Synergy of passive microwave observations, and optical/SAR observations for soil moisture estimates with emphasis on spatial disaggregation techniques

Researchers:	Bob Su
	Rogier van der Velde
	Dr. André Chanzy (INRA-Avignon, France)
	Dr Frédéric Baret (INRA-Avignon, France)
	Dr. Jean-Pierre Wigneron, INRA-Bordeaux, France
	Dr Béatrice Berthelot(NOVELTIS, France)
	Dr Marie Weiss (NOVELTIS, France)
	Dr J.-C. Calvet, METEO-FRANCE
	Dr Catherine Prigent (LERMA, France)

Organisations:	Department of Water Resources, ITC

Funding:	ESA, ITC IRF

Period:	2005 – 2007

Background and objectives

In this study the synergy of SMOS and SAR/optical observation will be addressed to increase soil moisture retrieval accuracy. The proposed synergy schemes will be designed to improve the retrieval algorithms along two main directions.

ITC is responsible for Task 2 and in particular the following WPs:

-	WP 210: SAR / ASAR method

-	WP 220: Microwave radiometer method

-	WP 240: Thermal method

-	WP 250: Synthesis.

Task 2: Analysis of methods used to retrieve soil moisture.

In this task, we will perform a state of the art review on the following techniques

-	Microwave radiometry at higher frequencies (C-band, X- band) which is already implemented on orbiting satellites;

-	The C-band scatterometry (wind scatterometer);

-	SAR operating at L and C bands;

-	Soil moisture products derived from thermal infrared observations.

This study will lead to an inventory list of soil moisture products. Three main outputs are expected:

-	identify the product redundancy with other source of soil moisture information. Such source of data could be further used to evaluate the quality of SMOS retrievals.

-	the performance of SAR system to produce soil moisture maps over large areas and with limited ancillary information. Such maps could be a key element in the dis-aggregation exercise.

the methodology used to derived soil moisture from microwave radiometry at higher frequencies (C Band and higher) or scatterometry, which already addressed difficulties similar than those expected with the implementation of SMOS retrieval algorithms. It would be instructive to evaluate the capability to estimate soil moisture of similar approaches, operating with much less appropriate measurement configurations.