I.

Introduction

Remote Sensing, process of obtaining information about land, water, or an object, without any physical contact between the sensor and the subject of analysis. The term remote sensing most often refers to the collection of data by instruments carried aboard aircraft or satellites. Remote sensing systems are commonly used to survey, map, and monitor the resources and environment of Earth. They also have been used to explore other planets (see Space Exploration).

There are several different types of remote sensing devices. Many systems take photographs with cameras, recording reflected energy in the visible spectrum. Other systems record electromagnetic energy beyond the range of human sight, such as infrared radiation and microwaves (see Electromagnetic Radiation). Multispectral scanners produce images across both the visible and the infrared spectrum.