scholarly journals A stationary impulse-radar system for autonomous deployment in cold and temperate environments

2020 ◽  
Vol 61 (81) ◽  
pp. 99-107 ◽  
Author(s):  
Laurent Mingo ◽  
Gwenn E. Flowers ◽  
Anna J. Crawford ◽  
Derek R. Mueller ◽  
David G. Bigelow
Keyword(s):  
Power Supply ◽  
Satellite Telemetry ◽  
Water Storage ◽  
Ice Sheets ◽  
Temporal Changes ◽  
Radar System ◽  
Fibre Optic ◽  
Autonomous Operation ◽  
Glacial Environments ◽  
Uncontrolled System

AbstractStationary ice-penetrating radar (sIPR) systems can be used to monitor temporal changes in electromagnetically sensitive properties of glaciers and ice sheets. We describe a system intended for autonomous operation in remote glacial environments, and document its performance during deployments in cold and temperate settings. The design is patterned after an existing impulse radar system, with the addition of a fibre-optic link and timing module to control transmitter pulses, a micro-UPS (uninterruptable power supply) to prevent uncontrolled system shutdown and a customized satellite telemetry scheme. Various implementations of the sIPR were deployed on the Kaskawulsh Glacier near an ice-marginal lake in Yukon, Canada, for 44–77 days in summers 2014, 2015 and 2017. Pronounced perturbations to englacial radiostratigraphy were observed commensurate with lake filling and drainage, and are interpreted as changes in englacial water storage. Another sIPR was deployed in 2015–2016 on ice island PII-A-1-f, which originated from the Petermann Glacier in northwest Greenland. This system operated autonomously for almost a year during which changes in thickness of the ice column were clearly detected.

scholarly journals A ground-based, multi-frequency ice-penetrating radar system

2002 ◽  
Vol 34 ◽  
pp. 171-176 ◽  
Author(s):  
Kenichi Matsuoka ◽  
Hideo Maeno ◽  
Seiho Uratsuka ◽  
Shuji Fujita ◽  
Teruo Furukawa ◽  
...  
Keyword(s):  
Ice Sheets ◽  
Radar System ◽  
Single Frequency ◽  
Radio Waves ◽  
Subsurface Structures ◽  
Underlying Principle ◽  
Timing Difference ◽  
Single Operator ◽  
Dronning Maud Land ◽  
Data Acquisition Unit

AbstractTo better understand how ice sheets respond to climate, we designed a new multi-frequency ice-penetrating radar system to investigate subsurface structures of ice sheets. The system is mounted on a single platform and handled by a single operator. Three radio frequencies, 30,60 and 179 MHz, were used. An underlying principle of these multi-frequency observations is that the lower frequencies are more sensitive to electrical conductivity changes, whereas the higher frequencies are more sensitive to dielectric permittivity fluctuations in the ice. The system is composed of three single-frequency pulse radars, a trigger-controller unit and a data-acquisition unit. The trigger controller is the key component of this system. It switches transmitters on at different timings to prevent mixing of signals among the three radars. The timing difference was set as 50 μs, which is equivalent to the two-way travel time for radio waves reflecting from 4250m below the surface. A field test was done along a 2000 km long traverse line in east Dronning Maud Land, Antarctica. The multi-frequency system successfully acquired data that are equivalent in quality to our earlier single-frequency measurements along the same traverse line. The details of the system and preliminary data are described.

scholarly journals Penguin heat-retention structures evolved in a greenhouse Earth

2010 ◽  
Vol 7 (3) ◽  
pp. 461-464 ◽  
Author(s):  
Daniel B. Thomas ◽  
Daniel T. Ksepka ◽  
R. Ewan Fordyce
Keyword(s):  
Cold Water ◽  
Global Climate ◽  
Extreme Environments ◽  
Ice Sheets ◽  
Global Cooling ◽  
Polar Ice Sheets ◽  
Subsurface Waters ◽  
Glacial Environments ◽  
Retention Structures ◽  
Counter Current

Penguins (Sphenisciformes) inhabit some of the most extreme environments on Earth. The 60+ Myr fossil record of penguins spans an interval that witnessed dramatic shifts in Cenozoic ocean temperatures and currents, indicating a long interplay between penguin evolution and environmental change. Perhaps the most celebrated example is the successful Late Cenozoic invasion of glacial environments by crown clade penguins. A major adaptation that allows penguins to forage in cold water is the humeral arterial plexus, a vascular counter-current heat exchanger (CCHE) that limits heat loss through the flipper. Fossil evidence reveals that the humeral plexus arose at least 49 Ma during a ‘Greenhouse Earth’ interval. The evolution of the CCHE is therefore unrelated to global cooling or development of polar ice sheets, but probably represents an adaptation to foraging in subsurface waters at temperate latitudes. As global climate cooled, the CCHE was key to invasion of thermally more demanding environments associated with Antarctic ice sheets.

A High Power Density, High Voltage Power Supply For A Pulsed Radar System

2005 ◽  
Author(s):  
E.E. Bowles ◽  
S. Chapelle ◽  
G.X. Ferguson ◽  
D.S. Furuno ◽  
M. Marietta
Keyword(s):  
Power Density ◽  
High Voltage ◽  
High Power ◽  
Power Supply ◽  
Radar System ◽  
High Power Density ◽  
High Voltage Power Supply

Realizacija besprekidnog napajanja komandno-upravljačkog centra u sistemu OOiU

2021 ◽  
Vol 23 (2) ◽  
pp. 64-72
Author(s):  
Marko Tajdić ◽  
◽  
Željko Despotović ◽  
Jovan Kon ◽  
Keyword(s):  
Power Supply ◽  
Warning System ◽  
Practical Implementation ◽  
Entire System ◽  
Uninterruptible Power Supply ◽  
Control Center ◽  
Fast Switching ◽  
Autonomous Operation ◽  
The Republic ◽  
Uninterruptible Power

The emergency and notification warning system has the task to, in accordance with legal regulations, rules and observances, perform all necessary measures in order to monitoring, inform, and if necessary, partial or general public alerting of the population in the endangered area. The emergency and notification warning system, which is, among other things, very important for the Emergency management sector of the Republic Serbia, is managed from the command-control center. The importance of this system is evidenced by the fact that it has data transmission on two transmission paths (WiFi and UHF). Based on the above, it follows that it is very important to ensure robust, reliable and uninterrupted operation of the CCC and thus the smooth operation of the emergency and notification warning system. Uninterruptible power supply (UPS) plays a significant role in ensuring reliable, uninterrupted and autonomous operation of the entire system. The role of BPN is very important, because in case of loss of mains power 230 V, 50 Hz, it should take over the power supply of the system. The control system should provide a very fast switching (switching time ≤10 ms) to the backup power supply without interruption and voltage failure of the entire system. When working on a battery bank, the autonomy of the designed system in the absence of mains power is 48 hours. The paper will present the practical implementation of such a system, as well as the experimental results obtained during the operational commissioning of the UPS system. The solution is in use in the CCC-Valjevo of the emergency and notification warning system, starting from June 30, 2020.

scholarly journals Voltage controller with energy management unit for microgrid with hybrid sources

2021 ◽  
pp. 014459872110153
Author(s):  
Sheeba Babu ◽  
L Ashok Kumar
Keyword(s):  
Simulation Model ◽  
Energy Management ◽  
Power Supply ◽  
Output Voltage ◽  
Maximum Load ◽  
Solar Pv ◽  
Load Variations ◽  
Wind Generator ◽  
Autonomous Operation ◽  
Pv Panel

An unprecedented year has past with Covid-19 lockdown. It has underscored the importance of reliable and uninterrupted power supply. Microgrid ensures reliability and continuity of power supply in a local region with its own local generation and load despatch system, thereby reducing or eliminating the need of a central generator. A microgrid is capable of autonomous operation or it can be connected to a central ac grid that it separates from during disturbances. In this paper results of a microgrid simulation model is presented. Here microgrid system uses two renewable sources namely, solar PV and wind generator along with a battery feeding an inverter supplying load. The system is modeled and implemented using Matlab/simulink environment. The simulation model consists of mono-crystalline solar PV panel of 2.5 kW and a wind turbine emulator having PMDC as wind generator of 1 kW rating as micro sources. For stabilisation of the system a battery bank of 48 V, 100 Ah is also provided. The system is designed to supply a maximum load of 2.5 kW. The system autonomy is approximately two hours for rated load of 2.5 kW. Stability of the system was tested during load variations. The voltage and frequency were found to be stable during load variations. The performance of the inverter to provide constant output voltage of 400 V is good and the output frequency of the inverter is also maintained at 50 Hz. The output voltage conforms to IEC 60038 Standards. An energy management scheme is also developed and simulation results show effectiveness of the scheme.

scholarly journals RESEARCH OF POWER GENERATOR PROTOTYPE DEVELOPMENT AND INTEGRATION INTO AUTONOMOUS ROBOTIC SYSTEMS

2021 ◽  
Vol 3 ◽  
pp. 372-377
Author(s):  
Matutis Vaidotas ◽  
Loreta Savulioniene ◽  
Paulius Sakalys ◽  
Simonas Cesnauskas
Keyword(s):  
Experimental Research ◽  
Power Supply ◽  
Research Methodology ◽  
Robotic Systems ◽  
Practical Application ◽  
Power Generator ◽  
Prototype Development ◽  
Autonomous Operation ◽  
Electric Car ◽  
Autonomous Robotic Systems

The aim of the research is to perform experimental research based on patented technology to study the efficiency and applicability of it in the power supply circuits of autonomous robotic systems. Ensuring longer autonomous operation of the robotic system, was chosen electric car as the object of practical application at this stage of investigations to improve a process generation, utilization and regeneration of electricity. The article reviews the difficulties of technologies and aspects of their practical application. Described research methodology and a stand of investigations. Presented the results and conclusions of the performed simulation tests and practical measurements of the prototype electrodynamic parameters.

scholarly journals Hybrid Gravimetry to Map Water Storage Dynamics in a Mountain Catchment

2022 ◽  
Vol 3 ◽  
Author(s):  
Quentin Chaffaut ◽  
Nolwenn Lesparre ◽  
Frédéric Masson ◽  
Jacques Hinderer ◽  
Daniel Viville ◽  
...  
Keyword(s):  
Hydrological Model ◽  
Local Population ◽  
Water Storage ◽  
Time Lapse ◽  
Temporal Changes ◽  
Distributed Hydrological Model ◽  
Topographic Wetness Index ◽  
Mountain Areas ◽  
Physically Based ◽  
Spatio Temporal

In mountain areas, both the ecosystem and the local population highly depend on water availability. However, water storage dynamics in mountains is challenging to assess because it is highly variable both in time and space. This calls for innovative observation methods that can tackle such measurement challenge. Among them, gravimetry is particularly well-suited as it is directly sensitive–in the sense it does not require any petrophysical relationship–to temporal changes in water content occurring at surface or underground at an intermediate spatial scale (i.e., in a radius of 100 m). To provide constrains on water storage changes in a small headwater catchment (Strengbach catchment, France), we implemented a hybrid gravity approach combining in-situ precise continuous gravity monitoring using a superconducting gravimeter, with relative time-lapse gravity made with a portable Scintrex CG5 gravimeter over a network of 16 stations. This paper presents the resulting spatio-temporal changes in gravity and discusses them in terms of spatial heterogeneities of water storage. We interpret the spatio-temporal changes in gravity by means of: (i) a topography model which assumes spatially homogeneous water storage changes within the catchment, (ii) the topographic wetness index, and (iii) for the first time to our knowledge in a mountain context, by means of a physically based distributed hydrological model. This study therefore demonstrates the ability of hybrid gravimetry to assess the water storage dynamics in a mountain hydrosystem and shows that it provides observations not presumed by the applied physically based distributed hydrological model.

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