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Study of soil moisture change effects on L-band DInSAR phase
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Sadegh Ranjbar   , Mehdi Akhoondzadeh * |
| University of Tehran |
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Abstract: (3135 Views) |
The Differential Synthetic Aperture Radar Interferometry (DInSAR) technique is recognized as a potential remote sensing tool for detecting ground surface displacements with less than a centimetre accuracy. The surface soil moisture changes (  ) during the time between the two images as an effective parameter on interferometry phase  ), leads to incorrect calculation of ground movement . In this research, the amount and the way that affects  on wheat, rapeseed, weed, pea and idle land fields have been investigated empirically using a regression model. To do this investigation, airborne data UAVSAR (L-band) along with ground-based data in the CanEx-SM10 campaign in 2010 were used. According to the scattergraphs between and , and observing a direct and approximately linear relationship between them, some hypotheses were taken into consideration in order to use a regression modeling . Comparing the estimated 𝜑 using the calibrated regression model and calculated 𝜑 from the interferometry technique shows that the model provided the best results for the bare field in VV and HH polarizations (RMSE) of 0.3 to 0.6 rad and R2 of 69% to 72%. In general, the results of the regression model showed that without other factors’ effects on , this parameter can be modelled based on a regression function in bare fields. The model also provided acceptable results in vegetated fields (RMS of 0.6 to 0.99 rad and R2 of 40% to 55% depending on the different vegetation types and different polarizations). Comparing polarizations, fluctuations in co-polarizations (HH and VV) showed a higher correlation with . Consequently, φ is directly affected by , and significant changes in brings about a considerable error in displacement estimation. |
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| Keywords: DInSAR, phase, temporal decorrelation, surface soil moisture change. |
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Full-Text [PDF 2261 kb]
(1190 Downloads)
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Type of Study: Research |
Subject:
RS
Received: 2020/12/24 | Accepted: 2021/04/17 | Published: 2021/04/20
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