that is, a mechanism based on the real-time supply of UA waypoints by the TV. By means of the TV-to-UA tether, the UA follows the TV keeping a specific relative TV-to-UA spatial configuration enabling the simultaneous operation of both systems to obtain highly redundant and complementary geodata. On the other side, mapKITE presents a novel concept for geodata post-processing favoured by the rich geometrical aspects derived from the mapKITE tandem simultaneous operation. The approach followed for sensor orientation and calibration of the aerial images captured by the UA inherits the principles of Integrated Sensor Orientation (ISO) and adds the pointing-and-scaling photogrammetric measurement of a distinctive element observed in every UA image, which is a coded target mounted on the roof of the TV. By means of the TV navigation system, the orientation of the TV coded target is performed and used in the post-processing UA image orientation approach as a Kinematic Ground Control Point (KGCP). The geometric strength of a mapKITE ISO network is therefore high as it counts with the traditional tie point image measurements, static ground control points, kinematic aerial control and the new point-and-scale measurements of the KGCPs. With such a geometry, reliable system and sensor orientation and calibration and eventual further reduction of the number of traditional ground control points is feasible. The different technical concepts, challenges and breakthroughs behind mapKITE are presented in this paper, such as the TV-to-UA virtual tether and the use of KGCP measurements for UA sensor orientation. In addition, the use in mapKITE of new European GNSS signals such as the Galileo E5 AltBOC is discussed. Because of the critical role of GNSS technologies and the potential impact on the corridor mapping market, the European Commission and the European GNSS Agency, in the frame of the European Union Framework Programme for Research and Innovation “Horizon 2020,” have recently awarded the “mapKITE” project to an international consortium of organizations coordinated by GeoNumerics S.L.

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Pereira, Pedro O., i Dimos V. Dimarogonas. "Pose stabilization of a bar tethered to two aerial vehicles". Automatica 112 (luty 2020): 108695. http://dx.doi.org/10.1016/j.automatica.2019.108695.

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KISHIDA, Tomoki, i Hirohisa KOJIMA. "20402 Yawing Motion Control of Aerial Tethered Load using Scissors CMGs". Proceedings of Conference of Kanto Branch 2015.21 (2015): _20402–1_—_20402–2_. http://dx.doi.org/10.1299/jsmekanto.2015.21._20402-1_.

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Jung, Sunghun, Yonghyeon Jo i Young-Joon Kim. "Aerial Surveillance with Low-Altitude Long-Endurance Tethered Multirotor UAVs Using Photovoltaic Power Management System". Energies 12, nr 7 (6.04.2019): 1323. http://dx.doi.org/10.3390/en12071323.

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For a continuous surveillance mission using a swarm of multiple tethered low-altitude long-endurance (LALE) multirotor-type unmanned aerial vehicles (UAVs), we developed a 500 W class photovoltaic power management system (PPMS) which monitors voltage and current flows of photovoltaic (PV) panels, battery pack, and UAV and controls power flows to support UAV flight operation. In contract to a fixed-wing UAV, a tethered multirotor UAV can generate continuously varying closed-circuit television (CCTV) like ground map images by stitching incoming images though the operation range is limited. With an indoor flight experiment, we demonstrated the usefulness of the PPMS and proved operation integrity. According to the results, a total of six multirotor UAVs were required to continuously perform a surveillance mission for 5 h 46 min from 11:04 to 16:50.

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Tognon, Marco, i Antonio Franchi. "Dynamics, Control, and Estimation for Aerial Robots Tethered by Cables or Bars". IEEE Transactions on Robotics 33, nr 4 (sierpień 2017): 834–45. http://dx.doi.org/10.1109/tro.2017.2677915.

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Flamm, Richard O., Edward C. G. Owen, Caryn F. W. Owen, Randall S. Wells i Doug Nowacek. "AERIAL VIDEOGRAMMETRY FROM A TETHERED AIRSHIP TO ASSESS MANATEE LIFE-STAGE STRUCTURE". Marine Mammal Science 16, nr 3 (lipiec 2000): 617–30. http://dx.doi.org/10.1111/j.1748-7692.2000.tb00955.x.

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ALESHIN, Boris S., Alexander I. CHERNOMORSKY, Eduard D. KURIS, Konstantin S. LELKOV i Maxim V. IVAKIN. "Robotic complex for inspection of the outer surface of the aircraft in its parking lot". INCAS BULLETIN 12, S (28.07.2020): 21–31. http://dx.doi.org/10.13111/2066-8201.2020.12.s.2.

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Through-flight inspection of the outer surface of the aircraft is necessary to identify possible damage to the surface of the aircraft caused by metal fatigue, lightning, birds collision, etc. The article discusses the method of robotic inspection of the outer surface of the aircraft in its open air parking area. The robotic complex (RC) consists of an unmanned ground vehicle (UGV) and an unmanned aerial vehicle (UAV) interconnected by a tether mechanism (TM). The algorithm of the RC functioning is presented. The main attention is paid to the formation of the TM control and the features of its work, ensuring the prevention of collisions of UAV with aircraft during extreme wind actions on UAV. The study of the most critical mode of the complex operation under extreme wind actions on an unmanned aerial vehicle is carried out. The results of modeling the typical process of the RC operation in an abnormal conditions of extreme wind exposure to UAV are presented.

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Zakaria, S., M. R. Mahadi, A. F. Abdullah i K. Abdan. "AERIAL PLATFORM RELIABILITY FOR FLOOD MONITORING UNDER VARIOUS WEATHER CONDITIONS: A REVIEW". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-3/W4 (6.03.2018): 591–602. http://dx.doi.org/10.5194/isprs-archives-xlii-3-w4-591-2018.

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Abstract. Flood is an annual disaster in Malaysia, especially in the east coast region. Recently, other regions in Malaysia have also experience devastating flood. A flood aerial monitoring is one of the approaches that involved in the flood disaster management. Compared to space borne remote sensing, aerial platforms are much reliable to obtain higher spatial resolution and real time data. Due to cloud coverage and revisit limitations, space borne remote sensing approach is a less desirable option for flood monitoring. In this paper, a review of existing aerial platforms that perform remote sensing task under various weather conditions, specifically for flood monitoring is presented. There are four types of aerial platforms being reviewed, which are rotary wings, fixed wings, blimps and helikites. The main criteria of the review are the payload capacity, endurance (flight time), altitudes, tolerable wind speed, cost, vertical take-off and landing ability, and the ability to perform under various weather conditions, such as heavy precipitation and winds. From this review, the applications of aerial platform in recent studies never mentioned the capability of aerial platform used in such weather conditions. From all types of aerial platform discussed, helikite seems to be the most suitable to fly in extreme weather. The only drawback is that helikite has mobility issue since it is tethered to the ground. The application of helikite is useful for a small area coverage of flood monitoring. The authors will continue the study to evaluate the reliability of helikite in performing such task in the future.

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Creamean, Jessie M., Katherine M. Primm, Margaret A. Tolbert, Emrys G. Hall, Jim Wendell, Allen Jordan, Patrick J. Sheridan, Jedediah Smith i Russell C. Schnell. "HOVERCAT: a novel aerial system for evaluation of aerosol–cloud interactions". Atmospheric Measurement Techniques 11, nr 7 (6.07.2018): 3969–85. http://dx.doi.org/10.5194/amt-11-3969-2018.

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Abstract. Aerosols have a profound impact on cloud microphysics through their ability to serve as ice nucleating particles (INPs). As a result, cloud radiative properties and precipitation processes can be modulated by such aerosol–cloud interactions. However, one of the largest uncertainties associated with atmospheric processes is the indirect effect of aerosols on clouds. The need for more advanced observations of INPs in the atmospheric vertical profile is apparent, yet most ice nucleation measurements are conducted on the ground or during infrequent and intensive airborne field campaigns. Here, we describe a novel measurement platform that is less expensive and smaller (< 5 kg) when compared to traditional aircraft and tethered balloon platforms and that can be used for evaluating two modes of ice nucleation (i.e., immersion and deposition). HOVERCAT (Honing On VERtical Cloud and Aerosol properTies) flew during a pilot study in Colorado, USA, up to 2.6 km above mean sea level (1.1 km above ground level) and consists of an aerosol module that includes an optical particle counter for size distributions (0.38–17 µm in diameter) and a new sampler that collects up to 10 filter samples for offline ice nucleation and aerosol analyses on a launched balloon platform. During the May 2017 test flight, total particle concentrations were highest closest to the ground (up to 50 cm−3 at < 50 m above ground level) and up to 2 in 102 particles were ice nucleation active in the immersion mode (at −23 ∘C). The warmest temperature immersion and deposition mode INPs (observed up to −6 and −40.4 ∘C, respectively) were observed closest to the ground, but overall INP concentrations did not exhibit an inverse correlation with increasing altitude. HOVERCAT is a prototype that can be further modified for other airborne platforms, including tethered balloon and unmanned aircraft systems. The versatility of HOVERCAT affords future opportunities to profile the atmospheric column for more comprehensive evaluations of aerosol–cloud interactions. Based on our test flight experiences, we provide a set of recommendations for future deployments of similar measurement systems and platforms.

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Nakanishi, Hiroaki, i Hiroyuki Hashimoto. "AR-Marker/IMU Hybrid Navigation System for Tether-Powered UAV". Journal of Robotics and Mechatronics 30, nr 1 (20.02.2018): 76–85. http://dx.doi.org/10.20965/jrm.2018.p0076.

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Electrically powered unmanned aerial vehicles (UAV) are useful in performing inspection at various infrastructures or plants. A power supply through a tether cable is effective in extending flight time. During inspection activities, some or all satellites may be occluded. UAVs for inspection must be operated even in GPS-denied areas; therefore, a navigation system for GPS-denied areas is required. Depth information cannot be obtained correctly by a monocular camera. The ARToolkit, which is widely applied in augmented reality (AR), is not sufficient as a UAV navigation system. We have proposed a hybrid navigation method that integrates the ARToolkit and an inertial measurement unit (IMU). An analytic solution for both the worst and best estimation of yaw angle can be obtained by simple computation and helps remove outliers in measurements. From experimental results, it was proven that position estimation using the proposed method corresponded reasonably; however, it was necessary to correct the difference between the camera origin and the body’s center of gravity.

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Chwaleba, Augustyn, Aleksander Olejnik, Tomasz Rapacki i Norbert Tuśnio. "ANALYSIS OF CAPABILITY OF AIR POLLUTION MONITORING FROM AN UNMANNED AIRCRAFT". Aviation 18, nr 1 (3.04.2014): 13–19. http://dx.doi.org/10.3846/16487788.2014.865936.

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Satellite monitoring systems can be used for remote monitoring of the atmosphere over a given area but they do not provide information on the state of pollution at a given time. Additional information could only be obtained after several days. Measurements from an aircraft may be obtained almost at real-time and in different geometries – vertical and horizontal. The future of this type of monitoring is remote-controlled unmanned aerial vehicles (airplanes, helicopters and balloons tethered), equipped with telemetric monitoring.

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Fesneau, Corinne, Jean-François Deconinck, Pierre Pellenard i Stéphane Reboulet. "Evidence of aerial volcanic activity during the Valanginian along the northern Tethys margin". Cretaceous Research 30, nr 3 (czerwiec 2009): 533–39. http://dx.doi.org/10.1016/j.cretres.2008.09.004.

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Adams, Kye, Allison Broad, David Ruiz-García i Andrew R. Davis. "Continuous wildlife monitoring using blimps as an aerial platform: a case study observing marine megafauna". Australian Zoologist 40, nr 3 (1.05.2020): 407–15. http://dx.doi.org/10.7882/az.2020.004.

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ABSTRACT Aerial surveys are a powerful means of collecting ecological data in terrestrial and marine systems that may otherwise be difficult to acquire. Increasingly aerial observations are made with Unmanned Aerial Vehicles (UAVs), such as drones. As this technology has improved in reliability and affordability it has replaced the traditional use of fixed-wing aircraft and helicopters. Drones do, however, have limitations; primarily in their limited flight duration, potential to disturb wildlife and concerns over safety. Here we introduce an aerostat, a ground tethered blimp, as a logistically simple and economical alternative to drones and other aircraft. Blimps differ from drones by using helium for lift, thereby conserving battery life. This technology offers the advantage of near-continuous coverage of locations, as well as providing a safe and accessible alternative aerial platform for a range of applications. We demonstrate the viability of blimp-mounted cameras in a notoriously difficult area to conduct research: the high-energy nearshore marine zone. Specifically, we sought to determine the likelihood of encountering marine megafauna using real-time video and whether their presence was correlated with the occurrence of baitfish. Stingrays were observed more often than other species and the occurrence of seals was correlated with the presence of baitfish. The continuous coverage allowed the observation of foraging behaviour in sharks and seals for extended periods. This demonstrates the utility of this novel technique to improve human safety and enhance ecological research.

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Bandini, Filippo, Daniel Olesen, Jakob Jakobsen, Cecile Marie Margaretha Kittel, Sheng Wang, Monica Garcia i Peter Bauer-Gottwein. "Technical note: Bathymetry observations of inland water bodies using a tethered single-beam sonar controlled by an unmanned aerial vehicle". Hydrology and Earth System Sciences 22, nr 8 (7.08.2018): 4165–81. http://dx.doi.org/10.5194/hess-22-4165-2018.

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Abstract. High-quality bathymetric maps of inland water bodies are a common requirement for hydraulic engineering and hydrological science applications. Remote sensing methods, such as space-borne and airborne multispectral imaging or lidar, have been developed to estimate water depth, but are ineffective for most inland water bodies, because of the attenuation of electromagnetic radiation in water, especially under turbid conditions. Surveys conducted with boats equipped with sonars can retrieve accurate water depths, but are expensive, time-consuming, and unsuitable for unnavigable water bodies. We develop and assess a novel approach to retrieve accurate and high-resolution bathymetry maps. We measured accurate water depths using a tethered floating sonar controlled by an unmanned aerial vehicle (UAV) in a lake and in two different rivers located in Denmark. The developed technique combines the advantages of remote sensing with the potential of bathymetric sonars. UAV surveys can be conducted also in unnavigable, inaccessible, or remote water bodies. The tethered sonar can measure bathymetry with an accuracy of ∼2.1 % of the actual depth for observations up to 35 m, without being significantly affected by water turbidity, bed form, or bed material.

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Wang, Hui-Feng, Lei Zhai, He Huang, Li-Min Guan, Ke-Nan Mu i Gui-ping Wang. "Measurement for cracks at the bottom of bridges based on tethered creeping unmanned aerial vehicle". Automation in Construction 119 (listopad 2020): 103330. http://dx.doi.org/10.1016/j.autcon.2020.103330.

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Gu, Beom W., Su Y. Choi, Young Soo Choi, Guowei Cai, Lakmal Seneviratne i Chun T. Rim. "Novel Roaming and Stationary Tethered Aerial Robots for Continuous Mobile Missions in Nuclear Power Plants". Nuclear Engineering and Technology 48, nr 4 (sierpień 2016): 982–96. http://dx.doi.org/10.1016/j.net.2016.02.014.

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Chapman, J. W., D. R. Reynolds, A. D. Smith, E. T. Smith i I. P. Woiwod. "An aerial netting study of insects migrating at high altitude over England". Bulletin of Entomological Research 94, nr 2 (kwiecień 2004): 123–36. http://dx.doi.org/10.1079/ber2004287.

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AbstractDay and night sampling of windborne arthropods at a height of 200 m above ground was undertaken at Cardington, Bedfordshire, UK, during July 1999, 2000 and 2002, using a net supported by a tethered balloon. The results from this study are compared with those from the classic aerial sampling programmes carried out by Hardy, Freeman and colleagues over the UK and North Sea in the 1930s. In the present study, aerial netting was undertaken at night as well as daytime, and so the diel periodicity of migration could be investigated, and comparisons made with the results from Lewis and Taylor’s extensive survey of flight periodicity near ground level. In some taxa with day-time emigration, quite large populations could continue in high-altitude flight after dark, perhaps to a previously underrated extent, and this would greatly increase their potential migratory range. Any trend towards increases in night temperatures, associated with global warming, would facilitate movements of this type in the UK. Observations on the windborne migration of a variety of species, particularly those of economic significance or of radar-detectable size, are briefly discussed.

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Molina, P., M. Blázquez, J. Sastre i I. Colomina. "PRECISION ANALYSIS OF POINT-AND-SCALE PHOTOGRAMMETRIC MEASUREMENTS FOR CORRIDOR MAPPING: PRELIMINARY RESULTS". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-3/W4 (17.03.2016): 85–90. http://dx.doi.org/10.5194/isprs-archives-xl-3-w4-85-2016.

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This paper addresses the key aspects of the sensor orientation and calibration approach within the mapKITE concept for corridor mapping, focusing on the contribution analysis of point-and-scale measurements of kinematic ground control points. MapKITE is a new mobile, simultaneous terrestrial and aerial, geodata acquisition and post-processing method. On one hand, the acquisition system is a tandem composed of a terrestrial mobile mapping system and an unmanned aerial system, the latter equipped with a remote sensing payload, and linked through a 'virtual tether', that is, a real-time waypoint supply from the terrestrial vehicle to the unmanned aircraft. On the other hand, mapKITE entails a method for geodata post-processing (specifically, sensor orientation and calibration) based on the described acquisition paradigm, focusing on few key aspects: the particular geometric relationship of a mapKITE network – the aerial vehicle always observes the terrestrial one as they both move –, precise air and ground trajectory determination – the terrestrial vehicle is regarded as a kinematic ground control point – and new photogrammetric measurements – pointing on and measuring the scale of an optical target on the roof of the terrestrial vehicle – are exploited. In this paper, we analyze the performance of aerial image orientation and calibration in mapKITE for corridor mapping, which is the natural application niche of mapKITE, based on the principles and procedures of integrated sensor orientation with the addition of point-and-scale photogrammetric measurements of the kinematic ground control points. To do so, traditional (static ground control points, photogrammetric tie points, aerial control) and new (pointing-and-scaling of kinematic ground control points) measurements have been simulated for mapKITE corridor mapping missions, consisting on takeoff and calibration pattern, single-pass corridor operation potentially performing calibration patterns, and landing and calibration pattern. Our preliminary results show that the exterior orientation, interior orientation and tie points precision estimates are better when using kinematic control with few static ground control, and even with excluding the latter. We conclude then that mapKITE can be a breakthrough on the UAS-based corridor mapping field, as precision requirements can be achieved for single-pass operation with no need for traditional static ground control points.

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Strand, Tara, Brian Gullett, Shawn Urbanski, Susan O'Neill, Brian Potter, Johanna Aurell, Amara Holder, Narasimhan Larkin, Mark Moore i Miriam Rorig. "Grassland and forest understorey biomass emissions from prescribed fires in the south-eastern United States – RxCADRE 2012". International Journal of Wildland Fire 25, nr 1 (2016): 102. http://dx.doi.org/10.1071/wf14166.

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Smoke measurements were made during grass and forest understorey prescribed fires as part of a comprehensive programme to understand fire and smoke behaviour. Instruments deployed on the ground, airplane and tethered aerostat platforms characterised the smoke plumes through measurements of carbon dioxide (CO2), carbon monoxide (CO), methane (CH4) and particulate matter (PM), and measurements of optical properties. Distinctions were observed in aerial and ground-based measurements, with aerial measurements exhibiting smaller particle size distributions and PM emission factors, likely due to particle settling. Black carbon emission factors were similar for both burns and were highest during the initial flaming phase. On average, the particles from the forest fire were less light absorbing than those from the grass fires due to the longer duration of smouldering combustion in the forest biomass. CO and CH4 emission factors were over twice as high for the forest burn than for the grass burn, corresponding with a lower modified combustion efficiency and greater smouldering combustion. This dataset reveals the evolution of smoke emissions from two different commonly burned fuel types and demonstrates the complexity of emission factors.

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Karásek, Matěj, Florian T. Muijres, Christophe De Wagter, Bart D. W. Remes i Guido C. H. E. de Croon. "A tailless aerial robotic flapper reveals that flies use torque coupling in rapid banked turns". Science 361, nr 6407 (13.09.2018): 1089–94. http://dx.doi.org/10.1126/science.aat0350.

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Insects are among the most agile natural flyers. Hypotheses on their flight control cannot always be validated by experiments with animals or tethered robots. To this end, we developed a programmable and agile autonomous free-flying robot controlled through bio-inspired motion changes of its flapping wings. Despite being 55 times the size of a fruit fly, the robot can accurately mimic the rapid escape maneuvers of flies, including a correcting yaw rotation toward the escape heading. Because the robot’s yaw control was turned off, we showed that these yaw rotations result from passive, translation-induced aerodynamic coupling between the yaw torque and the roll and pitch torques produced throughout the maneuver. The robot enables new methods for studying animal flight, and its flight characteristics allow for real-world flight missions.

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Marden, J. H., M. R. Wolf i K. E. Weber. "Aerial performance of Drosophila melanogaster from populations selected for upwind flight ability." Journal of Experimental Biology 200, nr 21 (1.11.1997): 2747–55. http://dx.doi.org/10.1242/jeb.200.21.2747.

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A computerized system for three-dimensional tracking of large numbers of individual free-flying insects was used to assess the performance of Drosophila melanogaster from populations that had undergone 160 generations of selection for upwind flight ability. Compared with control lines, the selected lines showed significant increases in mean flight velocity, decreases in angular trajectory and a significant change in the interaction between velocity and angular trajectory. Maximal flight velocity was apparent as a sharply defined upper boundary of the distribution of horizontal and vertical velocity as a function of angular trajectory; this upper bound (0.85 ms-1) differed little between the selected and control lines, although individuals from the selected lines attained maximal performance levels much more frequently. Maximum induced power output was calculated directly from the product of maximum vertical velocity and body weight. This measure (28 W kg-1 muscle) was closely predicted by a scaling relationship derived from the load-lifting limits of larger insects and vertebrates, as well as tethered D. melanogaster stimulated via their optomotor reflex to produce maximal lift. These results indicate that selection for flight performance can readily alter the relative effort and/or the frequency of phenotypes capable of attaining population-wise maximal performance levels, but shows little ability to increase population-wise maximal performance.

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ISHII, Tohru, Chiaki TODOROKI, Yasutake TAKAHASHI, Yoichiro MAEDA i Takayuki NAKAMURA. "2A1-A04 Development and Autonomous Flight Control for Tethered Flying Robot(Aerial Robot and Mechatronics (1))". Proceedings of JSME annual Conference on Robotics and Mechatronics (Robomec) 2014 (2014): _2A1—A04_1—_2A1—A04_4. http://dx.doi.org/10.1299/jsmermd.2014._2a1-a04_1.

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Tognon, Marco, Sanket S. Dash i Antonio Franchi. "Observer-Based Control of Position and Tension for an Aerial Robot Tethered to a Moving Platform". IEEE Robotics and Automation Letters 1, nr 2 (lipiec 2016): 732–37. http://dx.doi.org/10.1109/lra.2016.2523599.

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Kishk, Mustafa, Ahmed Bader i Mohamed-Slim Alouini. "Aerial Base Station Deployment in 6G Cellular Networks Using Tethered Drones: The Mobility and Endurance Tradeoff". IEEE Vehicular Technology Magazine 15, nr 4 (grudzień 2020): 103–11. http://dx.doi.org/10.1109/mvt.2020.3017885.

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32

Winstead, Tomon, Winstead i Mikolay. "Capturing aerial insects available as food for chimney swifts in western Pennsylvania using a tethered balloon". Journal of the Pennsylvania Academy of Science 94, nr 1-2 (2021): 103. http://dx.doi.org/10.5325/jpennacadscie.94.1-2.0103.

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33

Molina, P., M. Blázquez, J. Sastre i I. Colomina. "PRECISION ANALYSIS OF POINT-AND-SCALE PHOTOGRAMMETRIC MEASUREMENTS FOR CORRIDOR MAPPING: PRELIMINARY RESULTS". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-3/W4 (17.03.2016): 85–90. http://dx.doi.org/10.5194/isprsarchives-xl-3-w4-85-2016.

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This paper addresses the key aspects of the sensor orientation and calibration approach within the mapKITE concept for corridor mapping, focusing on the contribution analysis of point-and-scale measurements of kinematic ground control points. MapKITE is a new mobile, simultaneous terrestrial and aerial, geodata acquisition and post-processing method. On one hand, the acquisition system is a tandem composed of a terrestrial mobile mapping system and an unmanned aerial system, the latter equipped with a remote sensing payload, and linked through a 'virtual tether', that is, a real-time waypoint supply from the terrestrial vehicle to the unmanned aircraft. On the other hand, mapKITE entails a method for geodata post-processing (specifically, sensor orientation and calibration) based on the described acquisition paradigm, focusing on few key aspects: the particular geometric relationship of a mapKITE network – the aerial vehicle always observes the terrestrial one as they both move –, precise air and ground trajectory determination – the terrestrial vehicle is regarded as a kinematic ground control point – and new photogrammetric measurements – pointing on and measuring the scale of an optical target on the roof of the terrestrial vehicle – are exploited. In this paper, we analyze the performance of aerial image orientation and calibration in mapKITE for corridor mapping, which is the natural application niche of mapKITE, based on the principles and procedures of integrated sensor orientation with the addition of point-and-scale photogrammetric measurements of the kinematic ground control points. To do so, traditional (static ground control points, photogrammetric tie points, aerial control) and new (pointing-and-scaling of kinematic ground control points) measurements have been simulated for mapKITE corridor mapping missions, consisting on takeoff and calibration pattern, single-pass corridor operation potentially performing calibration patterns, and landing and calibration pattern. Our preliminary results show that the exterior orientation, interior orientation and tie points precision estimates are better when using kinematic control with few static ground control, and even with excluding the latter. We conclude then that mapKITE can be a breakthrough on the UAS-based corridor mapping field, as precision requirements can be achieved for single-pass operation with no need for traditional static ground control points.

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34

Stoffberg, Samantha, i David S. Jacobs. "The influence of wing morphology and echolocation on the gleaning ability of the insectivorous bat Myotis tricolor". Canadian Journal of Zoology 82, nr 12 (1.12.2004): 1854–63. http://dx.doi.org/10.1139/z04-172.

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On the basis of its external morphology, Myotis tricolor (Temminck, 1832) should be able to both aerial-feed and glean. Furthermore, this bat is known to use broadband calls of short duration, reinforcing the prediction that it gleans. However, results from this study indicate that M. tricolor does not commonly glean. This conclusion was reached after studying the foraging behaviour of M. tricolor in a flight room. We presented M. tricolor with mealworms, moths, mole crickets, beetles, and cicadas in a variety of ways that required either gleaning and (or) aerial feeding. Although M. tricolor readily took tethered prey, it did not take any of the variety of insects presented to it in a manner that required gleaning. We therefore compared its wing morphology and echolocation calls with those of several known gleaners, Nycteris thebaica E. Geoffroy, 1818, Myotis lucifugus (Le Conte, 1831), and Myotis septentrionalis (Trouessart, 1897), and an aerial forager, Neoromicia capensis (A. Smith, 1829). In a discriminant analysis wing-tip shape was the only variable to provide some degree of discrimination between species, with M. tricolor having more pointed wing tips than the known gleaners. Discriminant analysis of echolocation-call parameters grouped M. tricolor with the other Myotis species and separated it from N. capensis and N. thebaica. However, M. tricolor did not use harmonics as did the other Myotis species. The apparent failure of M. tricolor to glean might therefore be due to its relatively pointed wings and narrow-bandwidth echolocation calls, owing to the absence of harmonics in its calls.

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Molina, P., M. Blázquez, J. Sastre i I. Colomina. "mapKITE: A NEW PARADIGM FOR SIMULTANEOUS AERIAL AND TERRESTRIAL GEODATA ACQUISITION AND MAPPING". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B1 (6.06.2016): 957–62. http://dx.doi.org/10.5194/isprsarchives-xli-b1-957-2016.

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We introduce a new mobile, simultaneous terrestrial and aerial, geodata collection and post-processing method: mapKITE. By combining two mapping technologies such as terrestrial mobile mapping and unmanned aircraft aerial mapping, geodata are simultaneously acquired from air and ground. More in detail, a mapKITE geodata acquisition system consists on an unmanned aircraft and a terrestrial vehicle, which hosts the ground control station. By means of a real-time navigation system on the terrestrial vehicle, real-time waypoints are sent to the aircraft from the ground. By doing so, the aircraft is linked to the terrestrial vehicle through a “virtual tether,” acting as a “mapping kite.” In the article, we entail the concept of mapKITE as well as the various technologies and techniques involved, from aircraft guidance and navigation based on IMU and GNSS, optical cameras for mapping and tracking, sensor orientation and calibration, etc. Moreover, we report of a new measurement introduced in mapKITE, that is, point-and-scale photogrammetric measurements [of image coordinates and scale] for optical targets of known size installed on the ground vehicle roof. By means of accurate posteriori trajectory determination of the terrestrial vehicle, mapKITE benefits then from kinematic ground control points which are photogrametrically observed by point-and-scale measures. Initial results for simulated configurations show that these measurements added to the usual Integrated Sensor Orientation ones reduce or even eliminate the need of conventional ground control points –therefore, lowering mission costs– and enable selfcalibration of the unmanned aircraft interior orientation parameters in corridor configurations, in contrast to the situation of traditional corridor configurations. Finally, we report about current developments of the first mapKITE prototype, developed under the European Union Research and Innovation programme Horizon 2020. The first mapKITE mission will be held at the BCN Drone Center (Collsuspina, Moià, Spain) in mid 2016.

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36

Molina, P., M. Blázquez, J. Sastre i I. Colomina. "mapKITE: A NEW PARADIGM FOR SIMULTANEOUS AERIAL AND TERRESTRIAL GEODATA ACQUISITION AND MAPPING". ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B1 (6.06.2016): 957–62. http://dx.doi.org/10.5194/isprs-archives-xli-b1-957-2016.

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We introduce a new mobile, simultaneous terrestrial and aerial, geodata collection and post-processing method: mapKITE. By combining two mapping technologies such as terrestrial mobile mapping and unmanned aircraft aerial mapping, geodata are simultaneously acquired from air and ground. More in detail, a mapKITE geodata acquisition system consists on an unmanned aircraft and a terrestrial vehicle, which hosts the ground control station. By means of a real-time navigation system on the terrestrial vehicle, real-time waypoints are sent to the aircraft from the ground. By doing so, the aircraft is linked to the terrestrial vehicle through a “virtual tether,” acting as a “mapping kite.” In the article, we entail the concept of mapKITE as well as the various technologies and techniques involved, from aircraft guidance and navigation based on IMU and GNSS, optical cameras for mapping and tracking, sensor orientation and calibration, etc. Moreover, we report of a new measurement introduced in mapKITE, that is, point-and-scale photogrammetric measurements [of image coordinates and scale] for optical targets of known size installed on the ground vehicle roof. By means of accurate posteriori trajectory determination of the terrestrial vehicle, mapKITE benefits then from kinematic ground control points which are photogrametrically observed by point-and-scale measures. Initial results for simulated configurations show that these measurements added to the usual Integrated Sensor Orientation ones reduce or even eliminate the need of conventional ground control points –therefore, lowering mission costs– and enable selfcalibration of the unmanned aircraft interior orientation parameters in corridor configurations, in contrast to the situation of traditional corridor configurations. Finally, we report about current developments of the first mapKITE prototype, developed under the European Union Research and Innovation programme Horizon 2020. The first mapKITE mission will be held at the BCN Drone Center (Collsuspina, Moià, Spain) in mid 2016.

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Mei, Fan, Gavin McMeeking, Mikhail Pekour, Ru-Shan Gao, Gourihar Kulkarni, Swarup China, Hagen Telg, Darielle Dexheimer, Jason Tomlinson i Beat Schmid. "Performance Assessment of Portable Optical Particle Spectrometer (POPS)". Sensors 20, nr 21 (5.11.2020): 6294. http://dx.doi.org/10.3390/s20216294.

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Accurate representation of atmospheric aerosol properties is a long-standing problem in atmospheric research. Modern pilotless aerial systems provide a new platform for atmospheric in situ measurement. However, small airborne platforms require miniaturized instrumentation due to apparent size, power, and weight limitations. A Portable Optical Particle Spectrometer (POPS) is an emerged instrument to measure ambient aerosol size distribution with high time and size resolution, designed for deployment on a small unmanned aerial system (UAS) or tethered balloon system (TBS) platforms. This study evaluates the performance of a POPS with an upgraded laser heater and additional temperature sensors in the aerosol pathway. POPS maintains its performance under different environmental conditions as long as the laser temperature remains above 25 °C and the aerosol flow temperature inside the optical chamber is 15 °C higher than the ambient temperature. The comparison between POPS and an Ultra-High Sensitivity Aerosol Spectrometer (UHSAS) suggests that the coincidence error is less than 25% when the number concentration is less than 4000 cm−3. The size distributions measured by both of them remained unaffected up to 15,000 cm−3. While both instruments’ sizing accuracy is affected by the aerosol chemical composition and morphology, the influence is more profound on the POPS.

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38

Tognon, Marco, Rachid Alami i Bruno Siciliano. "Physical Human-Robot Interaction With a Tethered Aerial Vehicle: Application to a Force-Based Human Guiding Problem". IEEE Transactions on Robotics 37, nr 3 (czerwiec 2021): 723–34. http://dx.doi.org/10.1109/tro.2020.3038700.

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Dexheimer, Darielle, Martin Airey, Erika Roesler, Casey Longbottom, Keri Nicoll, Stefan Kneifel, Fan Mei, R. Giles Harrison, Graeme Marlton i Paul D. Williams. "Evaluation of ARM tethered-balloon system instrumentation for supercooled liquid water and distributed temperature sensing in mixed-phase Arctic clouds". Atmospheric Measurement Techniques 12, nr 12 (20.12.2019): 6845–64. http://dx.doi.org/10.5194/amt-12-6845-2019.

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Abstract. A tethered-balloon system (TBS) has been developed and is being operated by Sandia National Laboratories (SNL) on behalf of the U.S. Department of Energy's (DOE) Atmospheric Radiation Measurement (ARM) User Facility in order to collect in situ atmospheric measurements within mixed-phase Arctic clouds. Periodic tethered-balloon flights have been conducted since 2015 within restricted airspace at ARM's Advanced Mobile Facility 3 (AMF3) in Oliktok Point, Alaska, as part of the AALCO (Aerial Assessment of Liquid in Clouds at Oliktok), ERASMUS (Evaluation of Routine Atmospheric Sounding Measurements using Unmanned Systems), and POPEYE (Profiling at Oliktok Point to Enhance YOPP Experiments) field campaigns. The tethered-balloon system uses helium-filled 34 m3 helikites and 79 and 104 m3 aerostats to suspend instrumentation that is used to measure aerosol particle size distributions, temperature, horizontal wind, pressure, relative humidity, turbulence, and cloud particle properties and to calibrate ground-based remote sensing instruments. Supercooled liquid water content (SLWC) sondes using the vibrating-wire principle, developed by Anasphere Inc., were operated at Oliktok Point at multiple altitudes on the TBS within mixed-phase clouds for over 200 h. Sonde-collected SLWC data were compared with liquid water content derived from a microwave radiometer, Ka-band ARM zenith radar, and ceilometer at the AMF3, as well as liquid water content derived from AMF3 radiosonde flights. The in situ data collected by the Anasphere sensors were also compared with data collected simultaneously by an alternative SLWC sensor developed at the University of Reading, UK; both vibrating-wire instruments were typically observed to shed their ice quickly upon exiting the cloud or reaching maximum ice loading. Temperature sensing measurements distributed with fiber optic tethered balloons were also compared with AMF3 radiosonde temperature measurements. Combined, the results indicate that TBS-distributed temperature sensing and supercooled liquid water measurements are in reasonably good agreement with remote sensing and radiosonde-based measurements of both properties. From these measurements and sensor evaluations, tethered-balloon flights are shown to offer an effective method of collecting data to inform and constrain numerical models, calibrate and validate remote sensing instruments, and characterize the flight environment of unmanned aircraft, circumventing the difficulties of in-cloud unmanned aircraft flights such as limited flight time and in-flight icing.

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Sujandi, Eko Adi Prasetyanto, Dae-Soo Han, Seung-Cheol Lee i Sang-Eon Park. "Immobilization of Co(III) using tethered cyclam ligand on SBA-15 mesoporous silica for aerial oxidation of ethylbenzene". Catalysis Today 141, nr 3-4 (marzec 2009): 374–77. http://dx.doi.org/10.1016/j.cattod.2008.05.031.

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Jung, Sunghun. "Development and Verification of Hybrid Power Controller Using Indoor HIL Test for the Solar UAV". Energies 13, nr 8 (24.04.2020): 2110. http://dx.doi.org/10.3390/en13082110.

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A hybrid power system (HPS) is developed for the photovoltaic (PV) powered and tethered multirotor unmanned aerial vehicle (UAV) based on the robot operating system (ROS) and verified using an indoor hardware-in-the-loop (HIL) test. All the processes, including a UAV flight mode change (i.e., takeoff, hovering, and landing) and power flow control (consisting of PV modules, a LiPo battery pack, and a UAV) are completely automated using a combination of Pixhawk 2.1 and the Raspberry Pi 3 Model B (RPi 3B). Once the indoor HIL test starts, (1) the UAV takes off and hovers with a preassigned 10 m altitude at a fixed point and keeps hovering until the voltage drops below 13.4 V ; (2) the UAV lands when the voltage drops below 13.4 V, and the hybrid power controller (HPC) starts to charge the LiPo battery pack using the energy from PV modules; and (3) the UAV takes off when the voltage of the battery pack becomes more than 16.8 V, and the procedure repeats from (1). A PV-powered and tethered multirotor UAV using the proposed HPS can fly more safely for a longer time, particularly in an urban area, and so it is competitive to the traditional multirotor type UAV in the sense of both the flight time and the surveillance mission performance.

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42

JOUAULT, CORENTIN, i ANDRÉ NEL. "The oldest record of window fly supports a Gondwanan origin of the family (Diptera: Scenopinidae)". Palaeoentomology 3, nr 5 (30.10.2020): 483–91. http://dx.doi.org/10.11646/palaeoentomology.3.5.6.

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Palaeobiogeographic hypotheses need to be based on accurate palaeomaps and phylogenies of the concerned clades with a fossil record as complete as possible. Here we re-analyse the palaeobiogeography of the small fly family Scenopinidae, based on its first record in the mid-Cretaceous Burmese amber that we describe herein as Burmaprorates alagracilis gen. et sp. nov. and we assign to the subfamily Proratinae. At that time, the corresponding palaeobiota was an isolated island in the Southern part of the Tethys Ocean far away from the Laurasian plate and with general wind circulation unfavorable for aerial transport from Laurasia to the “Burmese Terrane”. Our results challenge and question the hypothesis of a North-Central American origin for the Scenopinidae at the beginning of the Cretaceous, and support a new hypothesis of a South Gondwanan origin.

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de Boer, Gijs, Mark Ivey, Beat Schmid, Dale Lawrence, Darielle Dexheimer, Fan Mei, John Hubbe i in. "A Bird’s-Eye View: Development of an Operational ARM Unmanned Aerial Capability for Atmospheric Research in Arctic Alaska". Bulletin of the American Meteorological Society 99, nr 6 (czerwiec 2018): 1197–212. http://dx.doi.org/10.1175/bams-d-17-0156.1.

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AbstractThorough understanding of aerosols, clouds, boundary layer structure, and radiation is required to improve the representation of the Arctic atmosphere in weather forecasting and climate models. To develop such understanding, new perspectives are needed to provide details on the vertical structure and spatial variability of key atmospheric properties, along with information over difficult-to-reach surfaces such as newly forming sea ice. Over the last three years, the U.S. Department of Energy (DOE) has supported various flight campaigns using unmanned aircraft systems [UASs, also known as unmanned aerial vehicles (UAVs) and drones] and tethered balloon systems (TBSs) at Oliktok Point, Alaska. These activities have featured in situ measurements of the thermodynamic state, turbulence, radiation, aerosol properties, cloud microphysics, and turbulent fluxes to provide a detailed characterization of the lower atmosphere. Alongside a suite of active and passive ground-based sensors and radiosondes deployed by the DOE Atmospheric Radiation Measurement (ARM) program through the third ARM Mobile Facility (AMF-3), these flight activities demonstrate the ability of such platforms to provide critically needed information. In addition to providing new and unique datasets, lessons learned during initial campaigns have assisted in the development of an exciting new community resource.

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Yager, D. D., i M. L. May. "Ultrasound-triggered, flight-gated evasive maneuvers in the praying mantis Parasphendale agrionina. II. Tethered flight". Journal of Experimental Biology 152, nr 1 (1.09.1990): 41–58. http://dx.doi.org/10.1242/jeb.152.1.41.

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In tethered flight, Parasphendale agrionina (Gerst.) males respond to ultrasonic stimuli with a unique suite of behaviors that includes full extension of the forelegs, strong dorsiflexion of the abdomen, a head roll, a 5% decrease in wingbeat frequency and a 33% increase in forewing excursion. Latency for the foreleg extension averages 66 ms while the latency to onset of yaw is 174 ms. The direction of the turn is unrelated to the location of the speaker. Yaw magnitude and latency are only weakly related to sound pressure level, and variability in these and other parameters is high. The behavior shows moderately sharp tuning to 40–60 kHz with a lowest mean threshold of 60 dB SPL. A male will not respond to ultrasound unless in flight, and the context-gating is independent of sensory input from the tarsi. Several components of the in-flight evasive behavior resemble defensive displays on the ground, and we suggest that this mantis has responded to predation pressure from bats with both flight-derived maneuvers and an aerial deimatic display.

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Schuyler, Travis J., Sean C. C. Bailey i Marcelo I. Guzman. "Monitoring Tropospheric Gases with Small Unmanned Aerial Systems (sUAS) during the Second CLOUDMAP Flight Campaign". Atmosphere 10, nr 8 (27.07.2019): 434. http://dx.doi.org/10.3390/atmos10080434.

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Small unmanned aerial systems (sUAS) are a promising technology for atmospheric monitoring of trace atmospheric gases. While sUAS can be navigated to provide information with higher spatiotemporal resolution than tethered balloons, they can also bridge the gap between the regions of the atmospheric boundary layer (ABL) sampled by ground stations and manned aircraft. Additionally, sUAS can be effectively employed in the petroleum industry, e.g., to constrain leaking regions of hydrocarbons from long gasoducts. Herein, sUAS are demonstrated to be a valuable technology for studying the concentration of important trace tropospheric gases in the ABL. The successful detection and quantification of gases is performed with lightweight sensor packages of low-power consumption that possess limits of detection on the ppm scale or below with reasonably fast response times. The datasets reported include timestamps with position, temperature, relative humidity, pressure, and variable mixing ratio values of ~400 ppm CO2, ~1900 ppb CH4, and ~5.5 ppb NH3. The sensor packages were deployed aboard two different sUAS operating simultaneously during the second CLOUDMAP flight campaign in Oklahoma, held during 26–29 June 2017. A Skywalker X8 fixed wing aircraft was used to fly horizontally at a constant altitude, while vertical profiles were provided by a DJI Phantom 3 (DJI P3) quadcopter flying upward and downward at fixed latitude-longitude coordinates. The results presented have been gathered during 8 experiments consisting of 32 simultaneous flights with both sUAS, which have been authorized by the United States Federal Aviation Authority (FAA) under the current regulations (Part 107). In conclusion, this work serves as proof of concept showing the atmospheric value of information provided by the developed sensor systems aboard sUAS.

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Pitt, D. G., i G. R. Glover. "Large-scale 35-mm aerial photographs for assessment of vegetation-management research plots in eastern Canada". Canadian Journal of Forest Research 23, nr 10 (1.10.1993): 2159–69. http://dx.doi.org/10.1139/x93-269.

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Two 35-mm cameras were mounted on a boom and suspended from a tethered helium-filled blimp to obtain nominally vertical aerial photographs (1:828 and 1:414 contact scale) of vegetation-management research plots. Photo and ground estimates of woody plant crown area (m2/ha) and rootstock density (number/ha) were compared for several experimental vegetation-control treatments. Horizontal point-sampling estimates of total crown area made directly on 1:93 scale prints (enlarged from 1:414) correlated strongly with equivalent estimates made on the ground (n = 62, r2 = 0.97). An estimated 20 ground-truth plots were required to adequately quantify photo bias and correct subsequent prediction of actual total crown area on the plots studied. Much of the observed photo bias could be attributed to the undersampling of small rootstocks. Exclusion of individual rootstocks less than 0.10 m2 in crown area (or, equivalently, <56 cm in height) resulted in a 1:1 relation between the two sampling methods for estimates of both total crown area (r2 = 0.98) and rootstock density (r2 = 0.97). If data for rootstocks in smaller size classes are not needed, uncorrected photo estimates may be appropriate for evaluation of treatment response. Ground-sampling costs averaged $200 (Canadian) per plot, compared with photo costs of $104 per plot (without ground truth) or $150 per plot (with 20 ground-truth plots). Smaller scale photos (1:828 contact) cost 11% less than the larger scale tested, but resulted in significant undersampling of individual rootstocks less than 0.2 m2 in crown area (or, equivalently, <80 cm in height).

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Palomaki, Ross T., Nathan T. Rose, Michael van den Bossche, Thomas J. Sherman i Stephan F. J. De Wekker. "Wind Estimation in the Lower Atmosphere Using Multirotor Aircraft". Journal of Atmospheric and Oceanic Technology 34, nr 5 (maj 2017): 1183–91. http://dx.doi.org/10.1175/jtech-d-16-0177.1.

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AbstractUnmanned aerial vehicles are increasingly used to study atmospheric structure and dynamics. While much emphasis has been on the development of fixed-wing unmanned aircraft for atmospheric investigations, the use of multirotor aircraft is relatively unexplored, especially for capturing atmospheric winds. The purpose of this article is to demonstrate the efficacy of estimating wind speed and direction with 1) a direct approach using a sonic anemometer mounted on top of a hexacopter and 2) an indirect approach using attitude data from a quadcopter. The data are collected by the multirotor aircraft hovering 10 m above ground adjacent to one or more sonic anemometers. Wind speed and direction show good agreement with sonic anemometer measurements in the initial experiments. Typical errors in wind speed and direction are smaller than 0.5 and 30°, respectively. Multirotor aircraft provide a promising alternative to traditional platforms for vertical profiling in the atmospheric boundary layer, especially in conditions where a tethered balloon system is typically deployed.

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Li, Xiao-Bing, Dongfang Wang, Qing-Chang Lu, Zhong-Ren Peng, Qingyan Fu, Xiao-Ming Hu, Juntao Huo i in. "Three-dimensional analysis of ozone and PM2.5 distributions obtained by observations of tethered balloon and unmanned aerial vehicle in Shanghai, China". Stochastic Environmental Research and Risk Assessment 32, nr 5 (5.03.2018): 1189–203. http://dx.doi.org/10.1007/s00477-018-1524-2.

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Shah, Adil, Joseph R. Pitt, Hugo Ricketts, J. Brian Leen, Paul I. Williams, Khristopher Kabbabe, Martin W. Gallagher i Grant Allen. "Testing the near-field Gaussian plume inversion flux quantification technique using unmanned aerial vehicle sampling". Atmospheric Measurement Techniques 13, nr 3 (30.03.2020): 1467–84. http://dx.doi.org/10.5194/amt-13-1467-2020.

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Abstract. Methane emission fluxes from many facility-scale sources may be poorly quantified, potentially leading to uncertainties in the global methane budget. Accurate atmospheric measurement-based flux quantification is urgently required to address this. This paper describes the first test (using unbiased sampling) of a near-field Gaussian plume inversion (NGI) technique, suitable for facility-scale flux quantification, using a controlled release of methane gas. Two unmanned-aerial-vehicle (UAV) platforms were used to perform 22 flight surveys downwind of a point-source methane gas release from a regulated cylinder with a flowmeter. One UAV was tethered to an instrument on the ground, while the other UAV carried an on-board prototype instrument (both of which used the same near-infrared laser technology). Both instruments were calibrated using certified standards to account for variability in the instrumental gain factor, assuming fixed temperature and pressure. Furthermore, a water vapour correction factor, specifically calculated for the instrument, was applied and is described here in detail. We also provide guidance on potential systematic uncertainties associated with temperature and pressure, which may require further characterisation for improved measurement accuracy. The NGI technique was then used to derive emission fluxes for each UAV flight survey. We found good agreement of most NGI fluxes with the known controlled emission flux, within uncertainty, verifying the flux quantification methodology. The lower and upper NGI flux uncertainty bounds were, on average, 17 %±10(1σ) % and 227 %±98(1σ) % of the controlled emission flux, respectively. This range of conservative uncertainty bounds incorporate factors including the variability in the position of the time-invariant plume and potential for under-sampling. While these average uncertainties are large compared to methods such as tracer dispersion, we suggest that UAV sampling can be highly complementary to a toolkit of flux quantification approaches and may be a valuable alternative in situations where site access for tracer release is problematic. We see tracer release combined with UAV sampling as an effective approach in future flux quantification studies. Successful flux quantification using the UAV sampling methodology described here demonstrates its future utility in identifying and quantifying emissions from methane sources such as oil and gas extraction infrastructure facilities, livestock agriculture, and landfill sites, where site access may be difficult.

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Renard, J. B., F. Dulac, G. Berthet, T. Lurton, D. Vignelles, F. Jégou, T. Tonnelier i in. "LOAC: a small aerosol optical counter/sizer for ground-based and balloon measurements of the size distribution and nature of atmospheric particles – Part 2: First results from balloon and unmanned aerial vehicle flights". Atmospheric Measurement Techniques Discussions 8, nr 9 (28.09.2015): 10057–96. http://dx.doi.org/10.5194/amtd-8-10057-2015.

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Abstract. In the companion paper (Renard et al., 2015), we have described and evaluated a new versatile optical particle counter/sizer named LOAC (Light Optical Aerosol Counter) based on scattering measurements at angles of 12 and 60° that allows some topology identification of particles (droplets, carbonaceous, salts, and mineral dust) in addition to size segregated counting in a large diameter range from 0.2 up to possibly more than 100 μm depending on sampling conditions. Its capabilities overpass those of preceding optical particle counters (OPCs) allowing the characterization of all kind of aerosols from submicronic-sized absorbing carbonaceous particles in polluted air to very coarse particles (> 10–20 μm in diameter) in desert dust plumes or fog and clouds. LOAC's light and compact design allows measurements under all kinds of balloons, on-board unmanned aerial vehicles (UAV) and at ground level. We illustrate here the first LOAC airborne results obtained from an unmanned aerial vehicle (UAV) and a variety of scientific balloons. The UAV was deployed in a peri-urban environment near Bordeaux in France. Balloon operations include (i) tethered balloons deployed in urban environments in Vienna (Austria) and Paris (France), (ii) pressurized balloons drifting in the lower troposphere over the western Mediterranean (during the Chemistry-Aerosol Mediterranean Experiment – ChArMEx campaigns), (iii) meteorological sounding balloons launched in the western Mediterranean region (ChArMEx) and from Aire-sur-l'Adour in south-western France (VOLTAIRE-LOAC campaign). More focus is put on measurements performed in the Mediterranean during (ChArMEx) and especially during African dust transport events to illustrate the original capability of balloon-borne LOAC to monitor in situ coarse mineral dust particles. In particular, LOAC has detected unexpected large particles in desert sand plumes.

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