For the definition of the Earth Explorer Land Surface Processes and Interactions Mission (LSPIM), multi-sensor hyper-spectral data were acquired by different airborne and ground-based systems during the 1999 DAISEX campaign (Digital Airborne I magi ng Spectrometer Experiment). Airborne instruments included the DAIS7915 and HYMAP which aquired data simultaneously with POLDER and LEANDRE. It is the purpose of this experiment to evidence the feasibility of quantitatively retrieving geo/biophysical variables by controlling atmospheric effects and analysing at the same time possible additional information present in directional anisotropy (BRDF). Two test sites were used during DAISEX '99, a site close to Colmar, France, and an agricultural site Barrax,, close to Albacete, Spain. Banax is also one of the LSPIM keyexperimental sites, a selection of about 100 globally distributed sites representing major ecosystems. Within LSPIM it is proposed to study these sites in detail for land surface process modelling and up-scaling from regional to global. It is the intention of this paper to outline the scientific objectives and to demonstrate first results of the DAISEX'W campaign.