 |
| Titel |
A fast TDR-inversion technique for the reconstruction of spatial soil moisture content |
| VerfasserIn |
S. Schlaeger |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 9, no. 5 ; Nr. 9, no. 5 (2005-10-13), S.481-492 |
| Datensatznummer |
250007039
|
| Publikation (Nr.) |
 copernicus.org/hess-9-481-2005.pdf |
|
|
|
|
|
| Zusammenfassung |
| Spatial moisture distribution in natural soil or other material is a
valuably information for many applications. Standard measurement techniques
give only mean or punctual results. Therefore a new inversion algorithm has
been developed to derive moisture profiles along single TDR sensor-probes.
The algorithm uses the full information content of TDR reflection data
measured from one or both sides of an embedded probe. The system consisting
of sensor probe and surrounded soil can be interpreted as a nonuniform
transmission-line. The algorithm is based on the telegraph equations for
nonuniform transmission-lines and an optimization approach to reconstruct
the distribution of the capacitance and effective conductance along the
transmission-line with high spatial resolution. The capacitance distribution
can be converted into permittivity and water content by means of a
capacitance model and dielectric mixing rules. Numerical investigations have
been carried out to verify the accuracy of the inversion algorithm. Single-
and double-sided time-domain reflection data were used to determine the
capacitance and effective conductance profiles of lossless and lossy
materials. The results show that single-sided reflection data are sufficient
for lossless (or low-loss) cases. In case of lossy material two independent
reflection measurements are required to reconstruct a reliable capacitance
profile. The inclusion of an additional effective conductivity profile leads
to an improved capacitance profile. The algorithm converges very fast and
yields a capacitance profile within a sufficiently short time. The
additional transformation to the water content requires no significant
calculation time. |
| |
|
| Teil von |
|
|
|
|
|
|
|