II - WHAT INSTRUMENTS ARE USED FOR OBSERVATION?
2- INSTRUMENTS
To measure via remote sensing the electromagnetic radiation that perceived surfaces reflect or emit, we use sensors. However, the term sensor covers a wide range of devices. Thus, the nature of the data recorded will vary greatly depending on the techniques used and the characteristics of these instruments.
The different types of sensors used in remote sensing. Source: Zhu, Lingli & al. (2018). A Review: Remote Sensing Sensors. 10.5772/intechopen.71049.
The different sensors used in remote sensing can be defined by a set of characteristics described in more detail on the following pages. Sensors can be
- analogue or digital
- imaging or non-imaging
- passive or active
- corner- or distance-based
- across or along
In general, remote sensing involves 2 main types of instruments according to the energy source: passive and active sensors.