Scientific objectives and derived system requirements of the European Space Agency's Earth Explorer 'Land-Surface Processes and Interactions Mission'

The Earth Explorer Missions are research/demonstration missions for Earth Observation that are planned for implementation in the frame of the European Space Agency's 'Living Planet' programme. The programme focuses on advancing understanding of different processes that contribute to govern the Earth Systems. One of the four Earth Explorer Missions which was the subject of a Phase A study is the Land-Surface Processes and Interactions Mission (LSPIM). The scientific objectives are the study of land surface processes and their interactions with the atmosphere. It focuses on the measurement of surface characteristics such as albedo, reflectance, bidirectional reflectance distribution function (BRDF) and surface temperature, which are linked to the processes driving bio/geophysical and biochemical variables. To fulfil the mission requirements a hyperspectral imager is proposed as the LSPIM core instrument. The LSPIM imaging spectrometer will provide contiguous spectral coverage in 142 bands within the VIS/NIR/SWIR spectral region with spectral resolution between 10 and 15 nm. Furthermore, TIR observations will be performed by a radiometer in two wavebands. A spatial resolution of 50 m x 50 m with a swath width of 50 km at nadir will be provided. This mission will also have a de-pointing capability for BRDF observations along-hack and areal access across-track such that each site of interest can be revisited at 3 days intervals. It is the purpose of this paper to outline the planned spaceborne mission, its scientific objectives and the derived system requirements.