Remote sensing is by USGS defined as “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”.
In addition to this definition there are two key concepts we need to mention at this point namely:
- The sensors or instrument i.e. the mechanism by which the amount of radiation (Electro Magnetic Radiation or EMR) is measured. The most common type of sensor is a multispectral radiometer so named because the measure the EMR at multiple different wavelengths.
- The platform is the device that caries the sensor over the target. Common platforms are drones, airplanes and not least satellites.