The basic definition of remote sensing is to acquire data without touching the object being studied. This is done by recording information using different wavelengths of the electromagnetic spectrum, such as ultraviolet, infrared and microwave. This data is obtained by visual and digital image processing using different equipment, the most common being; cameras, lasers and scanners.
What is ‘passive’ and ‘active’ remote sensing?
?Passive remote sensing? is the recording of the natural interaction between the object being studied and an electromagnetic radiation source, for example cameras use passive remote sensing.
But when the object being studied is affected by electromagnetic radiation emitted from the data collecting equipment this is called â€˜active remote sensingâ€™, an example of this would be when using radar.