1) La descarga del recurso depende de la página de origen
2) Para poder descargar el recurso, es necesario ser usuario registrado en Universia


Opción 1: Descargar recurso

Detalles del recurso

Descripción

For more than six years, the Soil Moisture and Ocean Salinity (SMOS) mission has provided multi angular and full-polarization brightness temperature (TB) measurements at L-band. Geophysical products such as soil moisture (SM) and vegetation optical depth at nadir (tau(sub nad)) are retrieved by an operational algorithm using TB observations at different angles of incidence and polarizations. However, the quality of the retrievals depends on several surface effects, such as vegetation, soil roughness and texture, etc. In the microwave forward emission model used in the retrievals (L-band Microwave Emission Model, L-MEB),soil roughness is modeled with a semi-empirical equation using four main parameters (Q(sub r), H(sub r), N(sub rp), with p = H or V polarizations). At present, these parameters are calibrated with data provided by airborne studies and in situ measurements made at a local scale that is not necessarily representative of the large SMOS footprints (43 km on average) at global scale. In this study, we evaluate the impact of the calibrated values of N(sub rp) and H(sub r) on the SM and tau(sub nad) retrievals based on SMOS TB measurements (SMOS Level 3 product) over the Soil Climate Analysis Network (SCAN) network located in North America over five years (2011-2015). In this study, Qr was set equal to zero and we assumed that N(sub rH)= N(sub rV). The retrievals were performed by varying N(sub rp) from 1 to 2 by steps of 1 and H(sub r) from 0 to 0.6 by steps of 0.1. At satellite scale, the results show that combining vegetation and roughness effects in a single parameter provides the best results in terms of soil moisture retrievals, as evaluated against the in situ SM data. Even though our retrieval approach was very simplified, as we did not account for pixel heterogeneity, the accuracy we obtained in the SM retrievals was almost systematically better than those of the Level 3 product. Improved results were also obtained in terms of optical depth retrievals. These new results may have key consequences in terms of calibration of roughness effects within the algorithms of the SMOS (ESA) and the SMAP (NASA) space missions.

Pertenece a

NASA Technical Reports Server (NTRS)  

Autor(es)

Fernandez -  Moran, Roberto -  Mialon, Arnaud -  Parrens, Marie -  Al -  Yarri, Amen -  Wigernon, Jean -  Pierre -  Kerr, Yann -  O'Neill, Peggy -  Al Bitar, Ahmad -  Richaume, Philippe - 

Id.: 69703671

Versión: 1.0

Estado: Final

Tipo:  text - 

Palabras claveEarth Resources and Remote Sensing - 

Cobertura:  Unclassified, Unlimited, Publicly available - 

Tipo de recurso: GSFC-E-DAA-TN39645  -  International Journal of Applied Earth Observation and Geoinformation (ISSN 0303-2434); Volume 55; 73-86  - 

Tipo de Interactividad: Expositivo

Nivel de Interactividad: muy bajo

Audiencia: Estudiante  -  Profesor  -  Autor  - 

Estructura: Atomic

Coste: no

Copyright: sí

: Copyright

Formatos:  text - 

Requerimientos técnicos:  Browser: Any - 

Relación: [IsBasedOn] Other Sources

Fecha de contribución: 11-mar-2017

Contacto:

Localización:

Otros recursos del mismo autor(es)

  1. Tear Cytokine Biomarkers in Dry Eye Patients Subjected to Environmental Stress and Treated with Topical 0.1% Fluorometholone
  2. Thyroid Surgery in Children: Clinical Outcomes © 2015 Georg Thieme Verlag KG Stuttgart New York.Aim The aim of this study was to review the outcome...
  3. Guia de campo dos cetáceos dos Açores Os Cetáceos (baleias e golfinhos) são um dos 5 grupos de mamíferos marinhos, juntamente com os piníp...
  4. Local stabilization of compressible Navier-Stokes equations in one dimension around non-zero velocity In this paper, we study the local stabilization of one dimensional compressible Navier-Stokes equati...
  5. Estudando e valorizando os cetáceos dos Açores Nos Açores ocorrem pelo menos 25 espécies diferentes de cetáceos (baleias e golfinhos). Algumas pode...

Otros recursos de la mismacolección

No existen otros recursos

Aviso de cookies: Usamos cookies propias y de terceros para mejorar nuestros servicios, para análisis estadístico y para mostrarle publicidad. Si continua navegando consideramos que acepta su uso en los términos establecidos en la Política de cookies.