Definition[]
A remote sensing system
| “ | observe[s] data that are either emitted or reflected by the earth and the atmosphere, collecting these data from a distance — such as from a satellite or an aerial platform.[1] | ” |
Overview[]
Remote sensing systems involve different observing technologies, including cameras, scanners, radar and sonar systems, radiometers, lasers, and thermal devices — to name a few — and are capable of collecting data from one or more bands of the electromagnetic spectrum. Data from different bands provide different kinds of information. For example, data observed in the infrared band can identify heat sources that are not observable in the visible band of the electromagnetic spectrum.
When data are collected from multiple bands, a more sophisticated analysis can be performed. Key factors that differentiate one sensor from another include the type(s) of data collected, the resolution of the images, the width (or swath) of area covered on the ground, and the rate at which the sensor's platform revisits an area on the ground.
After being observed, remotely sensed data need to be processed — a function that can include referencing the data to a position on earth, calibrating them, and then transforming them into a usable format. The resulting product can be an image or a quantitative data product, which can in turn be used as an input to other geospatial technologies, including geographic information systems and specialized software.