scholarly journals Cryoegg: development and field trials of a wireless subglacial probe for deep, fast-moving ice

2020 ◽  
Author(s):  
Michael Prior-Jones ◽  
Elizabeth Bagshaw ◽  
Jonathan Lees ◽  
Lindsay Clare ◽  
Stephen Burrow ◽  
...  
Keyword(s):  
Fast Moving ◽  
Field Trials ◽  
Battery Life ◽  
Radio Link ◽  
Very High Frequency ◽  
Radio System ◽  
Sensing Systems ◽  
Hydrological System ◽  
Link Budget ◽  
Reporting Rates

<p>Innovative technological solutions are required to access and observe subglacial hydrological systems beneath glaciers and ice sheets. Wireless sensing systems can be used to collect and return data without the risk of losing data from cable breakage, which is a major obstacle when studying fast flowing glaciers and other high-strain environments. However, the performance of wireless sensors in deep and fast-moving ice has yet to be evaluated formally. We report experimental results from Cryoegg: a spherical probe that can be deployed along an ice borehole and either remain fixed in place or potentially travel through the subglacial hydrological system. The probe makes measurements in-situ and sends them back to the surface via a wireless link. Cryoegg uses very high frequency (VHF) radio to transmit data through up to 1.3 km of cold ice to a surface receiving array. It measures temperature, pressure and electrical conductivity, returning all data in real time. This transmission uses Wireless M-Bus on 169 MHz; we present a simple “radio link budget” model for its performance in cold ice and confirm its validity experimentally. Power is supplied by an internal battery with sufficient capacity for two measurements per day for up to a year, although higher reporting rates are available at the expense of battery life. Field trials were conducted in 2019 at two locations in Greenland (the EastGRIP borehole and the RESPONDER project site on Sermeq Kujalleq/Store Glacier) and on the Rhone Glacier in Switzerland.  Our results from the field demonstrate Cryoegg’s utility in studying englacial channels and moulins, including estimating moulin discharge through salt dilution gauging with the instrument deployed deep within the moulin. Future iterations of the radio system will allow Cryoegg to transmit through up to 2.5 km of ice.</p>

scholarly journals Cryoegg: development and field trials of a wireless subglacial probe for deep, fast-moving ice

2021 ◽  
pp. 1-14
Author(s):  
Michael R. Prior-Jones ◽  
Elizabeth A. Bagshaw ◽  
Jonathan Lees ◽  
Lindsay Clare ◽  
Stephen Burrow ◽  
...  
Keyword(s):  
Fast Moving ◽  
Field Trials ◽  
Radio Link ◽  
Radio System ◽  
Sensor Platforms ◽  
Battery Capacity ◽  
Hydrological System ◽  
Link Budget ◽  
Previous Design

Abstract Subglacial hydrological systems require innovative technological solutions to access and observe. Wireless sensor platforms can be used to collect and return data, but their performance in deep and fast-moving ice requires quantification. We report experimental results from Cryoegg: a spherical probe that can be deployed into a borehole or moulin and transit through the subglacial hydrological system. The probe measures temperature, pressure and electrical conductivity in situ and returns all data wirelessly via a radio link. We demonstrate Cryoegg's utility in studying englacial channels and moulins, including in situ salt dilution gauging. Cryoegg uses VHF radio to transmit data to a surface receiving array. We demonstrate transmission through up to 1.3 km of cold ice – a significant improvement on the previous design. The wireless transmission uses Wireless M-Bus on 169 MHz; we present a simple radio link budget model for its performance in cold ice and experimentally confirm its validity. Cryoegg has also been tested successfully in temperate ice. The battery capacity should allow measurements to be made every 2 h for more than a year. Future iterations of the radio system will enable Cryoegg to transmit data through up to 2.5 km of ice.

scholarly journals Cryoegg: development and field trials of a wireless subglacial probe for deep, fast-moving ice

2020 ◽  
Author(s):  
Michael Prior-Jones ◽  
Elizabeth Bagshaw ◽  
Jonathan Lees ◽  
Lindsay Clare ◽  
Stephen Burrow ◽  
...  
Keyword(s):  
Fast Moving ◽  
Field Trials

scholarly journals 28 GHz Wireless Backhaul Transceiver Characterization and Radio Link Budget

ETRI Journal ◽  
2018 ◽  
Vol 40 (1) ◽  
pp. 89-100 ◽  
Author(s):  
Marko E. Leinonen ◽  
Giuseppe Destino ◽  
Olli Kursu ◽  
Marko Sonkki ◽  
Aarno Pärssinen
Keyword(s):  
Radio Link ◽  
Wireless Backhaul ◽  
Link Budget

A study of mercuric oxide and zinc-air battery life in hearing aids

1997 ◽  
Vol 111 (9) ◽  
pp. 814-819 ◽  
Author(s):  
Clive Sparkes ◽  
Neville K. Lacey
Keyword(s):  
Low Power ◽  
Hearing Aids ◽  
High Power ◽  
Hearing Aid ◽  
Poor Performance ◽  
Field Trials ◽  
Battery Life ◽  
Mercuric Oxide ◽  
Phase Out ◽  
Air Cells

AbstractThe requirement to phase out mercuric oxide (mercury) batteries on environmental grounds has led to the widespread introduction of zinc-air technology. The possibility arises that high drain hearing aids may not be adequately catered for by zinc-air cells, leading to poor performance. This study investigated the hearing aid user's ability to perceive differences between zinc-air and mercury cells in normal everyday usage. The data was collected for 100 experienced hearing aid users in field trials. Users report 50 per cent greater life for zinc-air cells in high power aids and 28 per cent in low power aids. The average life of the zinc-air cells range from 15 days in high power to 34 days in low power aids. Users are able to perceive a difference in sound quality in favour of zinc-air cells for low and medium power aids. The hearing aid population is not disadvantaged by phasing out mercury cells.

scholarly journals Coexistence of DTT and Mobile Broadband: A Survey and Guidelines for Field Measurements

2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Juha Kalliovaara ◽  
Reijo Ekman ◽  
Pekka Talmola ◽  
Marko Höyhtyä ◽  
Tero Jokela ◽  
...  
Keyword(s):  
Field Measurement ◽  
Spectrum Sharing ◽  
Field Measurements ◽  
Radio System ◽  
Mobile Broadband ◽  
Wide Range ◽  
Reception System ◽  
Link Budget ◽  
Digital Terrestrial Television ◽  
And Performance

This article provides a survey and a general methodology for coexistence studies between digital terrestrial television (DTT) and mobile broadband (MBB) systems in the ultra high frequency (UHF) broadcasting band. The methodology includes characterization of relevant field measurement scenarios and gives a step-by-step guideline on how to obtain reliable field measurement results to be used in conjunction with link budget analyses, laboratory measurements, and simulations. A survey of potential European coexistence scenarios and regulatory status is given to determine feasible future use scenarios for the UHF television (TV) broadcasting band. The DTT reception system behavior and performance are also described as they greatly affect the amount of spectrum potentially available for MBB use and determine the relevant coexistence field measurement scenarios. Simulation methods used in determining broadcast protection criteria and in coexistence studies are briefly described to demonstrate how the information obtained from field measurements can be used to improve their accuracy. The presented field measurement guidelines can be applied to any DTT-MBB coexistence scenarios and to a wide range of spectrum sharing and cognitive radio system coexistence measurements.

Detection and Localization of Micro-Leakages Using Distributed Fiber Optic Sensing

2008 ◽  
Author(s):  
Daniele Inaudi ◽  
Riccardo Belli ◽  
Roberto Walder
Keyword(s):  
Fiber Optic ◽  
Field Trials ◽  
Natural Gas Pipelines ◽  
Sensing Systems ◽  
Detection Volume ◽  
Temperature Contrast ◽  
Fiber Optic Sensing ◽  
Detection And Localization ◽  
Single Instrument ◽  
Better Than

Distributed fiber optic sensing offers the ability to measure temperatures and strain at thousands of points along a single fiber. This is particularly interesting for the monitoring of pipelines, where it allows the detection and localization of leakages of much smaller volume than conventional mass balance techniques. Fiber optic sensing systems are used to detect and localize leakages in liquid, gas and multiphase pipelines, allowing the monitoring of hundreds of kilometers of pipeline with a single instrument and the localization of the leakage with a precision of 1 or 2 meters. This contribution presents recent testing results on controlled field trials. The tests demonstrate that it is possible to reliably detect oil leakages of the order of 10 liters to 1’000 liters per hour, corresponding to 0.01% to 0.1% of the pipeline flow. Tests were performed with small temperature differences between liquid and ground. The detection time was between 1 minute and 90 minutes. All simulated leakages were detected and localized to better than 2m accuracy. The paper describes the main parameters that affect the response time and detection volume, including the relative position of the leak to the sensing cable, temperature contrast and instrument performance. We also briefly report on relevant full-scale installations for the permanent monitoring of oil, brine and natural gas pipelines.

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