NASA Plans for Spaceborne Lidar: The Earth Observing System

Abstract

Observations of the Earth’s atmosphere and surface from space platforms has made dramatic progress over the period of the last twenty-five years. A primary activity which occupied both scientists and engineers during this period was the design of passive imaging systems. The challenge of designing these systems was to make the delicate optics required to achieve reasonable spatial resolution such that it could survive the trauma of launch and still provide observations for a reasonable period of time. These instruments were designed to have widely differing spectral characteristics from the ultraviolet to the microwave. Engineering efforts were continually given to improving the lifetimes of both spacecraft systems and the observational instruments which, in turn, encouraged the development of standardized data processing hardware and software to display and analyze these data. These imaging systems have reached a high degree of sophistication in the Thematic Mapper instrument on Landsat and the High Resolution Infrared Sounder and the Microwave Sounding Unit on the operational NOAA spacecraft Operational satellites are the logical application of techniques developed in the research and development process. The existence of such operational systems signals the maturity of the satellite Earth observations effort using passive sensors.