scholarly journals Preflight Contingency Planning Approach for Fixed Wing UAVs with Engine Failure in the Presence of Winds

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 227 ◽  
Author(s):  
Bulent Ayhan ◽  
Chiman Kwan ◽  
Bence Budavari ◽  
Jude Larkin ◽  
David Gribben
Keyword(s):  
Geographical Area ◽  
Landing Site ◽  
Contingency Planning ◽  
Path Generation ◽  
Generation Process ◽  
Area Of Interest ◽  
Forced Landing ◽  
Planning Approach ◽  
Final Approach ◽  
Engine Failure

Preflight contingency planning that utilizes wind forecast in path planning can be highly beneficial to unmanned aerial vehicles (UAV) operators in preventing a possible mishap of the UAV. This especially becomes more important if the UAV has an engine failure resulting in the loss of all its thrust. Wind becomes a significant factor in determining reachability of the emergency landing site in a contingency like this. The preflight contingency plans can guide the UAV operators about how to glide the aircraft to the designated emergency landing site to make a safe landing. The need for a preflight or in-flight contingency plan is even more obvious in the case of a communication loss between the UAV operator and UAV since the UAV will then need to make the forced landing autonomously without the operator. In this paper, we introduce a preflight contingency planning approach that automates the forced landing path generation process for UAVs with engine failure. The contingency path generation aims true reachability to the emergency landing site by including the final approach part of the path in forecast wind conditions. In the contingency path generation, no-fly zones that could be in the area are accounted for and the contingency flight paths do not pass through them. If no plans can be found that fulfill reachability in the presence of no-fly zones, only then, as a last resort, the no-fly zone avoidance rule is relaxed. The contingency path generation utilizes hourly forecast wind data from National Oceanic and Atmospheric Administration for the geographical area of interest and time of the flight. Different from past works, we use trochoidal paths instead of Dubins curves and incorporate wind as a parameter in the contingency path design.

scholarly journals Landing Site Reachability in a Forced Landing of Unmanned Aircraft in Wind

2017 ◽  
Vol 54 (4) ◽  
pp. 1415-1427 ◽  
Author(s):  
Matthew Coombes ◽  
Wen-Hua Chen ◽  
Peter Render
Keyword(s):  
Landing Site ◽  
Unmanned Aircraft ◽  
Forced Landing

SAR, SARin, RDSAR and FF-SAR Altimetry Processing on Demand for CryoSat-2 and Sentinel-3 at ESA G-POD

2021 ◽  
Author(s):  
Jérôme Benveniste ◽  
Salvatore Dinardo ◽  
Christopher Buchhaupt ◽  
Michele Scagliola ◽  
Marcello Passaro ◽  
...  
Keyword(s):  
Geographical Area ◽  
Vertical Motion ◽  
Time Frame ◽  
Data Repository ◽  
On Demand ◽  
Area Of Interest ◽  
Range Cell ◽  
Data Products ◽  
The Status ◽  
Range Cell Migration

<p>The scope of this presentation is to feature and provide an update on the ESA G-POD/SARvatore family of altimetry services portfolio for the exploitation of CryoSat-2 and Sentinel-3 data from L1A (FBR) data products up to SAR/SARin Level-2 geophysical data products. At present, the following on-line & on-demand services compose the portfolio:</p><p>-       The SARvatore (SAR Versatile Altimetric TOolkit for Research & Exploitation) for CryoSat-2 and Sentinel-3 services developed by the Altimetry Team in the R&D division at ESA-ESRIN. These processor prototypes are versatile and allow the users to customize and adapt the processing at L1b & L2 according to their specific requirements by setting a list of configurable options. The scope is to provide users with specific processing options not available in the operational processing chains (e.g. range walk correction, stack sub-setting, extended receiving window, zero padding, high-posting rate and burst weighting at L1b & SAMOSA+, SAMOSA++ and ALES+ SAR retrackers at L2). AJoin & Share Forum (https://wiki.services.eoportal.org/tiki-custom_home.php) allows users to post questions and report issues. A data repository is also available to the Community to avoid the redundant reprocessing of already processed data (https://wiki.services.eoportal.org/tiki-index.php?page=SARvatore+Data+Repository&highlight=repository).</p><p>-       The TUDaBo SAR-RDSAR (Technical University Darmstadt – University Bonn SAR-Reduced SAR) for CryoSat-2 and Sentinel-3 service. It allows users to generate reduced SAR, unfocused SAR & LRMC data. Several configurable L1b & L2 processing options and retrackers (BMLE3, SINC2, TALES, SINCS) are available. The processor will be extended during an additional activity related to the ESA HYDROCOASTAL Project (https://www.satoc.eu/projects/hydrocoastal/) to account in the open ocean for the vertical motion of the wave particles (VMWP) in unfocused SAR and in a simplified form of the fully focused SAR called here Low Resolution Range Cell Migration Correction-Focused (LRMC-F).  </p><p>-       The ALES+ SAR for CryoSat-2 and Sentinel-3 service. It allows users to process official L1b data and produces L2 NetCDF products by applying the empirical ALES+ SAR subwaveform retracker, including a dedicated SSB solution, developed by the Technische Universität München in the frame of the ESA Sea Level CCI (http://www.esa-sealevel-cci.org/) & BALTIC+ SEAL Projects (http://balticseal.eu/).</p><p>-       The Aresys Fully Focused SAR for CryoSat-2 service. Currently under development, it will provide the capability to produce CS-2 FF-SAR L1b products thanks to the Aresys 2D transformed frequency domain AREALT-FF1 processor prototype. Output products will also include geophysical corrections and threshold peak & ALES-like subwaveform retracker estimates.</p><p>The G-POD graphical interface allows users to select, in all the services, a geographical area of interest within the time-frame related to the L1A (FBR) & L1b data products availability in the service catalogue.  </p><p>After the task submission, users can follow, in real time, the status of the processing. The output data products are generated in standard NetCDF format, therefore being compatible with the multi-mission “Broadview Radar Altimetry Toolbox” (BRAT, http://www.altimetry.info) and typical tools.</p><p>Services are open, free of charge (supported by ESA) for worldwide scientific applications and available, after registration and activation (to be requested for each chosen service to [email protected]), at https://gpod.eo.esa.int.</p>

A Graphical Approach for Freeform Surface Offsetting With GPU Acceleration for Subtractive 3D Printing

2016 ◽  
Author(s):  
Mohammad M. Hossain ◽  
Richard W. Vuduc ◽  
Chandra Nath ◽  
Thomas R. Kurfess ◽  
Thomas M. Tucker
Keyword(s):  
Free Form ◽  
Manufacturing Cost ◽  
Generation Process ◽  
Toolpath Planning ◽  
Planning Approach ◽  
Subtractive Manufacturing ◽  
Volumetric Representation ◽  
Processor Unit ◽  
Voxel Data ◽  
Graphics Processor Unit

The lack of plug-and-play programmability in conventional toolpath planning approach in subtractive manufacturing, i.e., machining leads to significantly higher manufacturing cost for CNC based prototyping. In computer aided manufacturing (CAM) packages, typical B-rep or NURBS based representations of the CAD interfaces challenge core computations of tool trajectories generation process, such as, surface offsetting to be completely automated. In this work, the problem of efficient generation of free-form surface offsets is addressed with a novel volumetric representation. It presents an image filter based offsetting algorithm, which leverages the parallel computing engines on modern graphics processor unit (GPU). The scalable voxel data structure and the proposed hardware-accelerated volumetric offsetting together advance the computation and memory efficiencies well beyond the capability of past studies. Additionally, in order to further accelerate the offset computation the problem of offsetting with a large distance is decomposed into successive offsetting using smaller distances. The accuracy of the offset algorithms is thoroughly analyzed. The developed GPU implementation of the offsetting algorithm is robust in computation, easy to comprehend, and achieves a 50-fold speedup on single graphics card (NVIDIA GTX780Ti) relative to prior best-performing dual socket quad-core CPU implementation.

scholarly journals Safe engine-out landing of a passenger plane under the wind conditions

2019 ◽  
Vol 22 (5) ◽  
pp. 76-84
Author(s):  
M. A. Kiselev ◽  
S. V. Levitsky ◽  
V. A. Podobedov
Keyword(s):  
Power Plant ◽  
Air Transport ◽  
Flight Safety ◽  
Aircraft Control ◽  
Aviation Accidents ◽  
Minimum Drag ◽  
Medium Range ◽  
Final Approach ◽  
Key Features ◽  
Engine Failure

The engine failure, according to the flight safety inspection of the Federal Air Transport Agency, caused 4 of 6 aviation accidents in 2017, including 2 air disasters. In general, from 2001 to 2017, events related to the engine failure became the second most frequent cause of aviation accidents (13% of aviation accidents and 12% of air disasters). The worst consequences are associated with the engine failure at the most difficult and crucial stage of the flight landing. For example, it was the engine failure on the final approach that caused the crash of the L-410UVP-E20 RA-67047 aircraft near the Nelkan airfield on November 15, 2017. The article discusses a limiting situation in some sense – the landing of an aircraft with all failed engines under the wind conditions. The authors have proposed for this situation a methodology of calculating the landing approach of an aircraft under the wind conditions in case of failure of all engines of its power plant to an aerodrome equipped with an outer marker. The key features of such methodology are, firstly, the absence of necessity to link the path to the landmarks in the landing aerodrome area, and, secondly, the simplicity of the synthesis and the implementation of the aircraft control based on the proposed methodology during landing in both manual and director or automatic modes. To calculate the approach using the proposed methodology, the crew only needs to know the following values: the minimum drag airspeed on final approach, the height of the flight over an outer marker before landing and spiral approach leg. The content of the methodology in the article is illustrated by the results of the approach calculation when all of the main engines of the Russian short-medium-range MS-21 aircraft fail under the wind conditions.

scholarly journals A Hydrogeologic Framework for Understanding Local Groundwater Flow Dynamics in the Southeast Deschutes Basin, Oregon, USA

Geosciences ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 57 ◽  
Author(s):  
Phil Caruso ◽  
Carlos Ochoa ◽  
W. Jarvis ◽  
Tim Deboodt
Keyword(s):  
Surface Water ◽  
Groundwater Resources ◽  
Geographical Area ◽  
Bulk Water ◽  
Groundwater Depletion ◽  
Groundwater Movement ◽  
Area Of Interest ◽  
Study Results ◽  
Local Geology ◽  
Hydrogeologic Framework

Understanding local hydrogeology is important for the management of groundwater resources and the ecosystems that depend on them. The main objective of this study conducted in central Oregon, USA was to characterize the hydrogeologic framework of a part of the semiarid Upper Deschutes Basin. Information on local geology and hydrology was synthesized to construct a hydrogeologic framework and a conceptual model of groundwater movement in shallow and previously unmapped deeper aquifers. Study results show that local geology drives many of the surface water and groundwater connections that sustain groundwater-related ecosystems and ranching-related activities in the geographical area of interest. Also, the findings of this study suggest that ecohydrological investigations can be used to mitigate concerns regarding groundwater development. Likewise, newly-developed conceptual models of the hydrogeology of previously unstudied areas within a groundwater basin undergoing regulation offer opportunities to not only address concerns regarding integrated surface water–groundwater interactions but also provide supplemental sources of water for nearby areas undergoing groundwater depletion through proposed bulk water transfers.

scholarly journals Genus-Physiognomy-Ecosystem (GPE) System for Satellite-Based Classification of Plant Communities

Ecologies ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 203-213
Author(s):  
Ram C. Sharma
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Plant Communities ◽  
Dominant Species ◽  
Geographical Area ◽  
Vegetation Mapping ◽  
Species Level ◽  
Landsat 8 ◽  
Area Of Interest

Vegetation mapping and monitoring is important as the composition and distribution of vegetation has been greatly influenced by land use change and the interaction of land use change and climate change. The purpose of vegetation mapping is to discover the extent and distribution of plant communities within a geographical area of interest. The paper introduces the Genus-Physiognomy-Ecosystem (GPE) system for the organization of plant communities from the perspective of satellite remote sensing. It was conceived for broadscale operational vegetation mapping by organizing plant communities according to shared genus and physiognomy/ecosystem inferences, and it offers an intermediate level between the physiognomy/ecosystem and dominant species for the organization of plant communities. A machine learning and cross-validation approach was employed by utilizing multi-temporal Landsat 8 satellite images on a regional scale for the classification of plant communities at three hierarchical levels: (i) physiognomy, (ii) GPE, and (iii) dominant species. The classification at the dominant species level showed many misclassifications and undermined its application for broadscale operational mapping, whereas the GPE system was able to lessen the complexities associated with the dominant species level classification while still being capable of distinguishing a wider variety of plant communities. The GPE system therefore provides an easy-to-understand approach for the operational mapping of plant communities, particularly on a broad scale.

scholarly journals Pemberdayaan pada Kelompok Remaja melalui Pendekatan Contingency Planning dalam Meningkatkan Kesiapsiagaan terhadap Ancaman Kematian Akibat Bencana

2017 ◽  
Vol 3 (2) ◽  
pp. 154
Author(s):  
Sehabudin Salasa ◽  
Tri Wahyu Murni ◽  
Etika Emaliyawati
Keyword(s):  
Experimental Design ◽  
Random Sampling ◽  
Influential Factor ◽  
Vulnerable Groups ◽  
Contingency Planning ◽  
Test Design ◽  
Planning Approach ◽  
Post Test ◽  
Quasi Experimental ◽  
Intention Formation

ABSTRAK Angka kematian kelompok rentan akibat bencana masih sangat tinggi, seperti kejadian banjir bandang Garut dari 34 orang korban jiwa 35,4% diantaranya berusia 55-80 tahun dan 29%  merupakan anak-anak usia 0-14 tahun. Upaya pengurangan resiko harus dilakukan dengan memberdayakan masyarakat sehingga proses penanggulangan lebih efektif dengan respon yang cepat. Usia remaja merupakan kelompok yang sangat potensial karena memiliki angka resiliensi yang sangat baik. Selain itu pertumbuhan jumlah remaja sangat pesat dari kelompok umur lainnya, sehingga pemberdayaan kelompok remaja dengan perencanaan kontinjensi diharapkan meningkatkan kesiapsiagaan terhadap ancaman kematian sehingga dapat melakukan pendampingan terhadap kelompok rentan. Penelitian ini bertujuan mengetahui pengaruh pemberdayaan (empowering) kelompok remaja akhir melalui pendekatan perencanaan kontinjensi dalam meningkatkan kesiapsiagaan remaja terhadap ancaman kematian akibat bencana. Penelitian menggunakan metoda quasi-experimental design dengan pendekatan rancangan one group pre-post test design. Populasi penelitian merupakan pelajar SMK diwilayah yang memiliki ancaman bencana. Jumlah sampel sebanyak 33 responden dengan teknik proporsional random sampling diambil dari empat sekolah yang berada di zona merah. Data diolah menggunakan analisis univariat menggunakan tendensi sentral, t-test dependent dengan tingkat kepercayaan 95% untuk melihat pengaruh dari intervensi, serta uji regresi linier ganda untuk menganalisis faktor mana yang paling berpengaruh terhadap kesiapsiagaan.Terdapat pengaruh pemberdayaan melalui pendekatan perencanaan kontinjensi dapat meningkatkan upaya kesiapsiagaan dengan nilai α (0.000). Peningkatan rerata (36,67%) didapatkan pada faktor yang mengawali kesiapsiagaan, diantaranya dilihat dari persepsi terhadap resiko, kewaspadaan terhadap ancaman, serta penurunan kecemasan. Faktor tersebut menstimulasi terbentuknya niat melakukan kesiapsiagaan dengan peningkatan (43,33%), bahkan meningkatkan upaya perencanaan kesiapsiagaan bencana sebesar (42,00%) sebelum dan setelah intervensi. Ketiga faktor tersebut saling berkaitan dan faktor pembentukan niat melakukan kesiapsiagaan menjadi faktor yang sangat berpengaruh terhadap kesiapsiagaan dengan nilai β (0,531). Hasil penelitian menunjukkan bahwa proses pemberdayaan melalui pendekatan perencanaan kontinjensi mampu meningkatkan kesiapsiagaan remaja terhadap ancaman kematian akibat bencana, sehingga dapat direkomendasikan bagi seluruh penggiat kebencanaan untuk memberdayakan remaja dengan perencanaan kontinjensi dalam upaya meningkatkan kesiapsiagaan terhadap ancaman kematian.  ABSTRACT The mortality rate of vulnerable groups due to the disaster is still very high, such as the incidence of flash floods at Garut,  of the 34 deaths among them  35.4% are 55-80 years old and 29% of children aged 0-14 years. Risk reduction efforts should be undertaken by empowering communities so that the countermeasures are more effective with rapid response. Adolescence is very potent because it has a very good resilience rate. In addition, the growth of adolescents is very rapidly from other age groups, so empowerment of adolescent groups with contingency planning is expected to increase preparedness against death threats so as to provide assistance to vulnerable groups. The purpose of this study was to determine the influence of empowering the late adolescent group through contingency planning approach in the effort of preparedness against the threat of death due to the disaster.This study used quasi-experimental design method with one group pre-post test design approach. The study population was a vocational school student in the region that has disaster threats. The number of samples was 33 respondents with proportional random sampling technique from 4 schools in the red zone. Data were tested for data were analyzed by a central tendency for univariate analysis, t-test dependent with 95% confidence level to see the effect of the intervention, and determination of the most influential factor, the researcher used multiple linear regression tests.  Results of the study showed there is the influence of empowerment through contingency planning approach can improve preparedness efforts with α value (0.000). Percentages before and after the intervention can significantly improve the precursor factor increase (36.67%), intention formation (43.33%), and preparation (42.00%). In addition, intention formation factor is the most influential factor in preparedness efforts with β value (0,531). This study concluded that the empowerment through contingency planning approach can improve preparedness efforts of adolescence group to the threat of death from disaster. So it is recommended for all disaster activists to empower adolescents with contingency planning in an effort to increase preparedness against death threats Keywords: adolescent preparedness, contingency planning, disaster preparedness

Empowering communities to carry out drought contingency planning

Water Policy ◽  
2005 ◽  
Vol 7 (6) ◽  
pp. 551-567 ◽  
Author(s):  
Jennifer L. Durley ◽  
Rob C. de Loë
Keyword(s):  
Natural Hazard ◽  
The United States ◽  
Contingency Planning ◽  
Management Approach ◽  
Drought Event ◽  
Roles And Responsibilities ◽  
Planning Approach ◽  
Management Capacity ◽  
Common Response ◽  
Local Actors

Drought is a pervasive natural hazard, even in relatively water rich areas such as the Province of Ontario, Canada. A common response to drought in many jurisdictions has been crisis management, especially involving drought relief during or after a drought event. Proactive drought contingency planning, which takes a risk management approach to reduce vulnerability, is much more appropriate. Unfortunately, the extent to which local communities have the capacity to participate effectively in this activity is highly variable. This paper explores factors that facilitate and constrain locally led drought contingency planning and highlights several that relate to management capacity, or the ability of local actors to accomplish their objectives and participate effectively in implementing appropriate drought responses. Drought planning experiences in Australia and the United States are used to frame an evaluation of Ontario's new drought contingency planning approach. We conclude that while Ontario's approach has many desirable features (e.g. organized around watersheds; locally driven), it also has several shortcomings, relating especially to the way in which droughts are understood, coordination of roles and responsibilities and community disempowerment during severe droughts.

scholarly journals GNSS Double Differences Used as Beacon Landing System for Aircraft Instrument Approach

2021 ◽  
Author(s):  
Thomas Dautermann ◽  
Bernd Korn ◽  
Karin Flaig ◽  
Maarten Uijt de Haag
Keyword(s):  
Measurement Data ◽  
Landing Site ◽  
Flight Test ◽  
Double Difference ◽  
Relative Navigation ◽  
Flight Tests ◽  
Final Approach ◽  
Double Differences ◽  
Long Term Measurement

AbstractWhen using GNSS navigation for final approach guidance of aircraft to a landing site, the only systems currently available are differential GNSS with additional integrity data called augmentation systems. These work well when the landing site is fixed in space and well surveyed. In all other cases, augmentation systems are difficult to use. Here, we propose relative navigation based on GNSS double difference measurement to accomplish the same task, but also onto moving landing platforms or at unsurveyed locations. We call this the Beacon Landing System. Furthermore, we show long term measurement data confirming the sub-meter accuracy and results from flight tests. During the flight test we successfully used the relative navigation for aircraft guidance.

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