What We're Measuring

A Quick Remote Sensing Primer

Remote sensing is the art and science of detecting, identifying, classifying, and analyzing the earth’s surface using special sensors onboard aircraft and satellites. The image below is a Landsat TM image of the greater Connecticut area (Long Island Sound is the dark area near the bottom).

All objects reflect energy (light) differently, giving them a unique “spectral” signature. As sunlight strikes an object (buildings, trees, water, etc.), the energy that is reflected is collected by sensors aboard aircrafts or satellites. This creates both a database and a remotely sensed image.

The height of each bar indicates the amount of light reflected for that color. The color of highest reflectance is what we see.