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*[http://en.wikipedia.org/wiki/15th_century 15th Century]

*[https://en.wikipedia.org/wiki/15th_century 15th Century]

==Definitions==

==Definitions==

*1: the act of detecting : the state or fact of being detected

*1: the act of detecting : the state or fact of being detected

In general, '''detection''' is the extraction of particular [[information]] from a larger stream of information without specific [[cooperation]] from or [[synchronization]] with the sender.

In general, '''detection''' is the extraction of particular [[information]] from a larger stream of information without specific [[cooperation]] from or [[synchronization]] with the sender.

In the [[history]] of [[radio]] communications, the term "[http://en.wikipedia.org/wiki/Detector_(radio) detector]" was first used for a device that detected the simple [[presence]] or absence of a radio [[signal]], since all communications were in [http://en.wikipedia.org/wiki/Morse_code Morse code]. The term is still in use today to describe a component that extracts a particular signal from all of the [[electromagnetic]] [[waves]] present. Detection is usually based on the [[frequency]] of the [http://en.wikipedia.org/wiki/Carrier_wave carrier wave], as in the familiar frequencies of radio broadcasting, but it may also involve filtering a faint signal from [[noise]], as in [http://en.wikipedia.org/wiki/Radio_astronomy radio astronomy], or reconstructing a hidden signal, as in [http://en.wikipedia.org/wiki/Steganography steganography].

In the [[history]] of [[radio]] communications, the term "[https://en.wikipedia.org/wiki/Detector_(radio) detector]" was first used for a device that detected the simple [[presence]] or absence of a radio [[signal]], since all communications were in [https://en.wikipedia.org/wiki/Morse_code Morse code]. The term is still in use today to describe a component that extracts a particular signal from all of the [[electromagnetic]] [[waves]] present. Detection is usually based on the [[frequency]] of the [https://en.wikipedia.org/wiki/Carrier_wave carrier wave], as in the familiar frequencies of radio broadcasting, but it may also involve filtering a faint signal from [[noise]], as in [https://en.wikipedia.org/wiki/Radio_astronomy radio astronomy], or reconstructing a hidden signal, as in [https://en.wikipedia.org/wiki/Steganography steganography].

In [http://en.wikipedia.org/wiki/Optoelectronics optoelectronics], "detection" means converting a received optical input to a electrical output. For example, the light signal received through an [http://en.wikipedia.org/wiki/Optical_fiber optical fiber] is converted to an electrical signal in a detector such as a [http://en.wikipedia.org/wiki/Photodiode photodiode].

In [https://en.wikipedia.org/wiki/Optoelectronics optoelectronics], "detection" means converting a received optical input to a electrical output. For example, the light signal received through an [https://en.wikipedia.org/wiki/Optical_fiber optical fiber] is converted to an electrical signal in a detector such as a [https://en.wikipedia.org/wiki/Photodiode photodiode].

In [http://en.wikipedia.org/wiki/Steganography steganography], attempts to detect hidden signals in suspected carrier material is referred to as [http://en.wikipedia.org/wiki/Steganalysis steganalysis]. Steganalysis has an interesting [[difference]] from most other types of ''detection'', in that it can often only determine the [[probability]] that a hidden message exists; this is in contrast to the detection of signals which are simply [http://en.wikipedia.org/wiki/Encryption encrypted], as the [http://en.wikipedia.org/wiki/Ciphertext ciphertext] can often be identified with [[certainty]], even if it cannot be decoded.

In [https://en.wikipedia.org/wiki/Steganography steganography], attempts to detect hidden signals in suspected carrier material is referred to as [https://en.wikipedia.org/wiki/Steganalysis steganalysis]. Steganalysis has an interesting [[difference]] from most other types of ''detection'', in that it can often only determine the [[probability]] that a hidden message exists; this is in contrast to the detection of signals which are simply [https://en.wikipedia.org/wiki/Encryption encrypted], as the [https://en.wikipedia.org/wiki/Ciphertext ciphertext] can often be identified with [[certainty]], even if it cannot be decoded.

In the [[military]], detection refers to the special [[discipline]] of [http://en.wikipedia.org/wiki/Reconnaissance reconnaissance] with the aim to recognize the presence of an object in a location or ambiance.

In the [[military]], detection refers to the special [[discipline]] of [https://en.wikipedia.org/wiki/Reconnaissance reconnaissance] with the aim to recognize the presence of an object in a location or ambiance.

Finally, the ''art of detection'', also known as following [[clues]], is the work of a [http://en.wikipedia.org/wiki/Detective detective] in attempting to reconstruct a [[sequence]] of [[events]] by identifying the relevant [[information]] in a situation.

Finally, the ''art of detection'', also known as following [[clues]], is the work of a [https://en.wikipedia.org/wiki/Detective detective] in attempting to reconstruct a [[sequence]] of [[events]] by identifying the relevant [[information]] in a situation.

[[Category: Physics]]

[[Category: Physics]]