Summary: Toward a new generation of satellite surface products?
and C. Prigent2
Received 3 April 2006; revised 18 September 2006; accepted 16 October 2006; published 11 November 2006.
 Despite the abundance and variety of remote sensing measurements, land surface
characterization from satellite observations is still very challenging. The links between the
three sources of surface information, namely the satellite observations, the in situ
measurements, and the land surface model outputs, are complex. Innovative techniques
have to be developed to merge these information sources and optimize the use of satellite
measurements for better surface products and more predictability. Concepts such as
multi-instrument/multiparameter retrieval algorithms are discussed, as well as the
synergetic use of satellite observations, model outputs, and in situ data. The need for
careful satellite calibration is stressed, and the scaling problem is emphasized. Recent
results are reviewed to indicate what the land surface remote sensing problems are and
how they might be attacked. Two concrete applications are presented: an ``all weather''
retrieval of surface skin temperature from combined microwave and infrared observations
and a soil moisture analysis from the merging of multisatellite observations and land
surface model outputs. This paper is intended to stimulate debates and collaborations
between the land surface modelers and the satellite remote sensing community for the
design of the next generation of land surface products.