@article{fdi:010066941,
  title = {{T}hree years of {L}-band brightness temperature measurements in a mountainous area : topography, vegetation and snowmelt issues},
  author = {{P}ellarin, {T}. and {M}ialon, {A}. and {B}iron, {R}omain and {C}oulaud, {C}. and {G}ibon, {F}. and {K}err, {Y}. and {L}afaysse, {M}. and {M}ercier, {B}. and {M}orin, {S}. and {R}edor, {I}. and {S}chwank, {M}. and {V}olksch, {I}.},
  editor = {},
  language = {{ENG}},
  abstract = {{L}-band passive measurements (1.4 {GH}z) over continental areas are known to be related to surface soil moisture. {T}wo satellite missions were recently launched to measure land surface emissions at this frequency band ({SMOS}-{S}oil {M}oisture and {O}cean {S}alinity in 2009 and {SMAP}-{S}oil {M}oisture {A}ctive/{P}assive in 2015). {I}n order to improve soil moisture retrievals from satellite data, ground-based radiometer systems operating at the same frequency were deployed over specified areas to investigate the {L}-band emission of various land covers under various climatological conditions. {I}n this study, three years of {L}-band passive measurements from a radiometer installed on top of a steep mountain in the {F}rench {A}lps were analyzed and compared to {L}-band passive simulations. {T}he innovative radiometer location led to large footprints due to the distance between the radiometer and the area under study. {T}his experiment also produced microwave measurements affected by various potential difficulties typically encountered in {SMOS}/{SMAP} satellite missions: topography, heterogeneous footprints, dry/wet snow events, dew and vegetation litter. {B}ased on in situ and modeling data, this paper investigates the potential of a radiative transfer model ({L}-band {M}icrowave {E}mission of the {B}iosphere, {L}-{MEB}) to simulate {L}-band measurements and analyzes the differences with {ELBARA} observations. {F}irst, it was found that the topography generated a mixing of the horizontal and vertical polarizations. {I}n addition, a large positive bias was found on {ELBARA} measurements (31 {K} and 12 {K} in horizontal and vertical polarizations respectively). {I}nvestigations showed that the sky reflection measured by the radiometer was partially substituted by land reflection coming from the surrounding topography. {S}econd, the low-vegetation emission was investigated and highlighted the inability of the {MODIS} {NDVI} product to correctly represent the vegetation dynamics. {F}inally, dry snow conditions were found to have non-negligible impact at {L}-band and a particular signature was found during snow melting periods, with potential applications at the {SMOS}/{SMAP} spatial scales (similar to 40 km).},
  keywords = {{FRANCE}},
  booktitle = {},
  journal = {{R}emote {S}ensing of {E}nvironment},
  volume = {180},
  numero = {{N}o {S}p{\'e}cial},
  pages = {85--98},
  ISSN = {0034-4257},
  year = {2016},
  DOI = {10.1016/j.rse.2016.02.047},
  URL = {https://www.documentation.ird.fr/hor/fdi:010066941},
}