Introduction: Remote Sensing and Clay (Soil Moisture Content)
Remote sensing is defined as the acquisition of information about the condition and/or state of a target by a sensor that is not in direct physical contact with it. This information is normally transmitted in the form of electromagnetic radiation (emr); hence it is a non-destructive, silent technology. The source of this energy may be 'active' or 'passive.'
The relationship between the 'source' signal interacting with a target and the 'received' signal being sensed provides information about the earth's surface and is used in remote sensing to characterize the surface. The information about an object is of 2 kinds: (1) it relates to the objects morphology (size, shape, and texture) from the way it is illuminated and
shadowed by its relationship to the source of light and; (2) the way light is reflected and absorbed by the object shows up as the object's brightness and color.
Remote sensing is both a science and an application. As a science we are interested in how electromagnetic energy interacts with the surface of the earth. As an application, remote sensing is a tool for observations to study, manage, and monitor range, forest, soil, and water resources.
Remote sensing 'sees' mainly the surface but this is the complex, dynamic interface between gas and solid, where human impact is first and most easily felt. It is an extension of our eyes in two respects: (1) we extend our eyes above a target for synoptic viewing, and (2) we extend our eyes to different parts of the electromagnetic spectrum where we are able to 'see' through clouds or 'see' at night.
Satellite-based remote sensing tools are valuable for their synoptic coverage that provides perspectives over broad regions and thus can be used to extend local knowledge of soils to regional and global scales. Multispectral remote sensing permits the estimation of soil properties associated with...