Document Type : Research Paper
Author
Associate Professor of Urban planning, Malek-Ashtar University of Technolog
Abstract
Remote sensing is a science that provides valuable information on objects and land features by
measuring distances from afar and without physical contact.
In remote sensing, information can be obtained by measuring and recording the reflections of electromagnetic waves of atmosphere and ground level, which are received by sensors installed on
satellites, and after their analysis, the necessary information is extracted.
There are three major factors of reflection, absorption and passage in the collision of electromagnetic waves with any phenomenon, each of which depends on the wavelength of radiated energy and physical and chemical properties of the phenomenon, and the energy reflection from any phenomenon on the Earth is a function of wavelength, molecular and intracellular properties of the phenomenon and other physical characteristics of the objects under measurement.
The satellite data originally contains various geometric and radiometric errors that are affected by satellite, sensor and atmospheric conditions, as well as errors in recording, transmission of
information and other related issues.
Satellite data become valuable and useful after making geometric and radiometric corrections. By performing geometric corrections, satellite information is readily to for analysis and utilization.