Error in Radar-Derived Soil Moisture due to Roughness Parameterization: An Analysis Based on Synthetical Surface...

Area of Science:

• Remote Sensing
• Geophysics
• Soil Science

Background:

• Soil moisture retrieval from Synthetic Aperture Radar (SAR) data often shows poor correlation with backscatter coefficients.
• This inaccuracy is primarily linked to challenges in parameterizing surface roughness.

Purpose of the Study:

• To investigate how errors in roughness parameters, introduced by standard measurement techniques, affect soil moisture retrieval.
• To analyze the propagation of these errors through the Integral Equation Model (IEM) for common SAR configurations.

Main Methods:

• Theoretical study using synthetical surface profiles.
• Analysis of error propagation through the Integral Equation Model (IEM).
• Evaluation across different SAR configurations (C-band and L-band).

Main Results:

• Identified key factors influencing roughness parameterization errors: profile length, measurement count, accuracy, and trend removal.
• Demonstrated error propagation into soil moisture retrieval using the IEM.
• Found C-band SAR configurations to be less sensitive to roughness parameterization inaccuracies compared to L-band.

Conclusions:

• Standard roughness measurement techniques introduce errors that significantly impact soil moisture retrieval accuracy.
• The choice of SAR configuration (e.g., C-band vs. L-band) affects the sensitivity to these roughness-related errors.