FOUNDATIONS OF REMOTE SENSING

INTRODUCTION 

Remote sensing is that the science and art of obtaining information about an object, area, or phenomenon through the analysis of knowledge acquired by a tool that's not in touch with the object, area, or phenomenon under investigation. As you read these words, you're employing remote sensing. Your eyes are acting as sensors that answer the sunshine reflected from this page. The "data" your eyes acquire are impulses like the quantity of sunshine reflected from the dark and lightweight areas on the page. These data are analyzed, or interpreted, in your mental computer to enable you to elucidate the dark areas on the page as a set of letters forming words. Beyond this, you recognize that the words form sentences and you interpret the knowledge that the sentences convey.

In many respects, remote sensing are often thought of as a reading process. Using various sensors, we remotely collect data which will be analyzed to get information about the objects, areas, or phenomena being investigated. The remotely collected data are often of the many forms, including variations effective distributions, sound wave distributions, or electromagnetic energy distributions. For example, a gravimeter acquires data on variations within the distribution of the force of gravity.  the atmosphere , airborne and/or spaceborne sensors, resulting in the generation of sensor data in pictorial and/or digital form (n. In short, we use sensors to record variations within the way earth surface features reflect and emit electromagnetic energy. The data analysis process (g) involves examining the info using various viewing and interpretation devices to research pictorial data and/or a computer to research digital sensor data.  With the help of the reference data, the analyst extracts information about the sort , extent, location, and condition of the varied resources over which the sensor data were collected. This information is then compiled (h), generally within the sort of hardcopy maps and tables or as computer files which will be merged with other "layers" of data in a geographic information system (GIS). Finally, the information is presented to users (i) who apply it to their decision making process.
 We begin with the basics of electromagnetic energy then consider how the energy interacts with the atmosphere and with earth surface features. We also treat the role that reference data play in the data analysis procedure and describe how the spatial 10-cation of reference data observed in the field is often determined using Global Positioning System (GPS) methods.  With that as a framework, we consider the restrictions encountered in "real" remote sensing systems.  At the top of this chapter, the reader should have a grasp of the overall concepts and foundations of remote sensing and an appreciation for the close relationship among remote sensing, GPS methods, and GIS operations.