@article{PAR00009929,
  title = {{C}omparison of two bare-soil reflectivity models and validation with {L}-band radiometer measurements},
  author = {{S}chwank, {M}. and {V}olksch, {I}. and {W}igneron, {J}.{P}. and {K}err, {Y}ann and {M}ialon, {A}. and de {R}osnay, {P}. and {M}atzler, {C}.},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he emission of bare soils at microwave {L}-band (1-2 {GH}z) frequencies is known to be correlated with surface soil moisture. {R}oughness plays an important role in determining soil emissivity although it is not clear which roughness length scales are most relevant. {S}mall-scale (i.e., smaller than the resolution limit) inhomogeneities across the soil surface and with soil depth caused by both spatially varying soil properties and topographic features may affect soil emissivity. {I}n this paper, roughness effects were investigated by comparing measured brightness temperatures of well-characterized bare soil surfaces with the results from two reflectivity models. {T}he selected models are the air-to-soil transition model and {S}hi's parameterization of the integral equation model ({IEM}). {T}he experimental data taken from the {S}urface {M}onitoring of the {S}oil {R}eservoir {E}xperiment ({SMOSREX}) consist of surface profiles, soil permittivities and temperatures, and brightness temperatures at 1.4 {GH}z with horizontal and vertical polarizations. {T}he types of correlation functions of the rough surfaces were investigated as required to evaluate {S}hi's parameterization of the {IEM}. {T}he correlation functions were found to be clearly more exponential than {G}aussian. {O}ver the experimental period, the diurnal mean root mean square (rms) height decreased, while the correlation length and the type of correlation function did not change. {C}omparing the reflectivity models with respect to their sensitivities to the surface rms height and correlation length revealed distinct differences. {M}odeled reflectivities were tested against reflectivities derived from measured brightness, which showed that the two models perform differently depending on the polarization and the observation angle.},
  keywords = {{E}lectromagnetic scattering by rough surfaces ; microwave radiometry ; permittivity ; soil moisture},
  booktitle = {},
  journal = {{IEEE} {T}ransactions on {G}eoscience and {R}emote {S}ensing},
  volume = {48},
  numero = {1},
  pages = {325--337},
  ISSN = {0196-2892},
  year = {2010},
  DOI = {10.1109/tgrs.2009.2026894},
  URL = {https://www.documentation.ird.fr/hor/{PAR}00009929},
}