Editing Telemetry (section)

{{Short description|Data and measurements transferred from a remote location to receiving equipment for monitoring}}
{{distinguish|Telemetry (company)|Telemetry (software)}}
{{Redirect|Telemeter|the device that measures distances|Rangefinder{{!}}Rangefinding telemeter|the former pay TV service|Telemeter (pay television)}}

[[File:Dropsonde U.S. Air Force.jpeg|thumb|An expendable [[dropsonde]] used to capture weather data. The telemetry consists of sensors for pressure, temperature, and humidity and a wireless transmitter to return the captured data to an aircraft.]]
[[File:Crocodylus porosus with GPS-based satellite transmitter attached to the nuchal rosette - journal.pone.0062127.g002.png|thumb|300px|A [[saltwater crocodile]] with a GPS-based satellite transmitter attached to its head for tracking]]

'''Telemetry''' is the [[in situ]] [[data collection|collection of measurements]] or other data at remote points and their automatic [[data transmission|transmission]] to receiving equipment ([[telecommunication]]) for monitoring.<ref name=NTRS>{{cite report|title=Telemetry: Summary of concept and rationale|bibcode=1987STIN...8913455.}}</ref> The word is derived from the [[Greek language|Greek]] roots ''tele'', 'far off', and ''metron'', 'measure'. Systems that need external instructions and data to operate require the counterpart of telemetry: [[telecommand]].<ref>Mary Bellis, "Telemetry"</ref>

Although the term commonly refers to [[wireless]] data transfer mechanisms (e.g., using [[radio]], ultrasonic, or [[Infrared#Communications|infrared]] systems), it also encompasses data transferred over other media such as a telephone or [[computer network]], optical link or other wired communications like power line carriers. Many modern telemetry systems take advantage of the low cost and ubiquity of [[GSM]] networks by using [[SMS]] to receive and transmit telemetry data.

A ''telemeter'' is a physical device used in telemetry. It consists of a [[sensor]], a transmission path, and a display, recording, or control device. Electronic devices are widely used in telemetry and can be wireless or hard-wired, [[analog signal|analog]] or [[Digital data|digital]]. Other technologies are also possible, such as mechanical, hydraulic and optical.<ref>Bakshi ''et al.'', pages 8.1–8.3</ref>

Telemetry may be [[commutation (telemetry)|commutated]] to allow the transmission of multiple data streams in a fixed [[frame (networking)|frame]].