Abstract
The remote sensing system requires a sensor which is located on a suitable platform to collect the radiation. Sensors used for remote sensing can be broadly classified as those operating in the Optical‐Infrared (OIR) region and those operating in the microwave region, because the technology for developing microwave sensors is quite different compared to that for OIR sensors. This paper presents an overview of different types of imaging sensors operating in the OIR and microwave region bringing out their principles of operation and various design trade‐offs for realizing the sensors. Engineering details of some of the current earth observation imaging sensors are described. Future trends in the imaging sensors for remote sensing are also brought out.