Question

What is remote sensing?

Answer 1

Remote sensing is the process of detecting and monitoring the physical characteristics of an area by measuring its reflected and emitted radiation at a distance from the targeted area. Remote sensing is used in numerous fields, including geography, land surveying and most Earth Science disciplines. Remote sensors can be either passive or active. Passive sensors respond to external stimuli. They record natural energy that is reflected or emitted from the Earth's surface. The most common source of radiation detected by passive sensors is reflected sunlight. In contrast, active sensors use internal stimuli to collect data about the Earth. For example, a laser-beam remote sensing system projects a laser onto the surface of the Earth and measures the time that it takes for the laser to reflect back to its sensor.