The Experts below are selected from a list of 62391 Experts worldwide ranked by ideXlab platform

Axel Bronstert - One of the best experts on this subject based on the ideXlab platform.

  • A quality assessment of Spatial TDR soil moisture measurements in homogenous and heterogeneous media with laboratory experiments
    Hydrology and Earth System Sciences, 2010
    Co-Authors: Thomas Graeff, Erwin Zehe, Stefan Schlaeger, Markus Morgner, Andreas Bauer, Rolf Becker, Benjamin Creutzfeldt, Axel Bronstert
    Abstract:

    Abstract. Investigation of transient soil moisture profiles yields valuable information of near- surface processes. A recently developed reconstruction algorithm based on the telegraph equation allows the inverse estimation of soil moisture profiles along coated, three rod TDR probes. Laboratory experiments were carried out to prove the results of the inversion and to understand the influence of probe rod deformation and solid objects close to the probe in heterogeneous media. Differences in rod geometry can lead to serious misinterpretations in the soil moisture profile, but have small influence on the average soil moisture along the probe. Solids in the Integration Volume have almost no effect on average soil moisture, but result in locally slightly decreased moisture values. Inverted profiles obtained in a loamy soil with a clay content of about 16% were in good agreement with independent measurements.

  • A quality assessment of spatial TDR soil moisture measurements in homogenous and heterogeneous media with laboratory experiments
    2010
    Co-Authors: Thomas Graeff, Erwin Zehe, Stefan Schlaeger, Markus Morgner, Andreas Bauer, Rolf Becker, Benjamin Creutzfeldt, Axel Bronstert
    Abstract:

    Abstract. Investigation of transient soil moisture profiles yields valuable information of near- surface processes. A recently developed reconstruction algorithm based on the telegraph equation allows the inverse estimation of soil moisture profiles along coated, three rod TDR probes. Laboratory experiments were carried out to prove the results of the inversion and to understand the influence of probe rod deformation and solid objects close to the probe in heterogonous media. Differences in rod geometry can lead to serious misinterpretations in the soil moisture profile but have small influence on the average soil moisture along the probe. Solids in the Integration Volume have almost no effect on average soil moisture but result in locally slightly decreased moisture values. Inverted profiles obtained in a loamy soil with a clay content of about 16% were in good agreement with independent measurements.

Thomas Graeff - One of the best experts on this subject based on the ideXlab platform.

  • A quality assessment of Spatial TDR soil moisture measurements in homogenous and heterogeneous media with laboratory experiments
    Hydrology and Earth System Sciences, 2010
    Co-Authors: Thomas Graeff, Erwin Zehe, Stefan Schlaeger, Markus Morgner, Andreas Bauer, Rolf Becker, Benjamin Creutzfeldt, Axel Bronstert
    Abstract:

    Abstract. Investigation of transient soil moisture profiles yields valuable information of near- surface processes. A recently developed reconstruction algorithm based on the telegraph equation allows the inverse estimation of soil moisture profiles along coated, three rod TDR probes. Laboratory experiments were carried out to prove the results of the inversion and to understand the influence of probe rod deformation and solid objects close to the probe in heterogeneous media. Differences in rod geometry can lead to serious misinterpretations in the soil moisture profile, but have small influence on the average soil moisture along the probe. Solids in the Integration Volume have almost no effect on average soil moisture, but result in locally slightly decreased moisture values. Inverted profiles obtained in a loamy soil with a clay content of about 16% were in good agreement with independent measurements.

  • A quality assessment of spatial TDR soil moisture measurements in homogenous and heterogeneous media with laboratory experiments
    2010
    Co-Authors: Thomas Graeff, Erwin Zehe, Stefan Schlaeger, Markus Morgner, Andreas Bauer, Rolf Becker, Benjamin Creutzfeldt, Axel Bronstert
    Abstract:

    Abstract. Investigation of transient soil moisture profiles yields valuable information of near- surface processes. A recently developed reconstruction algorithm based on the telegraph equation allows the inverse estimation of soil moisture profiles along coated, three rod TDR probes. Laboratory experiments were carried out to prove the results of the inversion and to understand the influence of probe rod deformation and solid objects close to the probe in heterogonous media. Differences in rod geometry can lead to serious misinterpretations in the soil moisture profile but have small influence on the average soil moisture along the probe. Solids in the Integration Volume have almost no effect on average soil moisture but result in locally slightly decreased moisture values. Inverted profiles obtained in a loamy soil with a clay content of about 16% were in good agreement with independent measurements.

Pierre Rochette - One of the best experts on this subject based on the ideXlab platform.

  • Calibration of in situ magnetic susceptibility measurements
    Geophysical Journal International, 2004
    Co-Authors: Jérôme Gattacceca, Philippe Eisenlohr, Pierre Rochette
    Abstract:

    SUMMARY The aim of this work is to calibrate a magnetic susceptibility field probe (SM30) in order to allow measurement on natural boulders of any shape and size. This calibration was performed through measurements on pebbles of different shapes, sizes and lithologies. We model a correction factor (geometric factor) that has to be applied to the SM30 measurement to obtain the real Volume magnetic susceptibility of a sample of known Volume. This geometric factor depends mostly on the Volume of the sample, and to a lesser extent on its shape. We also present an original magnetic measurement scheme that provides, with three SM30 measurements at different distances, an estimation of the Volume of a sample. By combining the two calibration models, it is possible to obtain the Volume magnetic susceptibility of a natural sample with only three SM30 measurements, without requiring additional information such as sample Volume. On the other hand, the calibration performed on a semi-infinite homogeneous body with variable measuring distance leads to a 2-D model of the SM30 response over its Integration Volume and allows the determination, with a sufficient number of discrete measurement at variable distance, of the thickness and susceptibility of the different layers of a composite body. Both types of calibration were successfully validated on natural or synthetic samples. Therefore the SM30 portable susceptometer appears to be a suitable instrument to perform in situ magnetic susceptibility measurement of individual boulders or to establish magnetic susceptibility profiles. In addition, the modest dimensions of the probe and the relative simplicity of the proposed measurement schemes should enable automation of the measurements that could find applications for robotic exploration of solid bodies of the solar system, for example.

  • GJI Geomagnetism, rock magnetism and palaeomagnetism Calibration of in situ magnetic susceptibility measurements
    2004
    Co-Authors: Jérôme Gattacceca, Philippe Eisenlohr, Pierre Rochette
    Abstract:

    SUMMARY The aim of this work is to calibrate a magnetic susceptibility field probe (SM30) in order to allow measurement on natural boulders of any shape and size. This calibration was performed through measurements on pebbles of different shapes, sizes and lithologies. We model a correction factor (geometric factor) that has to be applied to the SM30 measurement to obtain the real Volume magnetic susceptibility of a sample of known Volume. This geometric factor depends mostly on the Volume of the sample, and to a lesser extent on its shape. We also present an original magnetic measurement scheme that provides, with three SM30 measurements at different distances, an estimation of the Volume of a sample. By combining the two calibration models, it is possible to obtain the Volume magnetic susceptibility of a natural sample with only three SM30 measurements, without requiring additional information such as sample Volume. On the other hand, the calibration performed on a semi-infinite homogeneous body with variable measuring distance leads to a 2-D model of the SM30 response over its Integration Volume and allows the determination, with a sufficient number of discrete measurement at variable distance, of the thickness and susceptibility of the different layers of a composite body. Both types of calibration were successfully validated on natural or synthetic samples. Therefore the SM30 portable susceptometer appears to be a suitable instrument to perform in situ magnetic susceptibility measurement of individual boulders or to establish magnetic susceptibility profiles. In addition, the modest dimensions of the probe and the relative simplicity of the proposed measurement schemes should enable automation of the measurements that could find applications for robotic exploration of solid bodies of the solar system, for example.

Stefan Schlaeger - One of the best experts on this subject based on the ideXlab platform.

  • A quality assessment of Spatial TDR soil moisture measurements in homogenous and heterogeneous media with laboratory experiments
    Hydrology and Earth System Sciences, 2010
    Co-Authors: Thomas Graeff, Erwin Zehe, Stefan Schlaeger, Markus Morgner, Andreas Bauer, Rolf Becker, Benjamin Creutzfeldt, Axel Bronstert
    Abstract:

    Abstract. Investigation of transient soil moisture profiles yields valuable information of near- surface processes. A recently developed reconstruction algorithm based on the telegraph equation allows the inverse estimation of soil moisture profiles along coated, three rod TDR probes. Laboratory experiments were carried out to prove the results of the inversion and to understand the influence of probe rod deformation and solid objects close to the probe in heterogeneous media. Differences in rod geometry can lead to serious misinterpretations in the soil moisture profile, but have small influence on the average soil moisture along the probe. Solids in the Integration Volume have almost no effect on average soil moisture, but result in locally slightly decreased moisture values. Inverted profiles obtained in a loamy soil with a clay content of about 16% were in good agreement with independent measurements.

  • A quality assessment of spatial TDR soil moisture measurements in homogenous and heterogeneous media with laboratory experiments
    2010
    Co-Authors: Thomas Graeff, Erwin Zehe, Stefan Schlaeger, Markus Morgner, Andreas Bauer, Rolf Becker, Benjamin Creutzfeldt, Axel Bronstert
    Abstract:

    Abstract. Investigation of transient soil moisture profiles yields valuable information of near- surface processes. A recently developed reconstruction algorithm based on the telegraph equation allows the inverse estimation of soil moisture profiles along coated, three rod TDR probes. Laboratory experiments were carried out to prove the results of the inversion and to understand the influence of probe rod deformation and solid objects close to the probe in heterogonous media. Differences in rod geometry can lead to serious misinterpretations in the soil moisture profile but have small influence on the average soil moisture along the probe. Solids in the Integration Volume have almost no effect on average soil moisture but result in locally slightly decreased moisture values. Inverted profiles obtained in a loamy soil with a clay content of about 16% were in good agreement with independent measurements.

Markus Morgner - One of the best experts on this subject based on the ideXlab platform.

  • A quality assessment of Spatial TDR soil moisture measurements in homogenous and heterogeneous media with laboratory experiments
    Hydrology and Earth System Sciences, 2010
    Co-Authors: Thomas Graeff, Erwin Zehe, Stefan Schlaeger, Markus Morgner, Andreas Bauer, Rolf Becker, Benjamin Creutzfeldt, Axel Bronstert
    Abstract:

    Abstract. Investigation of transient soil moisture profiles yields valuable information of near- surface processes. A recently developed reconstruction algorithm based on the telegraph equation allows the inverse estimation of soil moisture profiles along coated, three rod TDR probes. Laboratory experiments were carried out to prove the results of the inversion and to understand the influence of probe rod deformation and solid objects close to the probe in heterogeneous media. Differences in rod geometry can lead to serious misinterpretations in the soil moisture profile, but have small influence on the average soil moisture along the probe. Solids in the Integration Volume have almost no effect on average soil moisture, but result in locally slightly decreased moisture values. Inverted profiles obtained in a loamy soil with a clay content of about 16% were in good agreement with independent measurements.

  • A quality assessment of spatial TDR soil moisture measurements in homogenous and heterogeneous media with laboratory experiments
    2010
    Co-Authors: Thomas Graeff, Erwin Zehe, Stefan Schlaeger, Markus Morgner, Andreas Bauer, Rolf Becker, Benjamin Creutzfeldt, Axel Bronstert
    Abstract:

    Abstract. Investigation of transient soil moisture profiles yields valuable information of near- surface processes. A recently developed reconstruction algorithm based on the telegraph equation allows the inverse estimation of soil moisture profiles along coated, three rod TDR probes. Laboratory experiments were carried out to prove the results of the inversion and to understand the influence of probe rod deformation and solid objects close to the probe in heterogonous media. Differences in rod geometry can lead to serious misinterpretations in the soil moisture profile but have small influence on the average soil moisture along the probe. Solids in the Integration Volume have almost no effect on average soil moisture but result in locally slightly decreased moisture values. Inverted profiles obtained in a loamy soil with a clay content of about 16% were in good agreement with independent measurements.