Passive sensors detect radiation that is emitted or reflected by the object or surrounding area being observed. Examples of passive sensors are film photography and radiometers. An active sensor is one that requires energy from a source other than from the device itself. An active sensor sends out a signal and measures a response.
Articles from our resource area experts.
Have a question? Try asking one of our Experts
Have a specific question? Try asking one of our Experts
Unlike most other resources on the web, we have experts from Universities around the country ready to answer your questions.