Sensors in perspective

A framework for the design of earth observational information systems, concentrating on systems for land observation, is presented, providing a perspective against which to judge the further potential for such technology. The entire process of collecting data and producing information is viewed from the standpoint of tracing the information flow from its origin at the surface of the earth through the sensor and processing system to the user. The system parameters which can influence the information flow are divided into six categories: spectral, spatial, and temporal sampling schemes, signal-to-noise characteristics, ancillary data, and information desired at output. Each of these categories is briefly examined.