Soil Moisture in Pasture Fields Using ERS-1 SAR Data: Preliminary Results

Filho, Otto Corrêa Rotunno; Soulis, E. D.; Kouwen, N.; Kolahchi, Abdolnabi Abdeh; Pultz, T.J.; Crevier, Y.

doi:10.1080/07038992.1996.10874640

Cited by 12 publications

(1 citation statement)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The most advantageous electromagnetic region for remote sensing of soil moisture is microwave region (Kerr et al 2001). Microwave remote sensing has the capability of direct measurement of soil moisture content at watershed scale under diverse conditions over long periods of time (Filho et al 1996, Jackson et al 1999. It remains largely unaffected by cloud cover and variable surface solar illumination (Njoku and Entekhabi, 1996).…”

Section: : Introductionmentioning

confidence: 99%

Analysis of the influence of soil temperature and soil surface conditions on soil moisture estimation using the Theta Probe

Dilawari

View full text Add to dashboard Cite

Soil moisture is an important component of numerous systems, influencing crop development, and runoff and infiltration partitioning, among other things. However, due to its spatial and temporal variability, it is difficult to estimate soil moisture consistently using conventional techniques such as gravimetric sampling, which is point-based and timeconsuming. Therefore, to overcome this drawback in soil moisture estimation and mapping, and to facilitate its measurement spatially and temporarily, remote sensing in microwave, visible, near infrared and short wave infrared is being explored and is proving to be a promising technique. But to develop models using spectral data there is a need to validate these models using ground truth data collected using gravimetric measurements and various dielectric and capacitance probes. Theta probe is one such dielectric probe, which is widely used by the remote sensing community. Not only does soil surface conditions change the response of reflectance data in various spectral ranges but has been observed to influence the measurements from Theta probe. As a part of this study an attempt has been made to understand the influence of soil temperature, roughness and crusting on Theta probe measurements by analyzing moisture content as a function of time. A nonlinear relationship was observed between the actual moisture content and Theta probe soil moisture content. A t-test conducted on the estimate of temperature concluded that the effect of temperature on Theta probe measurements was insignificant, but there is a possibility that soil surface conditions involving soil roughness and crusting could be a reason for observed nonlinear!ty between actual and Theta probe measurements. Therefore, future work is suggested to test the feasibility of using Theta probe under different soil surface conditions. iv Thesis OverviewThis study focuses on the effect of different soil surface conditions on soil moisture measurement. Section 1 introduces the concept of soil moisture and various techniques that are being used to estimate it. It also discusses the advantages of remote sensing techniques over conventional techniques, and the use of the Theta probe to collect the ground truth data for validation of models developed using spectral data. This section highlights the possible concerns that might arise due to spatial and temporal variability in the soil surface conditions. In addition to discussing the working of Theta probe I have pointed out the limited literature availability related to the calibration of this probe and a need to study the effect of change in soil surface conditions on Theta probe.Section 2 describes the importance of this study and helps us to formulate an objective for this study. This section describes and uses the data that collected during a study that was initially the main focus of my research. However, in the course of this study, some interesting observations about the Theta probe were made. Section two thus concentrates upon the response of Theta probe u...

show abstract