ELBARA Field Campaign 2003
For 25 years several
research groups have been using microwave radiometry successfully to retrieve
land surface parameters, with many signature studies over the years. However, there
is still a demand for additional measurements. To improve our understanding of
scattering and emission we need in addition to the microwave parameters a
detailed knowledge of the scene.
From 2000 to 2003 a research study was carried out to obtain the
land surface parameters soil moisture, soil temperature and vegetation optical
depth on a global scale from satellite derived passive microwave signals. The
main purpose of this study was to generate a global soil moisture data base
which could be used in global climate studies. After three years a methodology
was developed to obtain these land surface parameters from the 6.6 GHz scanning
multichannel microwave radiometer (SMMR) on board the Nimbus 7 satellite.
During this investigation a number of logical follow up studies
have been identified and one of the major topics was the derivation of
vegetation characteristics from the microwave signal. Attempts to derive these
biophysical properties from microwave signals have been limited and largely
empirical, for the most part. Although some research groups developed some
promising techniques to obtain vegetation water content and biomass values out
of microwave signals.
By setting up a completely controlled field experiment with an
L-band field radiometer it may be possible to retrieve vegetation
characteristics from the microwave signal and the main objective of this
experiment was to understand the microwave emission of vegetated and non
vegetated areas on both satellite and field scale and to improve the algorithms
to use the microwave brightness temperatures to estimate soil moisture, soil
temperature, canopy temperature and vegetation properties like biomass,
vegetation water content and vegetation structure.
We used an approach which has the advantage to make it possible to
measure almost simultaneously three different field sites with just one
microwave instrument. To our knowledge this is quite unique and gives us the
opportunity to study the differences en similarities of the temporal
development of the signatures of vegetated and non vegetated sites.
During this experiment we used the ELBARA Passive Microwave
Radiometer. This instrument is property of the Institute
of Terrestrial Ecosystems, ETH, in
Publications
related to the ELBARA Field Campain 2003
Ø Holmes, T.R.H. (2003). Measuring
surface soil parameters using passive microwave reomte sensing. The ELBARA
field campaign 2003. M.Sc. Thesis, Vrije Universiteit Amsterdam, Faculty of
Earth- and Life Sciences, 71 pp. Full text pdf
(869 kB)
Ø De Jeu, R.A.M., T.
Holmes, and M. Owe, (2004). Deriving land surface parameters from 3 different
vegetated sites with the ELBARA 1.4 GHz passive microwave radiometer. In Proceedings
of SPIE series, Remote Sensing for Agriculture, Ecosystems and Hydrology V,
Vol. 5232,
Ø De Jeu, R.A.M., B.G.
Heusinkveld, H.F. Vugts, T. Holmes, and M. Owe, (2004). Remote Sensing
Techniques to measure dew: the detection of canopy water with an L-band passive
microwave radiometer and a specral reflectance sensor. In Proceedings of
SPIE series, Remote Sensing for Agriculture, Ecosystems and Hydrology VI,
Vol. 5568, Maspalomas,
Ø De Jeu, R.A.M., T.
Holmes, and M. Owe, (2005). Determination of the Effect of Dew on Passive
Microwave Observations from Space. In Proceedings of SPIE series, Remote
Sensing for Agriculture, Ecosystems and Hydrology VII, Vol. 5976,
Publications
related to other ELBARA Field Campains
Ø Schneeberger, K., M.
Schwank, C. Stamm, P.D. Rosnay, C. Mätzler, and H. Flühler. 2004.
Topsoil structure influencing soil water retrieval by microwave radiometry. Vadose Zone Journal 3:1169-1179.
Ø Schwank, M., C.
Mätzler, M. Guglielmetti, and H. Flühler. 2005. L-Band Radiometer
Measurements of Soil Water under Growing Clover Grass. IEEE Trans. Geosci. Remote Sensing 43:2225-2237.
Ø Schwank, M., M.
Stähli, H. Wydler, J. Leuenberger, C. Mätzler, and H. Flühler.
2004. Microwave L-Band Emission of Freezing Soil. IEEE Trans. Geosci. Remote Sensing 42:1252-1261.
Ø Guglielmetti, M.,
Schwank, M., Mätzler, C., Oberdörster, C., Vanderborght, J., &
Flühler, H. 2006. Measured Microwave Radiative Transfer Properties of a
Deciduous Forest Canopy, Remote Sensing
of Environment, submitted
Pictures
Links
For futher information please contact Richard de Jeu