<title>Passive and active high-spectral-resolution systems: competition or cooperation?</title>

Abstract

In recent years the improvement of the spectral and radiometric performances of optical detection systems has allowed the development of high spectral resolution remote sensors. Both passive and active sensors have taken advantage of this technological improvement and, as to the active ones, also from the contemporary development of new laser sources. At present, passive hyperspectral scanners with the simultaneous detection of more than 100 spectral images for each frame and fluorescence lidars with some hundreds of channels or with imaging capability are available. These instruments can now perform a remote spectroscopy of environmental targets with a spectral resolution similar to the laboratory one. However, in order to reduce the amount of data, it is necessary to exploit all the possible synergisms between active and passive optical sensors. This paper deals with the evaluation, the advantages and disadvantages of different solutions for the integration of active and passive sensors and formulates some hypothesis for sensor development and their use from flying platforms.