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A Polarimetric First-Order Model of Soil Moisture Effects on the DInSAR Coherence

Zwieback, Simon and Hensley, Scott and Hajnsek, Irena (2015) A Polarimetric First-Order Model of Soil Moisture Effects on the DInSAR Coherence. Remote Sensing, 7 (6), pp. 7571-7596. Multidisciplinary Digital Publishing Institute (MDPI). doi: 10.3390/rs70607571. ISSN 2072-4292.

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Official URL: http://www.mdpi.com/2072-4292/7/6/7571

Abstract

Changes in soil moisture between two radar acquisitions can impact the observed coherence in differential interferometry: both coherence magnitude | | and phase � are affected. The influence on the latter potentially biases the estimation of deformations. These effects have been found to be variable in magnitude and sign, as well as dependent on polarization, as opposed to predictions by existing models. Such diversity can be explained when the soil is modelled as a half-space with spatially varying dielectric properties and a rough interface. The first-order perturbative solution achieves–upon calibration with airborne L band data–median correlations � at HH polarization of 0.77 for the phase �, of 0.50 for | |, and for the phase triplets � of 0.56. The predictions are sensitive to the choice of dielectric mixing model, in particular the absorptive properties; the differences between the mixing models are found to be partially compensatable by varying the relative importance of surface and volume scattering. However, for half of the agricultural fields the Hallikainen mixing model cannot reproduce the observed sensitivities of the phase to soil moisture. In addition, the first-order expansion does not predict any impact on the HV coherence, which is however empirically found to display similar sensitivities to soil moisture as the co-pol channels HH and VV. These results indicate that the first-order solution, while not able to reproduce all observed phenomena, can capture some of the more salient patterns of the effect of soil moisture changes on the HH and VV DInSAR signals. Hence it may prove useful in separating the deformations from the moisture signals, thus yielding improved displacement estimates or new ways for inferring soil moisture.

Item URL in elib:https://elib.dlr.de/96599/
Document Type:Article
Title:A Polarimetric First-Order Model of Soil Moisture Effects on the DInSAR Coherence
Authors:
AuthorsInstitution or Email of AuthorsAuthor's ORCID iDORCID Put Code
Zwieback, SimonETH ZürichUNSPECIFIEDUNSPECIFIED
Hensley, ScottJPL, PasadenaUNSPECIFIEDUNSPECIFIED
Hajnsek, IrenaUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Date:8 June 2015
Journal or Publication Title:Remote Sensing
Refereed publication:Yes
Open Access:Yes
Gold Open Access:Yes
In SCOPUS:Yes
In ISI Web of Science:Yes
Volume:7
DOI:10.3390/rs70607571
Page Range:pp. 7571-7596
Editors:
EditorsEmailEditor's ORCID iDORCID Put Code
Baghdadi, NicolasUNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Thenkabail, Prasad S.UNSPECIFIEDUNSPECIFIEDUNSPECIFIED
Publisher:Multidisciplinary Digital Publishing Institute (MDPI)
ISSN:2072-4292
Status:Published
Keywords:DInSAR; InSAR; interferometry; electromagnetic model; soil moisture; deformations; displacement
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Space
HGF - Program Themes:Earth Observation
DLR - Research area:Raumfahrt
DLR - Program:R EO - Earth Observation
DLR - Research theme (Project):R - Vorhaben Multi-dimensionale SAR-Auswertung (old)
Location: Oberpfaffenhofen
Institutes and Institutions:Microwaves and Radar Institute > Radar Concepts
Deposited By: Radzuweit, Sibylle
Deposited On:10 Jun 2015 13:08
Last Modified:14 Dec 2019 04:26

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