Introduction: Remote Sensing and Sensitivity Analysis

Abstract

By its basic definition, remote sensing is simply indirect measurement. In a vast variety of practical applications, we cannot measure quantities of interest directly, but we can measure some other quantities that are related to quantities of interest by some known relations. For example, targeted measurements of spectral radiances on top of the atmosphere in the thermal infrared spectral region provide a capability to measure atmospheric profiles of temperature and mixing ratios of atmospheric constituents. Another example: targeted measurements of position and velocity of a spacecraft orbiting a planet provide a capability to measure spherical harmonics of the gravity field of this planet.