Author: James Robert Brainard
Publisher:
ISBN:
Category :
Languages : en
Pages : 52
Book Description
Time domain reflectometry (TDR) operates by propagating a radar frequency electromagnetic pulse down a transmission line while monitoring the reflected signal. As the electromagnetic pulse propagates along the transmission line, it is subject to impedance by the dielectric properties of the media along the transmission line (e.g., air, water, sediment), reflection at dielectric discontinuities (e.g., air-water or water-sediment interface), and attenuation by electrically conductive materials (e.g., salts, clays). Taken together, these characteristics provide a basis for integrated stream monitoring; specifically, concurrent measurement of stream stage, channel profile and aqueous conductivity. Here, we make novel application of TDR within the context of stream monitoring. Efforts toward this goal followed three critical phases. First, a means of extracting the desired stream parameters from measured TDR traces was required. Analysis was complicated by the fact that interface location and aqueous conductivity vary concurrently and multiple interfaces may be present at any time. For this reason a physically based multisection model employing the S11 scatter function and Cole-Cole parameters for dielectric dispersion and loss was developed to analyze acquired TDR traces. Second, we explored the capability of this multisection modeling approach for interpreting TDR data acquired from complex environments, such as encountered in stream monitoring. A series of laboratory tank experiments were performed in which the depth of water, depth of sediment, and conductivity were varied systematically. Comparisons between modeled and independently measured data indicate that TDR measurements can be made with an accuracy of {+-}3.4x10{sup -3} m for sensing the location of an air/water or water/sediment interface and {+-}7.4% of actual for the aqueous conductivity. Third, monitoring stations were sited on the Rio Grande and Paria rivers to evaluate performance of the TDR system under normal field conditions. At the Rio Grande site (near Central Bridge in Albuquerque, New Mexico) continuous monitoring of stream stage and aqueous conductivity was performed for 6 months. Additionally, channel profile measurements were acquired at 7 locations across the river. At the Paria site (near Lee's Ferry, Arizona) stream stage and aqueous conductivity data were collected over a 4-month period. Comparisons drawn between our TDR measurements and USGS gage data indicate that the stream stage is accurate within {+-}0.88 cm, conductivity is accurate within {+-}11% of actual, and channel profile measurements agree within {+-}1.2 cm.
Monitoring Stream Stage, Channel Profile, and Aqueous Conductivity with Time Domain Reflectometry (TDR).
Author: James Robert Brainard
Publisher:
ISBN:
Category :
Languages : en
Pages : 52
Book Description
Time domain reflectometry (TDR) operates by propagating a radar frequency electromagnetic pulse down a transmission line while monitoring the reflected signal. As the electromagnetic pulse propagates along the transmission line, it is subject to impedance by the dielectric properties of the media along the transmission line (e.g., air, water, sediment), reflection at dielectric discontinuities (e.g., air-water or water-sediment interface), and attenuation by electrically conductive materials (e.g., salts, clays). Taken together, these characteristics provide a basis for integrated stream monitoring; specifically, concurrent measurement of stream stage, channel profile and aqueous conductivity. Here, we make novel application of TDR within the context of stream monitoring. Efforts toward this goal followed three critical phases. First, a means of extracting the desired stream parameters from measured TDR traces was required. Analysis was complicated by the fact that interface location and aqueous conductivity vary concurrently and multiple interfaces may be present at any time. For this reason a physically based multisection model employing the S11 scatter function and Cole-Cole parameters for dielectric dispersion and loss was developed to analyze acquired TDR traces. Second, we explored the capability of this multisection modeling approach for interpreting TDR data acquired from complex environments, such as encountered in stream monitoring. A series of laboratory tank experiments were performed in which the depth of water, depth of sediment, and conductivity were varied systematically. Comparisons between modeled and independently measured data indicate that TDR measurements can be made with an accuracy of {+-}3.4x10{sup -3} m for sensing the location of an air/water or water/sediment interface and {+-}7.4% of actual for the aqueous conductivity. Third, monitoring stations were sited on the Rio Grande and Paria rivers to evaluate performance of the TDR system under normal field conditions. At the Rio Grande site (near Central Bridge in Albuquerque, New Mexico) continuous monitoring of stream stage and aqueous conductivity was performed for 6 months. Additionally, channel profile measurements were acquired at 7 locations across the river. At the Paria site (near Lee's Ferry, Arizona) stream stage and aqueous conductivity data were collected over a 4-month period. Comparisons drawn between our TDR measurements and USGS gage data indicate that the stream stage is accurate within {+-}0.88 cm, conductivity is accurate within {+-}11% of actual, and channel profile measurements agree within {+-}1.2 cm.
Publisher:
ISBN:
Category :
Languages : en
Pages : 52
Book Description
Time domain reflectometry (TDR) operates by propagating a radar frequency electromagnetic pulse down a transmission line while monitoring the reflected signal. As the electromagnetic pulse propagates along the transmission line, it is subject to impedance by the dielectric properties of the media along the transmission line (e.g., air, water, sediment), reflection at dielectric discontinuities (e.g., air-water or water-sediment interface), and attenuation by electrically conductive materials (e.g., salts, clays). Taken together, these characteristics provide a basis for integrated stream monitoring; specifically, concurrent measurement of stream stage, channel profile and aqueous conductivity. Here, we make novel application of TDR within the context of stream monitoring. Efforts toward this goal followed three critical phases. First, a means of extracting the desired stream parameters from measured TDR traces was required. Analysis was complicated by the fact that interface location and aqueous conductivity vary concurrently and multiple interfaces may be present at any time. For this reason a physically based multisection model employing the S11 scatter function and Cole-Cole parameters for dielectric dispersion and loss was developed to analyze acquired TDR traces. Second, we explored the capability of this multisection modeling approach for interpreting TDR data acquired from complex environments, such as encountered in stream monitoring. A series of laboratory tank experiments were performed in which the depth of water, depth of sediment, and conductivity were varied systematically. Comparisons between modeled and independently measured data indicate that TDR measurements can be made with an accuracy of {+-}3.4x10{sup -3} m for sensing the location of an air/water or water/sediment interface and {+-}7.4% of actual for the aqueous conductivity. Third, monitoring stations were sited on the Rio Grande and Paria rivers to evaluate performance of the TDR system under normal field conditions. At the Rio Grande site (near Central Bridge in Albuquerque, New Mexico) continuous monitoring of stream stage and aqueous conductivity was performed for 6 months. Additionally, channel profile measurements were acquired at 7 locations across the river. At the Paria site (near Lee's Ferry, Arizona) stream stage and aqueous conductivity data were collected over a 4-month period. Comparisons drawn between our TDR measurements and USGS gage data indicate that the stream stage is accurate within {+-}0.88 cm, conductivity is accurate within {+-}11% of actual, and channel profile measurements agree within {+-}1.2 cm.
Monitoring Groundwater Levels Using a Time-domain Reflectometry (TDR) Pulser
Author: Glenn A. Nicholson
Publisher:
ISBN:
Category : Groundwater
Languages : en
Pages : 52
Book Description
A rugged, self-calibrating, time-domain reflectometer (TDR) device for monitoring groundwater elevations in piezometers was developed and demonstrated. The primary advantage of the TDR device over conventional downhole transducer technology is that the electronics are fixed at the surface where they are accessible and easy to maintain. The TDR instrumentation is also simple to install and does not require field calibration.
Publisher:
ISBN:
Category : Groundwater
Languages : en
Pages : 52
Book Description
A rugged, self-calibrating, time-domain reflectometer (TDR) device for monitoring groundwater elevations in piezometers was developed and demonstrated. The primary advantage of the TDR device over conventional downhole transducer technology is that the electronics are fixed at the surface where they are accessible and easy to maintain. The TDR instrumentation is also simple to install and does not require field calibration.
Using Time Domain Reflectometry (TDR) to Monitor Deep Ground-water Elevations
Author: Neil O. Anderson
Publisher:
ISBN:
Category : Groundwater
Languages : en
Pages : 74
Book Description
Publisher:
ISBN:
Category : Groundwater
Languages : en
Pages : 74
Book Description
Heat as a Tool for Studying the Movement of Ground Water Near Streams
Author: David Arthur Stonestrom
Publisher:
ISBN:
Category : Groundwater flow
Languages : en
Pages : 108
Book Description
Publisher:
ISBN:
Category : Groundwater flow
Languages : en
Pages : 108
Book Description
Advanced Sensors for Real-Time Monitoring Applications
Author: Olga Korostynska
Publisher: MDPI
ISBN: 3036504265
Category : Science
Languages : en
Pages : 350
Book Description
It is impossible to imagine the modern world without sensors, or without real-time information about almost everything—from local temperature to material composition and health parameters. We sense, measure, and process data and act accordingly all the time. In fact, real-time monitoring and information is key to a successful business, an assistant in life-saving decisions that healthcare professionals make, and a tool in research that could revolutionize the future. To ensure that sensors address the rapidly developing needs of various areas of our lives and activities, scientists, researchers, manufacturers, and end-users have established an efficient dialogue so that the newest technological achievements in all aspects of real-time sensing can be implemented for the benefit of the wider community. This book documents some of the results of such a dialogue and reports on advances in sensors and sensor systems for existing and emerging real-time monitoring applications.
Publisher: MDPI
ISBN: 3036504265
Category : Science
Languages : en
Pages : 350
Book Description
It is impossible to imagine the modern world without sensors, or without real-time information about almost everything—from local temperature to material composition and health parameters. We sense, measure, and process data and act accordingly all the time. In fact, real-time monitoring and information is key to a successful business, an assistant in life-saving decisions that healthcare professionals make, and a tool in research that could revolutionize the future. To ensure that sensors address the rapidly developing needs of various areas of our lives and activities, scientists, researchers, manufacturers, and end-users have established an efficient dialogue so that the newest technological achievements in all aspects of real-time sensing can be implemented for the benefit of the wider community. This book documents some of the results of such a dialogue and reports on advances in sensors and sensor systems for existing and emerging real-time monitoring applications.
Soil Salinity Assessment
Author: J. D. Rhoades
Publisher: Food & Agriculture Org.
ISBN: 9789251042816
Category : Technology & Engineering
Languages : en
Pages : 172
Book Description
Determination of soil salinity from aqueous electrical conductivity; determination of soil salinity from soil-paste and bulk soil electrical conductivity; example uses of salinity assessment technology; operational and equipment costs associated with salinity instrumentation measurement techniques.
Publisher: Food & Agriculture Org.
ISBN: 9789251042816
Category : Technology & Engineering
Languages : en
Pages : 172
Book Description
Determination of soil salinity from aqueous electrical conductivity; determination of soil salinity from soil-paste and bulk soil electrical conductivity; example uses of salinity assessment technology; operational and equipment costs associated with salinity instrumentation measurement techniques.
Proceedings of the Second International Symposium and Workshop on Time Domain Reflectometry for Innovative Geotechnical Applications
Author:
Publisher: Infrastructure Technology Institute Northwestern University
ISBN: 9780971263109
Category : Engineering geology
Languages : en
Pages :
Book Description
"This publication includes papers presented at the Second International Time Domain Reflectometry (TDR) Symposium and Workshop for Innovative Geotechnical Applications held at Northwestern University, September 5-7, 2001, in Evanston, Illinois. The objective of the Conference was to provide a forum for the exchange of information about the current state of TDR innovation between practitioners and researchers in all levels of the public and private sector"--Prelim. screens.
Publisher: Infrastructure Technology Institute Northwestern University
ISBN: 9780971263109
Category : Engineering geology
Languages : en
Pages :
Book Description
"This publication includes papers presented at the Second International Time Domain Reflectometry (TDR) Symposium and Workshop for Innovative Geotechnical Applications held at Northwestern University, September 5-7, 2001, in Evanston, Illinois. The objective of the Conference was to provide a forum for the exchange of information about the current state of TDR innovation between practitioners and researchers in all levels of the public and private sector"--Prelim. screens.
Aqueous Dielectrics
Author: J. B. Hasted
Publisher:
ISBN:
Category : Nature
Languages : en
Pages : 324
Book Description
Publisher:
ISBN:
Category : Nature
Languages : en
Pages : 324
Book Description
Integrating Multiscale Observations of U.S. Waters
Author: National Research Council
Publisher: National Academies Press
ISBN: 0309114578
Category : Science
Languages : en
Pages : 210
Book Description
Water is essential to life for humans and their food crops, and for ecosystems. Effective water management requires tracking the inflow, outflow, quantity and quality of ground-water and surface water, much like balancing a bank account. Currently, networks of ground-based instruments measure these in individual locations, while airborne and satellite sensors measure them over larger areas. Recent technological innovations offer unprecedented possibilities to integrate space, air, and land observations to advance water science and guide management decisions. This book concludes that in order to realize the potential of integrated data, agencies, universities, and the private sector must work together to develop new kinds of sensors, test them in field studies, and help users to apply this information to real problems.
Publisher: National Academies Press
ISBN: 0309114578
Category : Science
Languages : en
Pages : 210
Book Description
Water is essential to life for humans and their food crops, and for ecosystems. Effective water management requires tracking the inflow, outflow, quantity and quality of ground-water and surface water, much like balancing a bank account. Currently, networks of ground-based instruments measure these in individual locations, while airborne and satellite sensors measure them over larger areas. Recent technological innovations offer unprecedented possibilities to integrate space, air, and land observations to advance water science and guide management decisions. This book concludes that in order to realize the potential of integrated data, agencies, universities, and the private sector must work together to develop new kinds of sensors, test them in field studies, and help users to apply this information to real problems.
Soil & Water Research
Author: United States. Agricultural Research Service. Soil and Water Conservation Research Division
Publisher:
ISBN:
Category : Hydrology
Languages : en
Pages : 90
Book Description
Publisher:
ISBN:
Category : Hydrology
Languages : en
Pages : 90
Book Description