Measurements of Soil Surface Roughness During the Fourth Microwave Water and Energy Balance Experiment: April 18 through June 13, 2005

Abstract

Passive microwave signatures have been used to retrieve geophysical parameters, such as soil temperature [Njoku and Li, 1999], moisture [Jackson et al., 1995], and surface roughness [Wegmüller and Mätzler, 1999]. One of the challenges in the parameter retrieval is the effect of soil surface roughness on the microwave emission. We conducted soil surface roughness measurements as part of our fourth Microwave Water and Energy Balance Experiment (MicroWEX-4) to understand the effects of surface roughness on microwave signatures at 6.7 GHz (λ = 4.48 cm). The dataset will also be used to develop and validate surface roughness models. In this report, we summarize briefly the theoretical background of surface roughness characteristics and discuss methodology and results of the roughness experiments. This document is Circular 1483, one of a series of the Department of Agricultural and Biological Engineering, UF/IFAS Extension. Original publication date November 2005. CIR1483/AE363: Measurements of Soil Surface Roughness During the Fourth Microwave Water and Energy Balance Experiment: April 18–June 13, 2005 (ufl.edu)

Assessment of NASA SMAP Soil Moisture Products for Agricultural Regions in Central Mexico: An Analysis Based on the THEXMEX Dataset

“…Surface soil roughness measurements of root-mean-square (RMS) height (h RM S ) and correlation length (cl) were also collected using a traditional grid board method [41] during the sampling dates for each site (see Fig. 2).…”

“…Ten 2-D surface profiles pictures per site were taken using a 1.5-m-long grid board. The surface profile from each grid board was digitized individually to calculate h RMS and cl [41]. Each soil roughness measurement was acquired by averaging the ten independent h RMS and cl values.…”