Technologies and Operations for High Voltage Corona Detection with UAVs

Autonomous UAV transmission line inspection served as a reference mission for NASA demonstration of UAV deployment for economic benefit; this paper reports corona sensing advances in development of that reference mission. Unmanned aerial vehicles can serve as a platform for autonomous sensing and location of high voltage coronal discharge. Simple processing of commercial corona camera imagery can automate discharge localization and documentation. Inexpensive ultraviolet point sensors can sense discharge when carried close to the defect with a UAV. Augmented with a parabolic mirror, point sensor range can be increased to a safe inspection standoff distance, at the cost of a narrowed field of view. Results from a test flight of an augmented UV sensor are described. The imaging approach is superior in sensitivity and acquisition time, while the point sensor approach has superior size, weight, cost and durability advantages

A survey of electromagnetic influence on uavs from an ehv power converter stations and possible countermeasures

National Natural Science Foundation of China (Grant Nos. 11872148, U1908217, 61801034).It is inevitable that high-intensity, wide-spectrum electromagnetic emissions are generated by the power electronic equipment of the Extra High Voltage (EHV) power converter station. The surveillance flight of Unmanned Aerial Vehicles (UAVs) is thus, situated in a complex electromagnetic environment. The ubiquitous electromagnetic interference demands higher electromagnetic protection requirements from the UAV construction and operation. This article is related to the UAVs patrol inspections of the power line in the vicinity of the EHV converter station. The article analyzes the electromagnetic interference characteristics of the converter station equipment in the surrounding space and the impact of the electromagnetic emission on the communication circuits of the UAV. The anti-electromagnetic interference countermeasures strive to eliminate or reduce the threats of electromagnetic emissions on the UAV’s hardware and its communication network.publishersversionpublishe

Unmanned Aerial Vehicle (UAV) for monitoring soil erosion in Morocco

This article presents an environmental remote sensing application using a UAV that is specifically aimed at reducing the data gap between field scale and satellite scale in soil erosion monitoring in Morocco. A fixed-wing aircraft type Sirius I (MAVinci, Germany) equipped with a digital system camera (Panasonic) is employed. UAV surveys are conducted over different study sites with varying extents and flying heights in order to provide both very high resolution site-specific data and lower-resolution overviews, thus fully exploiting the large potential of the chosen UAV for multi-scale mapping purposes. Depending on the scale and area coverage, two different approaches for georeferencing are used, based on high-precision GCPs or the UAV’s log file with exterior orientation values respectively. The photogrammetric image processing enables the creation of Digital Terrain Models (DTMs) and ortho-image mosaics with very high resolution on a sub-decimetre level. The created data products were used for quantifying gully and badland erosion in 2D and 3D as well as for the analysis of the surrounding areas and landscape development for larger extents

Mass Loss From Calving in Himalayan Proglacial Lakes

The formation and expansion of Himalayan glacial lakes has implications for glacier dynamics, mass balance and glacial lake outburst floods (GLOFs). Subaerial and subaqueous calving is an important component of glacier mass loss but they have been difficult to track due to spatiotemporal resolution limitations in remote sensing data and few field observations. In this study, we used near-daily 3 m resolution PlanetScope imagery in conjunction with an uncrewed aerial vehicle (UAV) survey to quantify calving events and derive an empirical area–volume relationship to estimate calved glacier volume from planimetric iceberg areas. A calving event at Thulagi Glacier in 2017 was observed by satellite from before and during the event to nearly complete melting of the icebergs, and was observed in situ midway through the melting period, thus giving insights into the melting processes. In situ measurements of Thulagi Lake’s surface and water column indicate that daytime sunlight absorption heats mainly just the top metre of water, but this heat is efficiently mixed downwards through the top tens of metres due to forced convection by wind-blown icebergs; this heat then is retained by the lake and is available to melt the icebergs. Using satellite data, we assess seasonal glacier velocities, lake thermal regime and glacier surface elevation change for Thulagi, Lower Barun and Lhotse Shar glaciers and their associated lakes. The data reveal widely varying trends, likely signifying divergent future evolution. Glacier velocities derived from 1960/70s declassified Corona satellite imagery revealed evidence of glacier deceleration for Thulagi and Lhotse Shar glaciers, but acceleration at Lower Barun Glacier following lake development. We used published modelled ice thickness data to show that upon reaching their maximum extents, Imja, Lower Barun and Thulagi lakes will contain, respectively, about 90 × 106 , 62 × 106 and 5 × 106 m3 of additional water compared to their 2018 volumes. Understanding lake–glacier interactions is essential to predict future glacier mass loss, lake formation and associated hazards

Design of miniaturized sensors for a mission-oriented uav application: A new pathway for early warning

In recent decades, the increasing threats associated with Chemical and Radiological (CR) agents prompted the development of new tools to detect and collect samples without putting in danger first responders inside contaminated areas. A particularly promising branch of these technological developments relates to the integration of different detectors and sampling systems with Unmanned Aerial Vehicles (UAV). The adoption of this equipment may bring significant benefits for both military and civilian implementations. For instance, instrumented UAVs could be used in support of specialist military teams such as Sampling and Identification of Biological, Chemical and Radiological Agents (SIBCRA) team, tasked to perform sampling in contaminated areas, detecting the presence of CR substances in field and then confirming, collecting and evaluating the effective threats. Furthermore, instrumented UAVs may find dual-use application in the civil world in support of emergency teams during industrial accidents and in the monitoring activities of critical infrastructures. Small size drones equipped with different instruments for detection and collection of samples may enable, indeed, several applications, becoming a tool versatile and easy to use in different fields, and even featuring equipment normally utilized in manual operation. The authors hereby present the design of miniaturized sensors for a mission-oriented UAV application and the preliminary results from an experimental campaign performed in 2020

Design of Miniaturized Sensors for a Mission-Oriented UAV Application: A New Pathway for Early Warning

In recent decades, the increasing threats associated with Chemical and Radiological (CR) agents prompted the development of new tools to detect and collect samples without putting in danger first responders inside contaminated areas. A particularly promising branch of these technological developments relates to the integration of different detectors and sampling systems with Unmanned Aerial Vehicles (UAV). The adoption of this equipment may bring significant benefits for both military and civilian implementations. For instance, instrumented UAVs could be used in support of specialist military teams such as Sampling and Identification of Biological, Chemical and Radiological Agents (SIBCRA) team, tasked to perform sampling in contaminated areas, detecting the presence of CR substances in field and then confirming, collecting and evaluating the effective threats. Furthermore, instrumented UAVs may find dual-use application in the civil world in support of emergency teams during industrial accidents and in the monitoring activities of critical infrastructures. Small size drones equipped with different instruments for detection and collection of samples may enable, indeed, several applications, becoming a tool versatile and easy to use in different fields, and even featuring equipment normally utilized in manual operation. The authors hereby present the design of miniaturized sensors for a mission-oriented UAV application and the preliminary results from an experimental campaign performed in 2020

How Could Unmanned Aerial Systems (UAS) Be Used for Ecohydrological and Ecosystem Research? Experiences of First Operations with UAS in River Flood Plains of Northern Mongolia

This paper proposes the use of unmanned aerial systems (UAS) as a method for monitoring biotic resources and ecohydrological systems in river floodplains. Small scale mapping based on LANDSAT and SRTM or ASTER data is of limited applicability since a spatial resolution of 30 to 90 m is not sufficient to meet the demands of habitat mapping and large scale 3D -modelling. Newer satellites like WorldView2 and SENTINEL (space mission from European Space Agency within the Copernicus Programme) could be an option to gain a 0.5 m resolution, but the availability of image data is limited. UAS allow the collection of very high spatial and temporal resolution image data and the generation of digital elevation models (DEM). A spatial resolution of less than 10 cm and multispectral or hyperspectral image data, which can be provided by UAS sensors, is needed for mapping of habitats and riparian vegetation. Indicators for water quality such as chlorophyll (a) and suspended matter concentration can be efficiently derived from multispectral image data. Thermal image data, which can also be recorded by UAS-borne sensors, provides information on thermal heterogeneity of water temperature and the interaction of river and groundwater discharge from the river floodplain. In addition, cloud cover rarely affects UAS-generated aerial images because flying altitudes are usually low and flight missions can be timed very flexibly. UAS are also much more cost-effective to operate than manned aircraft. In a first field survey in September 2012, several field plots were investigated in northern Mongolia in different watersheds of the Selenge River Basin (SRB) with varying types of land use and environmental impacts. The regional focus was on the Kharaa River Basin (KRB), which is a paradigm for transformation from nearly natural conditions to an increasingly altered state by economic activities. Within the BMBF funded project “Integrated Water Resources Management in Central Asia: model region Mongolia (MoMo)” the actual situation of water quality, quantity and ecological impacts in this area has been investigated since 2006. A first analysis of nutrient and ecological gradients of the Kharaa Rver Basin indicates a ‘good’ chemical and ecological status for the headwaters and some parts of the middle reaches. Evidence for initial processes of ecosystem degradation and biodiversity loss were detected in the middle and increasingly in the lower reaches. Despite many efforts, several questions remained unsolved. Among them, the impact of erosion and particle transport on ecosystem degradation is a key issue. Fine sediment intrusion caused by erosion predominantly from the river banks but also from upland areas seems to be the most likely cause. However, based on the experiences of our existing monitoring scheme with a combination of intense fieldwork and continuous measuring with data loggers, the need of more spatial information (e.g. riparian vegetation structure, hydromorphology) with a high resolution became evident to confirm this hypothesis. Therefore, an unmanned aerial vehicle (UAV) equipped with a calibrated RGB camera was used to record image data for photogrammetric processing. DEM and orthophotos as well as spherical panoramic views were derived. Furthermore, thermal image data were terrestrially collected using an Infratec Variocam hr. Integration of thermal, multi- or hyperspectral sensors on various UAS (e.g. Archaeocopter), as well as analysis algorithms are the next steps for future work. The applicability of remote sensing approaches is discussed to better foster the development of ground truthing for a sustainable river basin management plan. The application of UAS offers a sound scientific base to assess especially the riparian zones in areas with difficult access

Advanced Materials and Technologies in Nanogenerators

This reprint discusses the various applications, new materials, and evolution in the field of nanogenerators. This lays the foundation for the popularization of their broad applications in energy science, environmental protection, wearable electronics, self-powered sensors, medical science, robotics, and artificial intelligence

Multi-Scale detection, mapping, and modelling geomorphic change in gravel-bed rivers with UAV remote sensing

Fluvial science is in particular need of surveying tools which can rapidly and accurately capture topographic data. The use of low-cost, consumer grade UAV (unmanned aerial vehicle) systems and Structure from Motion (SfM) processing methods has seen successful adoption by many other earth surface processes sub-fields however their use for monitoring within the field of fluvial geomorphology remains limited. This study tests the applicability of UAV photogrammetry to fluvial surveying, capturing centimetric resolution data across kilometric scales, providing an ideal perspective for geomorphic process interpretation. For a historically modified UK case study, four series of very high resolution DEMs (digital elevation model) and orthomosaic imagery are produced for a 2km reach of quasi-wandering gravel-bed river. Comparative analyses of DEMs between 2016 and 2018 reveals widening of the incised margin and significant geomorphic evolution characteristic of re-naturalization following the termination of gravel mining, channelization, and resultant aggressive incision. Whole reach volumetric analysis reveals a negative sediment budget approximating a net loss of 250m3/year. Budgetary segregation shows 22% of eroded material is sourced from the banks of the inset wandering margin and is a possible cause of a general fining (30% reduction in mean b axis) of bed material within active channels, detectable by grain scale analysis of high-resolution orthomosaic imagery. Vertical scour is seen to be prevented, even under extreme flows (~100 m3/s-1), by a bed armouring effect which is sustained by liberation of coarse clasts from the floodplain via lateral erosion and bank collapse. Woody debris dynamics, gravel bar creation and migration are intricately modelled throughout the site, their presence seen to be affecting flow-prioritization of sub-channels inside the incised margin. UAV surveying workflows and processing protocols are also developed for fluvial science: A means to neutralize and filter out surface error caused by vegetation occlusion in the SfM workflow, and a method to correct for geo-referencing error in large DEMs. Geomorphic findings at this UK case study hold valuable and transferable insights to river re-naturalization in the context of gravel extraction and channelization