Remote Sensing 101

Remote sensing is the science of obtaining information about an object or area through the analysis of measurements made at a distance from the object (i.e., not coming in contact with it).

The oldest form of remote sensing is aerial photography where the sensor system is the camera and film. More recently, the field of remote sensing has grown to include electronic-optical sensors which acquire multispectral digital images that can be processed and analyzed by computers. Many of these sensors are on satellites which regularly orbit the earth.

The quantity most frequently measured and recorded in images is the electromagnetic energy reflected by the object. The source of the electromagnetic energy is the sun and the spectral reflectance properties of many Earth surface features, such as soil, vegetation and water, can be used to uniquely identify and characterize them.

For more detailed information describing how remote sensing works, please visit:

The Electromagnetic Spectrum
The Electromagnetic Spectrum
How Satellite Imagery Works
Image iconHow Satellite Imagery Works

Education & Outreach