1.4 Use of Remote Sensing

A fundamental use of remote sensing is to extend our visual capability. In addition, remote sensing can enhance our memory because our brains tend not to remember every fine piece of details about what we see. With remote sensing images, we can do a lot more than refreshing our memories, which is a primary goal of conventional photography. We want to measure and map spatial dimensions of objects from remote sensing images. Furthermore, we use remotely sensed data to monitor the dynamics of the phenomena on the earth surface. These include monitoring the vigor and stress of vegetation and environmental quality, measuring the temperature of various objects, detecting and identifying catastrophic sites caused by fire, flood, volcano, earthquakes etc., estimating the mass of various components, such as biogeochemical constituents of a forest, volume of fish schools in water, crop production of agricultural systems, water storage and runoff of watersheds, population in rural and urbanized areas, and quantity and living conditions of wildlife species.

We organize the remaining chapters of this book that lead you to take more advantages of remote sensing in the applications mentioned above. In Chapter two, we will first introduce the very basic physics required to understand the imaging mechanism in remote sensing. In Chapter three, we introduce the development of sensing systems following a historical order. In Chapter four, we introduce imaging geometry and illustrate geometrical calibration methods that are required to achieve precise measurement of spatial dimensions of objects. In Chapter five, we explain various methods for recovering image radiometry affected by sensor malfunctioning, atmospheric interference and terrain relief. In Chapter six, we illustrate some of the most commonly used image processing methods for image enhancement. In Chapter seven, we focus on the introduction of various strategies for information extraction from remotely sensed data. In Chapter eight, following a brief introduction on map making, we introduce some methods that are used to combine maps and other spatial data with remotely sensed data for analysis and extraction of information on various targets.