Dielectric Approaches of Sediment-surface-level Estimation by Time Domain Reflectometry

DOI Web Site 2 Citations 15 References

Bibliographic Information

Other Title
  • 時間領域反射法による水中堆積土砂表面位の評価法
  • ジカン リョウイキ ハンシャホウ ニ ヨル スイチュウ タイセキ ドシャ ヒョウメンイ ノ ヒョウカホウ

Search this article

Abstract

To establish a method for monitoring the fluctuations of river or lake sedimentary volume by means of time domain reflectometry (TDR), the surface levels of sediments composed of sand or gravel were measured using a 48cm-length TDR probe in laboratory and compared with two dielectric estimation approaches. In the experiments, the probe was vertically set under water surface to be across two layers of water and sediment. Giving microwave step-pulse to the probe, we could obtain the TDR waveform which contained the pulse reflections at the water-sediment interface and the end of probe. The sediment surface level hsed estimated by partial-range propagation method PPM, where a linear function of the travel time (tw) determined from the former reflection is employed, was in good agreement with the actual level. In whole-range propagation method WPM based on the travel time (tt) given from the latter reflection and the sediment relative permittivity εsed, the estimation error of εsed augmented with increase in grain size of the sand or gravel resulted in low accuracy of hsed. The inaccuracy, however, was improved by modifying εsed with the correction coefficient (Cg) expressed as a linear function of the middle grain size (Dmid). PPM and WPM could be reasonably used for the hsed-estimation with TDR.

Journal

Citations (2)*help

See more

References(15)*help

See more

Related Projects

See more

Keywords

Details 詳細情報について

Report a problem

Back to top