Imaging spectrometry in the post-EOS era

It is argued that the next generation of imaging spectrometers will need greater capabilities and more flexibility than the High Resolution Imaging Spectrometer (HIRIS) and the Moderate Resolution Imaging Spectrometer (MODIS), which were designed for the first Earth Observation System platform. The emerging technology that represents a major advance in the scientific utility of imaging spectrometry is the acoustooptic tunable filters, (AOTFs). AOTFs are compact robust solid-state crystals which provide rapid (millisecond) electronically-controlled spectral tunability. This paper discusses the evolving requirements of imaging spectrometers and examines the basic system parameters of the HIRIS and the MODIS concepts involving the use of AOTFs, which will satisfy these requirements.