what is remote sensing?

Remote sensing is the process of acquiring data from a remote location for purposes of understanding the state of something at that location without having to be physically present.

Sometimes remote sensing is used in order to find out how something was before you arrived.

Remote sensing can be done in three main ways: by land, air, or space. By using satellites in orbit around Earth, someone on Earth may see images with contrast or color differences caused by certain atmospheric conditions or variation between vegetation types.