Feasibility of measuring directly distribution of the emissivities for territorial surface on the remote sensing platforms

This paper reviews the basic principle of measuring emissivity by using carbon dioxide laser in 10.6 μm for longer distance which was presented by authors several years ago. When the technique is extended to determine the two dimensional distribution of the territorial surface emissivities on airborne or spaceborne platforms, key points should be completed. (1) The power of the carbon dioxide laser must reach a level that can cause obvious change of signal in the thermal infrared detector for a distance between the detector and the ground surface. (2) The wavelength of the carbon dioxide laser should be coincident with th thermal infrared scanner. (3) Two images ought to be obtained (before and after irradiating with the carbon dioxide laser), and its beam must keep a simultaneous scanning with a phase difference of one pixel. That means dual scanning should be designed